We’ve just crossed a sobering milestone. For the first time since humans have walked the planet, the amount of carbon dioxide in the atmosphere at Mauna Loa Observatory has reached 400 parts per million. On May 9, scientists from both the National Oceanic and Atmospheric Administration (NOAA) and the Scripps Institution of Oceanography measured the daily average concentration of carbon dioxide in air above this value. I don’t know about you, but when I heard this I wanted to cry. Let me put this in context for you. Read More
