2008年06月18日

Autumn warming


Autumn warming

An analysis of variation in atmospheric CO2 and ecosystem CO2 fluxes in the Northern Hemisphere shows that warmer autumns have been associated with an earlier autumn-to-winter CO2 build-up in the atnisphere.

This seems counter-intuitive : warm autumns surely imply long growing seasons and a beneficial effect on terrestrial carbon sinks as trees and plants make more biomass.

Anexplanation isprovided by satellite observations and numerical modelling.

Enhanced respiration caused by higher tenperatures causes carbon losses that offest photosynthetic gains, limiting the potetial of these ecosystems to act as carbon sinks.

And CO2 loss due to autumn warming may offset most of the increased CO2 uptake during spring.

If future warming occurs more rapidly in autumn than in spring, the ability of northern ecosystems to sequester carbon may diminish more rapidly than previously predicted.


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### DataBace ###
nature Vol 451 | Issue no.7174 | 1-106 | 3 January 2008
Letter p.49 / Net carbon dioxide losses of northern ecosystem in response to autumn warming / CEA-CNRS(仏) S. Piao etal. (update)
News & Views p.26 / CARBON CYCLE : Sources, sinks and seasons / John B. Miller (update)
THIS ISSUE p.xvii / Autumn warming (update)
### related story ###
炭素サイクル:ソースとシンクとシーズン』 - science-de-survivor 2nd
posted by 0≠素子(由理政宗) at 00:00| Comment(0) | Climate Change | このブログの読者になる | 更新情報をチェックする
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