 In 2013, the National Oceanic and Atmospheric Administration NOAA reported that atmospheric concentrations of carbon dioxide CO2 had reached 400 parts per million ppm for the first time since the Pliocene Era ca. 3 million years ago. According to the IPCCs Sixth Assessment Report AR6, excess carbon dioxide in our atmosphere will result in a ... NASA Satellite Shows How We Can Track Local CO2 Emissions From... 