Methane is a greenhouse gas that, though it doesn’t stay in the atmosphere as long as carbon dioxide, actually traps heat more effectively. This means that it contributes more to global warming but for a shorter time. The amount of CO2, and the time it stays in the atmosphere, means that it still contributed more overall.
Methane concentrations have been increasing since 2007, with 2014 being a particularly bad year. In an interesting development, some recent research has shown that industry isn’t the culprit here as had been previously thought. In fact, biological sources are the main cause of increased methane, primarily agriculture and wetlands.
We’ve known for some time that cows produce a great deal of methane, and there are researchers looking specifically at that problem, trying to find ways to reduce emissions from cows other than having fewer cows. But cattle populations likely haven’t changed all that much between 2007 and 2014, so scientists believed there must be another cause.
Enter tropical wetlands. Tropical swamps release quite a bit of methane, but they’ve been around for millennia without producing too much methane. Combined with other sources it may be too much for natural processes to handle, but methane production by wetlands has been increasing as well, so researchers believe there’s another process causing increased methane emissions from tropical wetlands.
The researchers who identified tropical wetlands as the culprit haven’t quite figured out why they’re producing more methane than normal, but they think rising global temperatures might have something to do with it. If increased temperatures mean that wetlands are releasing more methane, they’re going to be part of a process that might spiral out of control. As wetlands get warmer and produce more methane, that extra gas gets stuck in the atmosphere and makes temperatures even warmer.
While purely human actions may not create the bulk of methane, the human race still needs to adjust its actions to produce less CO2, and thus have less of an impact on global temperatures and thus, on methane emissions.