Carbon Sequestration in Terrestrial Ecosystems
Encyclopedia
Carbon sequestration by terrestrial ecosystem
s is the net removal of carbon dioxide
(CO2) from the atmosphere or the avoidance of carbon dioxide (CO2) emissions from terrestrial ecosystems into the atmosphere. The removal process includes CO2 uptake from the atmosphere by all chlorophyllous plants, through photosynthesis. This C is stored as plant biomass (in the trunks, branches, leaves and roots of the plants) and organic matter in the soil (IPCC 2000). The terrestrial carbon sequestrations depend on land use practices and different ecosystem conditions that sustain established vegetation over longer periods.
Terrestrial carbon sequestration is not only of interest in those countries which have an obligation to reduce greenhouse gas
emission under the Kyoto Protocol
. Contemporary rational for its policy making includes that it (1) offers cost effective
solutions for limiting Greenhouse Gases (GHG) concentration in the atmosphere for countries while enhancing their natural capital
; (2) enhances cooperation for knowledge and technology transfer
amongst states; (3) provides opportunities in developing countries
(over US$30 billion/year) (Peskett et al. 2008); and (4) has potential for rural poverty reduction.
Numerous methodologies for carbon sequestration projects (CSP) have been developed targeted at reducing carbon fluxes primarily through management interventions involving land use, land use changes and forestry (LULUCF
) (Smith 2004; Lehmann et al. 2006; Bondeau et al. 2006; Batjes 1998; Smith et al. 1993; Brown et al. 1993). Two critical considerations to be borne in mind are impacts of planned project activities on ecology and human welfare. Therefore it is essential that carbon management is adequately formulated within national and international climate policies.
This article takes a pragmatic approach in discussing several features of carbon sequestration reflected in the discourses of science (biogeochemistry), social sciences, economics and policies. It looks at both normative and controversial aspects, and provides recommendations for scientists and policy makers.
practices. Land use changes account for about 1.6±1.0 Gt of CO2 to be released to the atmosphere annually (IPCC 1996a) with the deforestation of tropical forests
emit most GHGs (IPCC 2000; Meyers, 2007). This increasing release of GHGs into the atmosphere contributes to Global Warming
, which in turn limits the ability of TEs to sequester C (Heimann and Reichstein 2008).
Although natural and anthropogenic activities enhance GHG releases into the atmosphere, prospects for the use of CS by TEs as a strategy for mitigating climate change (Meyers, E.C. 2007) are increasing. It is considered to be a relatively cost-effective emission reduction strategy
, and has the potential of generating co-benefits for humans and environment. Aggressive CS programs could sequester and avoid carbon emissions equivalent to about 12–15% under the business-as-usual scenario over a 50-year period (IPCC 2001). However, these pessimisms straddle around assumptions and experimental modification of anthropogenic activities. Hence there are challenges for the eventual use of CS for climate change mitigation. Some of these include lack of scientific understanding of the biogeo-chemical cycle of C, socio-economic
and policy issues related to organizing human activities that may limit this opportunity and actually enhance the CO2 emission potential of TES (IPCC 2001).
Methods used for measuring carbon in biomass include: non-destructive sampling for biomass (application of algometric or cylinder equations or estimation tree root biomass from proximal root and algometric relations); destructive sampling of soil and vegetation (harvesting vegetation, taking samples of litter and soil); and remote sensing
methods that assess carbon in vegetation but less useful to measure soil C directly (unless bare) (Jacobs n.d.).
, region, climate, topography and management practices that can affect plant productivity (Lal 1999). At a local scale, CS in TE is largely influenced by light conditions, water availability, soil water holding capacity and its nutrient content. Local conditions could modify the frequency and severity of natural risks such as forest fires
, strong winds etc., increasing the probability of CO2 emissions and hence carbon loss from these systems (Heimann and Reichstein 2008). TEs sequestered about 2.6 x109 g C per year of all atmospheric emissions during the period 2000-2007 representing net reductions of about 30% (according to 2006 levels) (GCP 2008). They have the potential of eventually sequestrating about 2 Gt C/year under intensive management and/or manipulation scenarios of a significant fraction of these systems (DOE 1999). Table 1 shows the different present stocks and net primary production
(NPP) of various terrestrial biomes.
Table 1: Global estimates of land area, net primary productivity (NPP), and carbon stocks in livIng plants and soil organic matter for ecosystems of the world
Note:
Soil C values are for the top 1 m of soil only, except for peatlands, in which case they account for the total depth of peat. Pg = Petagram = Gigatonne.
Source: Amthor et al. 1998.
on which CS models are mainly constructed straddle on CO2 uptake by photosynthesis and release by respiration from sinks and emission sources (Kirschbaum, 2006) as well as feedback loops
. However, feed-back loops are more complicated. Other biological process
es associated with respiration respond to temperature exponentially but are not affected by the CO2 concentration except photosynthesis (Kirschbaum, 2006). Hence TEs can continue to sequester C, provided the temperature is below certain levels that have a stimulating effect for respiration to exceed the CO2 fertilization effect. In actual fact carbon dynamics and feedback patterns are much more complicated than ordinary respiration/photosynthesis loops and may encompass complex physical, chemical and biological processes within the ecosystem.
(GCP 2008) consensus that these trends will seriously enhance global warming.
Figure 1. Carbon Emissions from deforestation in tropical regions (Source: GCP 2008).
(minimum tillage, protective cover of upper soil) is very important for increasing soil organic matter (FAO 2001).
Table 2: Main effects of land management practices or land-use on carbon sequestration capacity (t C ha-1 yr-1) in dry-lands and tropical areas.
Source: Lal 1999; FAO 2001
• Afforestation
Afforestation is the conversion of previously non-forested land into forested land. This method is more commonly associated with the conversion of poor to marginal cropland into forested land. Afforestation can result in a large amount of carbon sequestered over a long period of time. A non-forested acre converted into a forested acre can result in a carbon sequestration rate of 0.6–2.6 MMT over a period of 90–120+ years (EPA 2006).
• Reforestation
Reforestation is the restoration of previously forested land. Doing so can produce an increase in carbon uptake of around 2.1 MMT per acre over a period of 90–120+ years (EPA 2006)
• Sustainable forest management
Sustainable forest management techniques include forest preservation, adoption of low-impact harvesting methods, lengthening of forest rotation cycles, agroforestry, and the adoption of other methods aimed at increasing carbon uptake (Richards et al. 2005). Forest preservation is the protection of current forestland from conversion into other land types. Doing so prevents the release of carbon from current carbon stocks (EPA 2006). Low-impact harvesting methods suggest the use of selective cutting to avoid unnecessary removal of biomass from forestlands (Richards et al. 2005). By increasing the rotation period between harvesting timber, a larger amount of wood is permitted to grow and greater carbon uptake is seen (Richards et al. 2005). Agroforestry is essentially the combination of forestry and agriculture, whereby trees are grown alongside traditional crops. Other forest management methods that can increase the sequestration rates of carbon included the thinning of forests, and the planting of tree species that produce a larger carbon uptake (Richards et al. 2005).
Methods for increasing carbon sequestration on agricultural land are:
Soil erosion management:
An estimated 115.2 MMT of carbon is removed from agricultural land via erosion every year, 20% of which is believed to return to the atmosphere (Nelson, 1999). Soil erosion management employs vegetative buffers, and residue management to reduce erosion on highly erodible land. Vegetative buffers, or riparian buffers, are plants and trees that are planted on the borders of agricultural land, or along the bank of streams and waterways (EPA, 2006). These plants reduce the impact of wind and water, which thereby reduces the amount of soil erosion, and consequently the water quality of adjoining waterways (EPA, 2006). Residue management is essentially the introduction of manure or animal by-products into the soil (Nelson, 1999). Doing so reduces the tendency of soil to be eroded, and increases the tendency for soil to uptake carbon (Nelson 1999).
Conservation tillage:
Traditional agricultural practices in the United States rely on intense tilling or plowing of the land. Tilling has many purposes, but it is primarily employed to prevent soil compaction and remove unwanted vegetation (Edwards et al. 1990). In removing unwanted vegetation, tilling reduces the carbon content of the top layer of the soil, and prevents the long-term storage of carbon deeper in the soil. Conservation tillage employs a variety of techniques to reduce the amount of tillage required to maintain productive cropland. Soil that undergoes conservation tillage as opposed to traditional tillage can contain 30–50% more carbon (Nelson, 1999). If conservation tillage were to be adopted on a large scale, as much as 32 MMT of additional carbon could be sequestered each year. Implementation of conservation tillage is often combined with the use of crop rotation.
