He said computer models can underscore risks, but can’t be used to made definitive predictions.
“You’re talking about an extraordinarily complicated scientific subject in which there are many elements not very well understood,” the professor said. “What’s going on with the models is people saying, ‘This could happen. If it does happen, we need to take precautions to deal with it.’ That’s quite different from saying that ‘I know the world will be warmer by X. I know there will be a drought in the mid-west that will last for decades.’ Models are simply telling us this is a real possibility.”
Wunsch stressed that “very little is actually proven in this subject” and possible policy solutions are beyond the reach of science.
“It’s an extraordinarily complicated social, economic, political and scientific problem that we’re now reducing to sound bites,” Wunsch said.
Daniel Lashof, senior scientist at the National Resources Defense Council, agreed that it’s impossible to know all aspects of the issue with scientific certainty.
“But there are some things that are quite fundamental that we know,” Lashof said. “We know that there’s more heat-trapping carbon dioxide in the atmosphere than there’s been for over 600,000 years. We know that the earth is warming up as a result. We see that in surface temperature records, satellite records as they’ve been corrected, we see that increasingly warm oceans, melting glaciers and ice sheets.”
He said policy makers should focus on the fact that the threat is real.
“We know what the solutions are,” Lashof said. “Cleaner energy, reduced emissions, higher vehicle (mileage) standards and a total cap on the amount of global warming pollution going in the atmosphere. We can take sensible steps to reduce this very serious threat.”