Q&A: Roger A. Pielke Sr.

The controversial climatologist argues that global warming has stopped.

Mother Jones: You’ve said that the Intergovernmental Panel on Climate Change didn’t quite get it.

Roger A. Pielke Sr.: I think the IPCC was basically a very narrowly focused document. In fact it was basically written mostly by atmospheric scientists. And they’re focusing on a very narrow issue where the atmospheric increase of CO2 feeds down to affect the climate that has all these effects on resources, and I think that is so narrowly confined as to be of little use to policymakers in terms of what’s really going to happen.

MJ: Can you give me an example of some of the things you thought they left out?

RAP: Okay, I’ll give you the example of Asia. If you go back 200 years ago, China and India had lots of natural forests. As the population grew, large areas of China and India had been converted to cropland and urban areas. So what happens is instead of having this source of transpiration of water from the forests, you’ve converted it to areas that have less transpiration of water. And this has been shown with general circulation models. The same kind of models that have been used by the IPCC. It says that if you change how much energy goes into heating in the atmosphere versus water vapor coming in from transpiration, it affects thunderstorm clouds over the region, which affects the monsoon circulation, which affects the weather patterns, the rainfall over Asia, and since that affects what happens over the North Pacific and downstream, it affects the global climate system. Amazon deforestation is the same thing. And in the US, we’ve taken areas in the eastern two-thirds of the US, and we’ve had huge conversion of landscape. We’ve taken away the forest that was in the east. We’ve done model studies there and shown that this has an enormous affect on temperature, on precipitation. Wherever you do a landscape change, it changes the fluxes of energy and moisture into the atmosphere. That changes cloud patterns, changes rainfall patterns, and so forth, and so it affects weather locally, regionally, and then through the global circulation.

MJ: So it’s not that you are a “global warming skeptic”; it’s that you think that global warming has been hyped at the expense of other problems.

RAP: That’s exactly right. I would also add that climate change is much more than global warming. We have altered the climate significantly, say by land-use change, without changing the global average surface temperature, yet it has big impacts. So I definitely think that we humans have altered the climate system. I think we have a strong component that has been warming—for some reason, it has stopped. And I don’t understand the reasons why.

MJ: I remember hearing that last year was the warmest year on record, and a few years before that was the warmest year on record. I hadn’t heard that global warming has stopped.

RAP: Josh Willis is one of the people I’ve worked with in the past, and he has a paper that came out recently that showed that at least since mid-2004, the upper oceans have not warmed. The trouble with the surface temperature that you hear about in the news is that it has all kinds of biases in it. It’s got a warm bias because of the land-use change that occurs, when they measure these sites, the actual locations have…they’re right next to buildings, right next to air conditioners. That data is, I think, extremely poor. The media has picked up on that particular metric, which is not the proper metric. If you look at the lower atmosphere, the troposphere, the troposphere hasn’t warmed up for about 10 years. So the data is conflicting with what the popular perception is. And I think that’s the real risk. If that would continue, if these metrics, Arctic ice melting, all these things, don’t behave the way people have claimed, then as you’ve said before, there’s a risk that some really good things could be lost, that we should do anyway.

MJ: So I understand your basic policy idea is to look at things more holistically instead of just carbon dioxide emissions.

RAP: Exactly right. And you start from the bottom up, and resource-based focus, so you take California for example, or part of California. What are the biggest environmental risks? Fires, for example. What can we do to reduce the risk of fire? Well, of course when people live in the hills, you can try to get them to cut their trees down that are right close to their houses; you could thin the brush.

MJ: So which environmental problem should we be most worried about, on a global level?

RAP: With respect to human impact on the climate system? I think first we need to identify which of these problems has the largest effect on drought and flood patterns. Because of human input of aerosols, from biomass burning in the tropics, from industrial activity, it’s spatially concentrated. And what we found out was when we compared the effect of these aerosols in altering wind circulations versus the effect of the greenhouse gases affecting wind circulations, the aerosol effect was 60 times greater. That number could change, but the bottom line is it’s a much greater impact, because the greenhouse gases are more spatially dispersed. And in fact, if one is concerned with CO2 addition, which I think is justifiable, it’s actually not global warming that people should focus in on, but the biogeochemical effect of added CO2, because it’s a fertilizer. And plants respond differently.

