Climate change on CBS's 60 Minutes

CBS's venerable newsmagazine, 60 Minutes (incidentally, the program that defined and pioneered the genre) tackled climate change on April 1. But despite the date, this was no joke. Correspondent Scott Pelley went to Chile's Patagonia region, Antarctica and New England for a close look at the leading edge of the planet's rising temperature, and even for people who've been following the facts and research on the subject, his report was sobering.

One of the main sources in Pelley's piece was glaciologist Gino Casassa, who's been scrutinizing Patagonia's O'Higgins glacier for years. The rate it's shrinking -- both in area and thickness -- is alarming. At one point in the story, he discovers that what had been glacial ice in 2004 is now a lake. Casassa used to be skeptical about climate change. "I just didn’t believe in global warming; I mean, in global warming being produced by mankind, by us contaminating the atmosphere. I just refused to believe that,” he says.

He's not a skeptic now. The evidence of the O'Higgins glacier changed that.

About 1.5 billion people rely on glaciers for fresh water, and the implications of their accelerating melting are obvious.

In Antarctica, where the ice is also shrinking faster than ever, climate scientist Paul Mayewski's Antarctic ice core samples show a definitive link: the planet started heating up when the level of carbon dioxide in the atmosphere increased, and that began with the industrial revolution. Biologist Wayne Trivelpiece shows how warmer water is killing the krill that chinstrap penguins need to survive.

Mayewski says his findings make greenhouse gas reduction even more urgent. But, he warns, "once we start it’s not going to be an immediate solution. We’re going to have to pay for a while for what we’ve done."