What it means to live in a world with CO2 concentrations above 400 ppm
Bad news comes from the Scripps Institute for Oceanography of San Diego, California. Atmospheric carbon dioxide has passed the 400 ppm (parts per million) threshold, maybe permanently. In September carbon dioxide in the atmosphere is usually at its minimum, but in 2016 it failed to drop below 400 parts per million. “Is it possible that October 2016