Mitigation of global warming

Mitigation of global warming

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Climate change mitigation is action to decrease the intensity of radiative forcing
Radiative forcing
In climate science, radiative forcing is generally defined as the change in net irradiance between different layers of the atmosphere. Typically, radiative forcing is quantified at the tropopause in units of watts per square meter. A positive forcing tends to warm the system, while a negative...

 in order to reduce the potential effects of global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

. Mitigation is distinguished from adaptation to global warming
Adaptation to global warming
Adaptation to global warming and climate change is a response to climate change that seeks to reduce the vulnerability of natural and human systems to climate change effects. Even if emissions are stabilized relatively soon, climate change and its effects will last many years, and adaptation will...

, which involves acting to tolerate the effects of global warming
Effects of global warming
This article is about the effects of global warming and climate change. The effects, or impacts, of climate change may be physical, ecological, social or economic. Evidence of observed climate change includes the instrumental temperature record, rising sea levels, and decreased snow cover in the...

. Most often, climate change mitigation scenarios
Climate change mitigation scenarios
Climate change mitigation scenarios are possible futures in which global warming is reduced by deliberate actions, such as a comprehensive switch to energy sources other than fossil fuels...

 involve reductions in the concentrations of greenhouse gases, either by reducing their sources or by increasing their sinks.

The UN defines mitigation in the context of climate change, as a human intervention to reduce the sources or enhance the sinks of greenhouse gases. Examples include using fossil fuel
Fossil fuel
Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years...

s more efficiently for industrial processes or electricity generation, switching to renewable energy
Renewable energy
Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable . About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3.4% from...

 (solar energy or wind power
Wind power
Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships....

), improving the insulation of building
Building insulation
building insulation refers broadly to any object in a building used as insulation for any purpose. While the majority of insulation in buildings is for thermal purposes, the term also applies to acoustic insulation, fire insulation, and impact insulation...

s, and expanding forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

s and other "sinks" to remove greater amounts of carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 from the atmosphere.

Scientific consensus on global warming
Scientific opinion on climate change
The predominant scientific opinion on climate change is that the Earth is in an ongoing phase of global warming primarily caused by an enhanced greenhouse effect due to the anthropogenic release of carbon dioxide and other greenhouse gases...

, together with the precautionary principle
Precautionary principle
The precautionary principle or precautionary approach states that if an action or policy has a suspected risk of causing harm to the public or to the environment, in the absence of scientific consensus that the action or policy is harmful, the burden of proof that it is not harmful falls on those...

 and the fear of abrupt climate change
Abrupt climate change
An abrupt climate change occurs when the climate system is forced to transition to a new state at a rate that is determined by the climate system itself, and which is more rapid than the rate of change of the external forcing...


is leading to increased effort to develop new technologies and sciences and carefully manage others in an attempt to mitigate global warming. Most means of mitigation appear effective only for preventing further warming, not at reversing existing warming. The Stern Review
Stern Review
The Stern Review on the Economics of Climate Change is a 700-page report released for the British government on 30 October 2006 by economist Nicholas Stern, chair of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and also chair of the Centre...

 identifies several ways of mitigating climate change. These include reducing demand for emissions-intensive goods and services, increasing efficiency gains, increasing use and development of low-carbon technologies, and reducing fossil fuel emissions.

The energy policy of the European Union
Energy policy of the European Union
Although the European Union has legislated in the area of energy policy for many years, and evolved out of the European Coal and Steel Community, the concept of introducing a mandatory and comprehensive European energy policy was only approved at the meeting of the European Council on 27 October...

 has set a target of limiting the global temperature rise to 2 °C
Celsius
Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...

 (3.6 °F) compared to preindustrial
Industrial Revolution
The Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, transportation, and technology had a profound effect on the social, economic and cultural conditions of the times...

 levels, of which 0.8 °C has already taken place and another 0.5–0.7 °C is already committed. The 2 °C rise is typically associated in climate model
Climate model
Climate models use quantitative methods to simulate the interactions of the atmosphere, oceans, land surface, and ice. They are used for a variety of purposes from study of the dynamics of the climate system to projections of future climate...

s with a carbon dioxide equivalent
Carbon dioxide equivalent
Carbon dioxide equivalent and Equivalent carbon dioxide are two related but distinct measures for describing how much global warming a given type and amount of greenhouse gas may cause, using the functionally equivalent amount or concentration of carbon dioxide as the reference.- Global warming...

 concentration of 400–500 ppm by volume; the current (April 2011) level of carbon dioxide alone is 393 ppm by volume, and rising at 1-3 ppm annually. Hence, to avoid a very likely breach of the 2 °C target, CO2 levels would have to be stabilised very soon; this is generally regarded as unlikely, based on current programs in place to date. The importance of change is illustrated by the fact that world economic energy efficiency is presently improving at only half the rate of world economic growth
Economic growth
In economics, economic growth is defined as the increasing capacity of the economy to satisfy the wants of goods and services of the members of society. Economic growth is enabled by increases in productivity, which lowers the inputs for a given amount of output. Lowered costs increase demand...

.

Greenhouse gas concentrations and stabilization


One of the issues often discussed in relation to climate change mitigation is the stabilization of greenhouse gas concentrations in the atmosphere. The United Nations Framework Convention on Climate Change
United Nations Framework Convention on Climate Change
The United Nations Framework Convention on Climate Change is an international environmental treaty produced at the United Nations Conference on Environment and Development , informally known as the Earth Summit, held in Rio de Janeiro from June 3 to 14, 1992...

 (UNFCCC) has the ultimate objective of preventing "dangerous" anthropogenic (i.e., human) interference of the climate system
Avoiding Dangerous Climate Change
The related terms "avoiding dangerous climate change" and "preventing dangerous anthropogenic interference with the climate system" date to 1995 and earlier, in the Second Assesment Report of the International Panel on Climate Change and previous science it cites.In 2002, the United Nations...

. As is stated in Article 2 of the Convention, this requires that greenhouse gas (GHG) concentrations are stabilized in the atmosphere at a level where ecosystems
Climate change and ecosystems
This article is about climate change and ecosystems.-Impacts:Unchecked global warming could affect most terrestrial ecoregions. Increasing global temperature means that ecosystems will change; some species are being forced out of their habitats because of changing conditions, while others are...

 can adapt naturally to climate change, food production
Climate change and agriculture
Climate change and agriculture are interrelated processes, both of which take place on a global scale. Global warming is projected to have significant impacts on conditions affecting agriculture, including temperature, carbon dioxide, glacial run-off, precipitation and the interaction of these...

 is not threatened, and economic development
Economics of global warming
-Definitions:In this article, the phrase “climate change” is used to describe a change in the climate, measured in terms of its statistical properties, e.g., the global mean surface temperature. In this context, “climate” is taken to mean the average weather. Climate can change over period of time...

 can proceed in a sustainable fashion.

A distinction needs to be made between stabilizing GHG emissions and GHG concentrations.

The two are not the same. The most important GHG emitted by human activities is carbon dioxide (chemical formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

: CO2).
Stabilizing emissions of CO2 at current levels would not lead to a stabilization in the atmospheric concentration of CO2. In fact, stabilizing emissions at current levels would result in the atmospheric concentration of CO2 continuing to rise over the 21st century and beyond (see the graphs opposite).

The reason for this is that human activities are adding CO2 to the atmosphere far faster than natural processes can remove it (see carbon dioxide in Earth's atmosphere for a more complete explanation).
This is analogous to a flow of water into a bathtub.
So long as the tap runs water (analogous to the emission of carbon dioxide) into the tub faster than water escapes through the plughole (the natural removal of carbon dioxide from the atmosphere), then the level of water in the tub (analogous to the concentration of carbon dioxide in the atmosphere) will continue to rise.

Stabilizing the atmospheric concentration of the other greenhouse gases humans emit also depends on how fast their emissions are added to the atmosphere, and how fast the GHGs are removed. Stabilization for these gases is described in the later section on non-CO2 GHGs.

Methods and means


At the core of most proposals is the reduction of greenhouse gas emissions through reducing energy waste and switching to cleaner energy sources. Frequently discussed energy conservation
Energy conservation
Energy conservation refers to efforts made to reduce energy consumption. Energy conservation can be achieved through increased efficient energy use, in conjunction with decreased energy consumption and/or reduced consumption from conventional energy sources...

 methods include increasing the fuel efficiency
Fuel efficiency
Fuel efficiency is a form of thermal efficiency, meaning the efficiency of a process that converts chemical potential energy contained in a carrier fuel into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is...

 of vehicles (often through hybrid
Hybrid vehicle
A hybrid vehicle is a vehicle that uses two or more distinct power sources to move the vehicle. The term most commonly refers to hybrid electric vehicles , which combine an internal combustion engine and one or more electric motors.-Power:...

, plug-in hybrid, and electric car
Electric car
An electric car is an automobile which is propelled by electric motor, using electrical energy stored in batteries or another energy storage device. Electric cars were popular in the late-19th century and early 20th century, until advances in internal combustion engine technology and mass...

s and improving conventional automobiles
Fuel economy in automobiles
Fuel usage in automobiles refers to the fuel efficiency relationship between distance traveled by an automobile and the amount of fuel consumed....

), individual-lifestyle changes
Individual and political action on climate change
Individual and political action on climate change can take many forms, most of which have the ultimate goal of limiting and/or reducing the concentration of greenhouse gases in the atmosphere, toward avoiding dangerous climate change.-Political action:...

 and changing business practices
Business action on climate change
Business action on climate change includes a range of activities relating to global warming, and to influencing political decisions on global-warming-related regulation, such as the Kyoto Protocol...

. Newly developed technologies and currently available technologies including renewable energy (such as solar power
Solar power
Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available...

, tidal
Tidal power
Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into useful forms of power - mainly electricity....

 and ocean energy, geothermal power
Geothermal power
Geothermal energy is thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. Earth's geothermal energy originates from the original formation of the planet and from radioactive decay of minerals...

, and wind power
Wind power
Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships....

) and more controversially nuclear power
Nuclear power
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...

 and the use of carbon sinks, carbon credits, and taxation
Carbon tax
A carbon tax is an environmental tax levied on the carbon content of fuels. It is a form of carbon pricing. Carbon is present in every hydrocarbon fuel and is released as carbon dioxide when they are burnt. In contrast, non-combustion energy sources—wind, sunlight, hydropower, and nuclear—do not...

 are aimed more precisely at countering continued greenhouse gas emissions. The ever-increasing global population and the planned growth of national GDP
Gross domestic product
Gross domestic product refers to the market value of all final goods and services produced within a country in a given period. GDP per capita is often considered an indicator of a country's standard of living....

s based on current technologies are counter-productive to most of these proposals.

