Scientists want to tackle ‘neglected stepchild of greenhouse gases’

It is high time that we – after CO2 – also remove methane from the atmosphere, according to American researchers.

Our climate is changing and that is a big problem. Fortunately, there are also solutions. It is therefore important that we reduce our emissions. But that is not enough; to achieve the Paris climate goals, it seems necessary that we also start extracting CO2 from the atmosphere. The technology required for this has been worked on for years. But while we focus so much on limiting emissions and capturing and storing CO2, we are overlooking an important, third solution to the climate problem, argue researchers from Stanford University: removing atmospheric methane.

After CO2, it’s time for methane

“Carbon dioxide is the most important greenhouse gas under our control,” said researcher Rob Jackson. “It makes sense to start with (removing, ed.) CO2.” Also because we have had equipment for decades with which CO2 can be removed from the air – albeit on a small scale. “For example, CO2 has long been extracted from industrial waste streams and filtered from the air in submarines.” Building on those commercial applications, capturing CO2 on a much larger scale seemed perfectly feasible and effective. That other, much more potent greenhouse gas was actually completely overlooked. “Methane has always been somewhat neglected,” says Jackson. But if it is up to him and his colleagues, that will now change.

0.21 degrees

in the sheet Philosophical Transactions of the Royal Society A the scientists show that removing methane – certainly in the short term – can have a huge, positive impact on our climate problem. For example, calculations show that the global surface temperature drops 0.21 degrees Celsius when we remove the amount of methane we have emitted from the atmosphere in a period of three years.

Health

And it is not only the climate that benefits from the removal of atmospheric methane. Our health also benefits. For example, researchers estimate that removing three years of methane emissions each year also prevents about 50,000 premature deaths. Not only is methane a greenhouse gas, it also causes air pollution and promotes the formation of ozone in the troposphere (the area closest to the earth’s surface). This tropospheric ozone causes smog and thus poses a serious threat to public health; It is estimated that tropospheric ozone causes premature death of approximately 1 million people each year. By reducing the methane concentration in the atmosphere, the concentration of ozone in the troposphere also decreases, thus saving tens of thousands of lives. “As the ozone concentration at the surface decreases, respiratory diseases also decrease,” Jackson said.

The atmospheric methane concentration has increased considerably in recent decades. Image: NOAA.

Powerful greenhouse gas

So by removing methane from the atmosphere, we can save lives. But we can also lower global temperatures. Much faster than when we remove a comparable amount of CO2 from the air. This has everything to do with the fact that methane is a much more potent greenhouse gas than CO2. “The removal of methane does not make the removal of CO2 redundant,” emphasizes Jackson. “We both need it.”

Stepchild becomes favorite

But where billions of dollars have already been invested in removing CO2, little attention has been paid to removing methane. “The technology for removing CO2 is well beyond that for removing methane,” Jackson acknowledges. “For example, there are already dozens of companies that focus on removing CO2.” So there is still a lot of work to be done. What does not help is that removing methane is quite difficult, because it can be found in relatively low concentrations in the atmosphere. But there is hope, the researchers emphasize. There are emerging technologies that can make the removal of atmospheric methane a reality. Attention for the ‘neglected’ greenhouse gas is also increasing. “Methane is the neglected stepchild of greenhouse gases,” Jackson says. “But recently it has received more attention, for example in the new IPCC report and the recently announced Global Methane Pledge of the US and the EU. In the latter agreement, the EU and the US agreed to cut methane emissions by 30 percent by 2030.

“The time is right to invest in methane removal technologies,” Jackson said. But if those investments come and pay off, that’s not a license to keep emitting methane. “We have to do both: reduce emissions faster than we have done to date and remove methane,” says Jackson.