Season creep
Encyclopedia
In phenology
, season creep is a neologism that refers to observed changes in the timing of the season
s,
especially earlier indications of spring widely observed in temperate
areas across the Northern Hemisphere
.
Phenological records analyzed by climate scientists have shown significant temporal trends in the observed time of seasonal events,
from the end of the 20th century and continuing into the 21st century. In Europe
, season creep has been associated with the arrival of spring moving up by approximately one week in a recent 30 year period.
Other studies have put the rate of season creep measured by plant phenology in the range of 2–3 days per decade advancement in spring, and 0.3–1.6 days per decade delay in autumn, over the past 30–80 years.
Observable changes in nature related to season creep include birds laying their eggs earlier and buds appearing on some trees in late winter. In addition to advanced budding, flowering trees have been blooming earlier, for example the culturally important cherry blossoms
in Japan
,
and Washington, D.C.
Northern hardwood forest
s have been trending toward leafing out sooner, and retaining their green canopies longer.
The agricultural growing season
has also expanded by 10–20 days over the last few decades.
The effects of season creep have been noted by non-scientists as well, including gardeners who have advanced their spring planting times,
and experimented with plantings of less hardy
warmer climate varieties of non-native plants. While summer growing seasons are expanding, winters are getting warmer and shorter, resulting in reduced winter ice cover on bodies of water,
earlier ice-out,
earlier melt water flows,
and earlier spring lake level peaks.
Some spring events, or "phenophases", have become intermittent or unobservable; for example, bodies of water that once froze regularly most winters now freeze less frequently,
and formerly migratory birds
are now seen year-round in some areas.
is forecast to happen in the future, but climate scientists have cited season creep as an easily observable effect of climate change
that has already occurred.
A large systematic phenological examination of data on 542 plant species in 21 European countries from 1971–2000 showed that 78% of all leafing, flowering, and fruiting records advanced while only 3% were significantly delayed, and these observations were consistent with measurements of observed warming.
Similar changes in the phenology of plants and animals are occurring across marine, freshwater, and terrestrial groups studied, and these changes are also consistent with the expected impact of global warming.
While phenology fairly consistently points to an earlier spring across temperate regions of North America, a recent comprehensive study of the subarctic
showed greater variability in the timing of green-up, with some areas advancing, and some having no discernible trend over a recent 44-year period.
Another 40 year phenological study in China found greater warming over that period in the more northerly sites studied, with sites experiencing cooling mostly in the south, indicating that the temperature variation with latitude is decreasing there.
This study also confirmed that season creep was correlated with warming, but the effect is non-linear—phenophases advanced less with greater warming, and retarded more with greater cooling.
Shorter winters and longer growing seasons may appear to be a benefit to society from global warming
, but the effects of advanced phenophases may also have serious consequences for human populations. Modeling of snowmelt predicted that warming of 3° to 5°C in the Western United States
could cause snowmelt-driven runoff to occur as much as two months earlier, with profound effects on hydroelectricity
, land use, agriculture, and water management.
Since 1980, earlier snowmelt and associated warming has also been associated with an increase in length and severity of the wildfire
season there.
published in London June 4, 2007.
The term was popularized in the media after the report titled "Season Creep: How Global Warming Is Already Affecting The World Around Us" was published by the American
environmental organization
Clear the Air on March 21, 2006.
In the "Season Creep" report, Jonathan Banks, Policy Director for Clear the Air, introduced the term as follows:
Phenology
Phenology is the study of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate...
, season creep is a neologism that refers to observed changes in the timing of the season
Season
A season is a division of the year, marked by changes in weather, ecology, and hours of daylight.Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth's axis relative to the plane of revolution...
s,
especially earlier indications of spring widely observed in temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
areas across the Northern Hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...
.
Phenological records analyzed by climate scientists have shown significant temporal trends in the observed time of seasonal events,
from the end of the 20th century and continuing into the 21st century. In Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, season creep has been associated with the arrival of spring moving up by approximately one week in a recent 30 year period.
Other studies have put the rate of season creep measured by plant phenology in the range of 2–3 days per decade advancement in spring, and 0.3–1.6 days per decade delay in autumn, over the past 30–80 years.
Observable changes in nature related to season creep include birds laying their eggs earlier and buds appearing on some trees in late winter. In addition to advanced budding, flowering trees have been blooming earlier, for example the culturally important cherry blossoms
Sakura
A cherry blossom is the flower of any of several trees of genus Prunus, particularly the Japanese Cherry, Prunus serrulata, which is sometimes called sakura after the Japanese . Many of the varieties that have been cultivated for ornamental use do not produce fruit...
in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
,
and Washington, D.C.
Washington, D.C.
Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....
Northern hardwood forest
Northern hardwood forest
The northern hardwood forest is a general type of North American forest ecosystem found over much of southeastern and south central Canada, extending south into the United States in northern New England and New York, and west along the Great Lakes to Minnesota and western Ontario...
s have been trending toward leafing out sooner, and retaining their green canopies longer.
The agricultural growing season
Growing season
In botany, horticulture, and agriculture the growing season is the period of each year when native plants and ornamental plants grow; and when crops can be grown....
has also expanded by 10–20 days over the last few decades.
