THE PENDULUM

by Hannah Williams, November 3, 2009

The earth is not likely trending toward cooler temperatures, several independent statisticians found in a blind study for the Associated Press.

The AP sent four statisticians the 130 years of year-to-year ground temperature data collected by the National Oceanic and Atmospheric Association and the 30 years of satellite-measured temperatures gathered by scientists at the University of Alabama in Huntsville, preferred by global warming skeptics.

The statisticians were not told what the numbers represented but only to evaluate the data and look for any trends. They found a distinct decades-long upward trend in the numbers, but could not find a significant drop in the past 10 years in either data set, according to the AP.

"Global warming can occur in fits. It's kind of like two steps forward, one step back," said climate-monitoring meteorologist Richard Heim of the NOAA National Climatic Data Center in Asheville, N.C. "The overall trend is going up, but you have short-term climate noise superimposed on this."
Global warming skeptics have claimed a decline in temperatures during the past 10 years following a peak in 1998, leading them to argue for a cooling trend.

"I think the cooling argument is not one that is being forwarded by valid climatologists," said David Vandermast, assistant professor of biology at Elon. "It's being forwarded by a few people who are cherry-picking data."

Vandermast and Heim both said 10 years is too short of a time frame and too small a sample to claim any climactic trend.

"I think to take one study that just looked at a small portion of the data that we have is irresponsible," said senior biology major Monica Poteat. "You have to look at the big picture."
The global surface temperatures have increased at a rate near 0.09°F per decade in the past century, and in the past 30 years this trend has increased to a rate of approximately 0.29°F per decade, according to the State of the Climate Global Analysis 2008 Annual Report by the NOAA's NCDC.

The rising temperatures are based on averages and do not indicate that each year is successively warmer than the last, Heim said. He said there is daily and annual variability in the temperatures creating peaks and valleys in the temperature charts, but it doesn't discount the overall upward trend.

"It's just going to be a cooler year," Vandermast said. "Does that mean that global warming isn't happening? No. It just means we have a cooler year."

Heim and Vandermast both said the warming trend increased much more rapidly following the industrial revolution, citing the link between increased carbon dioxide outputs and rising temperatures.

"It's kind of unbelievable that someone would ignore physics and science and say that there is no manmade global warming," Heim said.

Vandermast said some global cooling may resonate with people who want to ignore the link between increased carbon dioxide outputs and increased temperatures so they don't have to feel guilty or change their behavior.

The danger of climate change is a shift in the frequency of extremes, Heim said. With global warming, he said that means more instances of extremely hot weather and fewer instances of extremely cold weather, more heavy rains and less frequent light showers, which means both more floods and more droughts.

"If we have a global climate change so drastic that we have a temperature change happening over 100 years that would normally happen over thousands of years, it may have a destabilizing effect on civilization, culture and ecosystems," Heim said.

The climate has been fairly stable for the last 10,000 years, and any alteration to that stability, warming or cooling, is hazardous and undesirable, Vandermast said.

"Anything we can do to lower our carbon dioxide output would help," Poteat said. "If we make a group effort, nationally and internationally, we can start to curb global warming."