Trading Methane for Carbon Dioxide.

• Position: GREENHOUSE GASES

A relatively simple process could help turn the tide of climate change while also turning a healthy profit. That is one of the hopeful visions outlined in a Stanford University-led paper that highlights a seemingly counterintuitive solution: converting one greenhouse gas into another.

The study, published in Nature Sustainability, describes a potential process for converting methane into carbon dioxide, which is a much less-potent driver of global warming. The idea of intentionally releasing carbon dioxide into the atmosphere may seem surprising, but the authors contend that swapping methane for carbon dioxide is a significant net benefit for the climate.

"If perfected, this technology could return the atinosphere to pre-industrial concentrations of methane and other gases," says lead author Rob Jackson, professor of earth system science.

The basic idea is that some sources of methane emissions--from rice cultivation or cattle, for example--may be very difficult or expensive to eliminate. "An alternative is to offset these emissions via methane removal, so there is no net effect on warming the atmosphere," posits study coauthor Chris Field, director of the Stanford Institute for the Environment.

In 2018, methane--about 60% of which is generated by humans--reached atmospheric concentrations two-and-a-half times greater than pre-industrial levels. Although the amount of carbon dioxide in the atmosphere is much greater, methane is 84 times more potent in terms of warming the climate system over the first 20 years after its release.

Most scenarios for stabilizing average global temperatures at 2[degrees]C above pre-industrial levels depend on strategies for both reducing the overall amount of carbon dioxide entering the atmosphere and removing what already is in the atmosphere through approaches such as tree planting or underground sequestration. However, removing other greenhouse gases, particularly methane, could provide a complementary approach, according to the study's authors, who point to the gas' outsized influence on the climate.

Most scenarios for removing carbon dioxide typically assume hundreds of billions of tons removed over decades and do not restore the atmosphere to...