The effects of season creep have been noted by non-scientists as well, including gardeners who have advanced their spring planting times,
and experimented with plantings of less hardy
Hardiness (plants)
Hardiness of plants describe their ability to survive adverse growing conditions. It is usually limited to discussions of climatic adversity. Thus a plant's ability to tolerate cold, heat, drought, flooding, or wind are typically considered measurements of hardiness. Hardiness of plants is defined...
warmer climate varieties of non-native plants. While summer growing seasons are expanding, winters are getting warmer and shorter, resulting in reduced winter ice cover on bodies of water,
earlier ice-out,
earlier melt water flows,
and earlier spring lake level peaks.
Some spring events, or "phenophases", have become intermittent or unobservable; for example, bodies of water that once froze regularly most winters now freeze less frequently,
and formerly migratory birds
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
are now seen year-round in some areas.
Relationship to global warming
The full impact of global warmingEffects 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...
is forecast to happen in the future, but climate scientists have cited season creep as an easily observable effect of 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...
that has already occurred.
A large systematic phenological examination of data on 542 plant species in 21 European countries from 1971–2000 showed that 78% of all leafing, flowering, and fruiting records advanced while only 3% were significantly delayed, and these observations were consistent with measurements of observed warming.
Similar changes in the phenology of plants and animals are occurring across marine, freshwater, and terrestrial groups studied, and these changes are also consistent with the expected impact of global warming.
While phenology fairly consistently points to an earlier spring across temperate regions of North America, a recent comprehensive study of the subarctic
Subarctic
The Subarctic is a region in the Northern Hemisphere immediately south of the true Arctic and covering much of Alaska, Canada, the north of Scandinavia, Siberia, and northern Mongolia...
showed greater variability in the timing of green-up, with some areas advancing, and some having no discernible trend over a recent 44-year period.
Another 40 year phenological study in China found greater warming over that period in the more northerly sites studied, with sites experiencing cooling mostly in the south, indicating that the temperature variation with latitude is decreasing there.
This study also confirmed that season creep was correlated with warming, but the effect is non-linear—phenophases advanced less with greater warming, and retarded more with greater cooling.
Shorter winters and longer growing seasons may appear to be a benefit to society from 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...
, but the effects of advanced phenophases may also have serious consequences for human populations. Modeling of snowmelt predicted that warming of 3° to 5°C in the Western United States
Western United States
.The Western United States, commonly referred to as the American West or simply "the West," traditionally refers to the region comprising the westernmost states of the United States. Because the U.S. expanded westward after its founding, the meaning of the West has evolved over time...
could cause snowmelt-driven runoff to occur as much as two months earlier, with profound effects on hydroelectricity
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...
, land use, agriculture, and water management.
Since 1980, earlier snowmelt and associated warming has also been associated with an increase in length and severity of the wildfire
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...
season there.
Etymology
Season creep was included in the 9th edition of the Collins English DictionaryCollins English Dictionary
The Collins English Dictionary is an important printed dictionary of English. It is published by HarperCollins.The first edition of the Collins English Dictionary with Patrick Hanks as editor and Lawrence Urdang as editorial director, was a milestone in British dictionary making as it was the...
published in London June 4, 2007.
The term was popularized in the media after the report titled "Season Creep: How Global Warming Is Already Affecting The World Around Us" was published by the American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
environmental organization
Environmental organization
An environmental organization is an organization that seeks to protect, analyze or monitor the environment against misuse or degradation or lobby for these goals....
Clear the Air on March 21, 2006.
In the "Season Creep" report, Jonathan Banks, Policy Director for Clear the Air, introduced the term as follows:
Other uses
The term "season creep" has been applied in other contexts as well:- In professional sportsProfessional sportsProfessional sports, as opposed to amateur sports, are sports in which athletes receive payment for their performance. Professional athleticism has come to the fore through a combination of developments. Mass media and increased leisure have brought larger audiences, so that sports organizations...
, season creep refers to lengthening of the playing season, especially the extension of the MLB season to 162 games. - In college athleticsCollege athleticsCollege athletics refers primarily to sports and athletic competition organized and funded by institutions of tertiary education . In the United States, college athletics is a two-tiered system. The first tier includes the sports that are sanctioned by one of the collegiate sport governing bodies...
, season creep refers to longer periods athletes spend training in their sport. - In American politicsPolitics of the United StatesThe United States is a federal constitutional republic, in which the President of the United States , Congress, and judiciary share powers reserved to the national government, and the federal government shares sovereignty with the state governments.The executive branch is headed by the President...
, campaign season creep refers to the need for candidates to start fund raising activities sooner. - In retailingRetailingRetail consists of the sale of physical goods or merchandise from a fixed location, such as a department store, boutique or kiosk, or by mail, in small or individual lots for direct consumption by the purchaser. Retailing may include subordinated services, such as delivery. Purchasers may be...
, Christmas creepChristmas creepChristmas creep is a merchandising phenomenon in which merchants and retailers exploit the commercialized status of Christmas by moving up the start of the holiday shopping season. The term was first used in the mid 1980s...
refers to the earlier appearance of Christmas-themed merchandising, extending the holiday shopping season.