'We've Got Climate Change'
Lee Nichols interviews UT biologist Camille Parmesan
Last June, the Bush administration finally saw the light on global warming -- sort of. The Environmental Protection Agency released a report that, at long last, acknowledged that global warming is real and caused by human activity, especially the production of "greenhouse gases" like carbon dioxide. It is hardly a visionary document -- rather than attempt to stop rising temperatures, the EPA says, communities should simply find ways adapt to the havoc they will wreak.
But even that tepid green-ness was too much for the White House -- after only one day of getting hammered on right-wing talk radio, President Bush distanced himself from the document, sneering, "I read the report put out by the bureaucracy."
It was a typical moment for the Bush administration: repeating the mantra that global warming is unconfirmed and requires more "sound science" -- while the actual scientific evidence mounts that global warming is both real and an increasingly serious problem.
A bombshell of such evidence arrived in January from the biology department of the University of Texas. In a study reported in the scientific journal Nature, UT biologist Camille Parmesan and Wesleyan University economics professor Gary Yohe documented that hundreds of species of plants and animals are shifting their habitat range toward the poles (or higher in elevation), or are experiencing spring reproductive events earlier -- in response to decades of atmospheric warming.
The study covers its bases powerfully -- in examining the work of other biologists, Parmesan and Yohe intentionally excluded studies that might be biased toward the global warming conventional wisdom, seeking multi-species analyses -- some showing nature reacting to warming, some not. Yet, even using this conservative procedure, Parmesan and Yohe found a clear pattern: Over the past century, hundreds of species experienced range shifts averaging about four miles per decade poleward (or 20 feet per decade higher in elevation), or spring events occurring 2.3 days earlier per decade.
In January, Camille Parmesan talked with the Chronicle and discussed at length what her research means for the natural world and humanity, and the impact she hopes the study will have on political discourse.
The following is the full version of that interview, excerpted in the March 7, 2003, print edition of the Chronicle. -- L.N.
The Austin Chronicle: The articles I've seen on your study have focused only on the scientific findings. I also wanted to talk about the political angle, because it seems there is a strong political element to your study.
Dr. Camille Parmesan: Well, not really. The study is a scientific study. It has political implications, but it's not a study of policy, it doesn't address policy ...
AC: Right, but you directly mention [in the Nature article] that you would like it to affect policy.
CP: Oh, yeah. I would like policy makers to wake up, and I'm getting very, very tired of hearing politicians saying, "Oh, we don't know anything about global warming, the scientists are still having debates with each other, there's no sign that it's having any impact. ..." Among the scientists, it hasn't really been a debate for several years. There's been a strong consensus among the climate community that the trends we're seeing are linked to rising greenhouse gases, and amongst the biologists there's been a strong -- growing every year -- consensus that we're seeing impacts.
And yet, you still get politicians saying, "Oh, the science is inconclusive and we don't really know anything." So one of the motivations for this particular paper, for doing this huge global synthesis and doing a very hard-core, quantitative analysis that addresses a lot of the problems that skeptics have, the reason for doing it that way -- for essentially slanting it toward the skeptics -- was to have a final say, and say, "Okay, look, we've shown this now. There are impacts. They're global. They're across all kinds of different organisms. Let's go beyond this now," and say, "What do we do about it?" Or try to figure out which systems are most sensitive. Or try to get to the details. But let's stop having this argument about whether it's having impacts, because it is.
AC: What are some of the possible consequences of the shifts in range or the shifts in spring events?
CP: The shifts in spring events, I think it's harder to say what the consequences are going to be, because it really depends: When you've got all these species in a community interacting, the insects depend upon the plants for food, and the birds depend upon the insects for food, you have all these interactions, and they all have to come together. And so, if you've got warmer springs and, say, a plant starts blooming earlier, what then you have to know is whether the insect will start emerging earlier to be synchronized. And what we're seeing is that in some cases that is synchronized, and everything just kind of shifts earlier, but in other cases the plant is driven by photo period -- sunlight -- [but] the insect is driven by temperature, and so the insect is coming out earlier, the plant is not, and they're getting out of sync. So it's harder to say what the consequences are going to be, because it's almost, "Well, we'll just have to see." Either they'll be able to keep in sync and the whole system can remain relatively intact, or they're going to start getting out of sync, and to the extent they get out of sync, this could cause some problems.
