The annual growth rate of carbon dioxide in the atmosphere rose more in 2015 than scientists have ever seen in a single year, the National Oceanic and Atmospheric Administration announced Thursday. It was the fourth year in a row that carbon dioxide concentrations grew by more than 2 parts per million, with an annual growth rate of 3.05 parts per million in 2015. The spike comes in the same year that Earth reached an ominous global warming milestone — scientists last year measured the highest atmospheric concentrations of carbon dioxide ever recorded. The rate of increase in carbon dioxide concentrations is 200 times faster than the previous extreme jump between 11,000 and 17,000 years ago, when levels rose 80 ppm over about 6,000 years.
— source climatecentral.org