Renewable energy



Climate change concerns
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

 and the need to reduce carbon emissions are driving increasing growth in the renewable energy industries. Some 85 countries now have targets for their own renewable energy futures, and have enacted wide-ranging public policies to promote renewables. Low-carbon renewable energy replaces conventional fossil fuels in three main areas: power generation, hot water
Solar hot water
Solar water heating or solar hot water systems comprise several innovations and many mature renewable energy technologies that have been well established for many years...

/ space heating
Space heating
A space heater is a self-contained device for heating an enclosed area. Space heating is generally employed to warm a small space, and is usually held in contrast with central heating, which warms many connected spaces at once...

, and transport fuels.

In terms of power generation, renewable energy currently provides 18 percent of total electricity generation worldwide and this percentage is growing each year. Renewable power generators are spread across many countries, and wind power alone already provides a significant share of electricity in some areas: for example, 14 percent in the U.S. state of Iowa, 40 percent in the northern German state of Schleswig-Holstein, and 20 percent in Denmark. Some countries get most of their power from renewables, including Iceland (100 percent), Brazil (85 percent), Austria (62 percent), New Zealand (65 percent), and Sweden (54 percent).

Solar water heating
Solar water heating
Solar water heating or solar hot water systems comprise several innovations and many mature renewable energy technologies that have been well established for many years...

 makes an important and growing contribution in many countries, most notably in China, which now has 70 percent of the global total (180 GWth). Worldwide, total installed solar water heating systems meet a portion of the water heating needs of over 70 million households. The use of biomass
Biomass
Biomass, as a renewable energy source, is biological material from living, or recently living organisms. As an energy source, biomass can either be used directly, or converted into other energy products such as biofuel....

 for heating continues to grow as well. In Sweden, national use of biomass energy has surpassed that of oil. Direct geothermal heating
Geothermal heating
Geothermal heating is the direct use of geothermal energy for heating applications. Humans have taken advantage of geothermal heat this way since the Paleolithic era. Approximately seventy countries made direct use of a total of 270 PJ of geothermal heating in 2004...

 is also growing rapidly.

Renewable biofuel
Biofuel
Biofuel is a type of fuel whose energy is derived from biological carbon fixation. Biofuels include fuels derived from biomass conversion, as well as solid biomass, liquid fuels and various biogases...

s for transportation, such as ethanol fuel
Ethanol fuel
Ethanol fuel is ethanol , the same type of alcohol found in alcoholic beverages. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline. World ethanol production for transport fuel tripled between 2000 and 2007 from 17 billion to more than 52 billion litres...

 and biodiesel
Biodiesel
Biodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl esters. Biodiesel is typically made by chemically reacting lipids with an alcohol....

, have contributed to a significant decline in oil consumption in the United States since 2006. The 93 billion liters of biofuels produced worldwide in 2009 displaced the equivalent of an estimated 68 billion liters of gasoline, equal to about 5 percent of world gasoline production.

Scientists have advanced a plan to power 100% of the world's energy with wind
Wind power
Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships....

, hydroelectric
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...

, and solar power
Solar power
Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available...

 by the year 2030.

Nuclear power




Nuclear power currently produces 13-14% of the world's electricity. Since about 2001 the term nuclear renaissance
Nuclear renaissance
Since about 2001 the term nuclear renaissance has been used to refer to a possible nuclear power industry revival, driven by rising fossil fuel prices and new concerns about meeting greenhouse gas emission limits. At the same time, various barriers to a nuclear renaissance have been identified...

 has been used to refer to a possible nuclear power
Nuclear power
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...

 industry revival, driven by rising fossil fuel prices
Price of petroleum
The price of petroleum as quoted in news generally refers to the spot price per barrel of either WTI/light crude as traded on the New York Mercantile Exchange for delivery at Cushing, Oklahoma, or of Brent as traded on the Intercontinental Exchange for delivery at Sullom Voe.The price...

 and new concerns about meeting greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...

 emission limits. At the same time, various barriers to a nuclear renaissance have been identified. These barriers include unfavourable economics compared to other sources of energy and slowness in addressing climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...

.

New reactors under construction in Finland and France, which were meant to lead a nuclear renaissance, have been delayed and are running over-budget. China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 has 20 new reactors under construction, and there are also a considerable number of new reactors being built in South Korea, India, and Russia. At least 100 older and smaller reactors will "most probably be closed over the next 10-15 years".

Nuclear power brings with it important waste disposal
High-level radioactive waste management
High-level radioactive waste management concerns management and disposal of highly radioactive materials created during production of nuclear power and nuclear warheads. The technical issues in accomplishing this are daunting, due to the extremely long periods radioactive wastes remain deadly to...

, safety
Nuclear safety
Nuclear safety covers the actions taken to prevent nuclear and radiation accidents or to limit their consequences. This covers nuclear power plants as well as all other nuclear facilities, the transportation of nuclear materials, and the use and storage of nuclear materials for medical, power,...

, and security
Nuclear terrorism
Nuclear terrorism denotes the use, or threat of the use, of nuclear weapons or radiological weapons in acts of terrorism, includingattacks against facilities where radioactive materials are present...

 risks which are unique among low-carbon energy sources. Public attitudes towards nuclear power remain ambiguous in many developed countries, with significant anti-nuclear opposition even when majority opinion is in favour.

Carbon intensity of fossil fuels


Natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

 (predominantly methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...

) produces less greenhouses gases per energy unit gained than oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....

 which in turn produces less than coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...

, principally because coal has a larger ratio of carbon to hydrogen. The combustion of natural gas emits almost 30 percent less carbon dioxide than oil, and just under 45 percent less carbon dioxide than coal. In addition, there are also other environmental benefits.

A study performed by the Environmental Protection Agency (EPA) and the Gas Research Institute (GRI) in 1997 sought to discover whether the reduction in carbon dioxide emissions from increased natural gas (predominantly methane) use would be offset by a possible increased level of methane emissions from sources such as leaks and emissions. The study concluded that the reduction in emissions from increased natural gas use strongly outweighs the detrimental effects of increased methane emissions. Thus the increased use of natural gas in the place of other, dirtier fossil fuels can serve to lessen the emission of greenhouse gases in the United States.

Most mitigation proposals imply — rather than directly state — an eventual reduction in global fossil fuel production. Also proposed are direct quotas on global fossil fuel production.

Energy efficiency and conservation


Efficient energy use, sometimes simply called "energy efficiency", is the goal of efforts to reduce the amount of energy required to provide products and services. For example, insulating a home
Building insulation
building insulation refers broadly to any object in a building used as insulation for any purpose. While the majority of insulation in buildings is for thermal purposes, the term also applies to acoustic insulation, fire insulation, and impact insulation...

 allows a building to use less heating and cooling energy to achieve and maintain a comfortable temperature. Installing fluorescent lights or natural skylights reduces the amount of energy required to attain the same level of illumination compared to using traditional incandescent light bulbs. Compact fluorescent lights use two-thirds less energy and may last 6 to 10 times longer than incandescent lights.

Energy efficiency has proved to be a cost-effective strategy for building economies without necessarily growing energy consumption
World energy resources and consumption
]World energy consumption in 2010: over 5% growthEnergy markets have combined crisis recovery and strong industry dynamism. Energy consumption in the G20 soared by more than 5% in 2010, after the slight decrease of 2009. This strong increase is the result of two converging trends...

. For example, the state of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

 began implementing energy-efficiency measures in the mid-1970s, including building code and appliance standards with strict efficiency requirements. During the following years, California's energy consumption has remained approximately flat on a per capita basis while national U.S. consumption doubled. As part of its strategy, California implemented a "loading order" for new energy resources that puts energy efficiency first, renewable electricity supplies second, and new fossil-fired power plants last.

Energy conservation
Energy conservation
Energy conservation refers to efforts made to reduce energy consumption. Energy conservation can be achieved through increased efficient energy use, in conjunction with decreased energy consumption and/or reduced consumption from conventional energy sources...

 is broader than energy efficiency in that it encompasses using less energy to achieve a lesser energy service, for example through behavioural change, as well as encompassing energy efficiency. Examples of conservation without efficiency improvements would be heating a room less in winter, driving less, or working in a less brightly lit room. As with other definitions, the boundary between efficient energy use and energy conservation can be fuzzy, but both are important in environmental and economic terms. This is especially the case when actions are directed at the saving of fossil fuels.

Reducing energy use is seen as a key solution to the problem of reducing greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...

 emissions. According to the International Energy Agency
International Energy Agency
The International Energy Agency is a Paris-based autonomous intergovernmental organization established in the framework of the Organisation for Economic Co-operation and Development in 1974 in the wake of the 1973 oil crisis...

, improved energy efficiency in buildings, industrial processes and transportation could reduce the world's energy needs in 2050 by one third, and help control global emissions of greenhouse gases.

Transport




Modern energy efficient technologies
Efficient energy use
Efficient energy use, sometimes simply called energy efficiency, is the goal of efforts to reduce the amount of energy required to provide products and services. For example, insulating a home allows a building to use less heating and cooling energy to achieve and maintain a comfortable temperature...

, such as plug-in hybrid electric vehicles, and development of new technologies, such as hydrogen cars, may reduce the consumption of petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 and emissions of carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

. A shift from air transport and truck transport
Road transport
Road transport or road transportation is transport on roads of passengers or goods. A hybrid of road transport and ship transport is the historic horse-drawn boat.-History:...

 to electric rail transport
Rail transport
Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on...


would reduce emissions significantly.

Increased use of biofuel
Biofuel
Biofuel is a type of fuel whose energy is derived from biological carbon fixation. Biofuels include fuels derived from biomass conversion, as well as solid biomass, liquid fuels and various biogases...

s (such as ethanol fuel
Ethanol fuel
Ethanol fuel is ethanol , the same type of alcohol found in alcoholic beverages. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline. World ethanol production for transport fuel tripled between 2000 and 2007 from 17 billion to more than 52 billion litres...

 and biodiesel
Biodiesel
Biodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl esters. Biodiesel is typically made by chemically reacting lipids with an alcohol....

 that can be used in today's diesel and gasoline engines) could also reduce emissions if produced environmentally efficiently, especially in conjunction with regular hybrids
Hybrid vehicle
A hybrid vehicle is a vehicle that uses two or more distinct power sources to move the vehicle. The term most commonly refers to hybrid electric vehicles , which combine an internal combustion engine and one or more electric motors.-Power:...

 and plug-in hybrids. For electric vehicles, the reduction of carbon emissions will improve further if the way the required electricity is generated is low-carbon (from renewable energy
Renewable energy
Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable . About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3.4% from...

 sources).

