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Methane emissions from global rice fields: Magnitude, spatiotemporal patterns, and environmental controls
Author(s) -
Zhang Bowen,
Tian Hanqin,
Ren Wei,
Tao Bo,
Lu Chaoqun,
Yang Jia,
Banger Kamaljit,
Pan Shufen
Publication year - 2016
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1002/2016gb005381
Subject(s) - paddy field , magnitude (astronomy) , environmental science , biogeochemical cycle , irrigation , greenhouse gas , methane , climate change , fertilizer , flooding (psychology) , spatial variability , global warming , representative concentration pathways , atmospheric sciences , agronomy , climate model , environmental chemistry , ecology , chemistry , mathematics , geology , biology , physics , astronomy , psychology , statistics , psychotherapist
Given the importance of the potential positive feedback between methane (CH 4 ) emissions and climate change, it is critical to accurately estimate the magnitude and spatiotemporal patterns of CH 4 emissions from global rice fields and better understand the underlying determinants governing the emissions. Here we used a coupled biogeochemical model in combination with satellite‐derived contemporary inundation area to quantify the magnitude and spatiotemporal variation of CH 4 emissions from global rice fields and attribute the environmental controls of CH 4 emissions during 1901–2010. Our study estimated that CH 4 emissions from global rice fields varied from 18.3 ± 0.1 Tg CH 4 /yr (Avg. ±1 SD) under intermittent irrigation to 38.8 ± 1.0 Tg CH 4 /yr under continuous flooding in the 2000s, indicating that the magnitude of CH 4 emissions from global rice fields is largely dependent on different water schemes. Over the past 110 years, our simulated results showed that global CH 4 emissions from rice cultivation increased by 85%. The expansion of rice fields was the dominant factor for the increasing trends of CH 4 emissions, followed by elevated CO 2 concentration, and nitrogen fertilizer use. On the contrary, climate variability had reduced the cumulative CH 4 emissions for most of the years over the study period. Our results imply that CH 4 emissions from global rice fields could be reduced through optimizing irrigation practices. Therefore, the future magnitude of CH 4 emissions from rice fields will be determined by the human demand for rice production as well as the implementation of optimized water management practices.