UW News

August 5, 2010

10 climate indicators in new report point to marked warming in last 30 years

News and Information

A climate report just out, that’s different from other climate publications because it’s based on observed data and not computer models, says 10 climate indicators all point to marked warming during the past three decades.

And, “the past decade was the warmest on record,” according to a 10-page document highlighting findings from “The State of the Climate” issued Aug. 4 by the National Oceanic and Atmospheric Administration

The report, published in the Bulletin of the American Meteorological Society, involves work from 300 scientists, four of them faculty members here at the UW. From the Applied Physics Laboratory are Michael Steele, senior oceanographer; Jamie Morison, principal oceanographer; and Rebecca Woodgate, senior oceanographer. And from the Joint Institute for the Study of the Atmosphere and Ocean, Muyin Wang, climate scientist. Other co-authors include scientists with affiliate faculty appointments.

The data for the report came from many different technologies including weather stations, satellites, weather balloons, ships and buoys, the report says.

For the first time, researchers put data from 10 climate indicators together in one report. Consistent with a warming world, seven of the indicators — such as ocean heat content, humidity and air temperature in the lower atmosphere — all showed increases. Also consistent with warming, three of the indicators — sea ice cover, snow cover and glacier cover — were all lower.

The four UW co-authors study such things as polar conditions and sea ice.

Decreases in sea ice because of warming are a concern, but one of the UW experts, APL’s Steele, says he think the most compelling finding in the report concerns acidification of the Arctic Ocean. That’s where excess carbon dioxide from the atmosphere changes water chemistry, affecting the shells and skeletons of sea life.

“The input of sea ice meltwater, in combination with CO2 uptake and global ocean acidification, caused the surface waters of the Canada Basin to become corrosive to calcifying organisms in the upper layer in 2008,” the report says in the section on the Arctic.

“It’s actually happening at a rate faster than in other parts of the world, with potentially huge consequences such as a decline in plankton that could dramatically alter the food web,” Steele says.