Effective urban planning
Urban planning
Urban planning incorporates areas such as economics, design, ecology, sociology, geography, law, political science, and statistics to guide and ensure the orderly development of settlements and communities....

 to reduce sprawl
Urban sprawl
Urban sprawl, also known as suburban sprawl, is a multifaceted concept, which includes the spreading outwards of a city and its suburbs to its outskirts to low-density and auto-dependent development on rural land, high segregation of uses Urban sprawl, also known as suburban sprawl, is a...

 would decrease Vehicle Miles Travelled (VMT), lowering emissions from transportation. Increased use of public transport
Public transport
Public transport is a shared passenger transportation service which is available for use by the general public, as distinct from modes such as taxicab, car pooling or hired buses which are not shared by strangers without private arrangement.Public transport modes include buses, trolleybuses, trams...

 can also reduce greenhouse gas emissions per passenger kilometer.
Urban planning


Urban planning
Urban planning
Urban planning incorporates areas such as economics, design, ecology, sociology, geography, law, political science, and statistics to guide and ensure the orderly development of settlements and communities....

 also has an effect on energy use. Between 1982 and 1997, the amount of land consumed for urban development in the United States increased by 47 percent while the nation's population grew by only 17 percent.
Inefficient land use
Land use
Land use is the human use of land. Land use involves the management and modification of natural environment or wilderness into built environment such as fields, pastures, and settlements. It has also been defined as "the arrangements, activities and inputs people undertake in a certain land cover...

 development practices have increased infrastructure costs as well as the amount of energy needed for transportation, community services, and buildings.

At the same time, a growing number of citizens and government officials have begun advocating a smarter approach to land use planning. These smart growth
Smart growth
Smart growth is an urban planning and transportation theory that concentrates growth in compact walkable urban centers to avoid sprawl and advocates compact, transit-oriented, walkable, bicycle-friendly land use, including neighborhood schools, complete streets, and mixed-use development with a...

 practices include compact community development, multiple transportation choices, mixed land uses, and practices to conserve green space. These programs offer environmental, economic, and quality-of-life benefits; and they also serve to reduce energy usage and greenhouse gas emissions.

Approaches such as New Urbanism
New urbanism
New Urbanism is an urban design movement, which promotes walkable neighborhoods that contain a range of housing and job types. It arose in the United States in the early 1980s, and has gradually continued to reform many aspects of real estate development, urban planning, and municipal land-use...

 and Transit-oriented development
Transit-oriented development
A transit-oriented development is a mixed-use residential or commercial area designed to maximize access to public transport, and often incorporates features to encourage transit ridership...

 seek to reduce distances travelled, especially by private vehicles, encourage public transit and make walking
Walking
Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step...

 and cycling
Cycling
Cycling, also called bicycling or biking, is the use of bicycles for transport, recreation, or for sport. Persons engaged in cycling are cyclists or bicyclists...

 more attractive options. This is achieved through medium-density, mixed-use planning
Mixed-use development
Mixed-use development is the use of a building, set of buildings, or neighborhood for more than one purpose. Since the 1920s, zoning in some countries has required uses to be separated. However, when jobs, housing, and commercial activities are located close together, a community's transportation...

 and the concentration of housing within walking distance of town centers and transport nodes.

Smarter growth land use policies have both a direct and indirect effect on energy consuming behavior. For example, transportation energy usage, the number one user of petroleum fuels, could be significantly reduced through more compact and mixed use land development patterns, which in turn could be served by a greater variety of non-automotive based transportation choices.

Building design




Emissions from housing
House
A house is a building or structure that has the ability to be occupied for dwelling by human beings or other creatures. The term house includes many kinds of different dwellings ranging from rudimentary huts of nomadic tribes to free standing individual structures...

 are substantial, and government-supported energy efficiency programmes can make a difference.

For institutions of higher learning in the United States, greenhouse gas emissions depend primarily on total area of buildings and secondarily on climate. If climate is not taken into account, annual greenhouse gas emissions due to energy consumed on campuses plus purchased electricity can be estimated with the formula, E=aSb, where a =0.001621 metric tonnes of CO2 equivalent/square foot or 0.0241 metric tonnes of CO2 equivalent/square meter and b = 1.1354.

New buildings can be constructed using passive solar building design
Passive solar building design
In passive solar building design, windows, walls, and floors are made to collect, store, and distribute solar energy in the form of heat in the winter and reject solar heat in the summer...

, low-energy building, or zero-energy building techniques, using renewable heat
Renewable heat
Renewable heat is an application of renewable energy and it refers to the renewable generation of heat, rather than electrical power ....

 sources. Existing buildings can be made more efficient through the use of insulation, high-efficiency appliances (particularly hot water heaters and furnaces), double- or triple-glazed gas-filled windows
Insulated glazing
Insulated glazing also known as double glazing are double or triple glass window panes separated by an air or other gas filled space to reduce heat transfer across a part of the building envelope....

, external window shades, and building orientation and siting. Renewable heat sources such as shallow geothermal and passive solar energy reduce the amount of greenhouse gasses emitted. In addition to designing buildings which are more energy efficient to heat, it is possible to design buildings that are more energy efficient to cool by using lighter-coloured, more reflective materials in the development of urban areas (e.g. by painting roofs white) and planting trees. This saves energy because it cools buildings and reduces the urban heat island
Urban heat island
An urban heat island is a metropolitan area which is significantly warmer than its surrounding rural areas. The phenomenon was first investigated and described by Luke Howard in the 1810s, although he was not the one to name the phenomenon. The temperature difference usually is larger at night...

 effect thus reducing the use of air conditioning.

Reforestation and avoided deforestation


Almost 20% (8 GtCO2/year) of total greenhouse-gas emissions were from deforestation in 2007. The Stern Review found that, based on the opportunity costs of the landuse that would no longer be available for agriculture if deforestation were avoided, emission savings from avoided deforestation could potentially reduce CO2 emissions for under $5/tCO2, possiblly as little as $1/tCO2. Afforestation
Afforestation
Afforestation is the establishment of a forest or stand of trees in an area where there was no forest. Reforestation is the reestablishment of forest cover, either naturally or artificially...

 and reforestation
Reforestation
Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted, usually through deforestation....

 could save at least another 1GtCO2/year, at an estimated cost of $5/tCO2 to $15/tCO2. The Review determined these figures by assessing 8 countries responsible for 70% of global deforestation emissions.

The author of the influential 2006 Stern Review on climate change has stated "people will need to turn vegetarian if the world is to conquer climate change". This is due to emissions of methane (which is 23 times more potent of a greenhouse gas versus carbon dioxide) from cows and pigs via flatulence and eructation.

Pristine temperate forest
Temperate forest
Temperate forests correspond to forest concentrations formed in the northern hemisphere. Main characteristics include: wide leaves, big and tall trees and non seasonal vegetation...

 has been shown to store three times more carbon than IPCC
Intergovernmental Panel on Climate Change
The Intergovernmental Panel on Climate Change is a scientific intergovernmental body which provides comprehensive assessments of current scientific, technical and socio-economic information worldwide about the risk of climate change caused by human activity, its potential environmental and...

 estimates took into account, and 60% more carbon than plantation forest. Preventing these forests from being logged would have significant effects.

Further significant savings from other non-energy-related-emissions could be gained through cuts to agricultural emissions, fugitive emissions
Fugitive emissions
Fugitive emissions are emissions of gases or vapors from pressurized equipment due to leaks and various other unintended or irregular releases of gases, mostly from industrial activities. As well as the economic cost of lost commodities, fugitive emissions contribute to air pollution and climate...

, waste emissions, and emissions from various industrial processes.

Eliminating waste methane


Methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...

 is a significantly more powerful greenhouse gas than carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

. Burning one molecule of methane generates one molecule of carbon dioxide. Accordingly, burning methane which would otherwise be released into the atmosphere (such as at oil wells, landfills, coal mines, waste treatment plants, etc.) provides a net greenhouse gas emissions benefit. However, reducing the amount of waste methane produced in the first place has an even greater beneficial impact, as might other approaches to productive use of otherwise-wasted methane.

In terms of prevention, vaccines are in the works in Australia to reduce significant global warming contributions from methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...

 released by livestock via flatulence
Flatulence
Flatulence is the expulsion through the rectum of a mixture of gases that are byproducts of the digestion process of mammals and other animals. The medical term for the mixture of gases is flatus, informally known as a fart, or simply gas...

 and eructation.

Geoengineering


Geoengineering is seen by some as an alternative to mitigation and adaptation, but by others as an entirely separate response to climate change. In a literature
Scientific literature
Scientific literature comprises scientific publications that report original empirical and theoretical work in the natural and social sciences, and within a scientific field is often abbreviated as the literature. Academic publishing is the process of placing the results of one's research into the...

 assessment, Barker et al. (2007) described geoengineering as a type of mitigation policy. IPCC (2007) concluded that geoengineering options, such as ocean fertilization to remove CO2 from the atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...

, remained largely unproven. It was judged that reliable cost estimates for geoengineering had not yet been published.

Chapter 28 of the National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...

 report Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base (1992) defined geoengineering as "options that would involve large-scale engineering of our environment in order to combat or counteract the effects of changes in atmospheric chemistry." They evaluated a range of options to try to give preliminary answers to two questions: can these options work and could they be carried out with a reasonable cost. They also sought to encourage discussion of a third question — what adverse side effects might there be. The following types of option were examined: reforestation, increasing ocean absorption of carbon dioxide (carbon sequestration) and screening out some sunlight. NAS also argued "Engineered countermeasures need to be evaluated but should not be implemented without broad understanding of the direct effects and the potential side effects, the ethical issues, and the risks.".

Greenhouse gas remediation


Carbon sequestration
Carbon dioxide sink
A carbon sink is a natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period. The process by which carbon sinks remove carbon dioxide from the atmosphere is known as carbon sequestration...

 has been proposed as a method of reducing the amount of radiative forcing
Radiative forcing
In climate science, radiative forcing is generally defined as the change in net irradiance between different layers of the atmosphere. Typically, radiative forcing is quantified at the tropopause in units of watts per square meter. A positive forcing tends to warm the system, while a negative...

