http://www.sciencemag.org/podcast/cooling-earth-asteroid-dust-and-3-billion-missing-birds

On this week’s show, science journalist Josh Sokol talks about a global cooling event sparked by space dust that lead to a huge shift in animal and plant diversity 466 million years ago. (Read the related research article in Science Advances.)

And I talk with Kenneth Rosenberg, an applied conservation scientist at Cornell University, about steep declines in bird abundance in the United States and Canada. His team estimates about 3 billion birds have gone missing since the 1970s.