Climate scientists from the Pacific Northwest, many from the University of Washington, have played key roles in a major new international study that shows climate change will have serious effects on the world in the coming decades.

The report from the Intergovernmental Panel on Climate Change, released today in Paris, is designed to provide the world's policymakers with information on how to deal with the effects of climate warming.

The report provides an at-times stark picture of how climate has changed in the last half-century and how it is likely to change in the coming years, said Philip Mote, a UW research scientist with the Joint Institute for the Study of the Atmosphere and Ocean, a lead author of one of the report's 11 chapters.

Among other things, Mote said, the report states that:

• Observations of change provide clear evidence of rapid global warming in the past 50 years that is almost certainly a result of human activity.
• It is now possible to identify the human influence on climate at scales smaller than worldwide, and on conditions other than just temperature.
• Recent research shows a small possibility that climate sensitivity to greenhouse gases could be much higher than previously thought.
• Future projections of warming and of sea level rise appear more modest than they did in the 2001 report, but only because of changes in the way the statistics are described.
• Accelerated ice melting in Greenland and Antarctica probably is responsible in part for the increased rate of sea level rise, which changed from 2 millimeters a year for most of the 20th century to 3 millimeters a year since 1993.
• Average Northern Hemisphere temperatures in the second half of the 20th century very likely were warmer than any other 50-year period in the last five centuries, and probably in the last 1,300 years.

Mote is a lead author of the report's chapter titled "Observations: Changes in Snow, Ice and Frozen Ground," which is available online at http://jisao.washington.edu/. The full report's summary for policy makers is available at http://www.ipcc.ch/SPM2feb07.pdf

Other Northwest authors who contributed to the report include Todd Mitchell and Ignatius Rigor of the UW and Tim Bates, Michael McPhaden, Chris Sabine and Richard Feely of the National Oceanic and Atmospheric Administration. Northwest scientists who reviewed the work in the report include Mote and Edward Miles, Edward Sarachik and Justin Wettstein, all of the UW.

The intergovernmental panel was established in 1988 by the World Meteorological Organization and the United Nations Environment Program. This is the panel's fourth assessment report on climate change.

The report was based on the most recent peer-reviewed research in a variety of areas and was assembled over six years by more than 450 lead authors and more than 800 contributing authors. The work was reviewed by more than 2,500 scientific experts. More than 130 nations are represented in the report's list of authors.

The report assesses the current scientific knowledge about natural and human causes of climate change, as well as the observed changes in climate, the ability to attribute changes to various causes and projections for future climate change. It includes new projections of future climate change based on results from 19 climate models that employ methods that have improved from previous assessment reports. The report also deals with a range of human-produced greenhouse gases that are a major factor in climate change.

###

For more information, contact Mote at (206) 616-5346 or philip@atmos.washington.edu