Open AccessNet exchanges of CO 2 , CH 4 , and N 2 O between China's terrestrial ecosystems and the atmosphere and their contributions to global climate warming
Author(s) -
Tian Hanqin,
Xu Xiaofeng,
Lu Chaoqun,
Liu Mingliang,
Ren Wei,
Chen Guangsheng,
Melillo Jerry,
Liu Jiyuan
Publication year - 2011
Publication title -
journal of geophysical research: biogeosciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2010jg001393
Subject(s) - terrestrial ecosystem , environmental science , ecosystem , global warming , climate change , sink (geography) , atmospheric sciences , china , primary production , atmosphere (unit) , global change , climatology , ecology , geography , geology , meteorology , biology , archaeology , cartography
China's terrestrial ecosystems have been recognized as an atmospheric CO 2 sink ; however, it is uncertain whether this sink can alleviate global warming given the fluxes of CH 4 and N 2 O. In this study, we used a process‐based ecosystem model driven by multiple environmental factors to examine the net warming potential resulting from net exchanges of CO 2 , CH 4 , and N 2 O between China's terrestrial ecosystems and the atmosphere during 1961–2005. In the past 45 years, China's terrestrial ecosystems were found to sequestrate CO 2 at a rate of 179.3 Tg C yr −1 with a 95% confidence range of (62.0 Tg C yr −1 , 264.9 Tg C yr −1 ) while emitting CH 4 and N 2 O at rates of 8.3 Tg C yr −1 with a 95% confidence range of (3.3 Tg C yr −1 , 12.4 Tg C yr −1 ) and 0.6 Tg N yr −1 with a 95% confidence range of (0.2 Tg N yr −1 , 1.1 Tg N yr −1 ), respectively. When translated into global warming potential, it is highly possible that China's terrestrial ecosystems mitigated global climate warming at a rate of 96.9 Tg CO 2 eq yr −1 (1 Tg = 10 12 g), substantially varying from a source of 766.8 Tg CO 2 eq yr −1 in 1997 to a sink of 705.2 Tg CO 2 eq yr −1 in 2002. The southeast and northeast of China slightly contributed to global climate warming; while the northwest, north, and southwest of China imposed cooling effects on the climate system. Paddy land, followed by natural wetland and dry cropland, was the largest contributor to national warming potential; forest, followed by woodland and grassland, played the most significant role in alleviating climate warming. Our simulated results indicate that CH 4 and N 2 O emissions offset approximately 84.8% of terrestrial CO 2 sink in China during 1961–2005. This study suggests that the relieving effects of China's terrestrial ecosystems on climate warming through sequestering CO 2 might be gradually offset by increasing N 2 O emission, in combination with CH 4 emission.