The National Oceanic and Atmospheric Administration reports a worrying new milestone for CO2, the main global warming pollutant. Arctic monitoring stations now show 400 parts per million (ppm) of the heat-trapping gas in the atmosphere.
The global level now stands at 395ppm (see video below), and is expected to reach the Arctic level in the very near future. Scientists believe the maximum “safe” limit for a stable climate is around 350ppm.
On current trends, CO2 levels could reach 800-1000ppm by the end of this century – potentially resulting in 6°C of global warming.