1097. Methane Emissions Have Increased at an Unprecedented Rate Over the Past Five Years

Methane (CH4) is a potent greenhouse gas that contributes to climate change. Under the Global Methane Pledge, more than 150 countries have pledged to reduce methane emissions by 30% over a decade, but a study published on September 10 found that methane emissions have increased at an unprecedented rate over the past five years, with most emissions coming from agriculture and waste.
 

Methane concentrations in the atmosphere are now 2.6 times higher than before the Industrial Revolution and at least the highest levels in at least the last 800,000 years. According to the world's top climate scientists, methane emissions are projected to continue to rise under the worst-case scenario. If the current trend of methane emissions continues, global warming could reach more than 3°C by the end of the century.

Methane is a potent greenhouse gas that can come from natural sources, such as wetlands, or "anthropogenic" sources, such as agriculture, fossil fuels, and landfills. Methane tends to warm the atmosphere 90 times faster than carbon dioxide in the first 20 years of emissions, making methane reduction an effective target to limit warming in the short term.

Despite the increasing number of policies that advocate methane reduction in recent years, the analysis shows that annual methane emissions have increased by 20% over the past 20 years. The main factors were coal mining, oil and gas production and utilization, cattle and sheep ranching, and the decomposition of food and organic waste in landfills.

The European Union and Australia have succeeded in reducing methane emissions over the past 20 years, while China and Southeast Asia have been the largest regional emitters. In 2020, the latest data available, 400 million tonnes of global methane emissions, equivalent to 65%, were anthropogenic, and for every tonne of emissions from the fossil fuel industry, emissions from agriculture and waste were about 2 tonnes.

Reference
R B Jackson et al 2024 Environ. Res. Lett. 19 101002 https://iopscience.iop.org/article/10.1088/1748-9326/ad6463/pdf

Contributor: IIYAMA Miyuki, Information Program