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Climate change a 'questionable truth'

From Saturday's Globe and Mail

A n Inconvenient Truth, the hugely influential documentary starring Al Gore, is a shoo-in for an Oscar. Its riveting depictions of violent storms, collapsing ice mountains and parched deserts have scared millions of people into believing that the world faces a catastrophic fate unless we make dramatic changes to our way of life, starting now.

Climate change has made its way onto the agenda of every developed nation, even the United States, where some of the nation's biggest businesses, including energy companies, are pressing the government to take action. It even figured in George W. Bush's State of the Union speech this week.

And next week the International Panel on Climate Change (IPCC) will unleash another storm of headlines when it releases its latest consensus of scientific findings, stressing even more emphatically that human activity is causing global temperatures to rise.

Is the sky really falling? How fast and how hard? And if the vast majority of scientists agree, then why don't governments act? After all, nobody wants the world to melt.

If you're an average, concerned citizen, no one will blame you for being confused or angry. The global-warming debate has become so shrill, so political and so polarized that it's impossible for even a reasonably well-informed person to figure out who or what to believe. Only one thing is for sure: Science isn't all that is driving this debate. Politics, ideology and scaremongering are too.

Because I'm skeptical by nature, I've always discounted the environmental catastrophists. Their message is religious, not rational. But I've also spoken to enough brainy scientists to conclude that human activity is affecting the climate and that global warming is for real.

That's the famous consensus you keep hearing about. But that's where the consensus ends. Beyond that, the science is very far from settled. Scientists themselves are deeply split about how alarmed we should be, the nature of the threats we face, how imminent those threats are and what to do about them.

For apocalyptic predictions, you need only look to the bestseller list. Tim Flannery ( The Weather Makers) and George Monbiot ( Heat) both warn that civilization will collapse if we do nothing. So does Canada's David Suzuki. In Britain, James Lovelock argues that the Earth has already caught a “morbid fever,” and that “we are in a fool's climate and before this century is over billions of us will die.”

But many scientists are alarmed at the alarmism, and warn that catastrophic scenarios like the ones in Al Gore's film have pushed the science way too far. Kevin Vranes, a climate scientist who specializes in ocean/climate physics and water-resources management, has said, “Some of us are wondering if we have created a monster.”

Last fall, Professor Mike Hulme, the founding director of the Tyndall Centre for Climate Change Research in Britain, wrote a damning condemnation of climate alarmism: “Over the past few years, a new environmental phenomenon has been constructed in this country — the phenomenon of ‘catastrophic' climate change,” he wrote. “The increasing use of this term and its bedfellow qualifiers ‘chaotic,' ‘irreversible' and ‘rapid' has altered the public discourse, [which] is now characterized by phrases such as ‘irreversible tipping in the Earth's climate' and ‘we are at the point of no return.' ”

Prof. Hulme is no climate skeptic. He was the co-ordinating lead author of the chapter on “climate-change scenarios” for the last IPCC report in 2001.

To try to get a grip, I checked in with eight leading climate scientists, climate economists and climate-policy analysts. All believe that man-made climate change is a serious issue that demands action. And all reject the extremists at both ends. They represent the broad middle ground — the people whose voices have been all but drowned out by the shouting.

The first thing they stress is that while climate change is certain, what will actually happen is not. For example, scientists are pretty sure that sea levels will rise, and rising seas will pose a threat to coastal areas. But how much will they rise, and how fast, and where will they rise most? Sorry. Science can't tell you that.

“Nobody can really tell you what the probabilities are,” says Carl Wunsch, a leading climate and oceans expert at the Massachusetts Institute of Technology. “The probability of another metre of sea-level rise in the next 50 years isn't zero, but it isn't 90 per cent, either. And if you pinned me down to tell you what it really is, I couldn't do that.”

Robert Mendelsohn is an environmental scientist at Yale who specializes in modelling the regional impacts of climate change. “The drought issues are one of the great uncertainties,” he says. “We know precipitation will increase, but we don't know exactly where.”

The very great uncertainty of long-term climate impacts is a point that often gets lost in the debate. The scenarios range from mild to severe, but it's the extreme ones that get the ink.