The distributional changes are much easier to see, what the impacts are going to be. What you have to imagine is: You've got this globe, and you have species that exist over large areas. Half the USA. The size of a species' range is typically a continental state. But, on top of that, what you've got is that almost all that land that people draw this line around, "This is where the species exist," but you know that on top of that is all of this agricultural development and all of this urbanization.
So it's not really existing over that whole area, it's existing in little spots. And right now, those little spots, we've tried to make them reserves, parks. That's where our national parks are, that's where a lot of the Nature Conservancy preserves [are]. We've tried to place them [preserves] where the species currently exist and have fairly good habitat. So you imagine the climate envelope now is here, right over the species -- and that envelope shifts, that's the problem. If there weren't any humans, then the species would just shift, too.
And [in the past], that's what's happened. You can look back through the Ice Ages, you've seen these massive, thousands-of-kilometers shifts of species as they're tracking that climate change. But the problem now is they're all fragmented, they're in these little-bitty spots -- what's the chance that they can get from this reserve that they're in, to the next good spot where there's habitat? And what we're seeing is that for species that are fairly widespread and live in habitat that man has managed in some way -- things like grackles -- are probably not going to be severely affected by climate change because they will be able to just shift around. So common [species] -- what we think of as weedy species or urban species -- will probably be okay.
But the things that we're worried about are ... the endangered species, that we've already worked very hard at putting these lovely little reserve networks together to save -- you know, the black-capped vireo or the golden-cheeked warbler or whatever -- and suddenly those reserves may be in the wrong place. What happened with the golden toad down in Costa Rica is that it only occurred in Monte Verde National Reserve. That was the only spot in the world that it existed, and the recent changes of the last 30 years have effectively lifted the cloud forest and caused drought conditions and the frog went extinct. That's one case where the extinction was pretty clearly linked to recent climate change, and the reason it went extinct is because you've got this cloud forest [habitat] that can't go anywhere. It's on the top of the mountain, it doesn't really have anywhere it can move to, and the climate shifted just enough that it can't survive that.
AC: Speaking of the black-capped vireo and golden-cheeked warbler, how might local preserves such as the Balcones Canyonlands Preserve specifically be affected by these changes?
CP: In one sense, it's a worst-case scenario, because the warbler and the vireo are very tied toward a very specific habitat structure. They have to have certain species of trees at certain stages. Those trees grow on the limestone outcrops that we have in Central Texas. If you get a climate envelope shift in this area, you could get the kind that's shifting to where it would be a more appropriate climate say, in North Texas -- but you don't have the kind of soil, you don't have the kind of vegetation that they're going to need.
One of the problems with Texas is that, as any Texan knows, the weather here is really variable. We have huge year-to-year variation. We can get major drought periods followed by huge flood periods. This has made it actually very difficult to make any predictions for Texas. ... It depends on how low down those arctic fronts come, and if it stops short of here, you'll get one type of weather, if it goes further you'll get another type. So unfortunately, predictions for Texas are really lousy. The models go all across the board, so it's very hard to say.
Especially for areas like Texas, where we have very unsure scenarios, I think the most important thing to keep in mind is to have a flexible management program and flexible reserve designs, so that as we see things happening we can adjust what we're doing to try to fit the changes, because we're not going to have a hard-core prediction for this area.
AC: What could these shifts mean for mankind?
CP: One of the direct impacts, is that we don't have a lot of tropical diseases in the USA, because the organisms that carry those diseases live further south. As that tropical climate shifts up into Texas and the Southeast, we're going to start seeing a lot more incidence of tropical diseases. We're already seeing some of what used to be migrant birds, like the Rufous Hummingbird used to be a migrant that went up into the coastal states for breeding in the spring and summer, and then went down into Mexico in the winter; it's now become a year-round resident in parts of the southeast USA. So we are seeing tropical species coming more -- new species of butterfly, new species of dragonfly, that are supposed to be limited to the tropics.