. Carbon sequestration is a term that describes processes that remove carbon from the atmosphere. A variety of means of artificially capturing and storing carbon, as well as of enhancing natural sequestration processes, are being explored. The main natural process is photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...

 by plants and single-celled organisms (see biosequestration
Biosequestration
Biosequestration is the capture and storage of the atmospheric greenhouse gas carbon dioxide by biological processes.This may be by increased photosynthesis ; by enhanced soil carbon trapping in agriculture; or by the use of algal bio sequestration to absorb the carbon...

). Artificial processes vary, and concerns have been expressed about their long-term effects.

Although they require land, natural sinks can be enhanced by reforestation and afforestation carbon offset
Carbon offset
A carbon offset is a reduction in emissions of carbon dioxide or greenhouse gases made in order to compensate for or to offset an emission made elsewhere....

s, which fix carbon dioxide for as little as $0.11 per metric ton.

Sulfate aerosols


The ability of stratospheric sulfate aerosols
Sulfate aerosols
The term sulfate aerosols is used for a suspension of fine solid particles of a sulfate or tiny droplets of a solution of a sulfate or of sulfuric acid . They are produced by chemical reactions in the atmosphere from gaseous precursors...

 to create a global dimming
Global dimming
Global dimming is the gradual reduction in the amount of global direct irradiance at the Earth's surface that was observed for several decades after the start of systematic measurements in the 1950s. The effect varies by location, but worldwide it has been estimated to be of the order of a 4%...

 effect has made them a possible candidate for use in geoengineering
Geoengineering
The concept of Geoengineering refers to the deliberate large-scale engineering and manipulation of the planetary environment to combat or counteract anthropogenic changes in atmospheric chemistry The Intergovernmental Panel on Climate Change concluded in 2007 that geoengineering options, such...

 projects.

Biomass Energy


During its growth, vegetation traps carbon dioxide from the atmosphere through photosynthesis. When this biomass decomposes or is combusted, the carbon is again released as carbon dioxide. This process is part of the global carbon cycle
Carbon cycle
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth...

. Through the use of biomass for energy and materials, e.g. in biomass fuelled power plants, parts of this cycle is controlled by man. However, whether direct use of biomass for energy can be carbon neutral is case-specific and remains a matter of controversy.

Combining a biomass energy system with carbon capture and storage
Carbon capture and storage
Carbon capture and storage , alternatively referred to as carbon capture and sequestration, is a technology to prevent large quantities of from being released into the atmosphere from the use of fossil fuel in power generation and other industries. It is often regarded as a means of mitigating...

 technology (a form of Geoengineering
Geoengineering
The concept of Geoengineering refers to the deliberate large-scale engineering and manipulation of the planetary environment to combat or counteract anthropogenic changes in atmospheric chemistry The Intergovernmental Panel on Climate Change concluded in 2007 that geoengineering options, such...

, is so-called bio-energy with carbon capture and storage
Bio-energy with carbon capture and storage
Bio-energy with carbon capture and storage is a greenhouse gas mitigation technology which produces negative carbon emissions by combining biomass use with geologic carbon capture and storage....

 (BECCS). Proponents of BECCS, a technology yet to be proven, hope that it will result in net-negative carbon dioxide emissions, i.e. net removal of carbon dioxide from the atmosphere. In comparison with other geoengineering options, BECCS has been suggested as a low-risk, near-term tool to effectively remove carbon from the atmosphere. Even so, whether biomass can be sustainably obtained in significant quantities remains controversial. In July 2011 a report by the United States Government Accountability Office on geoengineering found that "[c]limate engineering technologies do not now offer a viable response to global climate change."
Carbon air capture

It is notable that the availability of cheap energy and appropriate sites for geological storage
Carbon capture and storage
Carbon capture and storage , alternatively referred to as carbon capture and sequestration, is a technology to prevent large quantities of from being released into the atmosphere from the use of fossil fuel in power generation and other industries. It is often regarded as a means of mitigating...

 of carbon may make carbon dioxide air capture
Carbon dioxide air capture
Carbon dioxide removal methods refers to a number of technologies which reduce the levels of carbon dioxide in the atmosphere. Among such technologies are bio-energy with carbon capture and storage, biochar, direct air capture, ocean fertilization and enhanced weathering.CDR is a different...

 viable commercially. It is, however, generally expected that carbon dioxide air capture may be uneconomic when compared to carbon capture and storage
Carbon capture and storage
Carbon capture and storage , alternatively referred to as carbon capture and sequestration, is a technology to prevent large quantities of from being released into the atmosphere from the use of fossil fuel in power generation and other industries. It is often regarded as a means of mitigating...

 from major sources — in particular, fossil fuel powered power stations, refineries, etc. In such cases, costs of energy produced will grow significantly. However, captured CO2 can be used to force more crude oil out of oil field
Oil field
An oil field is a region with an abundance of oil wells extracting petroleum from below ground. Because the oil reservoirs typically extend over a large area, possibly several hundred kilometres across, full exploitation entails multiple wells scattered across the area...

s, as Statoil
Statoil
Statoil ASA is a Norwegian petroleum company established in 1972. It merged with Norsk Hydro in 2007 and was known as StatoilHydro until 2009, when the name was changed back to Statoil ASA. The brand Statoil was retained as a chain of fuel stations owned by StatoilHydro...

 and Shell
Royal Dutch Shell
Royal Dutch Shell plc , commonly known as Shell, is a global oil and gas company headquartered in The Hague, Netherlands and with its registered office in London, United Kingdom. It is the fifth-largest company in the world according to a composite measure by Forbes magazine and one of the six...

 have made plans to do. CO2 can also be used in commercial greenhouse
Greenhouse
A greenhouse is a building in which plants are grown. These structures range in size from small sheds to very large buildings...

s, giving an opportunity to kick-start the technology. Some attempts have been made to use algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

 to capture smokestack emissions, notably the GreenFuel Technologies Corporation
GreenFuel Technologies Corporation
GreenFuel Technologies Corporation was a startup that developed a process of growing algae using emissions from fossil fuel, mainly to produce biofuel from algae.It was based in Cambridge, Massachusetts. Greenfuel shut down operations on May 13, 2009...

, who have now shut down operations.
Carbon capture and storage


Carbon capture and storage (CCS) is a plan to mitigate climate change by capturing carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 (CO2) from large point sources such as power plants and subsequently storing it away safely instead of releasing it into the atmosphere. The Intergovernmental Panel on Climate Change
Intergovernmental Panel on Climate Change
The Intergovernmental Panel on Climate Change is a scientific intergovernmental body which provides comprehensive assessments of current scientific, technical and socio-economic information worldwide about the risk of climate change caused by human activity, its potential environmental and...

 says CCS could contribute between 10% and 55% of the cumulative worldwide carbon-mitigation effort over the next 90 years. The Agency says CCS is "the most important single new technology for CO2 savings" in power generation and industry. Though it requires up to 40% more energy to run a CCS coal power plant than a regular coal plant, CCS could potentially capture about 90% of all the carbon emitted by the plant. Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

, which first began storing CO2, has cut its emissions by almost a million tons a year, or about 3% of the country's 1990 levels. Please see also direct conversion of CO2 to fuels.

Pacala and Socolow: 15 programs


Pacala and Socolow of Princeton
See also:

have proposed a program to reduce CO2 emissions by 1 billion metric tons per year − or 25 billion tons over the 50-year period. The proposed 15 different programs, any seven of which could achieve the goal, are:
  1. more efficient vehicles − increase fuel economy from 30 to 60 mpg (7.8 to 3.9 L/100 km) for 2 billion vehicles,
  2. reduce use of vehicles − improve urban design to reduce miles driven from 10,000 to 5,000 miles (16,000 to 8,000 km) per year for 2 billion vehicles,
  3. efficient buildings − reduce energy consumption by 25%,
  4. improve efficiency of coal plants from today's 40% to 60%,
  5. replace 1,400 GW (gigawatt) of coal power plants with natural gas,
  6. capture and store carbon emitted from 800 GW of new coal plants,
  7. capture and reuse hydrogen created by No. 6 above,
  8. capture and store carbon from coal to syn fuels conversion at 30 Moilbbl/d,
  9. displace 700 GW of coal power with nuclear,
  10. add 2 million 1 MW wind turbines (50 times current capacity),
  11. displace 700 GW of coal with 2,000 GW (peak) solar power (700 times current capacity),
  12. produce hydrogen fuel
    Hydrogen fuel
    An ecologically-friendly fuel which uses electrochemical cells or combusts in internal engines to power vehicles and electric devices. It is also used in the propulsion of spacecraft and can potentially be mass produced and commercialized for passenger vehicles and aircraft.In a flame of pure...

     from 4 million 1 MW wind turbines,
  13. use biomass to make fuel to displace oil (100 times current capacity),
  14. stop de-forestation and re-establish 300 million hectares of new tree plantations,
  15. conservation tillage − apply to all crop land (10 times current usage).


Nature.com argued in June 2008 that "If we are to have confidence in our ability to stabilize carbon dioxide levels below 450 p.p.m. emissions must average less than 5 billion metric tons of carbon per year over the century. This means accelerating the deployment of the wedges so they begin to take effect in 2015 and are completely operational in much less time than originally modelled by Socolow and Pacala."

Societal controls


Another method being examined is to make carbon a new currency by introducing tradeable "Personal Carbon Credits". The idea being it will encourage and motivate individuals to reduce their 'carbon footprint' by the way they live. Each citizen will receive a free annual quota of carbon that they can use to travel, buy food, and go about their business. It has been suggested that by using this concept it could actually solve two problems; pollution and poverty, old age pensioners will actually be better off because they fly less often, so they can cash in their quota at the end of the year to pay heating bills, etc.

Population



Various organizations promote population control
Population control
Human population control is the practice of artificially altering the rate of growth of a human population.Historically, human population control has been implemented by limiting the population's birth rate, usually by government mandate, and has been undertaken as a response to factors including...

 as a means for mitigating global warming. Proposed measures include improving access to family planning
Family planning
Family planning is the planning of when to have children, and the use of birth control and other techniques to implement such plans. Other techniques commonly used include sexuality education, prevention and management of sexually transmitted infections, pre-conception counseling and...

 and reproductive health
Reproductive health
Within the framework of the World Health Organization's definition of health as a state of complete physical, mental and social well-being, and not merely the absence of disease or infirmity, reproductive health, or sexual health/hygiene, addresses the reproductive processes, functions and system...

 care and information, reducing natalistic politics, public education about the consequences of continued population growth, and improving access of women to education and economic opportunities.

