Published on Apr 24, 2017
Illinois Professor Emeritus John E. Walsh delivers the 2017 Keeling lecture, named for Illinois alumnus Charles David Keeling, creator of the famed “Keeling Curve” or “Mauna Loa Curve.”
Abstract — Climate change is happening faster and with more visible impacts in the Arctic than in most of the rest of the world. The Arctic is warming at a rate of about twice the global average. Arctic amplification of the warming arises from a number of processes, one of which is the albedo-temperature feedback triggered by the loss of ace and snow. We will diagnose the recent Arctic warming in terms of the key drivers, which include external forcing (greenhouse gases) as well as internal variability. Coastal communities and wildlife in the Arctic are especially vulnerable to the ongoing warming. However, climate change in the Arctic is not just a local problem, as what happens in the Arctic does not stay in the Arctic. Sea level rise is augmented by the loss of ice from glaciers and the Greenland Ice Sheet, and there are indications that Arctic amplification affects the large-scale atmospheric circulation that impacts middle latitudes, especially during winter. The trajectory of the Arctic system, especially its ice and snow, varies strongly with the scenario of greenhouse gas emissions. In this respect, human actions can make a major difference in the future of the Arctic as well as the rest of the planet.