And people think, "That's great! Butterflies, dragonflies, I like that," but then you get all the mosquitoes, and the parasites that go along with the mosquitoes coming north as well. It's not something our health system definitely cannot deal with -- there are ways of dealing with this. The sanitation has to be completely up to snuff, you've got to prevent standing water to prevent buildups of mosquitoes.
So there are things we can do, it's not that it will definitely have an impact -- but once you get all these diseases out in the wild, you're having to constantly fight them back in the urban areas to keep them from taking over.
AC: What effect do you hope that this study will have on the Bush administration?
CP: I'm hoping that, one, they'll read it, and that they will recognize that this is saying that we've got very clear evidence that the recent warming trends have had big impacts on wild species. Because one of the lines that politicians have taken -- even if they'll accept that the climate change has been linked to rising carbon dioxide -- they'll say, "Well, but it's not very much. It's one degree. What's one degree?" That sounds like so little. In Austin, we'll have a 40-degree change in temperature in one day when a cold front comes in, so why on earth are people worried about a one-degree rise?
And what my study shows is that one-degree rise is having a huge impact. It's causing [some] species to go northward by 100 to 150 miles. That's a big change in a species' range. It's causing, as I said, tropical migrants to become resident in the USA that didn't occur here before. You're getting shifts in some of the large mammals -- the red fox has moved northward in Canada, and it's moved into the territory of the arctic fox, and caused the arctic fox to have to be pushed towards the Arctic Ocean. And these are species that have a real clear boundary -- the arctic fox only lived right along the coast as it was, and it's being pushed into even less territory.
So, that little one-degree warming is causing huge changes that are amazingly simple, really, and amazingly visible given everything else that's happening, given that we've got habitat loss and acid rain and all this other stuff. It's amazing that we can see such a clear impact just of climate change on all of these wild organisms. So what I'm hoping it'll do is it'll cause them to get beyond this idea that there's a debate going on, into acceptance of there isn't a debate, we've got climate change, we've shown its impacts, now what can we do about it?
AC: You wrote that environmental scientists "encountered difficulty in convincing other academic disciplines, policy-makers, and the general public." A Jan. 6 article in Salon.com speculated that some anti-environmentalists in Bush's camp are motivated not just by corporate greed, but also a religious desire to destroy the world and more quickly bring on Armageddon ...
CP: [laughing] That's a new twist.
AC: ... and on Jan. 23, a panel of scientists accused the administration of loading scientific advisory panels with members who support Bush's ideology, but perhaps lack scientific expertise. Do you suspect that this "difficulty" might be a product of willful ignorance?
CP: Some of it is. I do think the Bush administration is particularly bad about choosing people to tell them what they want to hear, and they are not particularly interested in actually knowing what the majority expert opinion is. But beyond that, I've actually found that an awful lot of people, including Texas businessmen, simply are not being given the information. The newspapers don't tend to report the scientific information, or when they do, they report it very skewed -- you have an issue where 98% of the scientists believe the warming trends are linked to CO2; well, you can find two climate scientists who'll counter that, and an awful lot of journalists will report that as a 50-50 debate, when it's not.
When I've given talks to the general public, I've found them very receptive to just hearing what the facts are, and I try to give a very straightforward, non-interpretive version of what the data show, and most people by the end of it will come to their own conclusion that the data are very strong. Which, in fact, they are -- you don't have to embellish it. All you have to do is show people what the graphs are, and even people without scientific training can see what is happening. So I think the majority of the people are ignorant, but not because they have a particular agenda; it's simply that they honestly do believe that more research needs to be done and that it's being debated, and they don't realize that that's the scientific story from 15 years ago -- that they're 15 years out of date, effectively, and that we've moved on and by now, we know a lot, and we're not communicating how much we know very well.
AC: You took a direct swipe in your article at The Skeptical Environmentalist, the anti-environmentalist book from 2001 by Danish statistics professor Bjorn Lomborg. What effect do you think his book has had on political discussions of climate change?
CP: Oh, it's been terrible. Lomborg is not a scientist at all. He has no training in environmentalism, he has no training in biology; he's a really, really good con man, though. So he writes articulately, and pretends as though he's citing scientific works, when in fact he mis-cites them. He'll put a little number down in the reference, but then what he says is completely counter to what's in that reference. And people who want to believe what he says have really picked up on it, and they don't care that he's been trashed by the scientific community. The Danish Academy of Science just came out with a declaration that his book was scientifically dishonest, and unfortunately, that's getting much less play than the original book did.