Population control efforts are impeded by there being somewhat of a taboo in some countries against considering any such efforts. Also, various religions discourage or prohibit
Religious views on birth control
Religious adherents vary widely in their views on birth control. This can be true even between different branches of one faith, as in the case of Judaism...

 some or all forms of birth control
Birth control
Birth control is an umbrella term for several techniques and methods used to prevent fertilization or to interrupt pregnancy at various stages. Birth control techniques and methods include contraception , contragestion and abortion...

.

Population size has a different per capita effect on global warming in different countries, since the per capita production of anthropogenic greenhouse gases varies greatly by country.

Non-CO2 greenhouse gases


CO2 is not the only GHG relevant to mitigation, and governments have acted to regulate the emissions of other GHGs emitted by human activities (anthropogenic GHGs). The emissions caps agreed to by most developed countries under the Kyoto Protocol
Kyoto Protocol
The Kyoto Protocol is a protocol to the United Nations Framework Convention on Climate Change , aimed at fighting global warming...

 regulate the emissions of almost all the anthropogenic GHGs.
These gases are CO2, methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...

 (chemical formula: CH4), nitrous oxide
Nitrous oxide
Nitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...

 (N2O), the hydrofluorocarbons
Halocarbon
Halocarbon compounds are chemicals in which one or more carbon atoms are linked by covalent bonds with one or more halogen atoms resulting in the formation of organofluorine compounds, organochlorine compounds, organobromine compounds, and organoiodine compounds...

 (abbreviated HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride
Sulfur hexafluoride
Sulfur hexafluoride is an inorganic, colorless, odorless, and non-flammable greenhouse gas. has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. It is a hypervalent molecule. Typical for a nonpolar gas, it is poorly soluble in water but soluble in...

 (SF6).

Stabilizing the atmospheric concentrations of the different anthropogenic GHGs requires an understanding of their different physical properties. Stabilization depends both on how quickly GHGs are added to the atmosphere and how fast they are removed. The rate of removal is measured by the atmospheric lifetime of the GHG in question (see the main GHG article for a list). Here, the lifetime is defined as the time required for a given perturbation of the GHG in the atmosphere to be reduced to 37% of its initial amount.
Methane has a relatively short atmospheric lifetime of about 12 years, while N2O's lifetime is about 110 years. For methane, a reduction of about 30% below current emission levels would lead to a stabilization in its atmospheric concentration, while for N2O, an emissions reduction of more than 50% would be required.

Another physical property of the anthropogenic GHGs relevant to mitigation is the different abilities of the gases to trap heat (in the form of infrared radiation). Some gases are more effective at trapping heat than others, e.g., SF6 is 22,200 times more effective a GHG than CO2 on a per-kilogram basis.
A measure for this physical property is the global warming potential
Global warming potential
Global-warming potential is a relative measure of how much heat a greenhouse gas traps in the atmosphere. It compares the amount of heat trapped by a certain mass of the gas in question to the amount of heat trapped by a similar mass of carbon dioxide. A GWP is calculated over a specific time...

 (GWP), and is used in the Kyoto Protocol.

Although not designed for this purpose, the Montreal Protocol
Montreal Protocol
The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances believed to be responsible for ozone depletion...

 has probably benefitted climate change mitigation efforts.
The Montreal Protocol is an international treaty
Treaty
A treaty is an express agreement under international law entered into by actors in international law, namely sovereign states and international organizations. A treaty may also be known as an agreement, protocol, covenant, convention or exchange of letters, among other terms...

 that has successfully reduced emissions of ozone-depleting substances (e.g., CFCs
Chlorofluorocarbon
A chlorofluorocarbon is an organic compound that contains carbon, chlorine, and fluorine, produced as a volatile derivative of methane and ethane. A common subclass are the hydrochlorofluorocarbons , which contain hydrogen, as well. They are also commonly known by the DuPont trade name Freon...

), which are also greenhouse gases.

Costs and benefits


Costs


The Stern Review
Stern Review
The Stern Review on the Economics of Climate Change is a 700-page report released for the British government on 30 October 2006 by economist Nicholas Stern, chair of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and also chair of the Centre...

 proposes stabilising the concentration of greenhouse-gas emissions in the atmosphere at a maximum of 550ppm CO2e by 2050. The Review estimates that this would mean cutting total greenhouse-gas emissions to three quarters of 2007 levels. The Review further estimates that the cost of these cuts would be in the range −1.0 to +3.5% of World GDP, (i.e. GWP
GWP
GWP can stand for:* Global warming potential, a relative measure of how much heat a greenhouse gas traps in the atmosphere.* Global Water Partnership, an international network offering practical advice for sustainably managing water resources....

), with an average estimate of approximately 1%. Stern has since revised his estimate to 2% of GWP. For comparison, the Gross World Product (GWP
GWP
GWP can stand for:* Global warming potential, a relative measure of how much heat a greenhouse gas traps in the atmosphere.* Global Water Partnership, an international network offering practical advice for sustainably managing water resources....

) at PPP
PPP
PPP is an abbreviation for:In politics:* Pakistan Peoples Party** Pakistan Peoples Party ** Pakistan Peoples Party * Palestinian People's Party...

 was estimated at $74.5 trillion in 2010, thus 2% is approximately $1.5 trillion. The Review emphasises that these costs are contingent on steady reductions in the cost of low-carbon technologies. Mitigation costs will also vary according to how and when emissions are cut: early, well-planned action will minimise the costs.

One way of estimating the cost of reducing emissions is by considering the likely costs of potential technological and output changes. Policy makers can compare the marginal abatement costs of different methods to assess the cost and amount of possible abatement over time. The marginal abatement costs of the various measures will differ by country, by sector, and over time.

Benefits


Yohe et al. (2007) assessed the literature on sustainability and climate change. With high confidence, they suggested that up to the year 2050, an effort to cap greenhouse gas (GHG) emissions at 550 ppm would benefit developing countries significantly. This was judged to be especially the case when combined with enhanced adaptation. By 2100, however, it was still judged likely that there would be significant climate change impacts. This was judged to be the case even with aggressive mitigation and significantly enhanced adaptive capacity
Adaptive capacity
Adaptive capacity is the capacity of a system to adapt if the environment where the system exists is changing. It is applied to e.g., ecological systems and human social systems.As applied to ecological systems, the adaptive capacity is determined by :...

.

Sharing


One of the aspects of mitigation is how to share the costs and benefits of mitigation policies. There is no scientific consensus over how to share these costs and benefits (Toth et al., 2001). In terms of the politics of mitigation, the UNFCCC's ultimate objective is to stabilize concentrations of GHG in the atmosphere at a level that would prevent "dangerous" climate change (Rogner et al., 2007). There is, however, no widespread agreement on how to define "dangerous" climate change.

GHG emissions are an important correlate of wealth
Wealth
Wealth is the abundance of valuable resources or material possessions. The word wealth is derived from the old English wela, which is from an Indo-European word stem...

, at least at present (Banuri et al., 1996, pp. 91–92). Wealth, as measured by per capita income (i.e., income per head of population), varies widely between different countries. Activities of the poor that involve emissions of GHGs are often associated with basic needs, such as heating to stay tolerably warm. In richer countries, emissions tend to be associated with things like car
Čar
Čar is a village in the municipality of Bujanovac, Serbia. According to the 2002 census, the town has a population of 296 people.-References:...

s, central heating
Central heating
A central heating system provides warmth to the whole interior of a building from one point to multiple rooms. When combined with other systems in order to control the building climate, the whole system may be a HVAC system.Central heating differs from local heating in that the heat generation...

, etc. The impacts of cutting emissions could therefore have different impacts on human welfare
Welfare economics
Welfare economics is a branch of economics that uses microeconomic techniques to evaluate economic well-being, especially relative to competitive general equilibrium within an economy as to economic efficiency and the resulting income distribution associated with it...

 according wealth.

Distributing emissions abatement costs


There have been different proposals on how to allocate responsibility for cutting emissions (Banuri et al., 1996, pp. 103–105):
  • Egalitarianism
    Egalitarianism
    Egalitarianism is a trend of thought that favors equality of some sort among moral agents, whether persons or animals. Emphasis is placed upon the fact that equality contains the idea of equity of quality...

    : this system interprets the problem as one where each person has equal rights to a global resource, i.e., polluting the atmosphere.
  • Basic needs and Rawlsian criteria: this system would have emissions allocated according to basic needs, as defined according to a minimum level of consumption
    Consumption (economics)
    Consumption is a common concept in economics, and gives rise to derived concepts such as consumer debt. Generally, consumption is defined in part by comparison to production. But the precise definition can vary because different schools of economists define production quite differently...

    . Consumption above basic needs would require countries to buy more emission rights. This can be related to Rawlsian
    John Rawls
    John Bordley Rawls was an American philosopher and a leading figure in moral and political philosophy. He held the James Bryant Conant University Professorship at Harvard University....

     philosophy
    Philosophy
    Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...

    . From this viewpoint, developing countries would need to be at least as well off under an emissions control regime as they would be outside the regime.
  • Proportionality and polluter-pays principle: Proportionality reflects the ancient Aristotelian
    Aristotelianism
    Aristotelianism is a tradition of philosophy that takes its defining inspiration from the work of Aristotle. The works of Aristotle were initially defended by the members of the Peripatetic school, and, later on, by the Neoplatonists, who produced many commentaries on Aristotle's writings...

     principle that people should receive in proportion to what they put in, and pay in proportion to the damages they cause. This has a potential relationship with the "polluter-pays principle", which can be interpreted in a number of ways:
    • Historical responsibilities: this asserts that allocation of emission rights should be based on patterns of past emissions. Two-thirds of the stock of GHGs in the atmosphere at present is due to the past actions of developed countries (Goldemberg et al., 1996, p. 29).
    • Comparable burdens and ability to pay: with this approach, countries would reduce emissions based on comparable burdens and their ability to take on the costs of reduction. Ways to assess burdens include monetary costs per head of population, as well as other, more complex measures, like the UNDP's Human Development Index
      Human Development Index
      The Human Development Index is a composite statistic used to rank countries by level of "human development" and separate "very high human development", "high human development", "medium human development", and "low human development" countries...

      .
    • Willingness to pay
      Willingness to pay
      In economics, the willingness to pay is the maximum amount a person would be willing to pay, sacrifice or exchange in order to receive a good or to avoid something undesired, such as pollution...

      : with this approach, countries take on emission reductions based on their ability to pay along with how much they benefit from reducing their emissions.

