In 1999, Alley was invited to testify about
climate change by Vice President
Al Gore after his research with Greenland ice cores indicated that the last Ice Age ended abruptly and violently rather than as a result of gradual change. He appeared again before the U.S. Senate Committee on Commerce, Science, and Transportation in 2003; before the U.S. House Committee on Science and Technology in 2007; and in 2010. Alley's 2007 testimony was due to his role as a lead author of "Chapter 4: Observations: Changes in Snow, Ice and Frozen Ground" for the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change (IPCC). He has participated in the joint
UN/
WMO panel since 1992, having been a contributing author to both the second and third IPCC assessment reports. Alley has written several papers in the journals
Nature and
Science, Alley gave the Bjerknes lecture to the 2009
American Geophysical Union meeting titled "The biggest control knob- Carbon Dioxide in Earth's climate history". A video of the presentation is available (also available on YouTube). His more recent work has examined
ice sheets and the factors that affect "calving", the process by which ice sheets break up. ==Awards and honors==