Crop rotation:
Crop Rotation is the alternation between summer and winter crops on the same plot of land. A common example of this is the rotation between wheat and peas. Maintaining a crop cover during the winter reduces soil compaction (decreasing the need for tillage), decreases the occurrence of erosion, and increases the organic content of the soil (Nelson 1999). Within the United States, 50 million hectares of cropland are suitable for crop rotation practices (Nelson 1999). If this technique were employed on all of that land, an additional 10.2 MMT of carbon would be sequestered each year (Nelson 1999).
Grazing land management:
Global Post-Pleistocene rangelands evolved under grazing systems that followed transhumance patterns determined by seasonality (e.g. North American Bison). These systems followed a ‘rest-recovery’ grazing system, which maintained hydrologic and nutrient cycle function. In North America, the near extirpation of bison and the introduction of cattle, grazing patterns drifted away from the historic rest-recovery grazing system towards season-long grazing. The resulting rangeland degradation (decrease soil carbon, nitrogen moisture) during the 19 th century prompted people to adopt alternatives to continuous or season-long grazing, such as rotational grazing (e.g. Management Intensive Rotational Grazing) (Briske et al. 2011).
Rotationally grazed rangelands have greater long-term potential to sequester atmospheric carbon than continuously grazed rangelands. Significantly higher increases in soil carbon (C) and C: N ratios have been recorded under rotational grazing compared to continuous grazing (Teague et al 2010). Increases patchiness observed under continuous grazing results in increased bare ground, soil surface temperature and decreased moisture retention (Teague et al. 2003, Savory. 1999). A 12 year study observe the number of runoff event (> or = 1mm) were significantly lower under rotationally grazed rangelands compared to continuously grazed rangelands, due to increased bare ground and compaction (Owens and Shipitalo, 2009). Rotational grazing emulates historic ‘rest-recovery’ grazing systems, allowing rangelands to rest, maintaining long-term site stability.
Rangeland management/conservation has a significant effect on global atmospheric carbon concentrations. Since livestock grazing is prominent throughout the world, proper rangeland management can be an effective large-scale carbon sequestration tool. Effective grazing land management can be expected to increase carbon sequestration rates by 0.02–0.5 MMT of carbon per acre (EPA, 2006). This conveys the significance grazing management has in anthropogenic contributions to atmospheric carbon concentration increases, and climate change.
Wetland restoration:
Wetlands are frequently drained to produce dry, fertile soil for agricultural use (Claassen et al. 1998). Wetland soil contains a very concentrated amount of carbon; 14.5% of the world’s soil carbon is found in wetlands, while only 6% of the world’s land is composed of wetlands (Nelson, 1999). The need to protect wetlands is particularly relevant in the United States, where over half of the nations wetlands have been drained (Nelson, 1999). Wetland restoration calls for agricultural producers to protest and/or restore the wetlands found on their property.
Biofuel substitution:
Biofuel Substitution is the use of agricultural land for the production of biomass that can be converted to biofuel. This fuel can be used onsite to offset the energy used for agricultural production or the biofuel can be transported offsite for large-scale energy production. Every acre used for biofuel production can produce a net sequestration rate of 1.5 MMT of carbon (EPA, 2006).
, reduced diffuse agro-related pollution resulting in improved water quality
, reduced local and regional air pollution (Plantinga and Wu 2003; Feng et al. 2004; Pattanayak et al. 2002; USEPA
2006b; Krupnick et al.. 2000).
cannot be achieved until and unless issues on active participation in the decision-making process
and intra/inter generational equity are addressed under the climate change regime. This is because poor people with limited choices due to lack of access to financial resources, education, skills and decision-making structures are more susceptible to suffer the burden of environmental problems. They are additionally vulnerable to problems such as soil erosion, air and water pollution
, resource depletion
etc. (Beder 2000). The Clean Development Mechanism
(CDM), the first global environmental investment and credit scheme under Kyoto protocol has provided a mechanism of technology and fund transfer from the developed to the developing world
in terms of reducing green house gases emission (UNFCCC
n.d.), thus giving leeway to common but differentiated responsibility among the nations and contributing towards intra generation equity to a certain extent.
CSP related to afforestation, re-forestation and renewable energy
programs that involve entire communities could help to establish intra generational equity between the poor and affluent in society, rendering a better environment (Pan and Kao 2008; Plantinga and Wu 2003; Pattanayak et al. 2002; Krupnick et al. 2000; USEPA 2006b). Also to be considered are the effects of carbon credit
s payments on social structures such as alteration of views and attitudes towards livelihood activities due to improved income. The possibility of increasing disparity within marginal communities can be tied to problems with benefit sharing. A direct cause of this would be the mere increase of household income
among families whose members would gain direct employment in CSP. An indirect cause would be difficulties in apportioning displacement benefits generated from changes in land-use, whose traditional tenure system among vulnerable and indigenous communities renders it a ‘common’ resource.
is essential to achieving sustainable development. The crucial role of forests in the carbon cycle (Pena and Grunbaum 2001) suggests that the forest management might be used to offset GHGs emissions from fossil-fuel use, and even to reduce the concentration of carbon dioxide in the atmosphere. Richards and Stokes (2004) estimate the cost of carbon sequestration for forestry projects in developing countries to be in the range of 0.5 US$ to 7 US$/tCO2.
However, Sathaye et al. (2001) notes that most of the forestation programme options have a high cost primarily due to their high opportunity cost
s. But this should be analyzed further for rural socio-economic benefits. The study done on the costs and benefits
of LULUCF carbon mitigation options in developing countries by Sathaye et al. (2001) showed that the mitigation potential of 6.2 Pg C between 2000 and 2030 could be obtained even at a negative cost, about 5 Pg C at a cost below $20 per Mg C, and most ranging up to $100 per Mg C. The study also highlighted that the benefit from non-carbon revenue could help offset the direct cost
of the options. However, the costs and benefits also vary with countries e.g. the annualised net cost per Mg C for the forestation programme option is negative in China, Mexico and Brazil and that for regeneration programme options are negative for India and the Philippines.
stands, maintain soil carbon stocks, and incorporate payable service options for prevention of reconversion of afforested areas to agricultural use (Blay 2002). Additionally there are high associated costs to CSP which are largely overlooked including high costs of organizing and monitoring numerous stakeholders as well as the competitiveness/effectiveness of scattered forestry activities undertaken by small isolated farming communities versus large-scale projects
by larger corporate players. Finally, countries importing wood products could be negatively impacted when their foreign exchange
reserve is drained to a certain extent via LULUCF CSP (Zhang et al. 2000).
a. Long gestation period: Forestry projects could take 50–100 years to provide significant carbon mitigation benefits. Such long gestation period leads to unwillingness of potential investors to participate in afforestation/reforestation projects due to uncertainties linked with permanence of carbon uptake and socio-economic impacts.
b. Low economic returns: Some forestry projects have low or even negative economic return. This impedes the investments from private (commercial) sectors.
c. Subject to natural disturbances: Forests and tree plantations are very susceptible to fires, droughts, pests and diseases.
d. Links to local and global environmental factors: Decisions on forestry mitigation will affect biodiversity and other ecological aspects such as watershed regime, resilience to climatic change and land degradation.
e. Participation of local communities: Local community
participation is required for implementing mitigation projects in regions where communities currently reside in or depend on the forest.
All these obstacles seriously impede the development of afforestation/reforestation for carbon sequestration in large scale. Increase of profitability of forestry carbon sequestration projects along with unambiguous carbon-related international policy framework would significantly help to raise the attractiveness of forestry projects. Furthermore, according to IPCC (2007) there are some researchers suggesting that the beneficial impacts of climate change are overestimated by ignoring some of the aspects. Also, the negative impacts might be larger than expected and some effects remain incompletely understood. Therefore more R&D in this area is needed.
Box 1: Moldova soil conservation project
One of the largest and promising CDM afforestation/reforestation projects was recently launched in Moldova. The Moldova Soil Conservation Project involves the conservation and restoration of 20,200 ha of degraded lands by means of reforestation with tree and shrub species adapted to adverse local conditions (UNFCCC 2008). The project area covers degraded lands in all districts of Republic of Moldova with the exception of the eastern territories of Transnistria. The project is planned to sequester 3,587,827 t CO2e during the first crediting period (2002–2022). It was registered as CDM project in January 2009. The cost of implementation the project during first 11 years (2002–2012) is estimated at US $18.74 million. The project is expected to generate revenue from the sale of timber from thinning and from the sale of Certified Emission Reduction (CER) credits over the first 20-year crediting period.
