The Reckoning

Global Warming is Likely to Cause Huge Climatic Changes — and Possibly a New Ice Age

What killed the saber-toothed tiger, the mastodon and the mammoth, formidable animals that were on top of the food chain in North America 20,000 years ago? Was it fierce Stone Age hunters as has commonly been assumed, or the little-studied but very real phenomenon of abrupt climate change?

Dr. Walt Oechel measures carbon dioxide levels in Alaska, where the tundra has gone from a "sink" for global warming gas to an emitter.© Gary Braasch

This question is not just of academic interest, to be debated by pipe-smoking professors at conferences. The rapid natural climate changes at the end of the Ice Age could be mirrored by man-made global warming in the 21st century, leading to devastating consequences for the planet’s biodiversity and the human race itself. As the Bush administration rebuffs international treaties and embarks on a leisurely and largely redundant 10-year study of global warming science, the evidence we have already amassed points to a climatic emergency, and a vastly changed Earth in 2100 and beyond. To avert that possibility, scientists say we’d need to reduce emissions of the most important greenhouse gas, carbon dioxide (CO2), from transportation and industry by 80 percent, a near impossibility given current political realities.

The Ice Evidence

While no scientists were available to record data 400,000 years ago, detailed studies of ancient ice, brought up in deep core samples, reveal that the level of CO2 has been steadily rising for the last 15,000 years, most dramatically since the Industrial Revolution first began pumping large quantities of CO2 into the atmosphere. Recent surface temperatures are probably higher than at any time since the Middle Ages. Work at the University of East Anglia reveals the period from 1970 to 2000 as the Northern Hemisphere’s warmest three decades in 1,000 years. Another study, cited in Coastal Heritage magazine, found that 80 percent of all species of plants and animals had made a climate-related shift in habitat.

Critics of global warming science point out that CO2 levels naturally rise and fall without human intervention. That’s true, because there has been a steady 20 percent rise and fall over time from a mean of 240 parts per million (ppm). But today all indicators are going off the scale, and in only one direction. The current concentrations are higher than at any time in the last 400,000 years, according to data accumulated from the Vostok ice core in Antarctica.

But that’s only the beginning. The influential Intergovernmental Panel on Climate Change (IPCC), composed of 2,500 climate scientists, envisions a series of scenarios for the end of this century. Like the United Nations" population projections, there are low, middle and high estimates, based on human activity.

Will we, finally, come together internationally and enforce a significant decrease in carbon emissions by 2100 to a modest 5.7 billion tons? Or will the world’s ever-growing automobile and truck fleet, coupled with soaring human population and escalating energy needs, fulfill the IPCC’s worst-case scenario, with five times that much CO2, 29 billion tons every year? The latter seems more likely, as energy demand in the Third World grows at 3.5 percent a year.

Britain’s BBC reports that an annual emission of 29 gigatons of CO2 would mean "the mass death of forests, with the trees releasing the CO2 they had stored up, adding to global warming instead of restraining it. It would be likely to make the eventual collapse of the Ross Ice Shelf in Antarctica inevitable. That, in turn, could trigger a significant global sea-level rise, and the loss of huge and densely populated coastal areas."

Carbon dioxide levels in the atmosphere have risen 30 percent in the last century, but, again, that’s only a beginning. Until 1999, two gigatons of CO2 were added to the atmosphere annually. Since then, with the addition of huge releases from large-scale forest fires, we’ve added six gigatons.

The lofty goals enunciated at the 1992 Earth Summit in Rio, to reduce CO2 to 1990 levels, have failed dismally. Also very unlikely to be realized are the 1997 Kyoto goals, in which 39 industrialized nations committed to cut their greenhouse gas emissions to an average of 5.2 percent below 1990 levels between 2008 and 2012. In fact, even such environmentally conscious countries as Iceland, Denmark, Finland and the Netherlands increased their CO2 output between the Earth Summit year of 1992 and 1999. Of the industrialized countries, only Great Britain, Sweden and Germany are on course to meet their commitments.