Specific proposals

  • Ad hoc: Lashof (1992) and Cline (1992) (referred to by Banuri et al., 1996, p. 106), for example, suggested that allocations based partly on GNP
    GNP
    Gross National Product is the market value of all products and services produced in one year by labor and property supplied by the residents of a country...

     could be a way of sharing the burdens of emission reductions. This is because GNP and economic activity are partially tied to carbon emissions.
  • Equal per capita entitlements: this is the most widely cited method of distributing abatement costs, and is derived from egalitarianism (Banuri et al., 1996, pp. 106–107). This approach can be divided into two categories. In the first category, emissions are allocated according to national population. In the second category, emissions are allocated in a way that attempts to account for historical (cumulative) emissions.
  • Status quo: with this approach, historical emissions are ignored, and current emission levels are taken as a status quo right to emit (Banuri et al., 1996, p. 107). An analogy for this approach can be made with fisheries
    Fishery
    Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...

    , which is a common, limited resource. The analogy would be with the atmosphere, which can be viewed as an exhaustible natural resource
    Natural resource
    Natural resources occur naturally within environments that exist relatively undisturbed by mankind, in a natural form. A natural resource is often characterized by amounts of biodiversity and geodiversity existent in various ecosystems....

     (Goldemberg et al., 1996, p. 27). In international law
    International law
    Public international law concerns the structure and conduct of sovereign states; analogous entities, such as the Holy See; and intergovernmental organizations. To a lesser degree, international law also may affect multinational corporations and individuals, an impact increasingly evolving beyond...

    , one state recognized the long-established use of another state's use of the fisheries resource. It was also recognized by the state that part of the other state's economy was dependent on that resource.

Governmental and intergovernmental action


Many countries, both developing and developed, are aiming to use cleaner technologies (World Bank, 2010, p. 192). Use of these technologies aids mitigation and could result in substantial reductions in CO2 emissions. Policies include targets for emissions reductions, increased use of renewable energy, and increased energy efficiency. It is often argued that the results of climate change are more damaging in poor nations, where infrastructures are weak and few social services exist. The Commitment to Development Index
Commitment to Development Index
The Commitment to Development Index , published annually by the Center for Global Development, ranks the world’s richest countries on their dedication to policies that benefit the five billion people living in poorer nations. Rich and poor countries are linked in many ways; thus the Index looks...

 is one attempt to analyze rich country policies taken to reduce their disproportionate use of the global commons. Countries do well if their greenhouse gas emissions are falling, if their gas taxes are high, if they do not subsidize the fishing industry, if they have a low fossil fuel rate per capita, and if they control imports of illegally cut tropical timber.

Kyoto Protocol


The main current international agreement on combating climate change is the Kyoto Protocol
Kyoto Protocol
The Kyoto Protocol is a protocol to the United Nations Framework Convention on Climate Change , aimed at fighting global warming...

, which came into force on 16 February 2005. The Kyoto Protocol is an amendment to the United Nations Framework Convention on Climate Change
United Nations Framework Convention on Climate Change
The United Nations Framework Convention on Climate Change is an international environmental treaty produced at the United Nations Conference on Environment and Development , informally known as the Earth Summit, held in Rio de Janeiro from June 3 to 14, 1992...

 (UNFCCC). Countries that have ratified this protocol have committed to reduce their emissions of carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 and five other greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...

es, or engage in emissions trading
Emissions trading
Emissions trading is a market-based approach used to control pollution by providing economic incentives for achieving reductions in the emissions of pollutants....

 if they maintain or increase emissions of these gases.

Copenhagen 2009


The first phase of the Kyoto Protocol expires in 2012. The United Nations Climate Change Conference in Copenhagen in December 2009 was the next in an annual series of UN meetings that followed the 1992 Earth Summit in Rio. In 1997 the talks led to the Kyoto Protocol, Copenhagen was considered the world's chance to agree a successor to Kyoto that would bring about meaningful carbon cuts.

Subsidies


A program of subsidization balanced against expected flood costs could pay for conversion to 100% renewable power by 2030. The proponents of such a plan expect the cost to generate and transmit power in 2020 will be less than 4 cents per kilowatt hour (in 2007 dollars) for wind, about 4 cents for wave and hydroelectric, from 4 to 7 cents for geothermal, and 8 cents per kwh for solar, fossil, and nuclear power.

Carbon emissions trading


With the creation of a market
Market
A market is one of many varieties of systems, institutions, procedures, social relations and infrastructures whereby parties engage in exchange. While parties may exchange goods and services by barter, most markets rely on sellers offering their goods or services in exchange for money from buyers...

 for trading carbon dioxide emissions within the Kyoto Protocol, it is likely that London financial markets will be the centre for this potentially highly lucrative business; the New York and Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...

 stock markets may have a lower trade volume than expected as long as the US maintains its rejection of the Kyoto
Kyoto Protocol
The Kyoto Protocol is a protocol to the United Nations Framework Convention on Climate Change , aimed at fighting global warming...

).

However, emissions trading may delay the phase-out of fossil fuels.

The European Union Emission Trading Scheme
European Union Emission Trading Scheme
The European Union Emissions Trading Scheme also known as the European Union Emissions Trading System, was the first large emissions trading scheme in the world. It was launched in 2005 to combat climate change and is a major pillar of EU climate policy...

 (EU ETS) is the largest multi-national, greenhouse gas emissions trading scheme in the world. It commenced operation on 1 January 2005, and all 25 member states of the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...

 participate in the scheme which has created a new market in carbon dioxide allowances estimated at 35 billion Euros (US$43 billion) per year. The Chicago Climate Exchange
Chicago Climate Exchange
The now defunct Chicago Climate Exchange was North America’s only voluntary, legally binding greenhouse gas reduction and trading system for emission sources and offset projects in North America and Brazil....

 was the first (voluntary) emissions market, and is soon to be followed by Asia's first market (Asia Carbon Exchange). A total of 107 million metric tonnes of carbon dioxide equivalent have been exchanged through projects in 2004, a 38% increase relative to 2003 (78 Mt CO2e).

Twenty three multinational corporation
Multinational corporation
A multi national corporation or enterprise , is a corporation or an enterprise that manages production or delivers services in more than one country. It can also be referred to as an international corporation...

s have come together in the G8 Climate Change Roundtable
G8 Climate Change Roundtable
The G8 Climate Change Roundtable was formed in January 2005 at the World Economic Forum in Davos. The first meeting was held in Gleneagles, Scotland, from 6–8 July 2005, to coincide with the 31st G8 summit....

, a business group formed at the January 2005 World Economic Forum
World Economic Forum
The World Economic Forum is a Swiss non-profit foundation, based in Cologny, Geneva, best known for its annual meeting in Davos, a mountain resort in Graubünden, in the eastern Alps region of Switzerland....

. The group includes Ford
Ford Motor Company
Ford Motor Company is an American multinational automaker based in Dearborn, Michigan, a suburb of Detroit. The automaker was founded by Henry Ford and incorporated on June 16, 1903. In addition to the Ford and Lincoln brands, Ford also owns a small stake in Mazda in Japan and Aston Martin in the UK...

, Toyota, British Airways
British Airways
British Airways is the flag carrier airline of the United Kingdom, based in Waterside, near its main hub at London Heathrow Airport. British Airways is the largest airline in the UK based on fleet size, international flights and international destinations...

 and BP
BP
BP p.l.c. is a global oil and gas company headquartered in London, United Kingdom. It is the third-largest energy company and fourth-largest company in the world measured by revenues and one of the six oil and gas "supermajors"...

. On 9 June 2005 the Group published a statement stating that there was a need to act on climate change and claiming that market-based solutions can help. It called on governments to establish "clear, transparent, and consistent price signals" through "creation of a long-term policy framework" that would include all major producers of greenhouse gases.

The Regional Greenhouse Gas Initiative
Regional Greenhouse Gas Initiative
Regional Greenhouse Gas Initiative is a regional initiative by states and provinces in the Northeastern United States and Eastern Canada regions to reduce greenhouse gas emissions...

 is a proposed carbon trading scheme being created by nine North-eastern and Mid-Atlantic American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 states; Connecticut
Connecticut
Connecticut is a state in the New England region of the northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, and the state of New York to the west and the south .Connecticut is named for the Connecticut River, the major U.S. river that approximately...

, Delaware
Delaware
Delaware is a U.S. state located on the Atlantic Coast in the Mid-Atlantic region of the United States. It is bordered to the south and west by Maryland, and to the north by Pennsylvania...

, Maine
Maine
Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...

, Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

, New Hampshire
New Hampshire
New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...

, New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...

, New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

, Rhode Island
Rhode Island
The state of Rhode Island and Providence Plantations, more commonly referred to as Rhode Island , is a state in the New England region of the United States. It is the smallest U.S. state by area...

 and Vermont
Vermont
Vermont is a state in the New England region of the northeastern United States of America. The state ranks 43rd in land area, , and 45th in total area. Its population according to the 2010 census, 630,337, is the second smallest in the country, larger only than Wyoming. It is the only New England...

. The scheme was due to be developed by April 2005 but has not yet been completed.

Emissions tax


An emissions tax on greenhouse gas emissions requires individual emitters to pay a fee, charge or tax for every tonne of greenhouse gas released into the atmosphere. Most environmentally related taxes with implications for greenhouse gas emissions in OECD countries are levied on energy products and motor vehicles, rather than on CO2 emissions directly.

Emission taxes can be both cost effective and environmentally effective. Difficulties with emission taxes include their potential unpopularity, and the fact that they cannot guarantee a particular level of emissions reduction. Emissions or energy taxes also often fall disproportionately on lower income classes. In developing countries, institutions may be insufficiently developed for the collection of emissions fees from a wide variety of sources.

Implementation


Implementation puts into effect climate change mitigation strategies and targets. These can be targets set by international bodies or voluntary action by individuals or institutions. This is the most important, expensive and least appealing aspect of environmental governance.

Funding


Implementation requires funding sources but is often beset by disputes over who should provide funds and under what conditions. A lack of funding can be a barrier to successful strategies as there are no formal arrangements to finance climate change development and implementation. Funding is often provided by nations, groups of nations and increasingly NGO and private sources. These funds are often channelled through the Global Environmental Facility (GEF). This is an environmental funding mechanism in the World Bank which is designed to deal with global environmental issues. The GEF was originally designed to tackle four main areas: biological diversity, climate change, international waters and ozone layer depletion, to which land degradation and persistent organic pollutant were added. The GEF funds projects that are agreed to achieve global environmental benefits that are endorsed by governments and screened by one of the GEF’s implementing agencies.