On top of that, many scientists say the average global surface temperature (which is the most popular way to talk about global warming) doesn't tell us very much at all about what's going to happen in any given region of the globe. “It's almost useless for what people care about, which is their growing season and how they live,” says Roger Pielke Sr., professor of climatology at Colorado State University and the state's official climatologist.

Dr. Pielke is steeped in decades of climate research. And he points out that carbon-dioxide emissions are just one of many man-made impacts on the climate. Land-use changes are another. “There are a lot of things that humans are doing to the climate beyond CO{-2}, and we don't understand them,” he says.

We also don't know enough to say with any degree of certainty whether taking action X will produce result Y. “Say you spend a trillion dollars to limit CO{-2} emissions. Will you be able to limit the sea-level rise, or droughts?” Prof. Wunsch says. “People are asking questions of the science that science can't answer.” (For the record, he believes that rising seas could cause “an awful lot of damage to an awful lot of people.”)

Science can, and must, inform policy decisions. But science by itself can't tell us what to do. What to do is a matter of great (and understandable) dispute, and making policy to deal with climate change is fraught with all kinds of real-world complications. Figuring out smart policies to adopt is hard, and implementing them is even harder. It's all very well to sign on to the Kyoto Protocol. But if nobody complies, then what's the point?

All this doesn't mean we should throw up our hands and give up. The challenge is to figure out what actions are feasible and give us a reasonable insurance policy against disaster.

At this point, most people say: Well, obviously we've got to start cutting greenhouse-gas emissions as fast as possible. Surely that's the way to make a difference.

This is one of the most common misunderstandings in the global-warming debate. To explain why, I called on Roger Pielke Jr., a leading climate-policy expert (and, coincidentally, Roger Sr.'s son.)

He supplied this analogy: Imagine that you are filling up a bathtub. Right now, it is 380 inches deep. You are filling up the tub at a rate that adds seven inches every year. The drain at the bottom lets out the equivalent of two inches a year.

Under these conditions, the bathtub will keep filling up at a rate of five inches a year. If we cut the rate of filling by, say, 20 per cent, to 5.6 inches per year, the bathtub will keep filling up by 3.6 inches a year. Cuts in the rate of filling do not mean that the level in the tub will go down. In fact, if you cut the rate of filling to zero, it will still take quite a while for the tub to drain down to, say, 280 inches.

Now, substitute CO{-2} concentrations for tub depth and emissions for water, and you have a rough analogy to the climate system. Carbon cuts will have an impact — but not for many, many years, because they represent only a tiny fraction of the total CO{-2} that's already in the atmosphere.

“ ‘Stop global warming' is a non-sequitur,” Prof. Pielke says. “Any emissions reductions won't have a perceptible impact on climate in our lifetimes. It's quite misleading, as Al Gore suggests, to say that if we drive a hybrid or change our light bulbs, we can reduce the risk from hurricanes.”

The climate debate focuses almost entirely on mitigation (how we can slow down global warming). But climate scientists and policy experts say that in the short term — our lifetimes — our most important insurance policy is adaptation. Nothing we do to cut emissions will reduce the risk from hurricanes or rising seas in the short term. But there are other ways to reduce the risk. We can build storm-surge defences, stop building in coastal areas and make sure we protect our fresh-water supplies from salination. We also can develop crops that will do well in hotter climates.

“Adaptation” is not a word that figures much in climate-change debates. Activists (and much of the general public) think it sounds lazy and defeatist. But the experts talk about adaptation all the time.

“Climate-change policy requires that both of these issues — adaptation and carbon reduction — be addressed simultaneously,” Yale's Prof. Mendelsohn says.

He adds another unpopular observation: Climate change won't necessarily be all bad. Moderate warming would even have some benefits. Large parts of Canada would become far more pleasant, with longer growing seasons, more arable land and warmer winters. Our energy consumption would go down, as would our heating bills. “The magnitude of the good things could be very large for Canada,” he says, while hastening to add that he hopes we are altruistic enough to curb our greenhouse-gas emissions anyway.

