Climate-driven increase of natural wetland methane emissions offset by human-induced wetland reduction in China over the past three decades

Abstract

Both anthropogenic activities and climate change can affect the biogeochemical processes of natural wetland methanogenesis. Quantifying possible impacts of changing climate and wetland area on wetland methane (CH4) emissions in China is important for improving our knowledge on CH4 budgets locally and globally. However, their respective and combined effects are uncertain. We incorporated changes in wetland area derived from remote sensing into a dynamic CH4 model to quantify the human and climate change induced contributions to natural wetland CH4 emissions in China over the past three decades. Here we found that human-induced wetland loss contributed 34.3% to the CH4 emissions reduction (0.92 TgCH4), and climate change contributed 20.4% to the CH4 emissions increase (0.31 TgCH4), suggesting that decreasing CH4 emissions due to human-induced wetland reductions has offset the increasing climate-driven CH4 emissions. With climate change only, temperature was a dominant controlling factor for wetland CH4 emissions in the northeast (high latitude) and Qinghai-Tibet Plateau (high altitude) regions, whereas precipitation had a considerable influence in relative arid north China. The inevitable uncertainties caused by the asynchronous for different regions or periods due to inter-annual or seasonal variations among remote sensing images should be considered in the wetland CH4 emissions estimation.

Interannual variation in methane emissions from tropical wetlands triggered by repeated El Niño Southern Oscillation

“…A water table module was also integrated into the model to improve hydrological processes for wetland simulation. The wetland CH 4 emission modeling performance of TRIPLEX‐GHG was evaluated using global field measurements from previous studies, and the corresponding results suggest that the model can be used to simulate magnitudes and capture reasonable temporal patterns in CH 4 emissions from global natural wetlands that underlie varying conditions, including in tropical areas (Zhu et al., , , ) (Figure S1).…”

Extrapolation and Uncertainty Evaluation of Carbon Dioxide and Methane Emissions in the Qinghai-Tibetan Plateau Wetlands Since the 1960s

“…Wetland distribution maps (1980, 1990, 2000, and 2008) were acquired from Niu et al (2009), which had been widely used in wetland classification and ecological regionalization (Liu et al, 2015;Zhu et al, 2016;Wang et al, 2020). In this study, the area overlapping across all four wetland distribution maps was defined as permanent wetland.…”

Temporal and Spatial Variation of Wetland CH4 Emissions from the Qinghai–Tibet Plateau under Future Climate Change Scenarios

“…The ratio of CH 4 release rate to CO 2 release rate (r) and the temperature control parameter of CH 4 production (Q 10 P) are sensitive parameters in the model, and we adapted values from our previous work in the present study [23,32,33]. The TRIPLEX-GHG model has been well calibrated and validated for simulating CH 4 emissions from wetlands in China [34] and elsewhere [23,32] under past climate conditions. This previous work provided a basis for predicting CH 4 emissions from Plateau wetlands under future climate conditions [23,[32][33][34].…”

“…The TRIPLEX-GHG model has been well calibrated and validated for simulating CH 4 emissions from wetlands in China [34] and elsewhere [23,32] under past climate conditions. This previous work provided a basis for predicting CH 4 emissions from Plateau wetlands under future climate conditions [23,[32][33][34].…”