The finding, reported in the journal Nature Geoscience, relies on ancient Antarctic ice bubbles that contain air samples going back 610,000 years.
Researcher Richard Zeebe measured CO2 in the air pockets in layers of Antarctic ice and found that amounts waxed and waned with known periods of cooling and warming on Earth. In the past CO2 upswings and downturns were smaller – an average change of around 22 parts per million (i.e. 22 CO2 molecules more or less) – and occurred when volcanoes erupted. Over time that extra was absorbed in deep sea beds. In the last 200 years, the amount of CO2 has risen by 100 parts (or 100 molecules) per million, and that jolt of extra CO2 will take hundreds or thousands of years to be absorbed. Zeebe said the feedback mechanism that controls emissions’ effect on climate operate so irritatingly slowly that we’re going to have to live with the results of our excess CO2 spewing for many, many lifetimes.
“The message is that nature will not clean up our mess for us quickly,” he said. “It’s our responsibility to do that and whatever measures we take to reduce emissions, it’s worth it.”
Plus, unfortunately for us all and our thus-far efforts, CO2 emissions are actually still increasing.
– from Guardian
Current CO2 level is 380 ppm and we are adding 2ppm every year.