“CO2 now is higher than any time in the last 4 to 4.5 million years when the atmosphere was about 7 degrees Fahrenheit (3.9 degrees Celsius) warmer and sea levels were 5 to 25 meters (16 to 82 feet) higher,”
Carbon dioxide levels in the air are now the highest they’ve been in more than 4 million years because of the burning of oil coal and gas. The last time the air had similar amounts was during a less hospitable hothouse Earth before human civilization took root, scientists said.
The National Oceanic Atmospheric Administration announced that the carbon dioxide level measured in May in Hawaii averaged 424 parts per million. That’s 3 parts per million more than last year’s May average and 51% higher than pre-industrial levels of 280 ppm. It is one of the largest annual May-to-May increases in carbon dioxide levels on record, behind only 2016 and 2019, which had jumps of 3.7 and 3.4 parts per million.
“Current emissions are going to remain in the atmosphere for thousands of years and they’re going to continue to trap heat energy near Earth’s surface for thousands of years,” Andrews said.