For the record, all these experts are highly critical of An Inconvenient Truth and the scary headlines that regularly sweep the media. (Climate alarmism sells, and the media know it.)

Prof. Wunsch, the ocean-currents expert, says that despite what Mr. Gore asserts, there is no chance whatsoever that the Gulf Stream will slow down or stop. Nor did Hurricane Katrina have any link with global warming, nor do this winter's storms and other strange weather. There are enough real worries about climate change that we don't have to invent imaginary ones.

There's something else on which the middle ground agrees. Curbing CO{-2} is in fact a very wise and prudent thing to do. Call it an insurance policy for the long term.

How to do that? We're back to policy again, and consensus is hard to find. But climate economists generally agree that the first and most important thing to do is put a value on the atmosphere. You do this with carbon taxes and emissions caps. If emitting carbon costs money, then people will have a big incentive to cut down on it.

Mark Jaccard is a professor of resource and environmental management at Simon Fraser University in Vancouver, and also the author of an award-winning book called Sustainable Fossil Fuels. It's not a zippy read like The Weather Makers, but it's way more important, and Prof. Jaccard is in big demand these days among people wrestling with climate policy.

He argues that the best way to cut down on emissions is to clean up fossil fuels — which, like it or not, will still be our main source of energy for the next few decades. Cleaning up fossil fuels is far more feasible than, say, imagining we can replace them any time soon with wind or solar or biomass or hydrogen.

How to clean up fossil fuels? Tell the energy industry that it must capture a growing amount of the carbon it emits, by scrubbing it out or dumping it back into the ground. Set the targets and let the industry figure out how to meet them. Start gradually and ramp up. Small changes starting now will reap huge benefits down the road — not in time for the next hurricane season, but in generations to come.

This is not as sexy as putting solar panels on your roof or riding your bike to work. But it's actually a better solution to the problem. California's Arnold Schwarzenegger is doing this already, by imposing carbon-reduction targets on the automakers. “They're market-oriented regulations,” Prof. Jaccard says. “What he says is, ‘You guys figure out how to get it done.' ”

By the way, Prof. Jaccard and other climate economists agree we should have started taking this type of action years ago, and they blast both business and governments for not getting off the dime.

Other experts have different (but not incompatible) takes. “We need to break out the challenges of energy policy and adaptation into many tens of thousands of parts,” Roger Pielke Jr. says. Despite the many uncertainties, we don't need to wait to act, if only because many of the things we should do are worth doing on their own. For example, reducing our reliance on fossil fuels from unstable parts of the world — through substitution, conservation and new technologies — is a no-brainer.

But what about the alarmists? The ones who argue that the only way to save the planet is to stop driving, stop flying and stop consuming? Prof. Jaccard (who told me that he himself tries to live with a “small material footprint”) says: “Environmental activists are using climate change to wrap around their message about how they want humans to behave differently.”

In other words, it's not just carbon emissions they object to. It's our whole materialist, growth-oriented, SUV-driving way of life. For this reason, he argues that people like Tim Flannery are actually dangerous. “He gives people the impression that putting solar panels on your roof is actually a solution to the problem. And it's not.”

Here's another thought from Yale's Robert Mendelsohn. “The mistake Al Gore and others are making is to look at the cumulative effects of all the emissions over the next 100 years if we do nothing. And they say that will be really bad. And they may well be right. But the economics of this is that the damage from emissions now is quite small. So what we ought to be doing now is relatively mild things that don't cost very much. You should start slow and get increasingly strict over time.”

Mark Jaccard agrees. In fact, he argues that if we start to do the right things now, we will scarcely notice because adjustment will be gradual. The important thing is to get started. Now.

So what can a worried citizen do? “Lobby the politicians to put policies in place immediately that put a value on the environment,” he says. “Drive your car to Ottawa if you have to. The most important thing is to get policies in place that are intelligent.” And go ahead and ride your bike to work. At the very least, it will be good for your health.

As for Al Gore, here's one prediction you can bank on: Even though much of what he says is dubious or just plain wrong, he's going to win that Oscar anyway.

Margaret Wente is a columnist for The Globe and Mail.

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