Global warming intensifies storms and flooding, as this postman in Werteim am Main, Germany has discovered.© P.Frischmuth / UNEP / Peter Arnold

By 2010, according to projections from the INNOVA Center for Sustainable Development, Brazil will be emitting between 79 and 153 percent above 1990 levels. India will be 113 to 198 percent above, Mexico 49 to 78 percent above, and Korea 233 percent above.

The consequences of this runaway carbon load on the atmosphere could be far worse—and much longer lasting—than we had previously anticipated, says Berrien Moore, director of the Institute for the Study of Earth, Oceans and Space at the University of New Hampshire and chair emeritus of the International Geosphere-Biosphere Institute. He was the lead author of the IPCC’s authoritative Third Assessment Report. He points out that beyond the generally recognized prediction of a 2.5- to 10.4-degree Fahrenheit increase in global temperature over the next 100 years, there is the "longer-term reality of an inherit and far greater climate change, even under the most optimistic assumptions about stabilization of the concentrations of greenhouse gases."

Specifically, even if nearly all greenhouse gas emissions are phased out by 2100 (a near impossibility), then global temperatures will still continue to increase for another 300 to 500 years. Because of the many factors involved, actual climate effects are delayed reactions from past greenhouse emissions. Course corrections are not processed quickly, so negative consequences will continue for centuries. The temperature is likely to rise another 3.8 to 11.2 degrees Fahrenheit over those five centuries, Moore writes, "and there would be little that we could do to avert this change."

The Consequences

Some of the consequences of accelerating CO2 buildup, such as melting polar ice and damage to forests, are well known. Others are relatively obscure, but no less devastating. Again, we’re drawn back to the ancient record. Russell Graham, chief curator of the Denver Museum of Nature and Science, has noted at least 63 sudden climatic changes in the last 1.6 million years, an average of one every 2,000 years. As Gregg Easterbrook noted in "A Skeptical Guide to Doomsday," a 2003 Wired article, "Ten thousand years have passed since the current pleasantly temperate period began, so another sudden shift is overdue. The notion that greenhouse gases could trigger such a rapid change keeps serious scientists up at night
.And since scientists today have little understanding of past climate flips, it’s impossible to say when the next one will start."

What may have killed mammoths and other large mammals 11,000 years ago is a glacial melt in Canada and the northern U.S. that led to extreme winters and summers, and also to a more homogenous landscape of forests and grasslands. Complex combinations of plants disappeared—a pattern that we’re already seeing today as temperatures again warm up. "The primary concerns for endangered specie

s today are habitat loss and geographic range reduction," says Graham. "These are the same concerns that the Pleistocene megafauna faced."

A 2002 National Research Council report says that abrupt climate change is a "wild card" in the global environmental future, noting, "Recent scientific evidence shows that major and widespread climate changes have occurred with startling speed. For example," it said, "roughly half the north Atlantic warming since the last Ice Age was achieved in only a decade
.Greenhouse warming and other human alterations of the Earth system may increase the possibility of large, abrupt, and unwelcome regional or global climatic events."

The term "global warming" doesn’t do the process justice; scientists are finding that the complex factors involved in climate change can also lead to dramatic cooling effects. "Are we on the brink of a new little Ice Age?" ask Lloyd Keigwin and Terrence Joyce, senior scientists at the Ocean and Climate Change Institute. The scientists find evidence of such past changes in ice cores from Greenland and Antarctica. In the Younger Dryas period (named for an arctic wildflower whose remains were found, completely unexpectedly, in Denmark) 12,000 years ago, temperatures were dramatically colder, by about nine degrees Fahrenheit. This cooler period lasted a millennium.

Asserting that human activity had nothing to do with changes 12,000 years ago is rather beside the point. Huge forest fires occurred before the invention of matches and forest management, but our presence has intensified the problem. It’s becoming plain that man-made greenhouse gases act on natural processes and accelerate their effects.

