Gov. Brian Schweitzer's remark this week that Montana lacks enough clout with automobile manufacturers to set its own fuel efficiency and emissions standards hardly comes as a surprise.

As he pointed out, the suggestion in a global warming report that the state should establish such standards is impractical because Montana, unlike California, doesn't buy enough vehicles to hold that kind of sway over automakers.

But in a larger sense, the governor said, a patchwork of different state regulations is unworkable, anyway. Manufacturers can't be expected to cater to a smorgasbord of different standards in different states. What's needed, Schweitzer said, is congressional action to set uniform standards throughout the country.

That's certainly true, as far as it goes. But the real difficulty goes well beyond Congress. Warming is a global issue that transcends any single country. Critics have long complained that the U.S. uses a disproportionate share of the world's energy, but it won't be long before places like China and India, with populations dwarfing that the United States, will be pouring out huge percentages of the Earth's pollution.

That doesn't mean the U.S. shouldn't do its share, despite the understandable difficulty many people have buying in. After all, wide and "perfectly natural" swings in climate always have marked the world's history, including most recently the many ice ages that occurred during the past three million years. And there were far warmer episodes as well, such as during much of the Cretaceous period from 65 to 145 million years ago when dinosaurs flourished. (Even Antarctica was a warm and creature-friendly place for much of that time, largely because plate tectonics had shaped the continents in such a way that warm ocean currents were directed down to far southern latitudes, much as, on a smaller scale, the Gulf Stream currently warms northern Europe.)

But all those wild swings, occurring over geological time, have no bearing on current evidence of man-caused warming. Humans, facing lightning-fast changes in climate and sea levels of their own making, are looking at the possibility of mass evacuations from drowning lowlands and global crop disruptions that would make today's economic woes seem laughably tiny. The sooner people worldwide come to grips with that, the better. And enforcing lower vehicle emissions standards, baby step that it may be, is one place to start.