Scientists once thought methane emissions weren’t a major point of concern compared to carbon dioxide. But now, the tables have turned.
A new study published in the journal Environmental Research Letters reports that the past 10 years have seen a surge of methane concentrations in the atmosphere. Just in the past two years, the amount of methane increased by more than 20 parts per billion, bringing the total to 1,830 parts per billion. The study also reveals that levels of carbon dioxide have been leveling off. In the first two decades after its release, methane is 84 times more potent than carbon dioxide—so naturally, experts are alarmed by these new findings.
Agriculture is likely the main source of methane’s growth spurt, but exploitation of fossil fuels—through fracking, coal mining, and oil drilling—could also be playing a role. The problem is that methane emissions are diffuse and not well understood, leaving policymakers with few reliable strategies for bringing those levels down. U.S. president-elect Donald Trump has vowed to re-energize the coal mining industry and cut budgets to NASA’s Earth-observing satellites, which wouldn’t help.
Another possible source of methane emissions is the natural gas industry; in 2015, NOVA Next contributor Phil McKenna reported that the U.S. Environmental Protection Agency had underestimated methane emissions in part because natural gas leaks are often overlooked.
Here’s Fiona Harvey, reporting for The Guardian:
Unlike carbon dioxide emissions, however, which have been tracked in various ways since the 1950s, emissions of methane are poorly understood and could represent a threat that scientists have still not accounted for.
For instance, the melting of the Arctic tundra releases methane as the vegetation underneath is gradually and sometimes suddenly exposed. This has been regarded by scientists as a potential “tipping point” whereby warming of the Arctic leads to greater releases of methane, therefore greater warming, in a runaway and uncontrollable cycle.
Given that methane emissions are so hard to keep track of, policymakers and the scientific community at large will have to double down on efforts to calculate and curtail methane emissions. For example, adding an “anti-burp” compound to cows’ feed could reduce emissions. In addition, experts can invest more time and money into researching natural methane sinks like hydroxyl radical.
Find out how kangaroo farts could help us alter cows’ gut microbiomes—and, consequently, save the planet—in this episode of Gross Science: