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Climate change makes the future seem terrifying. It could potentially portend rising sea levels, food supply shortages, and other globally disastrous consequences. Despite its potential for unleashing catastrophe on the world, scientists have repeatedly insisted that more needs to be done to counter it.
One group of scientists, in a study released May 20th, is stepping up to the plate with a truly radical proposal. The researchers behind this study, published in Nature Sustainability, claim that converting atmospheric methane to carbon dioxide could help to fight climate change.
The study’s main premise is inherently radical. It suggests turning one greenhouse gas into a different greenhouse gas, precisely the one most strongly correlated with climate change. To understand why climate experts would suggest something seemingly so counterintuitive, the distinctions between methane and the carbon dioxide to which it would theoretically be converted must be understood.
Methane has not contributed to the earth’s rising temperatures as strongly as carbon dioxide has, but its heat-trapping effects far outweigh that of carbon dioxide. Over two decades, methane can even trap a whopping 84 times as much heat as carbon dioxide can. Over the course of a century, that number drops to 28, because methane’s atmospheric lifetime is far shorter than that of carbon dioxide. The latter gas lasts several centuries, explaining why its contributions to climate change concern many people far more than those of methane, despite the difference in the gases’ lifetimes.
Furthermore, over the past two centuries, humanity has more than doubled the atmospheric concentration of methane, which is a byproduct of raising livestock, extracting fossil fuels (whereas carbon dioxide is a byproduct of burning fossil fuels), operating wastewater treatment facilities, and building landfills. Thus, the current atmospheric concentration of methane is 1.86 parts per million (ppm), though this number pales in comparison to carbon dioxide’s recently-achieved record high concentration of 415 ppm.
Thus, the study’s authors argue, converting methane to carbon dioxide could fully eliminate roughly one-sixth of human-caused climate change. The amount of carbon dioxide left after the methane conversion would only contribute the equivalent of what the world emits into the atmosphere in three months, a time period certainly not long enough to cause one-sixth of human-caused climate change.
It is not yet clear how methane would be converted to carbon dioxide. Among the Nature Sustainability study’s authors include Edward Solomon, a Stanford chemist who studies a potential method for doing so. Solomon is an expert on zeolites, minerals through which methane can be trapped and oxidized. Solomon and his fellow study researchers dream of a world in which facilities similar to those currently working to remove carbon dioxide from the environment direct methane to zeolites. With thousands of large fans and zeolite filters, the study’s vision for turning methane to carbon dioxide could become a reality.
As expected for such a radical idea, not everyone is on board. Myles Allen, an Oxford University climate scientist, has said that incentivizing the removal of methane from the environment would distract people from doing the same for carbon dioxide. Despite the promise of the Nature Sustainability study, carbon dioxide does indeed remain the more dangerous greenhouse gas.