[The following abstract introduces a research article in SCIENCE ADVANCES by Daniel H. Rothman. The article is complete with over 100 references and notes and all the data needed to evaluate the conclusions presented in the paper. Although the article itself is copyrighted, the abstract which we are reprinting here is in the public domain. Readers who are so inclined are encouraged to subscribe to SCIENCE ADVANCES (advances.sciencemag.org)]


The history of the Earth system is a story of change. Some changes are gradual and benign, but others, especially those associated with catastrophic mass extinction, are relatively abrupt and destructive. What sets one group apart from the other? Here, I hypothesize that perturbations of Earth’s carbon cycle lead to mass extinction if they exceed either a critical rate at long time scales or a critical size at short time scales. By analyzing 31 carbon isotopic events during the past 542 million years, I identify the critical rate with a limit imposed by mass conservation. Identification of the crossover time scale separating fast from slow events then yields the critical size. The modern critical size for the marine carbon cycle is roughly similar to the mass of carbon that human activities will likely have added to the oceans by the year 2100.

[from SCIENCE ADVANCES 20 Sep 1017: Vol. 3, no. 9. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited. Get the latest issue of SCIENCE ADVANCES delivered to your inbox as its published.]