Talking Climate Science With Physicist Glenn Marsch (Part One)
Editor’s note: After two leading newspapers ran climate-related pieces seemingly at odds with one another, The Center for Vision & Values discussed the contrast with Grove City College physicist Dr. Glenn Marsch. A New York Times article reported that President Obama is pursuing an international global warming treaty at the United Nations while a Wall Street Journal piece noted that there has been no evidence of global warming for the past 15-26 years. This is the first in a series of climate discussions with Dr. Marsch.
V&V: On August 26, the New York Times reported, “The Obama administration is working to forge a sweeping international climate change agreement to compel nations to cut their planet-warming fossil fuel emissions, but without ratification from Congress.” On September 4, Matthew Ridley wrote in the Wall Street Journal that the “U.N. no longer claims that there will be dangerous or rapid climate change in the next two decades” and that the “climate-research establishment has finally admitted that … global warming has stopped since shortly before this century began." We couldn’t help noticing the contrast. We’re curious, what are your thoughts about Ridley’s argument about a global warming hiatus?
Marsch: I think his arguments are very good. It doesn’t mean that there aren’t arguments against what he says. The problem is climate science is a highly multivariate topic to study. The climate is an intrinsically open system. Everything is more or less interacting with everything else. There are no test tubes, no bottles, no sample compartments, etc. It’s an incredibly complex system and I think people want simplistic answers that just can’t be given at our stage of knowledge. That troubles me.
V&V: What then is your message to both global warming skeptics and proponents?
Marsch: Most people don’t have a problem accepting that the temperature has increased a certain amount in the last century – that’s about a degree Fahrenheit or .6 degrees Celsius. There has been a mild warming of the globe that I think most people, including folks called skeptics, or even worse called "deniers,” believe in. The issue is that if you want societal action, if you want to scupper somebody’s economy, you’d better have something more than “the earth has warmed a little bit.” You’d better instead say, “We (humans) have caused it.” The issue is not whether the earth has warmed a little bit but, “Have we caused it?” And if so, how much of it have we caused and is it dangerous?
V&V: So, there’s a difference between recognizing that the earth has warmed, and understanding how it has warmed?
Marsch: Yes, it’s the anthropogenic – that is to say, the “human-caused” – aspect of it.
V&V: Got it.
Marsch: You have to determine how much of the warming is due to human activity. I’m not willing to say that none of it would be due to human activity. I’m certainly not willing to say that all of it was due to human activity. I would suspect that little of it, maybe less than half of it, is due to human activity. The point is I’m not sure. There are a lot of uncertainties in this. In my opinion, I think that the best thing to do is to “cool it” – that’s the title of Bjorn Lomborg’s book – and let the science speak over many decades and then see what happens. Moreover, I’m also skeptical that this 0.6 oC temp increase is necessarily a bad thing. That’s why people often differentiate between AGW (anthropogenic global warning) and CAGW (catastrophic anthropogenic global warming). Even if people did cause the majority of global warming, I doubt that it’s harmful overall.
V&V: Wouldn’t it be difficult for folks who are fearful of global warming to adopt the “cool it” approach?
Marsch: Yes, they advocate the “precautionary principle.” The precautionary principle – apparently displayed by the U.N. and President Obama in the New York Times article – advocates mitigating carbon emissions now, even if we’re not entirely sure what’s going to happen, just to be safe.
V&V: On the surface, that sounds reasonable. Is there anything wrong with that approach?
Marsch: Well, yes, the precautionary principle is not science. It has nothing to do with science. It’s political, or philosophical. And here’s the issue: What if they’re wrong and we’re actually about to embark on a period of global cooling? What if, in fact, the carbon dioxide we’re emitting is truly as potent a greenhouse gas as people say it is; and what if it’s keeping our temperatures relatively safer now and preventing them from plummeting? In that case, trying to eviscerate our economy so that we can’t combat the much greater threat of cooling is one of the worst things we can do. The problem with the precautionary principle is that on the basis of ignorance, it says that we must do something that could be deleterious. Rather than helping, we could be hurting when we can least afford it. By some metrics, such as the ones Ridley highlighted, global warming has paused for at least a decade and a half and some believe we’ll stay in this condition for at least two decades more. We should base our actions – to the best of our ability – on the science. Let the science speak for a while. Let’s see what happens.
V&V: Thank you, Dr. Marsch. We’ll address computer modeling in our next discussion.
Dr. Glenn A. Marsch is a professor of physics at Grove City College where he teaches physics and an innovative course, Studies in Science, Faith and Technology. A contributing scholar with The Center for Vision & Values, he is also an associate of the Center of Molecular Toxicology at Vanderbilt University.