CO2 at 400 ppm by Bill Sweet

CO2 at 400 ppm by Bill Sweet Last Thursday, global atmospheric concentrations of carbon dioxide, as measured atop the Mauna Loa volcano, in Hawaii, reached 400 parts per million. The good news is that most educated people now know what “400 ppm” refers to. The bad news is that the world is more confused than ever regarding what to do about global warming. So, what now? Is it not time for the United States to get into the game of climate diplomacy in a serious way? Read morehttp://spectrum.ieee.org/energywise/energy/environment/global-co2-reaches-400-ppm