Carbon Dioxide Level Passes Long-Feared Milestone
New York Times, May 11, 2013
New York Times, May 11, 2013
U-T San Diego, May 7, 2013
U-T San Diego, May 7, 2013
The New York Times, May 6, 2013
Smithsonian, May 6, 2013
NPR, May 2, 2013
The Guardian (U.K.), April 29, 2013
Yahoo Finance, April 29, 2013
U-T San Diego, April 28, 2013
U-T San Diego, April 28, 2013