The Next Ice Age Is 10,000 Years Off, but a Cooling Globe Has Us in Hot Water Now
11/24/1980 at 01:00 AM EST
"People expect changes in the weather, day to day and season to season," says climatologist Reid Bryson. "But they operate on the principle that overall climate is fixed. It is not, and that scares a lot of people." As director of the Institute for Environmental Studies at the University of Wisconsin, Bryson, 60, predicts the future will be colder and drier, with dire consequences for the earth's booming population unless resources are conserved and agricultural methods changed. Born and raised in Detroit, Bryson earned his Ph.D. in meteorology at the University of Chicago in 1948. That same year he founded the meteorology department at the University of Wisconsin and was named director of the institute in 1970. From the Madison campus, where Bryson and Frances, his wife of 38 years, raised four children, he has traveled as far as the Arctic Ocean to conduct research. With Sarah Moore Hall of PEOPLE, he discussed our cooling climate—"a problem," Bryson claims, "whose time has come."
Is the world headed for another ice age?
Yes; it's only a question of time. But the glaciers won't be here for another 10,000 years, so don't panic.
What's ominous about the future?
The earth's climate is very slowly cooling off and has been for roughly 2,000 years as the earth increasingly tilts away from the sun. Nobody is sure why this is happening. Along the way there have been a lot of unusual ups and downs in average temperature, some as brief as decades, others going on for centuries. But the overall cooling trend is unmistakable, and in coming years it will profoundly affect agriculture, geopolitics and human survival worldwide.
What are the consequences of a cooling climate?
Growing seasons shorten and the monsoons tend to fail. Half the world's population depends almost exclusively on rain from the monsoons to provide water for crop irrigation. There has already been a decade of drought-induced famines in India and in sub-Saharan Africa, but you didn't hear much about them because the people dying were subsistence farmers out in the boondocks. In the last three years, however, the average surface temperatures in the earth's Northern Hemisphere have dropped about one-tenth of a degree. This is significant because tiny variations in average temperature can produce large variations in local weather. If this trend continues for another few decades, the winds that bring monsoons to China's rice paddies could shift south, and permafrost could begin to creep over large sections of the Soviet Union's farmland. That you will hear about.
Are the Russians studying climatology?
Yes. They've also been listening very carefully to what we've had to say about crop failures in this century. I think they are a bit overly optimistic, however. Much of their land stands to suffer in a cooling climate and they don't like to hear that.
When did this cooling trend come to be recognized?
The pivotal year was 1972. There was disastrous weather all around. A terrible drought in the Sahel area of northern Africa resulted in a famine which affected 20 million people. Russia had to buy 18 million tons of grain from us and another 12 million in 1975. There was a frost in Brazil that sent coffee prices sky-high, and our corn crop suffered badly because of frost or heavy rain. We can't afford many more years like that.
Why wasn't the trend noticed earlier?
One reason is that most of this century—from about the end of World War I to the end of World War II—has been a time of unusually temperate weather. In the 1950s the temperatures began to drop again, with the difference becoming dramatically noticeable by the early 1970s. The coming decade will either be like the last few years or possibly even cooler. Historically speaking, the cooler temperature would be a return to normalcy.
How accurate are your long-range predictions?
Not as accurate as we'd like. We're correct about 60 percent of the time, but we can now do about as well for periods four years ahead as for one year. Accuracy varies with geographic location and season. Remember that we've only been involved in our intense research about seven years and we're on a peanuts budget.
What are your predictions based on?
Mountains of data about the atmosphere, but of a different kind than are used in daily weather reports. Those are based on what we call fast physics—elements of temperature and air pressure that are momentary. We work on the basis of slow physics—effects measurable in years and decades, like the wobbling of the earth's axis.
Is the sunspot cycle important?
Mine is very much a minority opinion, but I find no evidence that solar variations have any effect on climate. One thing that is significant, though, is the enormous system of winds which rotates around the North Pole and flows from west to east. This circumpolar vortex is expanding now, pushing areas of cold air southward and contributing to the cooling of the Northern Hemisphere.
Has this happened before?
Yes. About 1,000 years ago, when what is now northwestern Iowa changed from a lush fertile area to dry grassy prairie. The Mill Creek Indians were living there, raising corn. When their environment changed, their entire culture disappeared. In the 12th century a change in the westerlies ruined the English vineyards and it probably brought famine to Viking colonies in Greenland.
Do volcanic eruptions affect climate?
Far more than we realize. Ash that is spewed into the air—for instance, in last spring's Mount St. Helens eruption—will circulate in the atmosphere for one and a half to two years. The dust shuts out sunlight and can cause temperatures to drop in the lower atmosphere and at ground level. Not surprisingly, we've found a connection going back in history between periods of increased volcanic activity and the advance of glaciers. Although only 10 volcanoes erupted in the world this year, there have been about 1,700 recorded eruptions during this century. That is high volcanic activity.
Can populations relocate if harvests fail?
Centuries ago, when the globe was less crowded, they often could. But if the monsoons fail in northern India, where are the 300 million people there going to go—Bangladesh?
War, then, might be the result?
I'm not saying it will happen, but countries with starving populations would not have many choices. India, for instance, now has a well-developed nuclear capacity, a well-equipped army and air force. If the monsoons failed drastically, India would have to try to get food any way it could. It wouldn't matter if they lost a million or more people in such a war; in a larger sense, they've got nothing to lose.
What is the long-range outlook for U.S. agriculture as the climate cools?
There used to be a lot of grain-exporting nations. Currently there are only three: Canada, Australia and the United States. By the middle of the 21st century we won't be among them; it's a myth that we can go on feeding the world. Population is growing too fast. In the long run we're going to have trouble feeding ourselves.
What do you advocate in terms of public policy?
We need to project population trends more accurately before we can implement an agricultural policy that looks beyond this year's profits. We currently base our tax laws on land's potential for development, not on its actual current use, as they do in Europe. We've got to provide tax incentives to keep our farmland functioning as farmland.
Should we be stockpiling grain?
Absolutely, and we're not. On the contrary, we try to get rid of produce as fast as we can because our prices are depressed. Back in 1974 the World Food Conference recommended a policy of stockpiling. Then they got hung up on the question of who owns and who controls the stockpiles.
Is research on climatology being supported in this country?
The National Climate Program Act was passed in 1978, but there is still not an active, intense program. I think most people in government simply feel the problems are so immense they can't deal with them. They just hope the situation will go away. I'm trying to save people.
Are you discouraged?
I have great faith in the potential of the human brain to find solutions. People are going to have to worry out loud to their representatives, and I think they will listen. We have to take out some kind of insurance policy on making a habitable world for those who follow us.