I don’t think we know the consequences of what we’re doing. But our footprint on the environment is more than just CO2: It’s nitrogen deposition, it’s the other black carbon, the aerosols, it’s land-use change. And so we put all of these things together and say, “How can we come up with a policy that reduces our impact on the environment?” Because we don’t know the consequences.

MJ: So what does that mean in terms of energy and climate policy?

RAP: Energy policy and climate policy should be disconnected from each other. There are overlaps between the two, and the trouble is that people are using climate, mainly CO2, to invoke energy policy. I think that’s a very bad way to go about it. In terms of energy policy, which I’m not an expert on, you have to consider each energy source in terms of its pros and cons. The way it’s being done now, it’s just sort of one dimensional—it’s just assuming that carbon dioxide is the biggest threat to mankind, and I think that’s really an absurd oversimplification of the complexity of the issue.

MJ: What role does personal conservation play in all of this? Does it help at all, or is policy the only way to fix all these problems?

RAP: Well, I think [actions] should be looked at on their own merits. For example, what is the benefit of plastic bags? Because you have to recycle them and so forth, as opposed to bringing your own bags. So each of those issues has to be looked at on their own merit. I know Aspen has a pretty good program that they introduced for climate. In reality, it has cost benefit. If you can tell a consumer “You can save money if you do this, and you’re also going to have an environmental benefit,” it’s a win-win. But there’s an irony. We had a drought in 2002 in Colorado. So they put water rationing in place, and people mostly obeyed that. And so the drought went away. They found out that people didn’t start using more water because they learned they could get by with less water for their lawns, so they raised the price. So in other words, the water people were depending on a certain amount of revenue to come in. So all of these issues are multidimensional. I think we should focus on what the benefit is of doing individual actions and community actions. And I think if we do that in a holistic fashion, we’re going to come up with better decisions.

MJ: Are there any personal conservation techniques that you think are a waste of time, or any that you think are particularly important?

RAP: Water-use efficiency. If you can educate people that you don’t need as much water for your lawn and your trees, you save water for everybody, and you also save money for the consumer. So I think that’s an ideal one. It’s basically an education issue, and you can do that with electricity as well, in terms of lightbulbs. People can learn that they shouldn’t use incandescent light bulbs because they can save money with these other ones. So I think that’s the approach—education is the first one to do. In the US, we don’t have the littering you saw 30 or 40 years ago. Most people have learned that’s not the polite thing to do. And it’s not because there are litter laws, it’s because people have become more environmentally conscious. So I think education plays a big role with the ones that you’re talking about.

MJ: Even if you’re not just talking about global warming, there’s a point where there’s no going back. Do you have any sense of how long we have to get all of this under control?

RAP: The problem is, we don’t know if we’re pushing ourselves toward or away from some negative impact. That’s the problem. We could be making ourselves actually less likely to have some drought pattern, but since we don’t know, to me the prudent pattern is to try to minimize our impact. Don’t have too much CO2 in the atmosphere, but also limit our nitrogen deposition; try to get our landscape back to as close to the natural state as we possibly can. And if we can’t do that because we’re growing crops, try to understand the consequences.

MJ: Don’t we know that there are negative impacts already? There are more storms. The sea ice is melting. Couldn’t we look at those effects and say we do know that there are negative impacts?

RAP: I don’t think there are more storms. That’s actually in terms of tropical cyclones. There’s a lot of controversy in the tropical storm community, and I think that a lot of the claims for increase in tropical cyclone activity are flawed. [It seems like there are more now] because they didn’t have any satellites in the past.

In terms of sea ice, if you look at Antarctic sea ice, it actually has been well above average, although in the last couple days it’s close to average, but for about a year or longer, it’s been well above average, and the Arctic sea ice is not as low as it was last year. So in the global context, the sea ice has been fairly close to average. It doesn’t mean it can’t happen because we are altering the climate system. But whenever I look at the data, I see a much more complicated picture than what you typically hear about.


Mother Jones was founded as a nonprofit in 1976 because we knew corporations and the wealthy wouldn’t fund the type of hard-hitting journalism we set out to do.

Today, reader support makes up about two-thirds of our budget, allows us to dig deep on stories that matter, and lets us keep our reporting free for everyone. If you value what you get from Mother Jones, please join us with a tax-deductible donation so we can keep on doing the type of journalism that 2018 demands.

Donate Now