And so, yes, I think one of the problems is politicians are picking up that book and thinking that this is actually a scientific view of the problems, when in fact there's nothing scientific about it.
AC: How did you and Gary Yohe come to work together?
CP: We were both in the Intergovernmental Panel on Climate Change [a research project begun in 1988 by the World Meteorological Society and the United Nations Environmental Program] together, and he's an economist, and was one of the skeptics about the biological impacts. And the biologists felt like the data were very strong, but in talking with him, and in working through the IPCC process, I realized that biologists -- again, we have a lot of knowledge that we're not realizing we're drawing on when we're coming up with our conclusions. And they actually did have some good points ....
All of these are what we call correlational studies, so you see a change -- temperature increases and the range shifts north -- and it's connecting those two as cause and effect that's a little trickier. So I got together with Gary and said, look, actually we have a huge amount of biological information, we've done lots of experiments on thermal tolerances of lizards and turtles and butterflies. And so I wanted his perspective on how do I put all of the biological knowledge together into a format that actually is what he wants to see. What is he looking for, what is it he feels is missing from the argument?
And so, in doing that, we realized that we actually did need to go back to the literature and try to do a very strong quality control on the studies and really only select the studies that we felt were not prone to a lot of the biases that people were criticizing. One of the things people criticize is, the way publication works, you get a result, if you get a significant change and you can link it to something exciting like climate change, then it gets published. If you work on another species, and it hasn't done anything -- you've got 20 years of data and by golly, it's doing exactly what it did 20 years ago -- it's less likely to get published, because people will say "Well then, why do we care?" But what I realized is that at this point, the literature is so big that you can pick out what I call multi-species studies ... [studies that] not only picked out things that are changing but things that are not changing as well.
So by focusing on those kinds of studies, you get away from what some people consider to be a huge bias in the literature. And what we found is half of the species aren't doing anything. Which is evidence, I think, that we did a good job of getting rid of that bias. Fine, half of the species aren't responding -- there are lots of reasons why they might not be. Could be that they're not sensitive to climate, could be that they have some real boundary [so] that they can't respond. But then you can turn that around and say, man, out of all wild species, we have an estimate that 50 percent of them are showing a response to the last 30 years of climate change. And that's a tremendous number. And that across all kinds of different organisms -- plants and animals, mammals and insects, ranging from the Antarctic to the Arctic. So that's a powerful number. It's a much more powerful argument than the kind of standard literature that says this butterfly did this or that bird did that.
The economists deal with this a lot more than biologists have. They do deal with global economic issues, and they try to come up with global economic trends. So actually, it was very helpful, because biologists tend to work at one little study site, or one little study system, and it's very rare that biologists will try to put together some big picture on global trends. So it was helpful to me to find out from Gary how they go about doing this, how they go about coming up with a comprehensive statement.
The other thing that was really intriguing was that it only slowly dawned on me that one of the reasons biologists were having a hard time getting the economists to make a strong statement is that they really were thinking in terms of, "What are the impacts right now? What's really affecting wild species right now? Is climate change a major impact?"
And when you phrase it that way, you have to say no. The biggest impact is habitat loss. Everyone sees that. Climate change is having an impact, but it is small relative to habitat loss. And so they said, "Well then, who cares?" But the biologists instantly are thinking along the lines of, "Oh my god -- the reserve network we've set up is not going to do the job anymore." So we're instantly thinking 100 years ahead, and thinking, "We're not prepared for this."
It took me a while to realize that this is a really fundamental philosophical difference in whether or not you think something is important. So even if we convince them that we're seeing changes -- which by now I think we have, some of them are still saying -- "Well, but it's such a small effect, that we don't think it's important," because they're thinking in terms of here and now, or maybe the next few years. And yet, to biologists, it's even more important than habitat loss, or as important -- because we have to start planning for it now.
AC: So it's a matter of short-term vs. long-term perspective?
CP: It took us really months to figure out that that was one of the things that was going on, because you just get so used to thinking one way that you don't realize that someone else has a very fundamentally different perspective.