The State Forest Agency, Moldsilva is the main implementing entity of the project. By reforestation of degraded lands in Moldova, the project will sequester carbon and reduce GHG emissions that are real, measurable and give long-term benefits to the mitigation of climate change. According to validation report conducted in 2007 if the project will be implemented as designed, the project is very likely to achieve the targeted amount of certified emission reductions. The project is expected to reduce landslides, improve the productivity of degraded lands and will ensure the supply of fuel wood, timber, and non-timber products and employment opportunities to local communities. The timber supplies from the project will contribute to stable timber and fuelwood prices. The non-timber benefits such as medicinal plants, bee-keeping, fruits and berries (e.g. walnut), mushrooms, vines for basketry, game (rabbits, deer) and hunting leases are expected to improve near term revenue of the local councils. In the long run, additional benefits could result from tourism and recreation.
; Asia Pacific Partnership on Clean Development and Climate
(AP6); European Commission; World Business Council on Sustainable Development.
(UNFCCC 2009) with emission reductions in non-industrialized countries (Van Laake 2008) though three flexible policy mechanisms:
Other international development
assistance is now being channeled through Global Environment Facility
(GEF) and international financial institutions
like World Bank (Carbon Partnership Facility) and Asian Development Bank
in forest conservation for green house gas mitigation. In 2007, the European Commission developed ‘An Energy Policy
for Europe’, which also provides a framework to develop, research and invest in carbon sequestration (IEA 2007). The European Union
Trading System (EU ETS
) is strong on this, which provides the largest market, through which countries like Norway and Germany have invested in carbon sequestration and greenhouse gas mitigation in Latin America.
Future initiatives: Carbon sequestration activities have been integrated within the post-Kyoto dialogues (UNFCCC COP-15) as the ‘Land use, Land-use change and Forestry (LULUCF)’ policy issue. Several stakeholders like Food and Agricultural Organization
(UNFAO), United Nations Convention to Combat Desertification (UNCCD) and international NGOs have been negotiating the rules and modalities for accounting for LULUCF within the Kyoto targets (Jung n.d.). The LULUCF sector activities (Forest management, cropland management, grazing land
management and revegetation) have the opportunity to offset emissions through cost effective investments by planting trees or forest management (UNFCCC 2009). Another widely discussed mechanism is the “Reduced Emissions from Deforestation and Degradation (REDD)”. This aims to reduce emissions from both deforestation and degradation in developing countries, and is a formal part of the Bali Action Plan (Peskett et al. 2008).
However advances in technology and better awareness of issues are providing opportunities at the international level to overcome the barriers to international policy making. Policy making should now be geared towards:
Box 2: Terrestrial Carbon Sequestration in Africa
Forests in Africa have gained global attention for their carbon sequestration function, for both purposes on carbon credits trading under the Kyoto Protocol’s CDM as well as voluntary emission reductions. Up to 2008, there are more than 23 projects in 14 countries with additional projects being funded under the BioCarbon Fund of the World Bank
(Jindal 2006; Jindal et al. 2008), the largest carbon investor in Africa. These projects often follow the CDM instructions, even though most of them are not established under the Kyoto Protocol (Jindal 2006). To achieve the goal of CDM, one of the criteria is to respond to the sustainable development challenges.As such, terrestrial carbon sequestration projects in Africa also address the benefits to local communities especially for poverty alleviation
, both directly in terms of incomes from carbon credits trading and directly for instances access to non-timber forest products
from regenerated forests and employment opportunities in forestry businesses. Moreover, other indirect advantages from these projects include endemic species
protection, restoration of natural ecosystems and awareness raising on HIV/AIDS. However, as currently most projects are under responsibility of national governmental agencies (Jindal 2006), transparent regulatory systems, good governance
and adequate national institutional capacity are among the concerns emerged in order to sustain carbon projects in Africa (Jindal 2006; Climate Avenue 2008), where many countries are confronting political instability.
and development of renewable energy sources (Ahn 2008). Development of programs aimed at reduction of emissions through carbon sequestration gets much less attention and its potential is only being realised at the national level in developing countries.
The following short- and medium-term policy measures are being discussed to facilitate development and integration of carbon sequestration policies and programs:
conflicts bordering on rights of indigenous populations, as well as equitable benefits sharing among local stakeholders (Bass et al.. 2000). Accordingly, trade-offs involving sustainable land use, energy conservation
, ecological and economic development
in the name of CSP in terrestrial ecosystems should be critically assessed in light of current discourses. Finally, costs/benefits of CSP should be carefully weighed ex-ante in order to avoid potential conflict situations.
As carbon abatement costs are much lower in most developing countries, carbon trading allows reduced costs for industrialized countries. Policy making must give priority on assessing other land use options apart from afforestation and deforestation, making CDM type projects attractive in developing countries though streamlined processes, develop better incentive packages and overall, investment in national technological and capacity development.
Terrestrial ecosystem
A terrestrial ecosystem is an ecosystem found only on a landform. Four primary terrestrial ecosystems exist: tundra, taiga, temperate deciduous forest, and grassland...
s is the net removal 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...
(CO2) from the atmosphere or the avoidance of carbon dioxide (CO2) emissions from terrestrial ecosystems into the atmosphere. The removal process includes CO2 uptake from the atmosphere by all chlorophyllous plants, through photosynthesis. This C is stored as plant biomass (in the trunks, branches, leaves and roots of the plants) and organic matter in the soil (IPCC 2000). The terrestrial carbon sequestrations depend on land use practices and different ecosystem conditions that sustain established vegetation over longer periods.
Terrestrial carbon sequestration is not only of interest in those countries which have an obligation to reduce 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 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...
. Contemporary rational for its policy making includes that it (1) offers cost effective
Cost-effectiveness
Cost-effectiveness analysis is a form of economic analysis that compares the relative costs and outcomes of two or more courses of action. Cost-effectiveness analysis is distinct from cost-benefit analysis, which assigns a monetary value to the measure of effect...
solutions for limiting Greenhouse Gases (GHG) concentration in the atmosphere for countries while enhancing their natural capital
Natural capital
Natural capital is the extension of the economic notion of capital to goods and services relating to the natural environment. Natural capital is thus the stock of natural ecosystems that yields a flow of valuable ecosystem goods or services into the future...
; (2) enhances cooperation for knowledge and technology transfer
Technology transfer
Technology Transfer, also called Transfer of Technology and Technology Commercialisation, is the process of skill transferring, knowledge, technologies, methods of manufacturing, samples of manufacturing and facilities among governments or universities and other institutions to ensure that...
amongst states; (3) provides opportunities in developing countries
Developing country
A developing country, also known as a less-developed country, is a nation with a low level of material well-being. Since no single definition of the term developing country is recognized internationally, the levels of development may vary widely within so-called developing countries...
(over US$30 billion/year) (Peskett et al. 2008); and (4) has potential for rural poverty reduction.
Numerous methodologies for carbon sequestration projects (CSP) have been developed targeted at reducing carbon fluxes primarily through management interventions involving land use, land use changes and forestry (LULUCF
Land Use, Land-Use Change and Forestry
Land use, land-use change and forestry is defined by the United Nations Climate Change Secretariat as "A greenhouse gas inventory sector that covers emissions and removals of greenhouse gases resulting from direct human-induced land use, land-use change and forestry activities."LULUCF has impacts...
) (Smith 2004; Lehmann et al. 2006; Bondeau et al. 2006; Batjes 1998; Smith et al. 1993; Brown et al. 1993). Two critical considerations to be borne in mind are impacts of planned project activities on ecology and human welfare. Therefore it is essential that carbon management is adequately formulated within national and international climate policies.
This article takes a pragmatic approach in discussing several features of carbon sequestration reflected in the discourses of science (biogeochemistry), social sciences, economics and policies. It looks at both normative and controversial aspects, and provides recommendations for scientists and policy makers.
