RAY SUAREZ: Now, you used -- these may sound like tiny amounts to people who don't follow this, but you use the assumption that there would be 60 parts per million more of CO2 in the atmosphere and that the temperature would go up about another two degrees on average.
ANTHONY JANETOS: Well, that's roughly what -- two degrees might be a little much. That's roughly what would happen over the next three or four decades.
There's a lot of inertia in the climate system right now. There's a lot of heat that's essentially been trapped that will express itself, even if greenhouse gases -- if their emissions are cut, which, of course, we don't know exactly what will happen there yet.
And so what we wanted to do was begin to evaluate the question of, well, what are we going to have to cope with? Which consequences are we not going to be able to avoid, but that we're simply going to have to deal with?
What we hope we've done is establish the scientific baseline by which those kinds of strategies for coping and adaptation can begin to be developed and can be improved.
RAY SUAREZ: Well, just over the past week, you could see forest fires, large forest fires burning in the United States, tornadoes, a higher than average tempo of tornado activity. Are these the kinds of things that you conclude that we'll be seeing?
ANTHONY JANETOS: We've seen changes, especially in both the frequency and intensity of wildfire in forests. We've seen very large pest infestations in forests. And we've seen the beginnings of that in agricultural pests, where the increase in temperatures that we've seen allows the pest to accelerate their life cycle. They grow faster; they eat faster.
That increase in temperature in the summer months also stresses the forest. Those trees are now more susceptible to pests. They're more vulnerable to pests.
Interestingly, especially in forests, warmer winters also enhance these pest infestations, because generally, for many of these insect pests, they're killed off in the winter months by very low temperatures. If you don't get those really cold temperatures for long enough in the winter, the insect larvae over winter, instead of dying, and that infestation is even larger the next time around when spring starts.
RAY SUAREZ: Well, currently some of the fastest-growing places in America are also some of the driest places in America. From the report, it looks like they're going to get drier?
ANTHONY JANETOS: That's a very likely outcome. The precipitation and water supplies are extremely difficult to model and to forecast. All the science is certainly not in; there's a fair amount of uncertainty there.
But the simulations that we've looked at suggest that over the next few decades we'll see an acceleration of a trend that we're already seeing, which is that especially the Western part of the U.S. will continue to dry out. And we could be headed towards some very severe drying conditions in that part of the country.
RAY SUAREZ: This conclusion sort of popped out at me. Even under the most optimistic scenarios, you predicted "profound effects."
ANTHONY JANETOS: We believe that to be true. We're already starting to see them in a wide variety of resources.
The most optimistic scenarios for change in the climate system for the next few decades, frankly, are all very close to one another. And so there's going to be a certain amount of change that we are going to have to adapt to, that this will be part of the overall response portfolio.
RAY SUAREZ: And that increased CO2 concentration, there was a lot talk about the impact on agriculture. I thought CO2 was good for plants.
ANTHONY JANETOS: CO2 is good for plants. An increase in CO2 in the atmosphere will help accelerate plant growth.
But at the same time, the increase in temperatures both has the effect of making water supplies more precarious, so that potentially has a growth impact on agricultural crops.
Many crops are also quite sensitive to the temperature itself. And there are critical periods in their lifecycle where the temperature itself can affect the actual -- how much carbohydrate gets into the seeds and, therefore, the actual quality of the crop itself.
Agriculture is a tricky business. It's very adaptable. We don't know exactly how farmers will respond. We have modeled the physical effects, but not how the people will actually respond to those.
RAY SUAREZ: Anthony Janetos, thanks a lot.
ANTHONY JANETOS: Thank you.