Today’s rate of atmospheric carbon dioxide increase is 10 times faster than at any other point in the past 50,000 years.
Previous research showed that during the last ice age, which ended about 10,000 years ago, there were several periods where carbon dioxide levels appeared to jump much higher than the average.
Using samples from the West Antarctic Ice Sheet Divide ice core, Wendt and colleagues investigated what was occurring during those periods. They identified a pattern that showed that these jumps in carbon dioxide occurred alongside North Atlantic cold intervals known as Heinrich Events that are associated with abrupt climate shifts around the world.
During the largest of the natural rises, carbon dioxide increased by about 14 parts per million in 55 years. The jumps occurred about once every 7,000 years or so. At today’s rates, that magnitude of increase takes only 5 to 6 years.