Using methane dynamic model to estimate methane emission from natural wetlands in China

Natural wetlands are the largest land-based natural sources for methane (CH₄) emissions. China´s natural wetland area accounts for about 4% of the area of the natural wetlands worldwide. Based on the data of global lakes and wetlands, in this study we conducted modeling work of CH₄ emissions from natural wetlands in China by using terrestrial ecosystem model (TEM) of the 1995-2005. The results show that China´s terrestrial natural wetland based CH₄ emission is 7.48Tg/a, which is mainly distributed in the Qinghai-Tibet Plateau and in northwest region of China accounting for 68% of the emissions nationwide. Lake wetlands, marsh/floodplains and seasonal wetland are the major three types of wetlands are the major sources of CH₄ emissions in China, accounting for 65% of total emissions. Monthly simulations of CH₄ emissions from 1995-2005 show that regional maximum on CH₄ emissions are closely related to soil temperatures and in the period of June, July and August, of which the emission maximum is in July. These simulation based estimates will be of great importance to China´s climate change and greenhouse gas control study.