Back to Search
Start Over
Methane emissions associated with the conversion of marshland to cropland and climate change on the Sanjiang Plain of Northeast China from 1950 to 2100.
- Source :
- Biogeosciences Discussions; 2012, Vol. 9 Issue 5, p5887-5927, 51p
- Publication Year :
- 2012
-
Abstract
- Wetland loss and climate change are known to alter regional and global methane (CH<subscript>4</subscript>) budgets. Over the last six decades, an extensive area of marshland has been converted to cropland on the Sanjiang Plain in Northeast China, and a significant increase in air temperature has also been observed there, while the impacts on regional CH<subscript>4</subscript> budgets remain uncertain. Through model simulation, we estimated the changes in CH<subscript>4</subscript> emissions associated with the conversion of marshland to cropland and climate change in this area. Model simulations indicated a significant reduction of 1.1 Tgyr<superscript>-1</superscript> from the 1950s to the 2000s in regional CH<subscript>4</subscript> emissions. The cumulative reduction of CH<subscript>4</subscript> from 1960 to 2009 was estimated to be ~ 36Tg relative to the 1950s, and marshland conversion and the climate contributed 86% and 14% of this change, respectively. Interannual variation in precipitation (linear trend with P > 0.2) contributed to yearly fluctuations in CH<subscript>4</subscript> emissions, but the relatively lower amount of precipitation over the period 1960-2009 (47 mmyr<superscript>-1</superscript> lower on average than in the 1950s) contributed ~91% of the reduction in the area-weighted CH<subscript>4</subscript> flux. Global warming at a rate of 0.3 °C per decade (P < 0.001) has increased CH<subscript>4</subscript> emissions significantly since the 1990s. Relative to the mean of the 1950s, the warming-induced increase in the CH4 flux has averaged 19 kg ha<superscript>-1</superscript> yr<superscript>-1</superscript> over the last two decades. For the RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5 scenarios of the fifth IPCC assessment report (AR5), the CH<subscript>4</subscript> flux is predicted to increase by 36 %, 52 %, 78% and 95 %, respectively, by the 2080s compared to 1961-1990 in response to climate warming and wetting. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 18106277
- Volume :
- 9
- Issue :
- 5
- Database :
- Complementary Index
- Journal :
- Biogeosciences Discussions
- Publication Type :
- Academic Journal
- Accession number :
- 76922644
- Full Text :
- https://doi.org/10.5194/bgd-9-5887-2012