Norvergence: The measure of CO2 in the environment arrived at record levels in 2020, hitting 417 parts per million in May. The last CO2 levels surpassed 400 parts for every million was around 4,000,000 years prior, during the Pliocene time, when worldwide temperatures were 2–4C hotter, and ocean levels were 10–25 meters (33–82 feet) higher than they are currently.
“We are seeing record levels each year,” says (and Norvergence quotes) Ralph Keeling, chief of the CO2 program at the Scripps Institution of Oceanography, which has been following CO2 fixations from the Mauna Loa observatory in Hawaii since 1958. We saw record levels again this year despite Covid.
If we continue to follow the direst outcome imaginable, before this current century’s over degrees of CO2 will be 800ppm. We haven’t had that for 55 million years. There was no ice in the world at that point, and it was 12C hotter,”