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Den arktiska permafrostens degradering och metangasutsläpp

Hedgren, Boel (2010) In Lunds universitets Naturgeografiska institution - Seminarieuppsatser
Dept of Physical Geography and Ecosystem Science
Abstract (Swedish)
Populärvetenskaplig sammanfattning: Temperaturdata från de senaste 157 åren visar att jorden genomgår en uppvärmning. Forskare runt om i världen är eniga om att den globala medeltemperaturen även kommer att fortsätta öka de närmsta 100 åren. Dock är temperaturförändringen inte jämt fördelad över jordklotet; den arktiska regionen tros stå inför en snabbare och mer intensiv uppvärmning.
Den arktiska regionen är till stora delar täckt av frusen mark, s.k. permafrost. Permafrostens existens beror främst på det atmosfäriska klimatet, men också på regionala faktorer så som nederbörd, snötäcke och vegetation. Vid en större förändring i den globala medeltemperaturen finns alltså risken att permafrosten börjar tina.
Just den arktiska jorden... (More)
Populärvetenskaplig sammanfattning: Temperaturdata från de senaste 157 åren visar att jorden genomgår en uppvärmning. Forskare runt om i världen är eniga om att den globala medeltemperaturen även kommer att fortsätta öka de närmsta 100 åren. Dock är temperaturförändringen inte jämt fördelad över jordklotet; den arktiska regionen tros stå inför en snabbare och mer intensiv uppvärmning.
Den arktiska regionen är till stora delar täckt av frusen mark, s.k. permafrost. Permafrostens existens beror främst på det atmosfäriska klimatet, men också på regionala faktorer så som nederbörd, snötäcke och vegetation. Vid en större förändring i den globala medeltemperaturen finns alltså risken att permafrosten börjar tina.
Just den arktiska jorden innehåller stora mängder kol, närmare bestämt 14% av det kol som finns lagrat i jord globalt. När permafrosten tinar frigörs metangas vid syrefri nedbrytning som sker i den våtmark som bildas. Metangas är en 23 gånger kraftigare växthusgas än vad koldioxid är, vilket gör att den utgör ett stort hot mot vårt klimat.
Forskningsresultat visar att tinande permafrost kommer att släppa ut 100 miljarder ton kol inom de närmsta 100 åren, där de största utsläppen tros komma ifrån Sibirien och Kanada. (Less)
Abstract
According to temperature data for the past 157 years, the global mean temperature is increas-ing with an accelerating rate in the end of the 20th century. Climate models that have been developed on research centers around the world all show a warming trend the next coming 100 years. They also show that the increase in temperature will occur earlier and be more in-tense over the Arctic region.
In the northern hemisphere permafrost covers an area of 23 million km2. The main factor for the existence and degradation of permafrost is the atmospheric climate. However, regional factors such as precipitation, vegetation and snow cover also have some impact.
The Arctic soil contains about 14% of the global storage of soil carbon. When the... (More)
According to temperature data for the past 157 years, the global mean temperature is increas-ing with an accelerating rate in the end of the 20th century. Climate models that have been developed on research centers around the world all show a warming trend the next coming 100 years. They also show that the increase in temperature will occur earlier and be more in-tense over the Arctic region.
In the northern hemisphere permafrost covers an area of 23 million km2. The main factor for the existence and degradation of permafrost is the atmospheric climate. However, regional factors such as precipitation, vegetation and snow cover also have some impact.
The Arctic soil contains about 14% of the global storage of soil carbon. When the permafrost thaws, the carbon is released as methane gas in an anaerobic decomposition. Since methane has a GWP (Global Warming Potential) of 23, i.e. is a 23 times stronger greenhouse gas than carbon dioxide, an increase in emission means a threat to the climate.
Methane also exists as methane hydrates, which are a frozen compounds consisting of a me-thane molecule surrounded by water molecules. These are formed at low temperatures and high pressure. The estimates of the size of the pool of methane hydrate differ. Older estimates say 8-700 Gt carbon while newer estimates say 5-195 Gt.
Research results show that around 100 Gt of carbon will be released from thawing permafrost before year 2100. The largest emissions is expected to come from Siberia (40 Gt) and Canada (48 Gt). As emissions from methane hydrates probably require more warming before it be-comes significant, the emissions from this source are more uncertain. (Less)
Please use this url to cite or link to this publication:
author
Hedgren, Boel
supervisor
organization
year
type
M2 - Bachelor Degree
subject
keywords
permafrost, degradering, växthusgaser, metan, geografi, naturgeografi
publication/series
Lunds universitets Naturgeografiska institution - Seminarieuppsatser
report number
185
language
Swedish
id
1851741
date added to LUP
2011-03-14 11:40:30
date last changed
2011-12-20 12:06:16
@misc{1851741,
  abstract     = {According to temperature data for the past 157 years, the global mean temperature is increas-ing with an accelerating rate in the end of the 20th century. Climate models that have been developed on research centers around the world all show a warming trend the next coming 100 years. They also show that the increase in temperature will occur earlier and be more in-tense over the Arctic region.
In the northern hemisphere permafrost covers an area of 23 million km2. The main factor for the existence and degradation of permafrost is the atmospheric climate. However, regional factors such as precipitation, vegetation and snow cover also have some impact.
The Arctic soil contains about 14% of the global storage of soil carbon. When the permafrost thaws, the carbon is released as methane gas in an anaerobic decomposition. Since methane has a GWP (Global Warming Potential) of 23, i.e. is a 23 times stronger greenhouse gas than carbon dioxide, an increase in emission means a threat to the climate.
Methane also exists as methane hydrates, which are a frozen compounds consisting of a me-thane molecule surrounded by water molecules. These are formed at low temperatures and high pressure. The estimates of the size of the pool of methane hydrate differ. Older estimates say 8-700 Gt carbon while newer estimates say 5-195 Gt.
Research results show that around 100 Gt of carbon will be released from thawing permafrost before year 2100. The largest emissions is expected to come from Siberia (40 Gt) and Canada (48 Gt). As emissions from methane hydrates probably require more warming before it be-comes significant, the emissions from this source are more uncertain.},
  author       = {Hedgren, Boel},
  keyword      = {permafrost,degradering,växthusgaser,metan,geografi,naturgeografi},
  language     = {swe},
  note         = {Student Paper},
  series       = {Lunds universitets Naturgeografiska institution - Seminarieuppsatser},
  title        = {Den arktiska permafrostens degradering och metangasutsläpp},
  year         = {2010},
}