Mapping methane from the skies to limit warming on Earth

The Intergovernmental Panel on Climate Change (IPCC) set off alarm bells when it released a much-anticipated report earlier this week, noting the need for immediate action as heat, wildfire and other climate impacts become more threatening. Yet it also reveals a pathway to success by targeting methane emissions.

For the first time, the Sixth Assessment Report from the IPCC describes the importance of reducing “short lived” methane emissions. Methane (CH4) concentrations leveled off in the 1990s, but began rising again by 2007 and reached 1866 parts per billion in 2019. Scientists who authored the report with the IPCC’s Working Group I say the rise is driven primarily by fossil fuels, agricultural livestock and waste.

Methane matters because, although it doesn’t stay in the atmosphere on the time scale that carbon does, it has 80 times the global warming power of carbon dioxide (CO2) during the first two decades after it’s released. About a fourth of all methane emissions are because of human activity, and much of that is tied to the oil and gas industry.

It hasn’t commanded the attention that carbon emissions do because methane breaks down much faster (adding a comparatively small amount of carbon in the process), but curbing methane releases in the short term will keep overall temperature rise lower.

“Limiting human-induced global warming to a specific level requires limiting cumulative CO2 emissions, reaching at least net zero CO2 emissions, along with strong reductions in other greenhouse gas emissions,” the IPCC said. “Strong, rapid and sustained reductions in CH4 emissions would also limit the warming effect.”

One way to do that is by using satellites to pinpoint where methane leaks are and who is responsible for them. The Paris-based Kayrros firm works with data from the European Space Agency (ESA) to find methane hotspots in real time.

The Kayrros algorithms and platform use data from the Copernicus Sentinel-5P satellite, which was launched in 2017 for the specific purpose of monitoring atmospheric gases. It covers the whole world every four days to deliver far more accurate (and troubling) estimates on methane than were possible in the past. The methane tracking program also uses Sentinel-1 and Sentinel-2 data.

The ESA said last year that there are about 100 high-volume methane leaks at any one time around the world, about half of them in regions known for oil and gas, coal mining and other heavy industries. Jean Bastin of Kayrros says the methane amounts are equivalent to the annual CO2 emissions of both Germany and France combined.

Identifying the precise locations and the amount of methane involved means the problem can be addressed rather than remain invisible. And that gives Earth a fighting chance against extreme heat and its effects because, as Kayrros notes, you can’t manage what you can’t measure.

“As with carbon dioxide, human activities are increasing the methane concentration in the atmosphere faster than it can be offset by natural sinks,” says Claus Zehner, head of the Sentinel-5P program. “Effective global monitoring of methane emissions is therefore essential.”