A record-breaking week, after last year's scorching summer, could again ignite the battle over climate change and whether humans are to blame.
The latest salvo in the war over warming came in a report issued by the Environment Georgia Research & Policy Center. According to Feeling the Heat: Global Warming and Rising Temperatures in the United States, the mercury has been rising in the state for several years.
"Throw out the record books, because global warming is raising temperatures in Georgia and across the country," Jennettee Gayer, a policy advocate with the group, said in a statement accompanying the report's release.
Environment Georgia focused on the findings about 2006, which showed above-average heat in at least some temperature categories for every major weather station in the state.
For example, at Augusta's Bush Field, the average temperature in 2006 was 1.6 degrees higher than the average temperature from 1971 to 2000.
At Athens Municipal Airport, the difference was 1.8 degrees; at Savannah Municipal Airport, it was 0.6 degree.
"The long-term forecast is for more of the same unless we quickly and significantly reduce global warming pollution from power plants and passenger vehicles," Ms. Gayer said.
According to the report, the answers lie in national solutions to global warming, including cutting emissions of gases believed to cause climate change, boosting energy efficiency, increasing fuel efficiency for cars and other vehicles and relying more heavily on alternative fuels.
Actually getting cooler?
Others in Georgia aren't so sure global warming is happening now - or, if it is, that it poses a grave threat.
"Widespread locations in the world show no clear trend," wrote Harold Brown, an adjunct scholar at the Georgia Public Policy Foundation, in 2005. "Some have warmed; others have cooled. Average temperatures for the Southeastern United States haven't changed since 1895."
Mr. Brown, the author of The Greening of Georgia: The Improvement of the Environment in the Twentieth Century, also challenged the idea that climate change was necessarily a bad thing.
For example, an increase in the level of carbon dioxide would also boost plant growth, and a warmer climate also means "Arctic regions will become more habitable, the Arctic ocean navigable," Mr. Brown said.
David Stooksbury, Georgia's state climatologist, agrees that there hasn't been drastic warming in the state in the past century. It might even be the opposite.
"In the Southeast ... the temperatures have been flat or slightly cooling over the last 100 years," he said.
That doesn't change the fact that the global climate has been warming over a similar period, about the past 150 years, Dr. Stooksbury said.
The cooling likely springs from changes in the way the region's land is used, climatologists believe. The warmth of Earth comes not from heat absorbed by the atmosphere - sunlight largely passes through the air. Instead, the ground absorbs energy from sunlight. Some of that energy evaporates water, while the rest provides the warmth.
In recent decades, the Southeast has moved away from agriculture, leading to less farmland and more forests. Trees cause more evaporation than crops, meaning that forests divert more of the energy that would otherwise go into warming the region, possibly causing the cooling.
"What this shows, though, is what one region is doing versus the entire globe may not be in agreement," Dr. Stooksbury said.
More than a year
Besides, Dr. Stooksbury said, data from one year doesn't prove that Georgia is getting warmer or cooler - whether it's the warmth of 2006 or the heat wave of the past week.
For example, the average temperature in 2006 might have been up because of the La Nia weather phenomenon, which generally leads to above-average winter temperatures. Because summer temperatures stay relatively constant, a spike in the winter is the most likely cause of a rise in the mercury for any given year.
The Environment Georgia report does offer some evidence that the summer in 2006 was warmer also. And it points out that the average temperature from 2000 to 2006 was also up when compared with the period from 1971 to 2000, though the increases tend to be more modest.
Dr. Stooksbury said there is widespread agreement among climatologists that global warming is taking place and that humans are at least part of the cause. However, agreement can get harder after that.
Some steps that combat global warming make sense on other fronts, he said. Increasing energy efficiency could save money on electric bills; reducing the nation's reliance on oil would keep money away from hostile countries; cutting back on emissions from coal plants will reduce some negative health effects.
"To me," Dr. Stooksbury said, "this is where there are some things that we probably should be doing regardless of what you think about global warming."
Reach Brandon Larrabee at (678) 977-3709 or firstname.lastname@example.org.
A HOT YEAR
2006 was one of the hottest years on record, according to a recent report from Environment Georgia. Here's a look at the figures.
June-August 2006 average temperatures compared with normal (1971-2000):
|Athens Municipal Airport||78.2||80.1|
|Atlanta Hartsfield Airport||78.6||80.0|
|Augusta Bush Field||79.2||80.6|
|Columbus Metropolitan Airport||80.8||83.3|
|Macon Middle Ga. Regional Airport||79.7||81.5|
|Savannah Municipal Airport||80.6||81.0|
Number of days with temperatures over 90 degrees in 2006 against "historical average" (period varies):
|Athens Municipal Airport||50||69|
|Atlanta Hartsfield Airport||35||49|
|Augusta Bush Field||73||87|
|Columbus Metropolitan Airport||75||96|
|Macon Middle Ga. Regional Airport||80||99|
|Savannah Municipal Airport||69||81|
Average daily temperature
|Athens Municipal Airport||61.5||62.4||63.3|
|Atlanta Hartsfield Airport||62.1||62.7||63.6|
|Augusta Bush Field||63.2||63.9||64.8|
|Columbus Metropolitan Airport||65.1||66.2||67.2|
|Macon Middle Ga. Regional Airport||63.7||65.0||65.3|
|Savannah Municipal Airport||66.2||66.5||66.8|
Sources: Feeling the Heat: Global Warming and Rising Temperatures in the United States, Environment Georgia Research & Policy Center
The number of days when temperatures hit 90 degrees or above in Augusta in 2007:
*So far, including Saturday
Source: National Weather Service