A recent National Research Council report by a Committee on Understanding and Monitoring Abrupt Climate Change and Its Impacts recommends the formation of an Abrupt Change Early Warning System (ACEWS) to help monitor for climactic changes that will be abrupt, i.e., occurring over a few decades or a few years. Such abrupt changes could cross a “tipping point” leaving communities little time to react. The purpose of the ACEWS would be to “reduce the number of surprise abrupt climate events and increase the possibility for proactive risk management.” The report identifies increases in extinction threat for marine and terrestrial species and the disappearance of late-summer Arctic sea ice as two abrupt changes already underway.