Is it global warming yet? There's no point pretending that climate change is not at our door
Maybe this isn't the best moment to bring up the subject of global warming.
Here I sit, wrapped in a woolen blanket, hunched over my computer, trying to ignore the wind clawing at my shuttered windows. I have the thermostat down to foil officials from the natural gas company, who have chosen the coldest, steadiest winter in recent memory to curtail supplies and double prices. In 15 years of Illinois living, I simply cannot call to mind another winter quite so heartless. The calendar maintains we are close to the end, but the highs and lows on the weather map are less optimistic.
So this is global warming?
Perception is one of the essential problems in coming to grips with climate change. If there's one aspect of nature everyone has an opinion about, it's the weather. No matter what the phenomenon of the moment, we all have memories (generally false) of seasons past, when things were different. Winters aren't as snowy as they used to be; spring is late this year; humidity levels were way up last July; the leaves don't turn the way they used to - too much rain. Every Illinois native I have ever met assures me that winter is not what it was around here. These cold snaps are nothing compared to what they used to have, and there's hardly any snow at all anymore. Summers are hotter, though. They'll give me that.
Imagine my surprise when I discovered - after the slightest perusal of the past century's climate history - that Illinois weather has been colder than average over the past 50 years.
Illinois' spate of cold climate is one of the more fascinating details in a recent government report, Climate Change in the Upper Great Lakes Region, the summary of an interdisciplinary workshop that was sponsored by the U.S. Environmental Protection Agency and held at the University of Michigan at Ann Arbor three years ago. Scientists, environmentalists, industrialists, Native Americans and government officials from the six Great Lakes states got together to confront the reality that the region's climate was changing and figure out what to do about it.
And that brings us back to perception. Almost everyone confuses weather with climate. Just because it's cold today doesn't mean that global climate is plunging toward another ice age. Shifts in climate are far too minute to be sensed by the average person trying to cope with whatever weather is brewing outside. Our lifetimes are brief in the climatological scheme of things, our memories short and often focused on the spectacular, which is usually ephemeral.
This winter may be colder than the last seven, but that's no indication the annual mean temperature is not creeping upward. The annual mean is an averaging of all the average daily figures for a year's time - a single figure to represent a year's temperature behavior. A single number can disguise a great deal of temperature extreme within the 365 days, but it's the only way to make meaningful comparisons across decades, or even centuries. We can all recall episodes of extreme heat or cold, but in the past century, the mean has risen just 0.6 degrees Centigrade.
Now we are eyeing the distinct possibility of a rise of two or three additional degrees over the next 50 years. This is a big jump, climatologically. People might not notice, but plants will definitely react. Plants are far more narrowly adapted than we are. In this part of the world, warmer climes will encourage southerly hardwoods to migrate north, while colder weather conifers will pretty much disappear, unable to stand the heat. As vegetation patterns shift with the change in temperature, the birds and animals dependent on them will follow. We will be looking at an almost entirely new ecosystem here in Illinois.
Is global warming occurring?
This is one of those issues that tends to excite the worst in human culture, mainly because so much is at stake. There are more egregious falsehoods, deliberate misinformations and outright lies uttered about this than about any other environmental issue. Playing the blame game, we have pinned much of the onus for warming on carbon fuel consumption, which pumps excessive amounts of carbon dioxide into the air, in effect chemically thickening the atmosphere and allowing it to recapture more of the sun's radiation as it bounces off the earth and heads for space. The atmosphere heats up, and there we are, living in the greenhouse.
People tend to react poorly when blamed for something, and the petroleum distillers, the automakers and the heavy industrialists are as human as anybody. They also have a lot of money, which they have employed to hire scientists and publicists to confuse and mislead the rest of us. Global warming is a myth, they proclaim, the product of fruity environmental scientists with diseased imaginations who want us back in the stone age, grubbing for roots and gathering berries. The message that global warming is a lie is deliberate misinformation from well-paid non-neutral scientists.
Admittedly, independent scientists have not helped themselves in their efforts to inform the public. Back in 1988, when Illinois and the Midwest were suffering through one of the worst droughts since the 1930s, with absolutely no rainfall and temperatures over 95 just about every day, meteorologists appeared before Congress to announce that global warming was here. Naturally, the next two summers were unusually cool, and, in 1993, we got enough rain to temporarily turn the Mississippi Valley into a sixth Great Lake.
Global warming came and went that quickly?
Today's weather says nothing about climate trends. Even if four of the past 10 summers have been among the hottest on record, that doesn't prove anything. Weather records rarely go back much farther than a century, while rainfall and short-range temperatures generally jump up and down with little demonstrable regularity. Weather graphs for the last 100 years look like a chart of my heart rate after an hour on the exercise bike, irregular peaks and valleys. I simply pay no attention when anyone - of any authority - cites weather data as evidence for anything.
The only evidence that counts has got to be long term, measuring trends over thousands of years. That evidence is locked up in the polar ice caps, where layer upon frozen layer of permanent glacial ice records the chemical signatures from the atmosphere on an annual basis, like growth rings on a tree. The evidence from the Greenland ice caps, studied by a series of expeditionary teams over the past several years, is unequivocal. The world's climate is changing. The conditions that have held over the past 200 years - most of our country's history - are going to shift.
Climatic change is certainly nothing new to the earth. In the relatively short history of Homo sapiens, there has been tremendous change. Glaciers have advanced and retreated across the face of northern North America at least 11 times.
From paleontological evidence that reflects the evidence of the ice cores, we know that Illinois climate was much hotter 2,500 years ago than at any time since. The world was much warmer a thousand years ago than it is now, and colder just 300 years in the past.
