Heating Up

July 2007, copyright Town and Gown Magazine

By Tracey M. Dooms

Weather in general and global warming specifically have become major topics of discussion for everyone from politicians to entertainers to opine about. But what do some of the experts in this “meteorological hotbed” area have to say about what’s really going on with our planet?

Is the Earth getting warmer? Are humans causing a climate change? Will nature and society change as a result?
As thoughts about global warming become an increasingly major issue to study and debate, voices in State College are making themselves heard. In fact, a December 2006 analysis by Thomson Scientific’s Essential Science Indicators ranks Penn State University fifth in the world in total number of papers cited on the topic of global warming. Because State College is home to both Penn State and AccuWeather.com, the area is home base for numerous experts on the meteorological topic — and for a variety of opinions regarding global warming, its causes, and its effects.

It’s Getting Hot Out There
Local experts agree that, yes, global warming is happening. Its cause, however, remains a matter of contention. “It seems to be fairly clear that there has been some warming over the last decade,” says Laura Hannon, senior AccuWeather.com meteorologist and moderator of the forecasting company’s Global Warming Center, at http://global-warming.accuweather.com. “Is man responsible for that? I’m not 100 percent convinced. We may be responsible for a portion of it.”

Michael Mann, a Penn State faculty member in both meteorology and geosciences, says man is responsible for more than a portion. “The most recent warming of the globe over the past few decades appears to be outside the range of what’s been seen over the past 1,000 years. Working with theoretical models to see what has driven changes in temperature, we’ve come to the conclusion that this anomalous warming can only be explained by human influences. Human beings are indeed warming the globe and changing the climate.”

In general, global warming refers to climate change that causes an increase in the average temperature of the Earth’s lower atmosphere. When scientists discuss human causes of global warming, they most often refer to the production and release of greenhouse gases such as carbon dioxide and methane. These gases act like a greenhouse around the Earth, letting in heat from the sun but not allowing heat to escape. This greenhouse is a necessary part of the world’s climate, says William Easterling, director of the Penn State Institutes of Energy and the Environment, and dean of the College of Earth and Mineral Sciences. “Greenhouse gases act to trap the reradiated sunlight that the Earth is receiving and keep it warm near the surface,” he explains. “If there were no gases, it would be about 60 degrees Fahrenheit colder than it is today, and the Earth would be just about uninhabitable.”

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