This global map shows the annual increase in methane emissions relative to the global average annual increase and was created using data from the satellite Copernicus Sentinel-5P. Credit: Copernicus Sentinel data (2020) processed by ESA, CC BY-SA 3.0 IGO
Methane levels, the second most important greenhouse gas in our atmosphere, continued to rise steadily in 2020, despite the economic slowdown caused by the COVID-19 pandemic.
A team of scientists from the University of Leeds has used data from the satellite Copernicus Sentinel-5P to determine the places with large jumps in methane emissions. These findings were presented during ESA’s Living Planet symposium held last month in Bonn, Germany.
Methane has a mixture of both natural and anthropogenic sources. About 40% of methane emissions come from natural sources, while 60% come from anthropogenic sources such as agriculture, fossil fuels and landfills.
One of the biggest sources of methane emissions comes from wetlands – an area that is either waterlogged or saturated with water – but there is still uncertainty about how they respond to climate change and short-term variations, such as electricity. Ninja-South oscillation.
The combination of the high global warming potential of methane and the relatively short life in our atmosphere of approximately nine years means that if we reduce our methane emissions, we can partially mitigate the human impact of climate change in a relatively short period of time – while global emissions of carbon dioxide are reduced.
Methane in situ measurements from 2020 showed the largest annual increase in methane concentrations since the 1980s, breaking this record in 2021. 2020 was unique due to the global pandemic, but methane concentrations continued to grow despite declining economic activity.
Anthropogenic methane emissions have contributed an additional 23% to the radiation impact – a direct measure of the size of the Earth’s energy budget, which is out of balance – in the troposphere since 1750.
The graph shows the average monthly methane concentrations over South Sudan from January 2018 to January 2021. The dashed lines represent times when less Sentinel-5P satellite data is available. Credit: Emily Dowd – University of Leeds / ESA
It is not fully understood what drives recent trends in global methane concentrations due to uncertainty about sources and flows. It is therefore important to monitor changes in atmospheric methane using satellites such as Copernicus Sentinel-5P. The satellite maps a wide range of pollutants such as nitrogen dioxide, ozone, formaldehyde, sulfur dioxide, carbon monoxide and, of course, methane.
Using observations obtained from Sentinel-5P, the team found that the satellite measurements showed the same increase in methane as shown in the surface measurements. Using Sentinel-5P’s global coverage capabilities, the team identified regions that show large increases in 2020.
These regions include South Sudan and Uganda in Central Africa, as well as the northern latitudes, including Canada and Russia. In 2019, emissions associated with major positive rainfall anomalies from South Sudd wetlands in South Sudan were found to account for more than a quarter of global emissions growth.
Positive rainfall anomalies over South Sudan and Uganda continued in 2020. In addition to heavy rainfall, there was a high release of dam walls from Lake Victoria, leading to increased water flow in the White Nile, which feeds Uganda’s wetlands. and the Court.
The data obtained from Sentinel-5P show that 2020 was probably a period of large methane flows in these regions. The satellite data was also compared to a chemical transport model called TOMCAT, which simulates methane in our atmosphere.
In South Sudan, there is a discrepancy in the seasonal cycle between the TOMCAT model and the satellite observations that previous studies have linked to the wetland model used in the study. This suggests that wetlands may be the dominant factor in stimulating high methane concentrations over South Sudan in 2020.
In Canada, high concentrations of methane in 2020 were found in the east, where more wetlands are located. The regions with strong methane growth measured in these satellite observations show that wetlands may have made a significant contribution to the large increase in methane in 2020, but work with TOMCAT is still ongoing to further investigate these findings.
Emily Dowd, PhD, a student at the University of Leeds, said: “Observations by Copernicus Sentinel-5P show that global wetlands continue to make a major contribution to atmospheric methane budgets, and it is important that further work is done to fully understand how they will respond to changes in our climate. ”
The increase in atmospheric methane set a new record in 2021: NOAA provided by the European Space Agency
Citation: Methane levels increased in 2020 despite the blockade (2022, June 24) extracted on June 24, 2022 from
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