Root, a senior fellow at Stanford University, is co-author of a report on climate change that will be discussed at an international conference later this week in Belgium.
The report, "Climate Change 2007: Impacts, Adaptation and Vulnerability," investigates how global warming is already affecting the animal and plant kingdoms.
In an interview with CNET News.com on the eve of the conference, Root outlined her concerns about global warming as well as how a complex scientific question has been politicized.
Q: How do you think global warming is going to impact the plant and animal kingdoms?
Root: Global warming isn't something in the future; it's already happening. The species that lay eggs in the springtime, they are laying eggs earlier. There are species that migrate back in the springtime, they are coming back earlier, and flowers are blooming. Daffodils are coming up now much earlier than they used to, and the change that has happened is about three weeks in the last 30 years. So it's about a week per decade, and that is quite a change when you only think that we've had a 0.7-degree-centigrade increase in temperature--and we are talking about now that it could possibly go as high as 6 degrees C. That really is quite a concern because that can lead to extinction of various species.
The species that are going to be most vulnerable are the ones that are very, very specialized and the ones that have very small ranges. The ones that are on the top of mountains, for instance right now; as the globe warms, they want to move up in elevation, but there is no place for them to go. So they are going to end up going extinct, and we have already seen some of that happening.
How would we know the tipping point, and when it would be irreversible?
Root: In biology, each species has what you would call a tipping point, and some of them are very close to the tipping point already and some of them are not. The species that are not very close to tipping points right now are things that live with us in our cities, like raccoons and skunks and things like that, but there are several species that are very rare already and that is something to worry about. For some species it certainly has already been the tipping point, for the butterfly that is moving up in Baja California, the tipping point has been reached. For other species that are able to move through Tijuana or San Diego, they are doing fine.
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So each species has its own different way, and that actually is one of the things that I am most concerned about because the species communities that we know today are not going to move together up north or up in elevation. One species is going to go one way and one species is going to go the other way, and this one is going to go fast, and that one is going to go slow, and one is not going to move at all, and so we have this tearing apart of communities, and it's tearing apart the biotic interactions of the species. So if we have a predator-and-prey relationship, if the predator moves, that's good for the prey because it can go up in abundance. But if the prey is a pest on our crops, then we don't want to have that happen.
How is global warming going to affect the food crops?
Root: When we are talking about crops, there are going to be very many different things affecting our crops that we have to worry about. We could have more pests because the predators are moving out of the way as I just said, then we could also have stress in the crops themselves because it's warmer. We can have stress in the crops because there is not as much water, and so you put all of those things together and our crops could actually be in danger.
What about humans? How would they be affected by global warming?
Root: Well, humans are smart enough to...as a lot of people say, they just go indoors and have their air-conditioning. But that doesn't work. There are lots of people on this planet that do not have air-conditioning. So how are people really going to be affected? There is a whole wide range of things, like disease, that are going to be changing dramatically. We are going to have stresses because we are not going to have enough water. People will be stressed because it's going to be so warm.
Can you specify some of the diseases?
Root: The diseases are a little bit tough to understand because humans have been trying to suppress them, obviously. But now global warming is saying the vectors that are carrying the disease are able to move into new places where they have never been before...With malaria, it's changing; with dengue fever, it's changing; with hantavirus, it's changing. What we need to do is figure out how to control those and encounter what the global warming is doing.
Why do you think there continues to be so much resistance to evidence showing a correlation between carbon emissions and global warming?
Root: We could have done a lot more to work on the connection between the global warming and carbon. But there has been a that has been out there and has tried to actually confuse the public. People love to be in denial, but we can't have that anymore. A lot of people are going to be hurt monetarily, and we have to worry about that aspect, too.