For the earth, a couple of centuries with a stable mean temperature is about the most that can be hoped for. There was surprising widespread agreement among the participants at the Great Lakes Regional Workshop regarding the fact of global warming. Even the representatives from the big Detroit automotive manufacturers allowed that there is cause for concern.
There's no point pretending that climate change is not at our door. All credible evidence points to that. But this reality is merely a jumping off point for what shapes up to be an endless wrangle over policy. There seem to be at least two fault lines in the debate over climatic change. One is the potential effects of the change: What will happen in the Midwest as the annual mean temperature gains two or three degrees? The other is whether humans are at fault, and what, if anything, we can do to mitigate the shift.
Climate in the Great Lakes region is exceedingly resistant to predictive modeling. The lakes have measurable yet capricious influence on yearly weather patterns, while actual climate records for the region are spotty and difficult to interpret. The last century provides few clues. Generally, it's thought that the region will become hotter and drier, which will create a few benefits and a whole host of troubles. The chief advantage will be a longer growing season, though farmers probably will have to shift to more heat resistant crops, such as wheat. The disadvantages begin and end with the availability of water. In some ways, we are already pushing the limits of our fresh water supply. The Great Lakes represent one fifth of the world's potable water, a reservoir we have fouled and abused. Dwindling rainfall will only diminish this resource, further concentrating the chemicals and poisons we have dumped in over the past century and a half. Arid croplands will cry for irrigation, placing further pressure on the lakes. As they drain, shoreland business and industry, much of it dependent on lake water, will be left high and dry. If levels in Lake Superior drop very much, the basin will become a "terminal lake" - streams flowing in, but nothing flowing out. The lake is very young; outlet channels are shallow and carved high in the granite bowl.
The local problems - reduced supplies of fresh water coupled to increasing demand, soil aridity, vegetation shifts, rising pollution - will be aggravated by global changes. Few people realize that the past ten thousand years of human history have played out against a backdrop of very stable worldwide weather conditions. The polar ice cores indicate that throughout much of the earth's past, conditions were prone to shift far more quickly, and violently. Warming will bring a return of such conditions: more hurricanes, more tornadoes, more torrential rains. People will certainly talk more about the weather.
This list of difficulties is just a drop in the bucket, really. As the ecologists are wont to say, every time you try to isolate some aspect of nature, you realize it's hitched to everything else. The folks at the Michigan workshop produced some mighty long lists of intimidating impacts attending climate change. Beyond the natural, there are the social and political problems to consider. How will our current crop of politicians keep their jobs if there are five or six killer tornadoes every month of the year? Someone will have to take the blame.
Can we do something about this?
Probably not much. I have precious little faith in the ability of governments to address a crisis over something so mundane as the climate. We hold big international conferences in Rio and Kyoto, hammer out agreements to reduce carbon emissions, but the effect will be negligible. American industry howls that the agreements are unfair, that we are required to do much more than anyone else, neglecting to mention that our emissions far exceed anyone else's. Even if we do somehow succeed in meeting the emission standards, "underdeveloped" countries will continue to increase their carbon fuel consumption, trying to make themselves as materialistic as we are. The best hope we have on this front is that the ugly price increases in gasoline and natural gas will drive us to explore seriously nonfossil fuel alternatives.
If, by some sequence of happy historical accidents, we do manage to halt the atmospheric rise in greenhouse gasses, there is no guarantee we will escape the effects of changing climate. It's just like us human beings to think that our planet is passive, that it will change only because we screw it up. Climate change is a long-established fact of earthly existence. Ask any dinosaur.
When the changes do take place, it's the environment that will take the hit, in the immediate sense. Forests will shrink and often disappear; worldwide extinctions will be heavy; grasshoppers and cockroaches will do well.
Humans will survive in the short run, because our best quality is our adaptability. There are folks living in the Sahara Desert, in northernmost Alaska, way up in the Peruvian Andes, down along the Dead Sea. The human body can adapt to an amazing range of hot and cold. There will be troubles, arguments, adjustments, wars, but the human species can survive. The real challenges will derive from our dependence on the rest of nature. Can we make do with less water, with fewer forests, with drier croplands, with more pestilence, with fewer birds and animals? These are the adjustments the human species will need to make, the effects we will need to mitigate.
As far back as the invention of agriculture, humankind has dreamed of managing the earth, making nature perform to our bidding. Now nature shows abundant signs of tossing us a major curve by changing the basic rules of existence. As much as I admire the folks at the Michigan Workshop for their willingness to extend the management impulse to meet this challenge, I am not very sanguine about their chances for success.
They envision an orderly and rational response to climate change. That would certainly be a first in human history. Our collective range of vision is limited. Confronted with discussions of climate, we recall the winters of our youth, make the inevitable and misleading comparisons. Stepping out from ourselves, thinking not of our own histories, but that of the earth itself, is a profound cultural challenge. It will be hard for the culture to react in any meaningful way before the changes in climate are manifest. Given that there are lots of people out there who refuse to believe that climate change is even possible, the road is all uphill.
When all was said and done at the Michigan workshop, the best those folks could recommend was an adaptation strategy: learning to cope with the consequences of climate change. Boiled down, this amounts to an admission that humans cannot completely manage the earth. We would have to adjust our cultures, our societies to changing climate. It's a limited message, but an important one. Refusing to see the future is tantamount to courting disaster. Our survival depends on our ability to adapt water usage, agricultural practice and health strategies to meet the dictates of a dynamic environment. No matter who or what is responsible, the earth's climate is changing.
Say, is it getting hot around here, or is it just me?
Robert Kuhn McGregor, an environmental historian at the University of Illinois at Springfield, is a regular contributor to the magazine.