Arctic monitoring stations show carbon dioxide levels are now above 400 parts per million. Carbon dioxide is the chief climate-change gas and stays in the atmosphere for 100 years. Before the Industrial Age, carbon dioxide levels were 275 ppm.
The world's air has reached what scientists call a troubling new milestone for carbon dioxide, the main global warming pollutant.
LONDON, May 8 (Reuters) - Rising carbon dioxide emissions will cause a global average temperature rise of 2 degrees Celsius by 2052 and a 2.8 degree rise by 2080, as governments and markets are unlikely to do enough against climate change, the Club of Rome think tank said.