DotEarthAction blog interview from KVMR, Nevada City, California

KVMR: Through a video link, President-elect Barack Obama addressed a climate change conference convened today by Arnold Schwarzenegger in Los Angeles, saying he would more aggressively tackle the problem of climate change than the Bush Administration. But behind the politics of global warming, scientists are engaged in a robust debate about the effects of manmade CO2 in our atmosphere. Joining us now is a researcher involved in the debate over climate change.

Robert Balling Jr is a professor in the climatology program of the School of Geographical Sciences at Arizona State University. He has served as a climate consultant to the United Nations Environment Programme and served on the Intergovernmental Panel on Climate Change; Robert, welcome to the KVMR evening news. I want to start by asking - “Can you maybe describe the debate that’s going on among scientists and in peer reviewed journals and otherwise, over the issue of climate change?”

RCB: “Well I’ll do that, just as soon as you tell me what happened in the Civil War. It’s kind of a big question - if you were to go to a library or look at any top of the line science journal, you would quickly discover that every element of the greenhouse issue has its folks who seem to be supportive of certain ideas, and others who are not. The most fundamental questions, like, is the planet warming - in reality there’s quite a debate about that very subject; as I tell people, you would just discover that the climate change issue is very much more complicated than it is often presented to the public. And that’s somewhat the message I have on the circuit, is that no matter what thing you ask about, you find out there’s an incredible story behind it and quite a debate going on in the scientific community.”

KVMR: “Well, let’s just step back and tackle that question - “is the planet warming, and how do we know?” To me it’s scientists collecting data and then drawing conclusions based on that data, right? well, is the planet warming?”

RCB: “Yes and no. We have a there are a number of ways that the planetary temperature is taken - there are satellites that measure microwave emissions that come from the low atmosphere (those are directly related to the temperature of the low atmosphere, these polar orbiting satellites that allow for a global temperature to be measured); balloons are launched all over the world every day, the balloon record can give us a sense of the planetary temperature; and then there are literally millions of thermometer records from all over the world, and they’re not perfect by any means but they can all be averaged and get another sense of the planetary temperature; the good news is they’re all very highly correlated. So it would seem easy, is the earth warming or not? If you said how about the last 30 years, the answer’s absolutely, all three of those primary ways that we measure the temperature of the earth show warming. But if you said how about for the last 7 years from 2002 to present, all three show cooling.

So you could answer the question a thousand different ways - if you said is the earth warming and you mean the last 100 years, the answer’s yes; if you mean the last 1000 years the answer may not be yes, or if you mean how about the last million years, the answer is well, we’ve actually been rather cold the last million years. So that question is not as easy to answer as it sounds at first glance. Read much more here.