According to BBC News, methane levels were relatively stagnant in the 2000s, but have recently surged.
While Methane (CH4) is a smaller component than carbon dioxide (CO2), methane drives a more potent greenhouse effect.
“CO2 is still the dominant target for mitigation, for good reason. But we run the risk if we lose sight of methane of offsetting the gains we might make in bringing down levels of carbon dioxide,” Robert Jackson from Stanford University, U.S. told BBC News.
Professor Jackson authored an article in Environmental Research Letters on the issue.
The cause for this sudden spark is still unclear. According to BBC News, the amount of methane present in the atmosphere barely moved between 2000 and 2006, before slowly rising in 2007, and eventually skyrocketing in 2014 and 2015.
Between 2014 and 2015, methane levels rose rapidly by 10 or more parts per billion (ppb) annually.
Now, it is just above 1,850 ppb. In comparison, CO2 emissions have dropped.
“The leveling off we’ve seen in the last three years for carbon dioxide emissions is strikingly different from the recent rapid increase in methane,” Professor Jackson said.
“We think agriculture is the number one contributor to the increase.”
“There’s been a secondary increase from fossil fuel use, partly because there continues to be more fossil fuels extracted.” But, he continued, “we don’t see evidence for a huge spike in fossil fuel emissions over temperate systems. We do think they’ve increased, but we don’t see evidence for leaky oil and gas wells causing this spike in global methane.”
According to Professor Jackson, methane can come from a variety of sources, including natural sources such as marshes and other wetlands; 60 percent, however, comes from human activity, such as agriculture.
These agricultural sources include cattle and other ruminants, in addition to rice paddies.
“Looking at the scenarios for future emissions, methane is starting to approach the most greenhouse gas-intensive scenarios,” Professor Jackson continued. “That’s bad news. We’re going in the wrong direction.”
According to the Washington Post, over a 100-year period, the emission of a given amount of methane is approximately 28 times more powerful than carbon dioxide when it comes to global warming.
Scientists use computer models to predict how the Earth will warm when faced with a mix of gases, and at the moment, methane’s growth rate is putting us on a path to a challenging future.
“We should do more about methane emissions. If we want to stay below a 2 degrees (Celsius) temperature increase, we should not follow this track and need to make a rapid turnaround,” Dr. Marielle Saunois from the University of Versailles Saint Quentin, France said in a statement.
Saunois, a lead author of the study, cited data from the United Nations’ Food and Agriculture Organization indicating that livestock operations worldwide expanded from producing 1.3 billion head of cattle in 1994 to nearly 1.5 billion in 2014.
In an effort to further research the methane issue, scientists will soon be launching new satellites with built-in sensors that will specifically target carbon molecules.
“I’m optimistic that the scientific community and the policymakers will be able to have better information. I’m optimistic because there are new satellites coming along that will give us the power to see methane concentrations all over the world on a regular basis,” Professor Jackson explained.
“Methane is more difficult to study than CO2 because it’s more diffuse, but I think we’re poised to make really good progress over the next few years.”
Professor Jackson, in addition to other scientists involved in the editorial, is scheduled to discuss the issue during the fall meeting of the American Geophysical Union (AGU) in San Francisco on Tuesday, Dec. 13.
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