It’s been 800,000 years since Earth’s atmosphere looked anything like this. That’s according to the National Oceanic and Atmospheric Association (NOAA), which recorded CO2 levels of over 402 parts per million this week, Think Progress reports. The last time there was that much carbon dioxide in the atmosphere was 800,000 years ago, long before the start of recorded human history.
The news comes just days after the release of the latest report from the Intergovernmental Panel on Climate Change (IPCC), which predicts disastrous consequences unless global civilization reigns in its greenhouse gas production. For example, climate change could severely disrupt the global food supply, leading to worsening hunger around the globe. The places hardest hit would be among the most vulnerable, including South Asia and Sub-Saharan Africa.
A draft version of the IPCC report originally suggested that world leaders had roughly 15 years to avert disastrous climate change through affordable means. That was based on IPCC projections of how long it would take to raise the global temperature by two degrees Celsius, the threshold often described by climate scientists as the point of no return.
Climatologist Michael E. Mann has also recently projected that Earth will cross the two degrees Celsius marker by 2036 if humans continue to produce greenhouse gases at the same rate.
“If the world keeps burning fossil fuels at the current rate, it will cross a threshold into environmental ruin by 2036,” he wrote in Scientific American last month.