Winter 2007
In This Issue:
Focus On Energy
Seminar on Climate Change
FoM caught up with Bill Easterling, director of the Penn State Institutes of Energy and the Environment (PSIEE), at a seminar on campus recently. Easterling is a professor of geography specializing in the impact of 21st century climate change on agriculture and the ecology. He and his students use sophisticated computer modeling, along with field research, to try and predict what we may face in a future of continuously climbing global temperatures. His talk emphasized the difficulties of predicting the specific impacts of climate change, while showing that better data and faster computers have narrowed the range of likely outcomes. Here are a few of Prof. Easterling's remarks:
Dr. William Easterling is director of the Penn State Institutes of Energy and the Environment, the University's response to the perfect storm of climate change and oil instability.
“I have spent 25 years researching the effects of climate change. We are living now in a century when the signal of climate change will rise above the background noise. Climate change is one of a class of problems we know about primarily through reasoning through science.
“In the 1950s through the 1970s, there was a tug of war between advocates of global warming and global cooling. Fast computers solved the question. Warming became pretty much the consensus view over the last 25 years. However, there is still large uncertainty in the forecasts of global warming. We have relatively few undisputed facts.
“One fact we do have is that there is no question that carbon dioxide and greenhouse gases are rising. A second fact is that a lot is due to human activity. That is not widely debated anymore. There is little doubt that human beings are forcing climate change. Beyond that is uncertainty.
“If that is the case, then what we need to ask is whether climate change is affecting things we care about — food, forests, water. If so, then we need to ask about the future. New climate change charts will continue to show increases in temperature. There is still some question of whether this is part of a natural cycle, but there is less and less doubt.
“How will rising temperatures affect food production in the future? At present, our model is incomplete. The risk of hunger and other problems is still very uncertain. The uncertainty is propagated by linking models to other models, compounding the uncertainties.
“However, models can be controlled within a range of probabilities. On that scale, we have a range of 1½ to 5½ degrees C in potential warming, on average. That doesn't sound like much, but when you consider that we are only, on average, 5 degrees warmer than during the Ice Age, even 1½ degrees is huge.
“The world population is expected to double by 2100. Can the world's farmers meet the demand for another 10 billion people, especially when the climate is changing?”
