New research shows that global CO2 levels will likely hit 417 ppm this year, the highest ever in human history, and a level not seen since the oceans were 20 m higher:
This year's rise in atmospheric carbon dioxide is expected to be 10 percent higher than normal, according to University of Exeter geography professor Richard Betts, head of the climate impacts division at the Meteorological Office, the U.K.'s national weather service. About 1 percent to 2 percent of the increase will come fromAustralia's devastating wildfire season, [said Martin Siegert, co-director of the Grantham Institute at Imperial College London].
Australia's historic fires, which raged from September through early February, are thought to have unleashed about 900 million tons of carbon dioxide into the atmosphere.
When the planet last had an atmosphere that mirrored today's chemical makeup, Earth was in the midst of the Pliocene Epoch. During that geologic period, which lasted from about 5.3 million to 2.6 million years ago, humans had yet to appear on the planet, and average sea levels were up to 20 m higher than they are today. Global average temperatures were also around 3°C warmer, with temperatures at the poles likely double that, according to Siegert.
Well, here in Chicago, we're 183 m above sea level. If we were 163 m above sea level it would take us a lot less time to get to the Mississippi Delta by Vicksburg, Miss., or to the Atlantic Coast in Richmond, Va. (I'd really miss Boston and London, though.)
On the other hand, unless Lake Michigan drops about 4 m by Saturday, we're looking at the second consecutive month of record lake levels, after the record year we had in 2019.