Now that the summer doldrums are upon us, when politicians and other shakers of the news go on holiday, it’s a good time to ask what the big issue is. Is it Sunday shopping? Gas regulation? Health care? The economy? The war on terror?

Let me answer by saying that I went to see Al Gore’s film, An Inconvenient Truth, last week. It was a presentation — a masterful one — of the scientific facts that are well known about climate change: the increase in carbon dioxide in the atmosphere, the dramatically melting glaciers (40 per cent of the world’s population depends on water from glacial melt — and it’s disappearing), the increasingly violent weather and its consequences, the slowing North Atlantic current, and so on.

It is capped by a rousing argument by Gore, known for being cheated out of the U.S. presidency in the 2000 election, to the effect that reducing emissions can be done if the world can generate the will to do it.

The film, then, merely makes a good show of the obvious — the obvious being such that even that recalcitrant body, the U.S. Congress, last month finally produced a report admitting its reality. There is simply no reasonable doubt about climate change, about the threat it poses, or about the fact that human pollution is causing at least most of it. Or about the fact that action is urgent. That is the big issue.

Or, rather, it should be. But in reality, we’re not there yet because no matter how obvious the obvious is, the resistance to it is ferocious.

The real issue is the battle to get the obvious across. The anti-environmental insurgency is a fierce thing that has kept the U.S. government in its thrall, making it alter and suppress the conclusions of its own scientists, and can still claim new victories like the election of the mainly anti-conservation Harper government in Canada.

It has also kept the public confused despite the near-unanimity of the world’s scientific community, thus preventing the world from acting effectively.

At the heart of this resistance you’ll find the argument that, yes, global warming is real (a retreat from earlier denials), but doing something about it is too expensive. Economic growth, the profit motive, must always trump the environment even if the Earth itself is in danger.

The Global Climate Coalition in the U.S., made up of 46 major corporations and trade associations, is the main voice for this view. Although it has had some high-profile defections (GM, Daimler-Chrysler, Texaco, BP), it is still a powerful lobby.

My personal favourite among the lobbies and think tanks, however, is the Greening Earth Society, made up of coal-dependent utilities in the western U.S. states, which argues that C02 emissions are good for the planet, and the best way to get more is by burning more coal! Gotta love the chutzpah. And it works because the George W. Bush gang buys it.

You’d think that with oil prices rising, the time would be right to strike a blow for the necessary conservation — something I always thought would happen, naively as it turns out. Instead, perversely, it has just made the dirty alternatives — coal, tarsands — more attractive.

In the Calgary highrises, ripping Alberta apart to extract the oilsands as quickly as possible is a holy cause, with pollution effects quickly rising. In fact, it was Al Gore who recently pinned the tarsands frenzy down nicely by observing that “junkies find veins even in their toes,” steaming up Alberta Premier Ralph Klein, Canada’s grandest poobah of environmental destruction.

Then there’s the resistant psychology among a cynical public. There’s a novel — State of Fear by Michael Crichton, arguing that climate change is a plot — that has made a splash in the U.S. and been celebrated by anti-environmentalists. It plays on the same public incredulity as The Da Vinci Code — that is, if 99 per cent of scientists say global warming is so, then it must be a conspiracy. According to a review on the Union of Concerned Scientists website, the author has smartly cherry-picked through the graphs and charts to come up with his story, the usual route for climate change denial stories.

However, as this same reviewer points out, climate change is only a part of the story. To go with it, there’s the rampant destruction of species, of forests, of earth, of the ocean ecology and, increasingly, as the wipeout of New Orleans showed, of human habitat.

It’s time to get serious about this stuff. The fact that a hit movie can be made out of something as unlikely as an ex-politician’s lecture is hopefully a sign that we are.