According to experts, carbon dioxide (CO2) levels peaked more than 50% higher than pre-industrial levels in May, equal to levels observed around 4 million years ago.

The National Oceanic and Atmospheric Administration (NOAA) team reported that CO2 recorded at NOAA’s Mauna Loa Atmospheric Baseline Observatory peaked for 2022 in May at 421 parts per million, up 1.8 ppm from 2021.

A monthly average of 420.78 ppm was computed by scientists at the Scripps Institution of Oceanography at the University of California San Diego, which keeps an independent database.

For about 6,000 years prior to the Industrial Revolution, CO2 levels remained continuously around 280 ppm. Humans have produced an estimated 1.5 trillion tonnes of CO2 pollution since then, the most of which will continue to warm the atmosphere for thousands of years.

Temperatures were 7 degrees Fahrenheit hotter than they are now, and research show that vast woods formerly filled today’s Arctic Tundra.