[matthewdgreen]

The problem is not a single human-caused methane leak. The problem is that global methane levels are increasing, and they're increasing at an increasing rate. Current theory is that some of this is caused by human emissions, but most is a feedback effect of climate change where wetlands produce more methane. There are also big, terrifying methane feedback loops in the arctic (permafrost and undersea clathrates) that may or may not be in play. Methane is very, very bad news for humans.