MacLeod says it’s notable that the impact pumped up carbon dioxide over a short time span that, geologically speaking, is comparable to what humans have been doing in burning fossil fuels since the start of the Industrial Revolution.
“The atmosphere was loaded for a very brief interval of time, and the consequences of that change in atmospheric composition lasted for 100,000 years,” MacLeod says. “So it illustrates, I think, really strongly, even if we went back to 1850 levels of carbon dioxide emission, it’s going to take a 100,000 years for the carbon dioxide that we’ve already put in the atmosphere to cycle through the Earth’s systems.