Global climate models both agree and disagree with actual Antarctic data

COLUMBUS, Ohio – Scientists who compared recorded Antarctic temperatures and snowfall accumulation to predictions by major computer models of global climate change offer both good and bad news.

The models’ predictions covering the last 50 years broadly follow the actual observed temperatures and snowfall for the southernmost continent, although the observations are very variable. That’s the good news.

The bad news, however, is that a similar comparison that includes the entire last century is a poor match Projections of temperatures and snowfall ranged from 2.5 to five times what they actually were during that period.

The findings, reported last month in the journal Geophysical Research Letters, suggest that current computer models of the effects of global warming may not work as well for the remote Antarctic regions.

“This doesn’t say that global warming from a planetary perspective is wrong,” argues David Bromwich, professor of geography at Ohio State. “It says nothing about the tropics or the subtropics!

“It does imply that with the ocean north of Antarctica and the continent itself, there are some significant issues with the current climate models.”

Bromwich’s emphasis can be traced back to a preliminary report he gave a year ago at a major national science meeting.

He announced then that an apparent conflict existed between the models’ Antarctic predictions and the actual recorded data. People who deny climate change flocked to the report as evidence that the planet wasn’t at risk, in spite of overwhelming evidence that it is.

“I think the reaction to this new work may be pretty much what it was the last time,” Bromwich said sadly.

In their latest work, Bromwich, Andrew Monaghan, formerly a researcher at Ohio State’s Byrd Polar Research Center, and David Schneider from the National Center for Atmospheric Research, relied on two sets of data. Monaghan has since joined the staff at NCAR.

One set came from observations of snowfall and temperature recorded from Antarctica since the International Geophysical Year a half-century ago. The other consisted of temperature data derived from short ice cores recovered from the continent.