Problems


There are numerous issues which result in a current perceived lack of implementation. It has been suggested that the main barriers to implementation are, Uncertainty, Fragmentation, Institutional void, Short time horizon of policies and politicians and Missing motives and willingness to start adapting. The relationships between many climatic processes can cause large levels of uncertainty as they are not fully understood and can be a barrier to implementation. When information on climate change is held between the large numbers of actors involved it can be highly dispersed, context specific or difficult to access causing fragmentation to be a barrier. Institutional void is the lack of commonly accepted rules and norms for policy processes to take place, calling into question the legitimacy and efficacy of policy processes. The Short time horizon of policies and politicians often means that climate change policies are not implemented in favour of socially favoured societal issues. Statements are often posed to keep the illusion of political action to prevent or postpone decisions being made. Missing motives and willingness to start adapting is a large barrier as it prevents any implementation.

Occurrence


Despite a perceived lack of occurrence, evidence of implementation is emerging internationally. Some examples of this are the initiation of NAPA’s and of joint implementation. Many developing nations have made National Adaptation Programs of Action (NAPAs) which are frameworks to prioritize adaption needs. The implementation of many of these is supported by GEF agencies. Many developed countries are implementing ‘first generation’ institutional adaption plans particularly at the state and local government scale. There has also been a push towards joint implementation between countries by the UNFCC as this has been suggested as a cost effective way for objectives to be achieved.

United States


Efforts to reduce greenhouse gas emissions by the United States
Greenhouse gas emissions by the United States
Until 2006, the United States was the largest emitter of carbon dioxide emissions. China has been the top emitter since 2006. However both the emissions as a result of manufacturing exports and the emissions avoided by product imports are not considered...

 include energy policies
Energy policy of the United States
The energy policy of the United States is determined by federal, state and local public entities in the United States, which address issues of energy production, distribution, and consumption, such as building codes and gas mileage standards...

 which encourage efficiency through programs like Energy Star
Energy Star
Energy Star is an international standard for energy efficient consumer products originated in the United States of America. It was first created as a United States government program during the early 1990s, but Australia, Canada, Japan, New Zealand, Taiwan and the European Union have also adopted...

, Commercial Building Integration, and the Industrial Technologies Program. On 12 November 1998, Vice President Al Gore
Al Gore
Albert Arnold "Al" Gore, Jr. served as the 45th Vice President of the United States , under President Bill Clinton. He was the Democratic Party's nominee for President in the 2000 U.S. presidential election....

 symbolically signed the Kyoto Protocol, but he indicated participation by the developing nations was necessary prior its being submitted for ratification by the United States Senate
United States Senate
The United States Senate is the upper house of the bicameral legislature of the United States, and together with the United States House of Representatives comprises the United States Congress. The composition and powers of the Senate are established in Article One of the U.S. Constitution. Each...

.

In 2007, Transportation Secretary Mary Peters
Mary Peters (politician)
Mary E. Peters served as the United States Secretary of Transportation under President George W. Bush from 2006 to 2009. She is the second woman to hold the position.-Public service career:...

, with White House approval, urged governors and dozens of members of the House of Representatives to block California’s first-in-the-nation limits on greenhouse gases from cars and trucks, according to e-mails obtained by Congress. The U.S. Climate Change Science Program is a group of about twenty federal agencies and US Cabinet Departments, all working together to address global warming.

The Bush administration pressured American scientists to suppress discussion of global warming, according to the testimony of the Union of Concerned Scientists to the Oversight and Government Reform Committee of the U.S. House of Representatives. "High-quality science" was "struggling to get out," as the Bush administration pressured scientists to tailor their writings on global warming to fit the Bush administration's skepticism, in some cases at the behest of an ex-oil industry lobbyist. "Nearly half of all respondents perceived or personally experienced pressure to eliminate the words 'climate change,' 'global warming' or other similar terms from a variety of communications." Similarly, according to the testimony of senior officers of the Government Accountability Project
Government Accountability Project
The Government Accountability Project is a leading United States whistleblower protection organization. Through litigating of whistleblower cases, publicizing concerns and developing legal reforms, GAP’s mission is to protect the public interest by promoting government and corporate accountability...

, the White House attempted to bury the report "National Assessment of the Potential Consequences of Climate Variability and Change," produced by U.S. scientists pursuant to U.S. law. Some U.S. scientists resigned their jobs rather than give in to White House pressure to underreport global warming.

Developing countries


In order to reconcile economic development
Economic development
Economic development generally refers to the sustained, concerted actions of policymakers and communities that promote the standard of living and economic health of a specific area...

 with mitigating carbon emissions, developing countries need particular support, both financial and technical. One of the means of achieving this is the Kyoto Protocol's Clean Development Mechanism
Clean Development Mechanism
The Clean Development Mechanism is one of the "flexibility" mechanisms defined in the Kyoto Protocol . It is defined in Article 12 of the Protocol, and is intended to meet two objectives: to assist parties not included in Annex I in achieving sustainable development and in contributing to the...

 (CDM). The World Bank
World Bank
The World Bank is an international financial institution that provides loans to developing countries for capital programmes.The World Bank's official goal is the reduction of poverty...

's Prototype Carbon Fund is a public private partnership that operates within the CDM.

An important point of contention, however, is how overseas development assistance not directly related to climate change mitigation is affected by funds provided to climate change mitigation. One of the outcomes of the UNFCC Copenhagen Climate Conference was the Copenhagen Accord
Copenhagen Accord
The Copenhagen Accord is a document that delegates at the 15th session of the Conference of Parties to the United Nations Framework Convention on Climate Change agreed to "take note of" at the final plenary on 18 December 2009....

, in which developed countries promised to provide US $30 million between 2010–2012 of new and additional resources. Yet it remains unclear what exactly the definition of additional is and the European Commission
European Commission
The European Commission is the executive body of the European Union. The body is responsible for proposing legislation, implementing decisions, upholding the Union's treaties and the general day-to-day running of the Union....

 has requested its member states to define what they understand to be additional, and researchers at the Overseas Development Institute
Overseas Development Institute
The Overseas Development Institute is one of the leading independent think tanks on international development and humanitarian issues. Based in London, its mission is "to inspire and inform policy and practice which lead to the reduction of poverty, the alleviation of suffering and the achievement...

 have found 4 main understandings:
  1. Climate finance classified as aid, but additional to (over and above) the ‘0.7%’ ODA target;
  2. Increase on previous year's Official Development Assistance
    Official development assistance
    Official development assistance is a term compiled by the Development Assistance Committee of the Organisation for Economic Co-operation and Development to measure aid. The DAC first compiled the term in 1969. It is widely used by academics and journalists as a convenient indicator of...

     (ODA) spent on climate change mitigation;
  3. Rising ODA levels that include climate change finance but where it is limited to a specified percentage; and
  4. Increase in climate finance not connected to ODA.

The main point being that there is a conflict between the OECD states budget deficit cuts, the need to help developing countries adapt to develop sustainably and the need to ensure that funding does not come from cutting aid to other important Millennium Development Goals
Millennium Development Goals
The Millennium Development Goals are eight international development goals that all 193 United Nations member states and at least 23 international organizations have agreed to achieve by the year 2015...

.

In July 2005 the U.S., China, India, Australia, as well as Japan and South Korea, agreed to the Asia-Pacific Partnership for Clean Development and Climate. The pact aims to encourage technological development that may mitigate global warming, without coordinated emissions targets. The highest goal of the pact is to find and promote new technology that aid both growth and a cleaner environment simultaneously. An example is the Methane to Markets initiative which reduces methane emissions into the atmosphere by capturing the gas and using it for growth enhancing clean energy generation. Critics have raised concerns that the pact undermines the Kyoto Protocol.

However, none of these initiatives suggest a quantitative cap on the emissions from developing countries. This is considered as a particularly difficult policy proposal as the economic growth of developing countries are proportionally reflected in the growth of greenhouse emissions. Critics of mitigation often argue that, the developing countries' drive to attain a comparable living standard to the developed countries would doom the attempt at mitigation of global warming. Critics also argue that holding down emissions would shift the human cost of global warming from a general one to one that was borne most heavily by the poorest populations on the planet.

In an attempt to provide more opportunities for developing countries to adapt clean technologies, UNEP and WTO urged the international community to reduce trade barriers and to conclude the Doha trade round
Doha round
The Doha Development Round or Doha Development Agenda is the current trade-negotiation round of the World Trade Organization which commenced in November 2001. Its objective is to lower trade barriers around the world, which will help facilitate the increase of global trade...

 "which includes opening trade in environmental goods and services".

Non-governmental approaches


While many of the proposed methods of mitigating global warming require governmental funding, legislation and regulatory action, individuals and businesses
Business action on climate change
Business action on climate change includes a range of activities relating to global warming, and to influencing political decisions on global-warming-related regulation, such as the Kyoto Protocol...

 can also play a part in the mitigation effort.

Choices in personal actions and business operations


Environmental groups encourage individual action against global warming
Individual and political action on climate change
Individual and political action on climate change can take many forms, most of which have the ultimate goal of limiting and/or reducing the concentration of greenhouse gases in the atmosphere, toward avoiding dangerous climate change.-Political action:...

, often aimed at the consumer
Consumer
Consumer is a broad label for any individuals or households that use goods generated within the economy. The concept of a consumer occurs in different contexts, so that the usage and significance of the term may vary.-Economics and marketing:...

. Common recommendations include lowering home heating and cooling usage, burning less gasoline, supporting renewable energy sources, buying local products to reduce transportation, turning off unused devices, and various others.

A geophysicist at Utrecht University
Utrecht University
Utrecht University is a university in Utrecht, Netherlands. It is one of the oldest universities in the Netherlands and one of the largest in Europe. Established March 26, 1636, it had an enrollment of 29,082 students in 2008, and employed 8,614 faculty and staff, 570 of which are full professors....

 has urged similar institutions to hold the vanguard in voluntary mitigation, suggesting the use of communications technologies such as videoconferencing
Videoconferencing
Videoconferencing is the conduct of a videoconference by a set of telecommunication technologies which allow two or more locations to interact via two-way video and audio transmissions simultaneously...

 to reduce their dependence on long-haul flights.
Air travel and shipment

Climate scientist Kevin Anderson
Kevin Anderson (scientist)
Professor Kevin Anderson is the Deputy Director of the Tyndall Centre for Climate Change Research; holds a joint chair in Energy and Climate Change at the School of Mechanical, Aerospace and Civil Engineering at the University of Manchester and School of Environmental Sciences at University of East...

 raised concern about the growing effect of rapidly increasing global air transport on the climate in a paper and a presentation in 2008, suggesting that reversing this trend is necessary. Part of the difficulty is that when aviation emissions are made at high altitude, the climate impacts are much greater than otherwise. Others have been raising the related concerns of the increasing hypermobility
Hypermobility (travel)
The term hypermobility in regard to travelers arose around 1980 and is a concept that has increased in useage since the early 1990s: Damette ; Hepworth and Ducatel ; Whitelegg ; Lowe ; van der Stoep ; Shields ; Cox ; Adams ; Khisty and Zeitler ; Gössling et al. ; and Mander & Randles...

 of individuals, whether traveling for business or pleasure, involving frequent and often long distance air travel, as well as air shipment of goods.