Restless Seas

Consider ocean currents. John Gribbin, an English science professor and author of the popular physics book In Search of Schrodinger’s Cat, worries that global warming "may disrupt the entire system of ocean currents, affecting the entire world’s weather." This problem is of particular concern to England and the rest of western Europe, which are on the same latitudes as frigid Newfoundland and Labrador. Stockholm is at the same latitude as Anchorage, Alaska. They’re warmer because of the Gulf Stream, which carries warm water northward and eastward to the North Atlantic. In the course of a year, Gribbin says, the Gulf Stream provides western Europe with a third as much warmth as the sun itself, keeping it as much as 18 degrees Fahrenheit warmer than would otherwise be the case. If the Gulf Stream were switched off, it could plunge Europe (already subject to cold, dry winds blowing east from Canada) into a mini-Ice Age.

The process that keeps Europeans in shirtsleeves is a giant conveyer belt of moving water from the Pacific Ocean. Gribbin calls this tepid stream, moving at five miles an hour along the oceans" surface, "the longest river in the world." This warm, less-saline water makes an epic journey, traveling west over the top of Australia, around the Cape of Good Hope at South Africa’s tip and up into the Atlantic Ocean.

Deforestation, like this extreme case in Chiang Mai, Thailand, removes the trees that absorb carbon dioxide.© S.Chamnanrith / UNEP / Peter Arnold

The moving water is cooled by the northern chill and becomes increasingly salty, sinking to lower depths for the return journey to the Pacific. This process has changed little since the last Ice Age, but global warming is throwing in a monkey wrench by melting ice in the Arctic Ocean. A UN assessment says Arctic sea ice in summer time could diminish 60 percent by 2050. This fresh water could dilute the salinity of the Gulf Stream, which would mean that it would no longer sink to the bottom of the ocean near Iceland and begin its return trip to the Pacific. According to the Goddard Institute for Space Studies, just one quarter of one percent more melt water in the Arctic Ocean could cause the conveyer belt to stop, and Europe would usher in the Big Chill. Its agricultural productivity could sink to that of Canada, which supports less than a twentieth as many people.

This process is not theoretical; it is already underway. The BBC reports that since 1950 there has been a 20 percent decrease in the flow of cold water in the Faeroe Bank channel between Greenland and Scotland, which is one of the engines of the Gulf Stream. If greenhouse gas emissions continue to increase, the BBC adds, the water density differences that drive the Gulf Stream could decrease by 25 percent in the next 100 years. "As the Gulf Stream becomes weaker, it may become less stable and therefore be likely to shut down completely in the future," the network says.

Awakening the Angry Beast

The problem reaches beyond Europe to potentially affect the whole world. Wallace Broecker, Newberry Professor of Earth and Environmental Sciences at Columbia University, is concerned that "we’re poking the climate system by adding greenhouse gases," and annoying this "angry beast" could cause it to "lash out." Specifically, he sees global warming causing a worldwide rearrangement of ocean currents, with the possible result a decrease in evaporation from the tropics. Since atmospheric water vapor is itself a very powerful greenhouse gas, lowering humidity causes planetary cooling. "If you wanted to cool the planet by nine degrees Fahrenheit and could magically alter the water vapor content of the atmosphere," Broecker says, "a 30 percent decrease would do the job."

But global cooling does not simply cancel out global warming, preserving the status quo (as some simplistic analyses have claimed). William H. Calvin, a professor at the University of Washington, says, "We must be careful not to think of an abrupt cooling in response to global warming as just another self-regulatory device, a control system for cooling things down when it gets too hot. The scale of the response will be far beyond the bounds of regulation—more like when excess warming triggers fire extinguishers in the ceiling, ruining the contents of the room while cooling them down."

Calvin says the whole world could be chilled. "Tropical swamps decrease their production of methane at the same time that Europe cools," he wrote in Atlantic Monthly, "and the Gobi Desert whips much more dust in the air. When this happens something big, with worldwide connections, must be switching into a new mode of operation."

