Judy Woodruff:

We heard in the last segment a little about natural gas produced in the U.S.

It turns out it is a big factor in the overall growth of energy production in this country over the past decade.

But producing and transporting that gas releases methane, a potent greenhouse gas that's gotten a lot less attention when it comes to climate change.

Miles O'Brien reports on how California is zeroing in on this issue

It's part of our weekly segment on the Leading Edge of science, medicine and technology.