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Home / Washington Business - July/August 2007 / Q&A with Robert Balling, Climatologist, Arizona State University: The truth about global warming |
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Q&A with Robert Balling, Climatologist, Arizona State University: The truth about global warming |
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Written On: July/August 2007 |
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Robert Balling is a professor at Arizona State University and author of three books on climatology. He also worked for the United Nations for three years, producing a book on climate change in dry land areas.
Climate change is an important issue with global ramifications. In Washington state, laws addressing climate change have been implemented, and our state has joined with several western states and British Columbia in a pact to reduce greenhouse gases. While many climatologists embrace the theory that human activity is having a massive, potentially catastrophic impact on climate, others remain skeptical.
Q: What are the factors that affect climate change?
A: It depends on the timescale involved. The orbital mechanics of the Earth can cause the climate to change, and there are times when the Earth gets less radiation from the sun—based on orbital parameters—and the planet tends to go into ice ages. During warm times like we have today, Earth’s orbit is conducive to a warmer climate. We know that the Earth was very warm about a thousand years ago. Then it cooled off about 500 years ago, warming up again about a hundred years ago. That’s very closely related to the sun, and it’s well understood that, about 500 years ago, the sun had low output and Earth cooled substantially. But the question is, did a buildup of greenhouse gases somehow elevate the temperature of the Earth?
There’s little doubt that the Earth’s temperature went up over the last 30 or so years, and it does seem that humans emitting gases by burning fossil fuels have contributed to some of that warming. So, the big questions are: Has the Earth warmed recently? The answer is yes. Has a buildup of greenhouse gases caused it? They certainly contributed to it to some degree.
Q: Is this rise in temperature something to be concerned about?
A: I suppose if we lived on an island nation and we saw the sea level rising due to the warmth of the Earth, we’d be very concerned about it. But if we wanted the climate to remain exactly as it has been for the past 30 years and stay that way forever—well, that’s never going to work. The Earth’s climate history shows that we get much warmer and much colder than we are right now. We’ll have to face one or the other sooner or later, so there are certainly people who are very worried about global warming. I happen not to be one of them.
Q: How reliable are the computer models that are predicting catastrophic climate change?
A: We’ve spent billions of dollars developing those models. They do show that if you build up greenhouse gases—everything else being constant—the world warms up. We’ve known this for 120 years. So, in terms of computer models predicting that the world will warm up, there’s great certainty that that’s the case. I don’t know of any scientists who don’t believe that, as we continue to build up greenhouse gases, the Earth will warm up to some degree. The problem is that their models don’t handle the clouds very well, they don’t handle the interaction of the ozone layer and the atmosphere very well, they don’t handle the ice very well, and they don’t handle the biological systems at all. You find out that there are a thousand weaknesses in the model but, overall, it’s pretty simple to show that if we build up greenhouse gases the Earth will warm up.
Q: Recently, there have been reports that Mars is also warming up. Would this suggest that the sun is playing a major role in warming?
A: The sun controls the temperature of the Earth to a large degree. In the past 30 years there have been explanations for global warming that involve the sun, but it’s not just the total amount of energy that the sun puts out that may have caused the warming of the Earth. The sun varies its output of cosmic rays, which interact with clouds in the Earth’s upper atmosphere. There are many scientists who believe that cosmic rays from the sun have increased the amount of high cloudiness, and that helps explain the warming of the Earth. There was a finding recently that Mars warmed up in one year about the same amount that Earth has warmed up in the past 30 years. There was a very impressive piece of research published recently showing that the temperature of Neptune has closely followed the temperature of the Earth, and it does suggest that maybe there’s a solar control factor involved. When I said that the buildup of greenhouse gases has made the Earth warm, I said "to some degree." I’m very sympathetic to the argument that there are terrific explanations for the warming of the past 30 years. I’m just not ready to say that the buildup of greenhouse gases did not contribute anything to the warming, but I’m fully aware that there are explanations for the warming.
Q: How much consensus is there in the scientific community regarding global warming?
A: Al Gore says there is consensus that the buildup of greenhouse gases is occurring. Of course there is a consensus. There are instruments all over the world that that show that greenhouse gas concentration is going up. I can fairly say that there is a consensus among scientists that there’s a buildup of greenhouse gases. Looking at satellite data, balloon records and thermometer records, it’s fair to say there’s a consensus that the Earth has warmed over the last 30 years. So, then I could say there’s nearly a consensus of scientists that think the buildup of greenhouse gases should cause warming overall. But when Al Gore starts saying hurricanes are increasing in magnitude or frequency—there’s no consensus there at all. In fact, he is very much in the minority view. It’s easy to go out and say the scientific debate is over and we need to talk about policy, but you have to decide what you mean by debate.
Q: What would be the effect on the United States if it ratified the Kyoto Protocol to reduce greenhouse gases?
A: Well, first of all, the protocol expires in four years, so ratification will not happen. The fact is, if the United States made a commitment to the goals of Kyoto where we would have to reduce greenhouse gas emissions to 7 percent below 1990 levels—and today we’re almost 20 percent above 1990 levels—we would have to do something in a very short time period to enormously reduce carbon emissions in the United States. It’s absolutely unthinkable how you could ever do that. So, it’s just a hypothetical question that will never come to fruition. There will never be a commitment to Kyoto where we achieve 7 percent reductions below 1990 levels. This would be analogous to saying, "What would happen in the United States if federal spending dropped to 7 percent below 1990 levels?" It’s just unthinkable.
Q: What, if any, steps should we be taking to mitigate climate change?
A: Actually, none. The fact is that the United States could do anything it wants, including vanishing from the face of the Earth, and it wouldn’t really make much difference. Every year the reports indicate that the emissions of carbon dioxide by the United States get smaller and smaller. The rest of the world, particularly China and India, are becoming monopoly emitters of carbon dioxide. They put out so much carbon dioxide now, and China is building thousands of coal-fired electric generation plants. So, in the background of the inevitable emissions from India and China, the United States can do anything it wants and it really will have no impact whatsoever.
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