Biogeochemistry of sequestering carbon in terrestrial ecosystems
Anthropogenic activities coupled with some natural processes have led to dramatic net flows of CO2 to the atmosphere over the last three centuries (IPCC 1996b). Carbon losses occur through decreased vegetation productivity, increased respiration, deforestation, biomass combustion and other poor land managementLand management
Land management is the process of managing the use and development of land resources. Land resources are used for a variety of purposes which may include organic agriculture, reforestation, water resource management and eco-tourism projects.-See also:*Sustainable land management*Acreage...
practices. Land use changes account for about 1.6±1.0 Gt of CO2 to be released to the atmosphere annually (IPCC 1996a) with the deforestation of tropical forests
Tropical and subtropical moist broadleaf forests
Tropical and subtropical moist broadleaf forests , also known as tropical moist forests, are a tropical and subtropical forest biome....
emit most GHGs (IPCC 2000; Meyers, 2007). This increasing release of GHGs into the atmosphere contributes to 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...
, which in turn limits the ability of TEs to sequester C (Heimann and Reichstein 2008).
Although natural and anthropogenic activities enhance GHG releases into the atmosphere, prospects for the use of CS by TEs as a strategy for mitigating climate change (Meyers, E.C. 2007) are increasing. It is considered to be a relatively cost-effective emission reduction strategy
Reduction strategy
In code optimization during the translation of computer programs into an executable form, and in mathematical reduction generally, a reduction strategy for a term rewriting system determines which reducible subterms should be reduced within a term; it may be the case that a term may contain...
, and has the potential of generating co-benefits for humans and environment. Aggressive CS programs could sequester and avoid carbon emissions equivalent to about 12–15% under the business-as-usual scenario over a 50-year period (IPCC 2001). However, these pessimisms straddle around assumptions and experimental modification of anthropogenic activities. Hence there are challenges for the eventual use of CS for climate change mitigation. Some of these include lack of scientific understanding of the biogeo-chemical cycle of C, socio-economic
Socioeconomics
Socioeconomics or socio-economics or social economics is an umbrella term with different usages. 'Social economics' may refer broadly to the "use of economics in the study of society." More narrowly, contemporary practice considers behavioral interactions of individuals and groups through social...
and policy issues related to organizing human activities that may limit this opportunity and actually enhance the CO2 emission potential of TES (IPCC 2001).
Measurement of carbon biomass
Different methods are used for measuring carbon in soil, water or atmosphere. There are conventional methods such as dry combustion as well as sophisticated methods such as laser-induced breakdown spectroscopy (LIBS) for rapid carbon analysis (Ebinger n.d).Methods used for measuring carbon in biomass include: non-destructive sampling for biomass (application of algometric or cylinder equations or estimation tree root biomass from proximal root and algometric relations); destructive sampling of soil and vegetation (harvesting vegetation, taking samples of litter and soil); and remote sensing
Remote sensing
Remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with the object. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth by means of propagated signals Remote sensing...
methods that assess carbon in vegetation but less useful to measure soil C directly (unless bare) (Jacobs n.d.).
Measurements of carbon fluxes and assessment of carbon sequestration
Different methods such as closed chamber, eddy-covariance and remote sensing are used to measure fluxes of carbon. Normally whole-ecosystem C exchange is measured in harvested and nearby un-harvested forest through meteorological and mensuration methodologies for assessment of carbon sequestration (Jacobs n.d.).Nature of sequestration in terrestrial ecosystems
Various TEs such as forests, grasslands, agricultural systems and degraded land, have different potential of carbon storage (DOE 1999). For instance, forest ecosystems contain more carbon per unit area than any other land types (accounting for 60% of total C in TEs) and their soils are of major importance for CS (FAO 2001). However, CS rates vary depending on plant species, soil typeSoil type
In terms of soil texture, soil type usually refers to the different sizes of mineral particles in a particular sample. Soil is made up in part of finely ground rock particles, grouped according to size as sand, silt and clay...
, region, climate, topography and management practices that can affect plant productivity (Lal 1999). At a local scale, CS in TE is largely influenced by light conditions, water availability, soil water holding capacity and its nutrient content. Local conditions could modify the frequency and severity of natural risks such as forest fires
Wildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
, strong winds etc., increasing the probability of CO2 emissions and hence carbon loss from these systems (Heimann and Reichstein 2008). TEs sequestered about 2.6 x109 g C per year of all atmospheric emissions during the period 2000-2007 representing net reductions of about 30% (according to 2006 levels) (GCP 2008). They have the potential of eventually sequestrating about 2 Gt C/year under intensive management and/or manipulation scenarios of a significant fraction of these systems (DOE 1999). Table 1 shows the different present stocks and net primary production
Primary production
400px|thumb|Global oceanic and terrestrial photoautotroph abundance, from September [[1997]] to August 2000. As an estimate of autotroph biomass, it is only a rough indicator of primary production potential, and not an actual estimate of it...
(NPP) of various terrestrial biomes.
Table 1: Global estimates of land area, net primary productivity (NPP), and carbon stocks in livIng plants and soil organic matter for ecosystems of the world
| Ecosystem | Area (1012 m2) | NPP (gC/m2/year) | NPP(PgC/year) | Plant C (g/m2) | Plant C (PgC) | Soil C (g/m2) | Soil (PgC) | Total (PgC) |
|---|---|---|---|---|---|---|---|---|
| Tropical forest | 14.8 | 925 | 13.7 | 16500 | 244.2 | 8300 | 123 | 367 |
| Forest Temperate and plantation | 7.5 | 670 | 5.0 | 12270 | 92.0 | 12000 | 90 | 182 |
| Boreal forest | 9.0 | 355 | 3.2 | 2445 | 22.0 | 15000 | 135 | 157 |
| Temperate Wood land | 2.0 | 700 | 1.4 | 8000 | 16.0 | 12000 | 24 | 40 |
| Chaparral | 2.5 | 360 | 0.9 | 3200 | 8.0 | 12000 | 30 | 38 |
| Tropical Savannas | 22.5 | 790 | 17.8 | 2950 | 65.9 | 11700 | 263 | 329 |
| Temperate grasslands | 12.5 | 350 | 4.4 | 720 | 9.0 | 23600 | 295 | 304 |
| Tundra, arctic and alpine | 9.5 | 105 | 1 | 630 | 6 | 12750 | 121 | 127 |
| Desert and semi desert scrub | 21 | 67 | 1.4 | 330 | 6.9 | 8000 | 168 | 175 |
| Extreme desert | 9 | 11 | 0.1 | 35 | 0.3 | 2500 | 23 | 23 |
| Perpetual ice | 15 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Lake and streams | 2 | 200 | 0.4 | 10 | 0 | 0 | 0 | 0 |
| Wetland | 2.8 | 1180 | 3.3 | 4300 | 12.0 | 72000 | 202 | 214 |
| Northern Peatland | 3.4 | 0 | 0.0 | 0 | 0.0 | 133800 | 455 | 455 |
| Cultivated and permanent crop | 14.8 | 423 | 6.3 | 200 | 3 | 7900 | 117 | 120 |
| Human areas | 2.0 | 100 | 0.2 | 500 | 1.0 | 5000 | 10 | 11 |
| Total | 150.8 | 59.1 | 2056 | 2542 |
Note:
Soil C values are for the top 1 m of soil only, except for peatlands, in which case they account for the total depth of peat. Pg = Petagram = Gigatonne.
Source: Amthor et al. 1998.
Carbon flows, feed-back loops and trends in terrestrial ecosystems
Scientific knowledgeScience
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...
on which CS models are mainly constructed straddle on CO2 uptake by photosynthesis and release by respiration from sinks and emission sources (Kirschbaum, 2006) as well as feedback loops
Feedback
Feedback describes the situation when output from an event or phenomenon in the past will influence an occurrence or occurrences of the same Feedback describes the situation when output from (or information about the result of) an event or phenomenon in the past will influence an occurrence or...
. However, feed-back loops are more complicated. Other biological process
Biological process
A biological process is a process of a living organism. Biological processes are made up of any number of chemical reactions or other events that results in a transformation....
es associated with respiration respond to temperature exponentially but are not affected by the CO2 concentration except photosynthesis (Kirschbaum, 2006). Hence TEs can continue to sequester C, provided the temperature is below certain levels that have a stimulating effect for respiration to exceed the CO2 fertilization effect. In actual fact carbon dynamics and feedback patterns are much more complicated than ordinary respiration/photosynthesis loops and may encompass complex physical, chemical and biological processes within the ecosystem.
Carbon emission trends
Mean annual concentrations in CO2 have been increasing since pre-industrial times as a result of anthropogenic land use changes as illustrated in Figure 1 (GCP 2008). When harvested trees are burned, 1 to 4 Pg C are released to the atmosphere in tropical latitudes (Iverson et al. 1993). Carbon dioxide emissions from deforestation contributed about 1.5 x 109 GC/ year while land use change contributed an estimated of 1.5 Pg C per year with about 43% coming from South and Southeast AsiaSoutheast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
(GCP 2008) consensus that these trends will seriously enhance global warming.
