Carbon dioxide in Earth’s atmosphere reaches record high, researchers say
On May 14, the daily concentration of carbon dioxide in the atmosphere hit the highest level ever recorded in human history, at 415 parts per million.
Methane is an especially potent greenhouse gas and global average concentrations of methane in 2018 reached 1,869 parts per billion, a 259 percent increase over pre-industrial levels.
Nitrous oxide, which is emitted from agricultural and industrial activities, is the third-most potent greenhouse gas and depletes the ozone layer that shields the planet from the sun’s ultraviolet radiation.
Atmospheric concentrations of nitrous oxide — a chemical compound commonly known as laughing gas — in 2018 reached an average of 331.1 parts per billion, which was a 123 percent increase over pre-industrial levels.