In the more pessimistic of several possible scenarios, Calvin sees planetary cooling causing crop yields to plummet, creating famine and aggravating conflict between nations and possibly leading to World War III.

A starving polar bear crosses open water as the ice floes he depends on are reduced by global warming.© Hinrich Baesemann / UNEP / Peter Arnold

To avert such disasters without drastically reducing CO2, Calvin sees solutions straight out of the Buck Rogers catalog: blowing up ice dams, anchoring bargeloads of chemicals to enhance evaporation, creating a "rain shadow" by seeding clouds to drop unsalted water, and regulating the salty outflow of the Mediterranean Sea. There’s no guarantee that any of these desperate measures would work, or even that cutting CO2 emissions would avert disaster. "To the long list of predicted consequences of global warming—stronger storms, methane release, habitat changes, ice-sheet melting, rising seas, stronger El Niños, killer heat waves—we must now add abrupt, catastrophic coolings," Calvin concludes. "Whereas the familiar consequences of global warming will simply force expensive but gradual adjustments, the abrupt cooling promoted by man-made warming looks like a particularly efficient means of committing mass suicide.&quo

t; In his new book The 2030 Spike, author Colin Mason cautions that global climate change could combine with famine, a world water shortage and fossil fuel deficits to produce "a new Dark Age" in just 30 years.

Beyond Business as Usual

Aggressive, unified worldwide action on global warming would be unlikely even without the determined opposition of the Bush administration. Fulfilling the provisions of the Kyoto Treaty (called too little, too late by many environmentalists) would require a massive behavioral change in industrialized societies, as well as a reversal in aspirations throughout the developing world. People now driving alone to work would have to switch to public transit, coal would have to be abandoned as a fuel for power plants, and forest protection would have to become sacrosanct.

Instead, we’re moving in the opposite direction. As an example, the U.S. (where cars now outnumber licensed drivers) had 128 million vehicles in 2000, and according to the Worldwatch Institute, they were driven 2.3 trillion miles, consuming 8.2 million barrels of fuel per day and emitting 302 million tons of carbon. America is five percent of the world’s population owning a quarter of its cars, but in the 21st century it is Third World car ownership that is accelerating rapidly. Between 1950 and 1996 the vehicle population outside the U.S. grew almost four times faster than the human population. If China had one car for every 1.3 people, the country would have a fleet of some 970 million cars, which is almost 50 percent more than today’s worldwide fleet.

The idea that the planet has finite limits was pioneered in the influential books The Limits of Growth (1972) and Beyond the Limits (1992), written by Donella and Dennis Meadows, Jorgen Randers and (the first book only) William Behrens, III. Mathis Wackernagel is program director of Redefining Progress and lead researcher of a new study that measures the ecological footprint of the human race, concluding that we are currently using 120 percent of the Earth’s resources (up from 70 percent in 1961). Humanity’s impact has increased by half in less than 40 years. According to the study, the planet would require a year and three months to renew the resources used by humanity in a single year.

"Many nations, including the U.S., are running even larger deficits," Wackernagel says. "As a consequence of this overuse, the human economy is liquidating the Earth’s natural capital." Wackernagel’s footprint analysis allows individuals, cities and even countries to measure their own environmental impact. "Any company that doesn’t have its books in order will go bankrupt over time," he says. "And that’s what we are preparing for ecologically."

Waiting for a Catastrophe

Global warming is suspected as a cause of these bleached anemones in the Maldives Islands.© Pascal Kobeh / Peter Arnold

It may take a catastrophe to change our direction from business as usual, says Dennis Meadows, director of the Institute for Policy and Social Science Research at the University of New Hampshire and a co-author of the Limits books. Meadows points out that "when the climate starts to change, it will do so rapidly, going from one extreme to another. By the time we finally try to do something, it will be too late."

