ENVIRONMENT

Feeling the heat

Some scientists say that climate change has already begun to affect the globe

MARK NICHOLS April 24 1995
ENVIRONMENT

Feeling the heat

Some scientists say that climate change has already begun to affect the globe

MARK NICHOLS April 24 1995

Feeling the heat

ENVIRONMENT

Imagine a world of relentlessly rising temperatures, where farmlands are scorched into desert and inland waters like the Great Lakes shrink in the heat. As global warming intensifies, the polar ice caps dissolve and ocean levels rise by more than 100 feet, swamping low-lying islands and coastal areas. Vancouver, Halifax, New York City, Amsterdam, Shanghai and other port cities are inundated. As the global floodwaters rise, more than a quarter of the world’s population is displaced. Take the nightmarish vision a little further and it becomes the weird scenario conjured by Kevin Costner’s overbudget movie-in-progress Waterworld—the human race clinging to survival in an oceanic habitat. And so it must all be fiction, right? Not necessarily. Plenty of scientists believe that the growing accumulation of manmade gases in the Earth’s atmosphere could someday push temperatures to dangerously high levels and bring cataclysmic changes to the planet. And after a year that has seen unseasonably warm weather in some places, violent flooding in others and an ice shelf crumbling in the Antarctic, some scientists think that funda-

Some scientists say that climate change has already begun to affect the globe

mental climate change is no longer just a possibility—it might be happening now.

That thought could inject a note of urgency as thousands of Canadians flock to sunrise ceremonies, plant trees or take their kids on nature walks on April 22 to mark Earth Day. On the 25th anniversary of the first Earth Day, environmentalists have something to celebrate: their efforts over the years have helped to prod governments into cleaning up lakes, reducing acid rain and enacting a growing array of legislation aimed at preserving the planet’s eco-system. Yet many key environmental goals remain unfulfilled—not least

of all the task of persuading nations to drastically cut back the manmade emissions that may be superheating the Earth’s atmosphere.

In recent years, experts have calculated that global temperatures could rise by as much as 4.5° C by the end of the next century—if the human race does not stop contributing to the greenhouse effect by spewing heat-trapping gases like carbon dioxide (C02) into the atmosphere. So far, efforts to reduce the emissions have achieved little. “If you look at current C02 levels compared with historical levels in the planet’s history,” says Philip Austin, an atmospheric scientist at the University of British Columbia in Vancouver, “it’s clear we’re headed right off the chart.”

The latest attempt at engineering a major reduction in emissions was only a limited success. At a meeting of about 130 nations in Berlin earlier this month, Canada was cast in the unaccustomed role of environmental bad guy. The Canadian delegation joined with the United States, Australia and Japan to block a proposal under which the signatories would have agreed to a 20-per-cent reduction in emissions by 2005. Instead, the conference

had to settle for a compromise agreement by the industrialized nations to embark on another two years of negotiations to decide what reductions they are willing to attempt after the year 2000. “It was the best we could squeeze out of the political process at this time,” said Louise Comeau, climate change expert for the Ottawabased Sierra Club of Canada. “But in terms of what needs to be done for the atmosphere, it was a very big failure.” Worse still, many of the industrialized nations admitted in Berlin that they probably will not even meet the modest goals agreed to at the 1992 Rio de Janeiro Earth Summit of reducing emissions to 1990 levels by the end of the century. Environment Canada officials say that, so far, Canada’s national plan for voluntary emission reduction appears likely to fall 13 per cent short of the Rio targets. De-

spite that, Environment Minister Sheila Copps, who led the Canadian delegation in Berlin, insists that Canada will ultimately meet the Rio commitment. To help do that, Copps said that Ottawa would work towards tougher auto emission standards, consider converting federal vehicle fleets to alternate fuels and amend the federal building code to require greater energy efficiency. She said that lifestyle changes were needed to reduce energy consumption. “I think when Canadians realize there is a crisis,” Copps told Maclean’s, “they will act.”