Figure 1. Carbon Emissions from deforestation in tropical regions (Source: GCP 2008).
Different scenarios for carbon sequestration
The potential capacity for different TEs to sequester carbon is highly dependent on land-use practices and forestry activities (Table 2). The CS potential of ecosystems depends on the type of land, while in the case of forests management determines substantially the CS rates. The most common methods to increase the sequestration rate in terrestrial ecosystems are reforestation and afforestation (dealt in article 3.3 of the Kyoto Protocol) (IPCC 2000). Conversion of cropland to grassland can also provide relatively large annual increase in carbon stock while shift to conservation agricultureConservation agriculture
Conservation agriculture [CA] can be defined by a statement given by the as “a concept for resource-saving agricultural crop production that strives to achieve acceptable profits together with high and sustained production levels while concurrently conserving the environment” .Agriculture...
(minimum tillage, protective cover of upper soil) is very important for increasing soil organic matter (FAO 2001).
Table 2: Main effects of land management practices or land-use on carbon sequestration capacity (t C ha-1 yr-1) in dry-lands and tropical areas.
| Management activities | Dry-lands (3 billion ha) | Tropical areas(humid and sub-humid)(2 billion ha) | |
|---|---|---|---|
| Croplands | 700 billion | ||
| Conservation tillage | 0.1–0.2 | 0.2–0.5 | |
| Mulch farming or plant cover | 0.05–0.1 | 0.1–0.3 | |
| Conservation agriculture | 0.15–0.3 | 0.3–0.8 | |
| Composting | 0.1–0.3 | 0.2–0.5 | |
| Nutrient management | 0.1–0.3 | 0.2–0.5 | |
| Water management | 0.05–0.1 | ||
| Grass lands and pasture | 0.05–0.10 | 0.1–0.2 | 3 billion |
| Afforestation | 4–8 | ||
| Agro-forestry | 0.2–3.1 | 1 billion |
Source: Lal 1999; FAO 2001
Methods of terrestrial carbon sequestration
Forested land and agricultural land are the land types most commonly associated with carbon sequestration. Within forested lands, the primary methods for promoting carbon sequestration are:• Afforestation
Afforestation is the conversion of previously non-forested land into forested land. This method is more commonly associated with the conversion of poor to marginal cropland into forested land. Afforestation can result in a large amount of carbon sequestered over a long period of time. A non-forested acre converted into a forested acre can result in a carbon sequestration rate of 0.6–2.6 MMT over a period of 90–120+ years (EPA 2006).
• Reforestation
Reforestation is the restoration of previously forested land. Doing so can produce an increase in carbon uptake of around 2.1 MMT per acre over a period of 90–120+ years (EPA 2006)
• Sustainable forest management
Sustainable forest management techniques include forest preservation, adoption of low-impact harvesting methods, lengthening of forest rotation cycles, agroforestry, and the adoption of other methods aimed at increasing carbon uptake (Richards et al. 2005). Forest preservation is the protection of current forestland from conversion into other land types. Doing so prevents the release of carbon from current carbon stocks (EPA 2006). Low-impact harvesting methods suggest the use of selective cutting to avoid unnecessary removal of biomass from forestlands (Richards et al. 2005). By increasing the rotation period between harvesting timber, a larger amount of wood is permitted to grow and greater carbon uptake is seen (Richards et al. 2005). Agroforestry is essentially the combination of forestry and agriculture, whereby trees are grown alongside traditional crops. Other forest management methods that can increase the sequestration rates of carbon included the thinning of forests, and the planting of tree species that produce a larger carbon uptake (Richards et al. 2005).
Methods for increasing carbon sequestration on agricultural land are:
Soil erosion management:
An estimated 115.2 MMT of carbon is removed from agricultural land via erosion every year, 20% of which is believed to return to the atmosphere (Nelson, 1999). Soil erosion management employs vegetative buffers, and residue management to reduce erosion on highly erodible land. Vegetative buffers, or riparian buffers, are plants and trees that are planted on the borders of agricultural land, or along the bank of streams and waterways (EPA, 2006). These plants reduce the impact of wind and water, which thereby reduces the amount of soil erosion, and consequently the water quality of adjoining waterways (EPA, 2006). Residue management is essentially the introduction of manure or animal by-products into the soil (Nelson, 1999). Doing so reduces the tendency of soil to be eroded, and increases the tendency for soil to uptake carbon (Nelson 1999).
Conservation tillage:
Traditional agricultural practices in the United States rely on intense tilling or plowing of the land. Tilling has many purposes, but it is primarily employed to prevent soil compaction and remove unwanted vegetation (Edwards et al. 1990). In removing unwanted vegetation, tilling reduces the carbon content of the top layer of the soil, and prevents the long-term storage of carbon deeper in the soil. Conservation tillage employs a variety of techniques to reduce the amount of tillage required to maintain productive cropland. Soil that undergoes conservation tillage as opposed to traditional tillage can contain 30–50% more carbon (Nelson, 1999). If conservation tillage were to be adopted on a large scale, as much as 32 MMT of additional carbon could be sequestered each year. Implementation of conservation tillage is often combined with the use of crop rotation.
Crop rotation:
Crop Rotation is the alternation between summer and winter crops on the same plot of land. A common example of this is the rotation between wheat and peas. Maintaining a crop cover during the winter reduces soil compaction (decreasing the need for tillage), decreases the occurrence of erosion, and increases the organic content of the soil (Nelson 1999). Within the United States, 50 million hectares of cropland are suitable for crop rotation practices (Nelson 1999). If this technique were employed on all of that land, an additional 10.2 MMT of carbon would be sequestered each year (Nelson 1999).
Grazing land management:
Global Post-Pleistocene rangelands evolved under grazing systems that followed transhumance patterns determined by seasonality (e.g. North American Bison). These systems followed a ‘rest-recovery’ grazing system, which maintained hydrologic and nutrient cycle function. In North America, the near extirpation of bison and the introduction of cattle, grazing patterns drifted away from the historic rest-recovery grazing system towards season-long grazing. The resulting rangeland degradation (decrease soil carbon, nitrogen moisture) during the 19 th century prompted people to adopt alternatives to continuous or season-long grazing, such as rotational grazing (e.g. Management Intensive Rotational Grazing) (Briske et al. 2011).
Rotationally grazed rangelands have greater long-term potential to sequester atmospheric carbon than continuously grazed rangelands. Significantly higher increases in soil carbon (C) and C: N ratios have been recorded under rotational grazing compared to continuous grazing (Teague et al 2010). Increases patchiness observed under continuous grazing results in increased bare ground, soil surface temperature and decreased moisture retention (Teague et al. 2003, Savory. 1999). A 12 year study observe the number of runoff event (> or = 1mm) were significantly lower under rotationally grazed rangelands compared to continuously grazed rangelands, due to increased bare ground and compaction (Owens and Shipitalo, 2009). Rotational grazing emulates historic ‘rest-recovery’ grazing systems, allowing rangelands to rest, maintaining long-term site stability.
Rangeland management/conservation has a significant effect on global atmospheric carbon concentrations. Since livestock grazing is prominent throughout the world, proper rangeland management can be an effective large-scale carbon sequestration tool. Effective grazing land management can be expected to increase carbon sequestration rates by 0.02–0.5 MMT of carbon per acre (EPA, 2006). This conveys the significance grazing management has in anthropogenic contributions to atmospheric carbon concentration increases, and climate change.
Wetland restoration:
Wetlands are frequently drained to produce dry, fertile soil for agricultural use (Claassen et al. 1998). Wetland soil contains a very concentrated amount of carbon; 14.5% of the world’s soil carbon is found in wetlands, while only 6% of the world’s land is composed of wetlands (Nelson, 1999). The need to protect wetlands is particularly relevant in the United States, where over half of the nations wetlands have been drained (Nelson, 1999). Wetland restoration calls for agricultural producers to protest and/or restore the wetlands found on their property.
Biofuel substitution:
Biofuel Substitution is the use of agricultural land for the production of biomass that can be converted to biofuel. This fuel can be used onsite to offset the energy used for agricultural production or the biofuel can be transported offsite for large-scale energy production. Every acre used for biofuel production can produce a net sequestration rate of 1.5 MMT of carbon (EPA, 2006).
