It’s a record we didn’t want to break. The carbon dioxide concentration in the atmosphere hits the 400 parts-per-million mark, a level which some scientists say is a point of no return for stopping climate change. A few days later, a leading newspaper prints an op-ed essay that claims CO2 is getting a bad rap: it’s actually good for the planet. The more the better. Skeptic Phil Plait rebuts the CO2-is-awesome idea while a paleontologist paints a picture of what Earth was like when the notorious gas last ruled the planet. Note: humans weren’t around. Plus, our skit says NO to O2 … and a claim that climate change skeptics have borrowed from the Creationists’ playbook in challenging the teaching of established science in schools. Guests: Phil Plait – Astronomer, skeptic, and author of Slate Magazine’s blog Bad Astronomy Peter Ward – Paleontologist and biologist, Department of Earth and Space Sciences, University of Washington in Seattle Josh Rosenau – Programs and Policy Director at the National Center for Science Education Eugenie Scott – Executive Director of the National Center for Science Education Descripción en español Learn more about your ad choices. Visit megaphone.fm/adchoices