Climate scientists long ago settled among themselves the question of whether human emissions of greenhouse gases are a problem, concluding that we are running some grave risks. But the field still features vigorous debate about how bad global warming will get, how quickly, and how to combat it.

One of the biggest fights involves how much effort to put into stopping leaks of methane gas into the atmosphere. It may sound like an obscure topic, but the leaks could have a great effect on the climate that people living today experience.

This issue has grown in importance with the release of President Obama’s new climate plan. It calls for greater use of natural gas, which consists mostly of methane. Among a few academics and on the far left of the environmental movement, cries are going up that the president is about to lock America into a supposed solution to climate change that will be worse than burning coal.

Is that claim plausible?

The basic scientific facts are pretty clear. By far the most important greenhouse gas that humans are spewing into the atmosphere is carbon dioxide, which comes from burning fossil fuels. The second most important is methane, which comes from many sources. It is released when coal is mined; it escapes when wells are drilled for oil or natural gas; and it leaks from pipes that distribute natural gas. Certain agricultural practices also throw up a huge amount.