Scientists from around the globe warn that one particular gas may be surging.
While scientists observed relative stagnation for much of the 2000’s, the concentration of methane gas has surged.
Methane—a smaller component than carbon dioxide but a more potent driver of the greenhouse effect— has researchers warning that efforts to address climate change may be undermined unless it is brought under tighter control.
Robert Jackson, a professor at Stanford University, told BBC that carbon dioxide is still the dominant target for mitigation but warned not to lose sight of trying to reduce methane.
Jackson is the co-author of a new study on methane gas, which was published in Environmental Research Letters.
“The reasons for this renewed growth are still unclear, primarily because of uncertainties in the global methane budget,” the study concluded. “New analysis suggests that the recent rapid rise in global methane concentrations is predominantly biogenic—most likely from agriculture—with smaller contributions from fossil fuel use and possibly wetlands.”
According to the study, methane levels barely moved between 2000 and 2006, but has ticked upward from 2007 and then jumped sharply in 2014 and 2015 where methane rose by 10 or more parts per billion annually.
Jackson said the sharp rise in methane is likely due to agriculture sources like cattle and other ruminants as well as rice paddies.
He also said that while there has been a rise in fossil fuel use, biological and tropical sources are the most likely cause.
Methane is currently just about 1,830 parts per billion, while global carbon dioxide emissions have plateaued somewhat of late, giving hope that the rise in its atmosphere concentration of just above 400 parts per million might also slow.
Scientists primarily use computer models to project how Earth will warm given a certain mix of gases. Marielle Saunois, a professor from the University of Versailles Saint Quentin in France and co-author of the study, warned that a rapid turnaround is needed to reduce methane levels.
Over a century timescale methane is about 30 times better than carbon dioxide at trapping heat in the atmosphere.
According to Jackson, new satellites with a number of sensors that will specifically target carbon molecules are being launched, which should provide better information.