Meadows says the team’s investigation into the limits to growth "came to one basic conclusion: that improvements to human welfare cannot be achieved with traditional growth. That will cause the carrying capacity of the globe to collapse." Given present trends, they arrived at these basic principles: 1) We can reach planetary limits and see a catastrophic collapse; 2) We can alter the trends to live within Earthly limits still consistent with everyone having an adequate standard of living; 3) And the sooner we start working on the problem, the greater the chance of success.

Meadows says the data make it clear that resources are deteriorating instead of generating. "We are above carrying capacity," he says. Meadows holds some hope that the European Union, which has a more forward-looking culture, will lead the way to standards that reflect concern about these issues. American inaction, he notes, is partly due to an ill-informed public that is "deprived of information on long-term issues." Meadows says an updated edition of Beyond the Limits will appear in 2004.

One promising approach is to consider global development models. Gerald O. Barney is president of the Millennium Institute, which, he says, "builds awareness of the deficiencies of the World Bank and International Monetary Fund models." The institute’s Threshold 21 (T21) computer model is designed to provide a sustainable alternative for policy planners.

"How are we going to take care of the needs of 12 billion people without undermining the capacity of the planet to sustain them?" asks Barney, who developed the Global 2000 Report to the President for Jimmy Carter. He notes that the World Bank’s motto is "a world without poverty," but "if we promote economic growth so the world’s poor can live as the world’s rich do, we will need an economy with an ecological footprint of seven to 10 Earths—an impossibility. Recycling and solar energy alone won’t get us there."

An Institute for Policy Studies report entitled "Changing the Earth’s Climate for Business" revealed last June that oil, gas and coal projects financed by the World Bank will, over the course of their lifetimes, "release more CO2 than is now being produced per year by the entire planet." The report says that Bank financing leads to the generation of seven billion tons of CO2 annually, and that it spends 100 times more on fossil fuel development than its Global Environmental Facility spends on projects to avert global warming. "This is not only environmentally unsustainable," says report co-author Daphne Wysham, "it is the height of hypocrisy for an institution entrusted with poverty alleviation, sustainable development and climate change mitigation."

Many scientists recognize that the only legitimate response to the depressing data they’re generating is a movement toward a sustainable society, living within clear limits. "Right now the issue of sustainability is not that high on our social agenda," says Berrien Moore. "This is a global concern. There are no magic solutions, but there are paths to a more sustainable society worldwide."

Industrial emissions from coal-fired power plants is a major global warming aggravator.© Age Fotostock

We’ve obviously gone beyond the point where sustainability is just a buzzword for corporate greenwashers. It has to be bedrock policy. The case for this is best made by two visionaries, the late Donella Meadows (who was married to and worked closely with Dennis Meadows) and Father Thomas Berry. During the Harvard Seminar on Environmental Values in 1996, Father Berry observed, "We find ourselves ethically destitute just when, for the first time, we are faced with ultimacy, the irreversible closing down of the Earth’s functioning in its major life systems
Now after centuries of plundering the Earth for our own advantage, we begin to reflect on who we are and what has happened both to the planet and to ourselves. A sudden reversal has taken place. Our bright, new, antiseptic, mechanical world is collapsing about us or dissolving in its own toxic wastes."

Donella Meadows said in an interview with the Center for a New American Dream, "The Earth is huge and can spare a lot of material and energy

for us to support our lives. But there are limits. When we start taking resources faster than the Earth can regenerate them, and when we start putting out wastes and poisons from our consumption faster than the Earth can absorb those wastes and poisons or render them harmless, then something suffers
.In the long run, if we take too much of a resource, renewable or nonrenewable, it runs out. Then we have undercut not only all the rest of nature, but our own selves, and our children, and our grandchildren and their possibilities for having materially rich lives
.In the short term we devastate nature, and in the long term we devastate our own future."

In 2003, knowing what we know about our planetary systems, no one can dismiss these words as alarmist rhetoric.

JIM MOTAVALLI is editor of E.