Question No. 1: How much methane leaks into the air as a result of fracking? Incredibly, nobody knows. The Environmental Protection Agency has estimated the leak rate at a little more than 2 percent, but a recent study suggested it might be twice that. And a controversial Cornell University study last year said it was closer to 6 percent. Clearly, it is critical to know the answer, which is why the Environmental Defenses Fund is currently participating in a study that is expected to provide one.
Question No. 2: How big a difference will it make to the environment if industry can minimize methane leaks? A lot. To illustrate the point, Steven Hamburg, the group’s chief scientist, showed me a model he had devised. It allowed me to see the effect on greenhouse gas emissions as methane leaks were reduced. Suppose, for instance, the current leak rate turns out to be 4 percent. Suppose we then reduce it in half. That would mean an immediate reduction in overall U.S. greenhouse gases by — are you sitting down for this? — 9 percent. If the leaks are reduced to 1 percent, the decrease in greenhouse gases jumps to 14 percent. (That number eventually gets smaller as the potency of the methane wears off.) Meanwhile, failing to reduce methane leaks largely eliminates the environmental advantage of natural gas over coal. You can plug in different estimates and get different results, but the point is this: There is no denying the huge difference it can make to the environment to reduce methane gas leaks.