Abstract:

Since industrialization, methane (CH₄) has caused a global mean surface temperature rise of about 0.5℃, and a reduction in CH₄ emissions is critical to achieving the Paris Agreement’s long-term temperature goal. According to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), the relative contribution of CH₄ to total effective radiative forcing (ERF) was 11% from 1960 to 2019, compared with the decrease in the relative contribution of CH₄ to total ERF from 1750 to 2019. It was related to the change in the growth rate of CH₄ concentration in the atmosphere since the 1970s. Projections show that global CH₄ emissions are expected to be reduced by up to 45% by 2050, which will benefit reducing peak warming levels and global surface ozone concentration and helping to improve air quality. The report also points out that there is still a large uncertainty in the source and sink of CH₄, and it is still challenging to accurately quantify the CH₄ flux and attribute its changes. With the release of the Methane Emission Control Action Plan in China, the academic community needs to strengthen the research on CH₄ source and sink estimations and make progress in the inversion algorithm for satellite monitoring of atmospheric CH₄ concentration, to provide data support for CH₄-related mitigation policies in China.

Key words: IPCC Sixth Assessment Report (AR6), Methane (CH₄), Mitigation potential