Ecological co-benefits
Ecological impacts of CSP on biodiversity must be considered since land use changes alter habitats, thereby compromising the survival of species. It is from healthy biota that humans derive ecosystem benefits such as food, raw materials, climate regulation, pollution control, etc. (NETL 2009) amounting to an estimated several billion US$/yr ecosystem service benefits (Constanza et al. 1997). Other ancillary benefits resulting from intact biodiversity through CSP programmes include improved wildlife populations, reduced soil erosionErosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
, reduced diffuse agro-related pollution resulting in improved water quality
Water quality
Water quality is the physical, chemical and biological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. It is most frequently used by reference to a set of standards against which...
, reduced local and regional air pollution (Plantinga and Wu 2003; Feng et al. 2004; Pattanayak et al. 2002; USEPA
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...
2006b; Krupnick et al.. 2000).
Equity and sustainable development
According to Macleod (2000), carbon sequestration activities aiming towards the sustainable developmentSustainable development
Sustainable development is a pattern of resource use, that aims to meet human needs while preserving the environment so that these needs can be met not only in the present, but also for generations to come...
cannot be achieved until and unless issues on active participation in the decision-making process
Decision making
Decision making can be regarded as the mental processes resulting in the selection of a course of action among several alternative scenarios. Every decision making process produces a final choice. The output can be an action or an opinion of choice.- Overview :Human performance in decision terms...
and intra/inter generational equity are addressed under the climate change regime. This is because poor people with limited choices due to lack of access to financial resources, education, skills and decision-making structures are more susceptible to suffer the burden of environmental problems. They are additionally vulnerable to problems such as soil erosion, air and water pollution
Water pollution
Water pollution is the contamination of water bodies . Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds....
, resource depletion
Resource depletion
Resource depletion is an economic term referring to the exhaustion of raw materials within a region. Resources are commonly divided between renewable resources and non-renewable resources...
etc. (Beder 2000). The 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 first global environmental investment and credit scheme under Kyoto protocol has provided a mechanism of technology and fund transfer from the developed to the developing world
Third World
The term Third World arose during the Cold War to define countries that remained non-aligned with either capitalism and NATO , or communism and the Soviet Union...
in terms of reducing green house gases emission (UNFCCC
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...
n.d.), thus giving leeway to common but differentiated responsibility among the nations and contributing towards intra generation equity to a certain extent.
CSP related to afforestation, re-forestation and 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...
programs that involve entire communities could help to establish intra generational equity between the poor and affluent in society, rendering a better environment (Pan and Kao 2008; Plantinga and Wu 2003; Pattanayak et al. 2002; Krupnick et al. 2000; USEPA 2006b). Also to be considered are the effects of carbon credit
Carbon credit
A carbon credit is a generic term for any tradable certificate or permit representing the right to emit one tonne of carbon dioxide or the mass of another greenhouse gas with a carbon dioxide equivalent equivalent to one tonne of carbon dioxide....
s payments on social structures such as alteration of views and attitudes towards livelihood activities due to improved income. The possibility of increasing disparity within marginal communities can be tied to problems with benefit sharing. A direct cause of this would be the mere increase of household income
Household income
Household income is a measure of the combined incomes of all people sharing a particular household or place of residence. It includes every form of income, e.g., salaries and wages, retirement income, near cash government transfers like food stamps, and investment gains.Average household income can...
among families whose members would gain direct employment in CSP. An indirect cause would be difficulties in apportioning displacement benefits generated from changes in land-use, whose traditional tenure system among vulnerable and indigenous communities renders it a ‘common’ resource.
Economic considerations
Sustainable forest managementSustainable forest management
Sustainable forest management is the management of forests according to the principles of sustainable development. Sustainable forest management uses very broad social, economic and environmental goals...
is essential to achieving sustainable development. The crucial role of forests in the carbon cycle (Pena and Grunbaum 2001) suggests that the forest management might be used to offset GHGs emissions from fossil-fuel use, and even to reduce the concentration of carbon dioxide in the atmosphere. Richards and Stokes (2004) estimate the cost of carbon sequestration for forestry projects in developing countries to be in the range of 0.5 US$ to 7 US$/tCO2.
However, Sathaye et al. (2001) notes that most of the forestation programme options have a high cost primarily due to their high opportunity cost
Opportunity cost
Opportunity cost is the cost of any activity measured in terms of the value of the best alternative that is not chosen . It is the sacrifice related to the second best choice available to someone, or group, who has picked among several mutually exclusive choices. The opportunity cost is also the...
s. But this should be analyzed further for rural socio-economic benefits. The study done on the costs and benefits
Cost-benefit analysis
Cost–benefit analysis , sometimes called benefit–cost analysis , is a systematic process for calculating and comparing benefits and costs of a project for two purposes: to determine if it is a sound investment , to see how it compares with alternate projects...
of LULUCF carbon mitigation options in developing countries by Sathaye et al. (2001) showed that the mitigation potential of 6.2 Pg C between 2000 and 2030 could be obtained even at a negative cost, about 5 Pg C at a cost below $20 per Mg C, and most ranging up to $100 per Mg C. The study also highlighted that the benefit from non-carbon revenue could help offset the direct cost
Variable cost
Variable costs are expenses that change in proportion to the activity of a business. Variable cost is the sum of marginal costs over all units produced. It can also be considered normal costs. Fixed costs and variable costs make up the two components of total cost. Direct Costs, however,...
of the options. However, the costs and benefits also vary with countries e.g. the annualised net cost per Mg C for the forestation programme option is negative in China, Mexico and Brazil and that for regeneration programme options are negative for India and the Philippines.
Current discourses on trade-offs and potential conflict areas
CSP albeit having several benefits (employment opportunities, revenue generation through taxes, investment incentives, etc.) are riddled with numerous uncertainties and potential negative implications when inappropriately implemented. While pre-2004 debate on the subject centred around technical aspects, policy frameworks and the political arena, current discourses have brought social implications of CSP and policies (such as community disruption and equity issues as discussed previously) to the fore. CSP that do not take careful account of key issues such as halting driving forces for deforestation and remediating carbon pool losses are doomed to failure from the onset (Grace et al. 2003; Jindal 2004). Suggested alternatives are mitigative measures that create incentives for retaining secondary forestSecondary forest
A secondary forest is a forest or woodland area which has re-grown after a major disturbance such as fire, insect infestation, timber harvest or windthrow, until a long enough period has passed so that the effects of the disturbance are no longer evident...
stands, maintain soil carbon stocks, and incorporate payable service options for prevention of reconversion of afforested areas to agricultural use (Blay 2002). Additionally there are high associated costs to CSP which are largely overlooked including high costs of organizing and monitoring numerous stakeholders as well as the competitiveness/effectiveness of scattered forestry activities undertaken by small isolated farming communities versus large-scale projects
Megaproject
A megaproject is an extremely large-scale investment project. Megaprojects are typically defined as costing more than US$1 billion and attracting a lot of public attention because of substantial impacts on communities, environment, and budgets. Megaprojects can also be defined as "initiatives that...
by larger corporate players. Finally, countries importing wood products could be negatively impacted when their foreign exchange
Foreign exchange reserves
Foreign-exchange reserves in a strict sense are 'only' the foreign currency deposits and bonds held by central banks and monetary authorities. However, the term in popular usage commonly includes foreign exchange and gold, Special Drawing Rights and International Monetary Fund reserve positions...
reserve is drained to a certain extent via LULUCF CSP (Zhang et al. 2000).
Controversies related to afforestation/reforestation projects
Forestry can make a significant contribution to a global carbon sequestration portfolio. However, this opportunity is being largely missed in the current context and has resulted in only a small portion of this potential being realized at present (IPCC 2007). Ravindranath (2007) suggested that among most salient reasons for such modest popularity of forestry projects would be the following factors:a. Long gestation period: Forestry projects could take 50–100 years to provide significant carbon mitigation benefits. Such long gestation period leads to unwillingness of potential investors to participate in afforestation/reforestation projects due to uncertainties linked with permanence of carbon uptake and socio-economic impacts.
b. Low economic returns: Some forestry projects have low or even negative economic return. This impedes the investments from private (commercial) sectors.
c. Subject to natural disturbances: Forests and tree plantations are very susceptible to fires, droughts, pests and diseases.
d. Links to local and global environmental factors: Decisions on forestry mitigation will affect biodiversity and other ecological aspects such as watershed regime, resilience to climatic change and land degradation.
e. Participation of local communities: Local community
Local community
A local community is a group of interacting people sharing an environment. In human communities, intent, belief, resources, preferences, needs, risks, and a number of other conditions may be present and common, affecting the identity of the participants and their degree of cohesiveness.- Overview...
participation is required for implementing mitigation projects in regions where communities currently reside in or depend on the forest.