While the political process lurches forward, scientists remain divided over how global warming will unfold. Already, there is clear evidence that some warming is occurring— average temperatures around the globe have increased by between .5° C and Io C during the past century. But that could be the result of a routine climate fluctuation. And many scientists reject any suggestion that recent unusual events—massive flooding in Western Europe and California, balmy winter tempera-

tures in Eastern Canada, the crumbling of an Antarctic ice shelf—are the result of global warming. “It is still an open question,” says Richard Peltier, a University of Toronto climatologist who uses computer-based models to study the Earth’s historical weather patterns, “as to whether anything that is happening now can be attributed to the greenhouse effect.” Other experts, including James Hansen, a New York-based climatologist for the U.S. National Aeronautics and Space Administration, are not so sure. Seven years ago, as North Americans sweltered through a recordmelting heat wave, Hansen became one of the first prominent scientists to suggest that the world was in fact feeling the effects of global warming. Since then, says Hansen, the evidence has grown even more persuasive. ‘We can’t blame everything that happens on the greenhouse effect,” says Hansen. “But what global warming has done is load the dice in favor of warmer-than-normal seasons and extreme climatic events.”

Meanwhile, two scientists working in widely different disciplines have come up with findings that may offer new evidence that climate change is occurring—and could suddenly accelerate. David Thomson, a Canadian statistical expert who works for Bell Laboratories in Murray Hill, N.J., has uncovered evidence that suggests that the timing of the seasons has been changing as carbon dioxide builds up in the atmosphere. After analyzing weather records from more than 220 points on the globe, Thomson discovered that winter has been arriving earlier in some places, including most of North America—but later in parts of Western Europe. Thomson, whose findings were published this month in the journal Science, said that his conclusion “is an aspect of global warming that nobody had predicted— and you wonder how many other unpleasant surprises may be sitting there.”

Michael Risk, a McMaster University geologist and biologist who studies coral reefs, has found evidence that may convey a dramatic message about the speed of global warm-

ing. Coral is formed by seagoing organisms that cling to rock and leave their limestone skeletons behind when they die. Because the skeletons grow in annual bands, scientists can gather detailed information about the climatic history of an ocean region. Three years ago, Risk and graduate student Jodie Smith began analyzing coral taken from the peak of an undersea mountain about 300 miles northeast of Newfoundland. The coral showed that 12,000 years ago, the Gulf Stream, which carries warm water from the Caribbean to northern Europe, suddenly stopped.

The surprise, says Risk, was that the unexplained event occurred so abruptly—within a period of between 10 and 50 years. “If you close the Gulf Stream down, you would freeze much of the Northern Hemisphere,” says Risk, “and my guess is that we’re setting things up where this could happen again”— if, for example, the Greenland ice shelf melted and massive amounts of cold water diverted the Gulf Stream. “What we have here,”

adds Risk, “is a case in the past where an alteration in oceanographic conditions caused the climate to fundamentally reorganize itself in just a few years. We have to be aware that it could happen again.”

Meanwhile, scientists are grappling with evidence that shows that, while the planet is experiencing an overall warming trend, parts of it— including eastern North America— may be getting cooler. The likely reason: water droplets that form around sulphur particles from fossil fuelburning power plants build up into clouds that reflect the sun’s heat back into space. Now, computer models have shown that sulphur dioxide (S02) emissions may indeed be having a slight cooling effect— but not enough to significantly offset

global warming. Moreover, notes Hansen, while S02 emissions are short-lived—they remain in the atmosphere for less than a week—“carbon dioxide will stay up there for hundreds of years.” For that reason, problems created by manmade emissions could continue long after nations launch concerted efforts to cleanse the atmosphere.

One of the easiest ways of removing C02 from the atmosphere is by letting trees and other vegetation do it. But logging operations are rapidly erasing the world’s forests. To protest that destruction, environmentalists in Vancouver will mark Earth Day by unveiling an eight-foot-wide tree-trunk section that loggers cut from a giant yellow cedar estimated to be 1,830 years old. The point of the exhibit, says Paul George, director of the Western Canada Wilderness Committee, is “to remind people that the destruction of our old-growth forests is continuing, and that we need to look after the planet much better than we have”— a thought negotiators might bear in mind as they embark on the next round of deliberations on greenhouse gas emissions.

MARK NICHOLS