Business opportunities and risks


On 9 May 2005 Jeff Immelt, the chief executive of General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...

 (GE), announced plans to reduce GE's global warming related emissions by one percent by 2012. "GE said that given its projected growth, those emissions would have risen by 40 percent without such action."

On 21 June 2005 a group of leading airline
Airline
An airline provides air transport services for traveling passengers and freight. Airlines lease or own their aircraft with which to supply these services and may form partnerships or alliances with other airlines for mutual benefit...

s, airport
Airport
An airport is a location where aircraft such as fixed-wing aircraft, helicopters, and blimps take off and land. Aircraft may be stored or maintained at an airport...

s and aerospace
Aerospace
Aerospace comprises the atmosphere of Earth and surrounding space. Typically the term is used to refer to the industry that researches, designs, manufactures, operates, and maintains vehicles moving through air and space...

 manufacturers pledged to work together to reduce the negative environmental impact of aviation, including limiting the impact of air travel on climate change by improving fuel efficiency
Fuel efficiency
Fuel efficiency is a form of thermal efficiency, meaning the efficiency of a process that converts chemical potential energy contained in a carrier fuel into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is...

 and reducing carbon dioxide emissions of new aircraft by fifty percent per seat kilometre by 2020 from 2000 levels. The group aims to develop a common reporting system for carbon dioxide emissions per aircraft by the end of 2005, and pressed for the early inclusion of aviation in the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...

's carbon emission trading scheme.

Legal action


In some countries, those affected by climate change may be able to sue major producers, in a parallel to the lawsuits against tobacco
Tobacco
Tobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as a pesticide and, in the form of nicotine tartrate, used in some medicines...

 companies. Although proving that particular weather events are due specifically to global warming may never be possible, methodologies have been developed to show the increased risk of such events caused by global warming.

For a legal action for negligence
Negligence
Negligence is a failure to exercise the care that a reasonably prudent person would exercise in like circumstances. The area of tort law known as negligence involves harm caused by carelessness, not intentional harm.According to Jay M...

 (or similar) to succeed, "Plaintiffs ... must show that, more probably than not, their individual injuries were caused by the risk factor in question, as opposed to any other cause. This has sometimes been translated to a requirement of a relative risk of at least two." Another route (though with little legal bite) is the World Heritage Convention, if it can be shown that climate change is affecting World Heritage Site
World Heritage Site
A UNESCO World Heritage Site is a place that is listed by the UNESCO as of special cultural or physical significance...

s like Mount Everest
Mount Everest
Mount Everest is the world's highest mountain, with a peak at above sea level. It is located in the Mahalangur section of the Himalayas. The international boundary runs across the precise summit point...

.

Legal action has also been taken to try to force the U.S. Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...

 to regulate greenhouse gas emissions under the Clean Air Act
Clean Air Act
A Clean Air Act is one of a number of pieces of legislation relating to the reduction of airborne contaminants, smog and air pollution in general. The use by governments to enforce clean air standards has contributed to an improvement in human health and longer life spans...

, and against the Export-Import Bank
Export-Import Bank of the United States
The Export-Import Bank of the United States is the official export credit agency of the United States federal government. It was established in 1934 by an executive order, and made an independent agency in the Executive branch by Congress in 1945, for the purposes of financing and insuring...

 and OPIC for failing to assess environmental impacts (including global warming impacts) under NEPA
Nepa
Nepa is a village development committee in Dailekh District in the Bheri Zone of western-central Nepal. At the time of the 1991 Nepal census it had a population of 3621 people living in 739 individual households.-External links:*...

.

According to a 2004 study commissioned by Friends of the Earth
Friends of the Earth
Friends of the Earth International is an international network of environmental organizations in 76 countries.FOEI is assisted by a small secretariat which provides support for the network and its agreed major campaigns...

, ExxonMobil
ExxonMobil
Exxon Mobil Corporation or ExxonMobil, is an American multinational oil and gas corporation. It is a direct descendant of John D. Rockefeller's Standard Oil company, and was formed on November 30, 1999, by the merger of Exxon and Mobil. Its headquarters are in Irving, Texas...

 and its predecessors caused 4.7 to 5.3 percent of the world's man-made carbon dioxide emissions between 1882 and 2002. The group suggested that such studies could form the basis for eventual legal action.

See also


  • 4 Degrees and Beyond International Climate Conference
    4 Degrees and Beyond International Climate Conference
    The 4 Degrees and Beyond International Climate Conference, subtitled Implications of a Global Climate Change of 4+ Degrees for People, Ecosystems and the Earth-system, was held 28-30 September 2009 at Oxford, United Kingdom. Implications of...

  • Alternative propulsion
  • Avoiding Dangerous Climate Change
    Avoiding Dangerous Climate Change
    The related terms "avoiding dangerous climate change" and "preventing dangerous anthropogenic interference with the climate system" date to 1995 and earlier, in the Second Assesment Report of the International Panel on Climate Change and previous science it cites.In 2002, the United Nations...

  • Biochar
    Biochar
    Biochar or terra preta is charcoal created by pyrolysis of biomass. Biochar is under investigation as an approach to carbon sequestration via bio-energy with carbon capture and storage. Biochar thus has the potential to help mitigate climate change, via carbon sequestration...

  • Black carbon
    Black carbon
    In Climatology, black carbon or BC is a climate forcing agent formed through the incomplete combustion of fossil fuels, biofuel, and biomass, and is emitted in both anthropogenic and naturally occurring soot. It consists of pure carbon in several linked forms...

  • Carbon diet
    Carbon Diet
    A carbon diet refers to reducing the impact on climate change by reducing greenhouse gas production.Individuals and businesses produce carbon dioxide from daily activities such as driving, heating, and the consumption of products and services...

  • Climate bond
    Climate bond
    Climate bonds are fixed-income financial instruments linked in some way to climate change solutions.Climate Bonds are issued in order to raise finance for climate change solutions - climate change mitigation or adaptation related projects or programs...

  • Coalization
  • Contraction and Convergence
    Contraction and Convergence
    Contraction and Convergence is a proposed global framework for reducing greenhouse gas emissions to combat climate change. Conceived by the Global Commons Institute [GCI] in the early 1990s, the Contraction and Convergence strategy consists of reducing overall emissions of greenhouse gases to a...

  • Forestalment
  • Emissions reduction#Reduction efforts
  • Green IT
  • Hell and High Water: Global Warming
  • Hypermobility
    Hypermobility (travel)
    The term hypermobility in regard to travelers arose around 1980 and is a concept that has increased in useage since the early 1990s: Damette ; Hepworth and Ducatel ; Whitelegg ; Lowe ; van der Stoep ; Shields ; Cox ; Adams ; Khisty and Zeitler ; Gössling et al. ; and Mander & Randles...

  • Iron fertilization
    Iron fertilization
    Iron fertilization is the intentional introduction of iron to the upper ocean to stimulate a phytoplankton bloom. This is intended to enhance biological productivity, which can benefit the marine food chain and remove carbon dioxide from the atmosphere. Iron is a trace element necessary for...

  • Low carbon diet
    Low carbon diet
    A low carbon diet refers to making lifestyle choices to reduce the greenhouse gas emissions resulting from energy use. It is estimated that the U.S. food system is responsible for at least 20 percent of U.S. greenhouse gases. This estimate may be low, as it counts only direct sources of GHGe....

  • Mitigation of peak oil
    Mitigation of peak oil
    The mitigation of peak oil is the attempt to delay the date and minimize the social and economic impact of peak oil by reducing the world's consumption and reliance on petroleum. By reducing petroleum consumption, mitigation efforts seek to favorably change the shape of the Hubbert curve, which is...

  • Oil phase-out
  • Overpopulation
    Overpopulation
    Overpopulation is a condition where an organism's numbers exceed the carrying capacity of its habitat. The term often refers to the relationship between the human population and its environment, the Earth...

  • QELRO
  • Stratospheric sulfur aerosols (geoengineering)
    Stratospheric sulfur aerosols (geoengineering)
    The ability of stratospheric sulfate aerosols to create a global dimming effect has made them a possible candidate for use in geoengineering projects to limit the effect and impact of climate change due to rising levels of greenhouse gases...

  • Zero-carbon economy

By country

  • Debate over China's economic responsibilities for climate change mitigation
    Debate over China's economic responsibilities for climate change mitigation
    This article documents the debate over China's economic responsibilities for climate change mitigation and mitigation of climate change in China....

  • European Climate Change Programme
    European Climate Change Programme
    The European Climate Change Programme was launched in June 2000 by the European Union's European Commission, toward avoiding dangerous climate change....

  • Mitigation of global warming in Australia
    Mitigation of global warming in Australia
    Mitigation of global warming involves taking actions to reduce greenhouse gas emissions and to enhance sinks aimed at reducing the extent of global warming. This is in distinction to adaptation to global warming, which involves taking action to minimise the effects of global warming...


External links

  • Intergovernmental Panel on Climate Change – Includes the Working Group III Report "Mitigation of Climate Change" as part of the Fourth Assessment Report
  • Why Black Carbon and Ozone Also Matter, in September/October 2009 Foreign Affairs
    Foreign Affairs
    Foreign Affairs is an American magazine and website on international relations and U.S. foreign policy published since 1922 by the Council on Foreign Relations six times annually...

     with Veerabhadran Ramanathan
    Veerabhadran Ramanathan
    Veerabhadran Ramanathan is Victor Alderson Professor of Applied Ocean Sciences and director of the Center for Atmospheric Sciences at the Scripps Institution of Oceanography, University of California, San Diego. He has contributed to many areas of the atmospheric sciences including developments to...

     and Jessica Seddon Wallack.

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