All these obstacles seriously impede the development of afforestation/reforestation for carbon sequestration in large scale. Increase of profitability of forestry carbon sequestration projects along with unambiguous carbon-related international policy framework would significantly help to raise the attractiveness of forestry projects. Furthermore, according to IPCC (2007) there are some researchers suggesting that the beneficial impacts of climate change are overestimated by ignoring some of the aspects. Also, the negative impacts might be larger than expected and some effects remain incompletely understood. Therefore more R&D in this area is needed.
Box 1: Moldova soil conservation project
One of the largest and promising CDM afforestation/reforestation projects was recently launched in Moldova. The Moldova Soil Conservation Project involves the conservation and restoration of 20,200 ha of degraded lands by means of reforestation with tree and shrub species adapted to adverse local conditions (UNFCCC 2008). The project area covers degraded lands in all districts of Republic of Moldova with the exception of the eastern territories of Transnistria. The project is planned to sequester 3,587,827 t CO2e during the first crediting period (2002–2022). It was registered as CDM project in January 2009. The cost of implementation the project during first 11 years (2002–2012) is estimated at US $18.74 million. The project is expected to generate revenue from the sale of timber from thinning and from the sale of Certified Emission Reduction (CER) credits over the first 20-year crediting period.
The State Forest Agency, Moldsilva is the main implementing entity of the project. By reforestation of degraded lands in Moldova, the project will sequester carbon and reduce GHG emissions that are real, measurable and give long-term benefits to the mitigation of climate change. According to validation report conducted in 2007 if the project will be implemented as designed, the project is very likely to achieve the targeted amount of certified emission reductions. The project is expected to reduce landslides, improve the productivity of degraded lands and will ensure the supply of fuel wood, timber, and non-timber products and employment opportunities to local communities. The timber supplies from the project will contribute to stable timber and fuelwood prices. The non-timber benefits such as medicinal plants, bee-keeping, fruits and berries (e.g. walnut), mushrooms, vines for basketry, game (rabbits, deer) and hunting leases are expected to improve near term revenue of the local councils. In the long run, additional benefits could result from tourism and recreation.
International policy measures/innovations
The most influential international policy in carbon sequestration and management has been the United Nations Framework Convention on Climate Change (UNFCCC). Under its 1997 Kyoto Protocol, Annex B countries have agreed to reduce their overall greenhouse gas emissions by at least 5% below 1990 levels in the first commitment period (2008–2012). Several networks and agencies today address the issues of carbon sequestration in terrestrial ecosystems e.g. Carbon Sequestration Leadership Forum (CSLF); International Energy AgencyInternational 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...
; Asia Pacific Partnership on Clean Development and Climate
Asia-Pacific Partnership on Clean Development and Climate
The Asia-Pacific Partnership on Clean Development and Climate, also known as APP, was an international, voluntary, public-private partnership among Australia, Canada, India, Japan, the People's Republic of China, South Korea, and the United States announced July 28, 2005 at an Association of South...
(AP6); European Commission; World Business Council on Sustainable Development.
Current and future initiatives
Current mechanisms: The Kyoto Protocol includes mechanisms to offset emissions (article 3.3) in industrialized countriesDeveloped country
A developed country is a country that has a high level of development according to some criteria. Which criteria, and which countries are classified as being developed, is a contentious issue...
(UNFCCC 2009) with emission reductions in non-industrialized countries (Van Laake 2008) though three flexible policy mechanisms:
- Clean Development Mechanism (CDM) allows industrialized countries to undertake afforestation and deforestation projects in developing countries to “meet their emission reduction targets” (IEA 2007).
- Joint Implementation (JI) is a project based mechanism that allows implementation of sink enhancement projects based on agreed emission reduction targets (UNFCCC 2009).
- Emission Trading Schemes (ETS) provides a market-based mechanism for selling and buying of emission allowances and reduction credits in order to “enable countries and companies to meet their greenhouse gas emission targets” (IEA 2007).
Other international development
International development
International development or global development is a concept that lacks a universally accepted definition, but it is most used in a holistic and multi-disciplinary context of human development — the development of greater quality of life for humans...
assistance is now being channeled through Global Environment Facility
Global Environment Facility
The Global Environment Facility unites 182 member governments — in partnership with international institutions, nongovernmental organizations, and the private sector — to address global environmental issues....
(GEF) and international financial institutions
Global financial system
The global financial system is the financial system consisting of institutions and regulators that act on the international level, as opposed to those that act on a national or regional level...
like World Bank (Carbon Partnership Facility) and Asian Development Bank
Asian Development Bank
The Asian Development Bank is a regional development bank established on 22 August 1966 to facilitate economic development of countries in Asia...
in forest conservation for green house gas mitigation. In 2007, the European Commission developed ‘An Energy Policy
Energy policy
Energy policy is the manner in which a given entity has decided to address issues of energy development including energy production, distribution and consumption...
for Europe’, which also provides a framework to develop, research and invest in carbon sequestration (IEA 2007). 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...
Trading System (EU ETS
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...
) is strong on this, which provides the largest market, through which countries like Norway and Germany have invested in carbon sequestration and greenhouse gas mitigation in Latin America.
Future initiatives: Carbon sequestration activities have been integrated within the post-Kyoto dialogues (UNFCCC COP-15) as the ‘Land use, Land-use change and Forestry (LULUCF)’ policy issue. Several stakeholders like Food and Agricultural Organization
Food and Agriculture Organization
The Food and Agriculture Organization of the United Nations is a specialised agency of the United Nations that leads international efforts to defeat hunger. Serving both developed and developing countries, FAO acts as a neutral forum where all nations meet as equals to negotiate agreements and...
(UNFAO), United Nations Convention to Combat Desertification (UNCCD) and international NGOs have been negotiating the rules and modalities for accounting for LULUCF within the Kyoto targets (Jung n.d.). The LULUCF sector activities (Forest management, cropland management, grazing land
Pasture
Pasture is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep or swine. The vegetation of tended pasture, forage, consists mainly of grasses, with an interspersion of legumes and other forbs...
management and revegetation) have the opportunity to offset emissions through cost effective investments by planting trees or forest management (UNFCCC 2009). Another widely discussed mechanism is the “Reduced Emissions from Deforestation and Degradation (REDD)”. This aims to reduce emissions from both deforestation and degradation in developing countries, and is a formal part of the Bali Action Plan (Peskett et al. 2008).
Challenges and opportunities
The main challenges in devising international policies for carbon sequestration can be summarized as follows:- Technical difficulties associated with estimating carbon emissions from land use options (thus the problem of determining additionally of projects) (UNFCCC 2009)
- Differences between developing and developed countries on emission reduction targets after 2012 under the Kyoto Protocol.
- A general lack of best practiceBest practiceA best practice is a method or technique that has consistently shown results superior to those achieved with other means, and that is used as a benchmark...
s and standards to be used as a basis for policy making. - Economic challenges vs. market effects of the inclusion of forestry projects in the CDM – price of emission permits in the international market varies.
- How to make CDM attractive for developing countries based on their geographical distribution, redistribution of benefits and losses between countries and regions (equity).
- Inventorying and accounting of CCS under the Kyoto Protocol considering different cross-border cases and non-permanence of storage (Jung n.d.).
- Large scale and formal carbon sequestration programmes (e.g. REDD), can have effects on food and commodity prices, should land area be reduced for food productionFood industryThe food production is a complex, global collective of diverse businesses that together supply much of the food energy consumed by the world population...
Peskett et al. 2008). - Expensive, bureaucratic and overlapping policy processes associated with qualified afforestation and reforestation projects.
However advances in technology and better awareness of issues are providing opportunities at the international level to overcome the barriers to international policy making. Policy making should now be geared towards:
- Alignment of carbon sequestration policies with national and international development strategies (PRS, MDGs, CBD POWA).
- Identification of incentives to address carbon sequestration investments in terrestrial ecosystems due to technical uncertainties (IEA 2007).
- Post-Kyoto discussions on LULUCF, REDD and carbon sequestration takes broad participatory process, with regional side events to build an account for equity and benefit sharing issues.
- Improve information flows amongst UNFCCC parties, development partners, indigenous people and local stakeholders via informal networks and consultations.
