If we fully develop Alberta's oilsands and burn the oil they produce, we will raise the temperature measurably all over the planet. That's the conclusion of an analysis by University of Victoria scientists Andrew Weaver and Neil Swart and published in the journal Nature.

Rather a big deal, one would think. But that's not what we read in the media this week.

The banner headline on the front page of the Globe and Mail: "Science rides to aid of oilsands."

Weaver and Swart found that burning all the economically accessible oil in the oilsands would raise the average global temperature by .02 C to .05 C, the Globe noted. "By comparison, burning all of the world's enormous coal resources would raise temperatures 15 degrees, while consuming the new global bounty of shale gas would produce a lift of just under three degrees. (Using up economically accessible reserves of natural gas and coal will raise temperatures .16 and .9 per degrees, respectively.)"

Seen that way, the oilsands look totally insignificant. And that was the way the story was portrayed throughout the media: Everybody relax. The oilsands are no big deal. Science says so.

Now, Friedrich Nietzsche got a little carried away when he said "there are no facts, only interpretations," but he had a point.

To understand facts, we must interpret them. And even when we interpret facts in good faith, interpretations can vary widely.

So how are we to interpret Weaver and Swart's study? The no-big-deal interpretation is one way to see it. But it's not the only way. There are others, including the one I opened this column with.

And yet it was the no-big-deal interpretation that dominated media reports. Why? Was it the insidious manipulation of the oil industry? A conspiracy in the corporate media?

No. It was James Hansen and Bill McKibben. They're responsible.

Hansen is the NASA climatologist who has led the charge against climate change from the earliest days. McKibben is a renowned environmentalist who heads 350.org, one of the leading climate change advocacy organizations.

Obviously, Hansen and McKibben do not believe the oilsands are no big deal. And we can surmise that both men were appalled to to see "science says oilsands are no big deal" in the media this week. But still, they were responsible.

That's because James Hansen famously called the oilsands a "carbon bomb." If they are fully exploited, he said, it's "game over." And Bill McKibben repeated these claims constantly when he led the fight against the Keystone XL pipeline.

Keystone was a remarkable victory for McKibben and Company. The forces arrayed against them were formidable. But the environmentalists succeeded in elevating the issue, stigmatizing the oilsands, and bringing political counter-pressure to bear on the White House.

During that struggle, some climate scientists and activists criticized the rhetoric of Hansen and McKibben. The oilsands are significant, they said. But a "carbon bomb"? And "game over"? That's wildly out of proportion. It's hype.

But McKibben and Company won. And you can't argue with success. Lots of environmentalists saw the fight against Keystone as a model for the future.

I hope they're reconsidering now.

Hansen and McKibben won a tactical victory by portraying the oilsands as a mammoth threat that could produce catastrophic climate change.

But they also set a benchmark. It was inevitable that when a proper analysis was done the results would be compared to that benchmark.

And it was inevitable that there would be headlines like "Science rides to aid of oilsands."

And that isn't the only damage Hansen and McKibben's hyperbole will do to their cause. Having made wildly inflated claims, and then been so publicly contradicted by solid science, Hansen and McKibben will find their credibility has taken a big hit.

And they can be sure that the next time they make any claim about the oilsands, or anything else, this will be flung at them from every direction.

They won a tactical victory. But it cost them a strategic defeat.

This is an old story in the environmental movement.

In 1968, Stanford biologist Paul Ehrlich published The Population Bomb, which forecast famine and collapse if radical change wasn't undertaken immediately. Ehrlich's powerful language helped make The Population Bomb a smash.

Millions of copies were sold. Ehrlich's advocacy group - "Zero Population Growth" - mushroomed. Ehrlich became a prominent leader in the burgeoning environmental movement.

But as the years passed, events turned out differently than Ehrlich expected. His predictions failed. The strong, clear, confident, and frightening language he used - the language which had done so much to grab attention and advance the cause - started to look ridiculous. And Ehrlich became a useful weapon in the arsenal of anti-environmentalists.

Whenever an environmentalist says climate change is dangerous. Whenever a scientist worries about feeding a global population of nine billion. Whenever anyone anywhere issues a warning the anti-environmentalists don't want people to take seriously. They mock Paul Ehrlich.

The logic is false, of course. The fact that Paul Ehrlich was wrong doesn't mean others who raise an alarm are wrong. But it's a powerful rhetorical bludgeon. And Paul Ehrlich gave it to them.

Hyperbole works in the short term. There's no doubt about that. It gets attention and action. But the long term is something else entirely.

And if the struggle against climate change is about anything, it's about the long term.