- Use of a cap and trade system through which states take on emission targets and levels based on the costs required for mitigation.
- Focus of carbon sequestration polices give due consideration of land use options beyond forest management and degradation.
- Finance and investmentFinance"Finance" is often defined simply as the management of money or “funds” management Modern finance, however, is a family of business activity that includes the origination, marketing, and management of cash and money surrogates through a variety of capital accounts, instruments, and markets created...
into R&D to assess biomass, forest degradation and other accounting measures for sequestration (including demonstration projects).
Box 2: Terrestrial Carbon Sequestration in Africa
Forests in Africa have gained global attention for their carbon sequestration function, for both purposes on carbon credits trading under the Kyoto Protocol’s CDM as well as voluntary emission reductions. Up to 2008, there are more than 23 projects in 14 countries with additional projects being funded under the BioCarbon Fund of the World Bank
World Bank Group
The World Bank Group is a family of five international organizations that makes leveraged loans, generally to poor countries.The Bank came into formal existence on 27 December 1945 following international ratification of the Bretton Woods agreements, which emerged from the United Nations Monetary...
(Jindal 2006; Jindal et al. 2008), the largest carbon investor in Africa. These projects often follow the CDM instructions, even though most of them are not established under the Kyoto Protocol (Jindal 2006). To achieve the goal of CDM, one of the criteria is to respond to the sustainable development challenges.As such, terrestrial carbon sequestration projects in Africa also address the benefits to local communities especially for poverty alleviation
Poverty reduction
Poverty is the state of human beings who are poor. That is, they have little or no material means of surviving—little or no food, shelter, clothes, healthcare, education, and other physical means of living and improving one's life....
, both directly in terms of incomes from carbon credits trading and directly for instances access to non-timber forest products
Non-timber forest products
Non-timber forest products are considered as any commodity obtained from the forest that does not necessitate harvesting trees. It includes game animals, fur-bearers, nuts and seeds, berries,...
from regenerated forests and employment opportunities in forestry businesses. Moreover, other indirect advantages from these projects include endemic species
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
protection, restoration of natural ecosystems and awareness raising on HIV/AIDS. However, as currently most projects are under responsibility of national governmental agencies (Jindal 2006), transparent regulatory systems, good governance
Good governance
Good governance is an indeterminate term used in development literature to describe how public institutions conduct public affairs and manage public resources in order to guarantee the realization of human rights. Governance describes "the process of decision-making and the process by which...
and adequate national institutional capacity are among the concerns emerged in order to sustain carbon projects in Africa (Jindal 2006; Climate Avenue 2008), where many countries are confronting political instability.
National policy measure
At national level, policies on climate change mitigation and carbon sequestration in particular, are mainly incorporated in National Communications under the UNFCCC and National Action Plans on Climate Change Mitigation. In spite of the great potential of carbon sequestration to achieve the emission reduction target, the main focus of the policies has been made on the energy and industrial sector, including improvement of fuel efficiencyFuel 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 development of renewable energy sources (Ahn 2008). Development of programs aimed at reduction of emissions through carbon sequestration gets much less attention and its potential is only being realised at the national level in developing countries.
Current and future initiatives
The majority of national policies on carbon sequestration, especially in developing countries, are focused on reforestation and afforestation activities to increase the carbon sink. An approach, which is quite popular in developed countries, is to improve the agricultural practice to enhance the capacity of soils to store carbon and to prevent GHG emissions from irrational agricultural practice and soil erosion. The combination of these two approaches is also being considered and implemented by a number of countries. The measures used in the policies, include both market-based and non-market incentives and approaches (Bangsund and Letistritz 2008). A number of examples on current policy intitaives are being directed includes:- In a number of developed countries, a system for the forest carbon market has been developed in order to bring forest carbon into a broader carbon accountingCarbon accountingCarbon accounting is the accounting process undertaken to measure the amount of carbon dioxide equivalents that will not be released into the atmosphere as a result of Flexible Mechanisms projects under the Kyoto Protocol. These projects thus include renewable energy projects and biomass, forage...
framework. Examples of forest carbon markets include the Chicago Climate ExchangeChicago Climate ExchangeThe 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....
, the New South Wales Greenhouse Gas Abatement SchemeNew South Wales Greenhouse Gas Abatement SchemeThe New South Wales Greenhouse Gas Abatement Scheme , which commenced on 1 January 2003, is a mandatory greenhouse gas emissions trading scheme that aims to lower greenhouse gas emissions to 7.27 tonnes of carbon dioxide per capita by the year 2007.-External links:*...
and the New Zealand Emission Trading Scheme (Bigsby 2009). - In developing countries, a number of Payment for Ecosystem Services (PES) initiatives aimed at conservation of forests, reforestation and afforestation activities in order to provide a number of ecosystem services, including carbon sequestration (Wunder et al. 2005) are being implemented. The economic incentives are provided to landowners to encourage them to change the land use and to conserve valuable ecosystem services. PES schemes are being implementing in many countries in Latin AmericaLatin AmericaLatin America is a region of the Americas where Romance languages – particularly Spanish and Portuguese, and variably French – are primarily spoken. Latin America has an area of approximately 21,069,500 km² , almost 3.9% of the Earth's surface or 14.1% of its land surface area...
, including Costa-RicaCosta RicaCosta Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
, Bolivia, Mexico, and other developing countries, as well as number of developed countries, mainly in Europe. PES initiatives also get considerable support from international organizationInternational organizationAn intergovernmental organization, sometimes rendered as an international governmental organization and both abbreviated as IGO, is an organization composed primarily of sovereign states , or of other intergovernmental organizations...
s, including IUCN, World Bank, WWF and others. - Development of programs aimed at carbon sequestration in agricultural soils is getting more and more attention. Studies have shown that it is a readily implementable option for the mitigation of GHG emissions and can provide mitigation comparable in costs to current abatement options in other industries (Bangsund and Letistrritz 2008; Lu et al. 2009). Increasing area of marginalised crop land in some countries also makes this measure more favorable as well (Ahn 2008).
Challenges and opportunities
The main challenges for incorporation and development of carbon sequestration policies at national level can be summarized as follows:- Lack of knowledge on carbon sequestration options and their cost-effectiveness, as well as lack of human and technical capacity to tackle the issue.
- Lack of attention to carbon sequestration programs and dominance of energy-related policies due to the large contributions of energy sector to the green house gases emission and strong competition for the land use (Ahn 2008).
- Lack of incentives provided for the landowners to improve the capacity and quality of the ecosystem services, including carbon sequestration. Development of policies aimed at providing economic incentives, as well as policy towards land use and regional development (Graff-Zivin and Lipper 2008; Han and Youn 2009) are needed to improve the situation.
- Lack of finance available for developing countries. A higher priority is given by donors to CDM projects aimed at development of renewable energy sources, and not for carbon sequestration initiatives.
The following short- and medium-term policy measures are being discussed to facilitate development and integration of carbon sequestration policies and programs:
- Short-term policy measures: Application of new market-based policy measures such as the Carbon OffsetCarbon offsetA 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....
System; raising awareness on the role of the land on mitigation and adaptation to climate change and in particular the importance of enhancing the sequestration of carbon in terrestrial ecosystems; financial flows to developing countries. - Medium-to-long-term policy measures: National implementation of JI and CDM projects, Emission rights Trading, development of REED and its poverty reduction potential; Technology transfer to developing countries.
Conclusions
Issues of human welfare in CSP encompass such thorny areas as vulnerability (especially in developing regions), health risks, possible negative impacts on culture and livelihoods, land tenureLand tenure
Land tenure is the name given, particularly in common law systems, to the legal regime in which land is owned by an individual, who is said to "hold" the land . The sovereign monarch, known as The Crown, held land in its own right. All private owners are either its tenants or sub-tenants...
conflicts bordering on rights of indigenous populations, as well as equitable benefits sharing among local stakeholders (Bass et al.. 2000). Accordingly, trade-offs involving sustainable land use, 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...
, ecological and 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...
in the name of CSP in terrestrial ecosystems should be critically assessed in light of current discourses. Finally, costs/benefits of CSP should be carefully weighed ex-ante in order to avoid potential conflict situations.
As carbon abatement costs are much lower in most developing countries, carbon trading allows reduced costs for industrialized countries. Policy making must give priority on assessing other land use options apart from afforestation and deforestation, making CDM type projects attractive in developing countries though streamlined processes, develop better incentive packages and overall, investment in national technological and capacity development.