One can argue from disaster—and I do a lot of that. I wrote the first book about global warming, and it was called The End of Nature. I've helped organize demonstrations in thousands of places around the world that have felt the sting of climate change—places like the Maldives that are going to disappear underwater, or the Sudan where drought leads to war. Or for that matter, South Royalton, where in 2011 the rain wouldn't stop and the water kept rising till all was sodden.

Or one can argue from joy—from the list of glories we’re trying to save in the fight against climate change. The list stretches wide: from the species we love and honor (the noble moose, now in steep decline as warm winters load ticks by the ten thousand upon his broad back) to the foods we cherish (in recent months, news stories have chronicled the decline of coffee, cacao, and beer in a warming world—since those are the basic food groups in a happy, well-rounded life, it’s easy to get upset). But for me, even now as the summer bounty arrives and the Green Mountains take up their namesake color, the greatest joy of all may be winter.

Why? Because for a stretch every year at our latitude, friction lets go its insistent grip. Sometime in November (though I start watching the weather forecasts in late September) the gray sky above Vermont’s mountains starts to spit not drops but crystals, and they begin to pile. It takes a while before they stick to the warm ground, but as it chills and as they accumulate, friction begins to disappear. Yes, if you’re driving in an ice storm this is a problem. But for any other purpose, it’s a blessing of the highest order. Suddenly, equipped with a pair of skis or skates, the annoying Newtonian existence gives way to slipping grace. You push and then you...glide. It’s as magic as magic comes, and just the fact that it happens every year keeps us from fully appreciating its extraplanetary charm.

But it happens a little less reliably now. Up north, the deep binding cold has given way to long stretches of warm weather. Last winter much of the Iditarod sled dog course was actually more useful for mountain biking. In Siberia, forest fires are occurring four and five degrees of latitude north of where they’ve ever been before. Greenland is slowly dwindling.

This is a premonition for the rest of us. Already, on average, winters are shorter than they were, losing a week or two at either end. (We have good records, among other things, of ice-out dates on New england lakes, because so many rotary Clubs have always held that contest where you guess when the junked car is going to drop through the weakening floes.) Already we have too many snowstorms that turn into a rotten rain halfway through. And even when winter is stern and sweet, as it was last year, scientists explain it’s likely because of the complications of climate change, particularly a jet stream that ridges more shaprly as Arctic ice disappears.

Much worse is to come, of course. So far we’ve only raised global temperatures about a degree Celsius, orless than two degrees Fahrenheit. This is the equivalent of less than a watt per square meter, or less than one of those tiny white Christmas tree lights. (There are, it must be said, a lot of square meters on the planet; by another measurement each day we add the heat equivalent of 400,000 Hiroshima bombs.) Going forward that number will steadily increase: the scientists say with robust confidence that we’re on track to see the temperature rise three or four degrees before the century is out.

That will do many things. Seawater is already 30 percent more acidic than it was 40 years ago, but its pH is forecast on present trends to just keep plummeting till, as one oceanographer put it, the great seas are “hot, sour, and suffocating.” Seas will rise past the point where even rich cities can safely defend themselves. Forests will continue to burn at an accelerated rate.

And winter? Well, when the EPA commissioned a series of regional reports on the effects of climate change, the first one published concerned northern New england. By mid-to late century, they said, snowmobiling and cross-country skiing would be “extinct.” Downhill skiing might survive on manmade snow at high elevations and north-facing slopes for a reduced season. But forget all the Currier and Ives images: No pond hockey. No sleighs to grandma’s house. No magical, frictionless winter dance. Just an endless mud season, punctuating the time till the summer’s heat waves return.

Having been duly warned by scientists, we now get to decide. If we continue on with business more or less as usual, we know what will happen; pleading ignorance before our children is no longer plausible. If we act swiftly to get off fossil fuel, we can’t stop global warming (too late for that), but we can keep it from getting entirely out of control. Or so we still think—there are some researchers who believe we’ve waited too long already, but they are still in the minority.

Acting won’t be easy. It will take every tool that policy-makers and legislators can devise, and it will take a society willing to subvert selfish interest and emphasize the future good. It will take creating friction of a different kind, friction that slows down the fossil fuel industry. Some of us may have to go to jail (and some of us may have to lawyer those folks back out of jail). None of it’s easy: it happened last century mostly in the face of fascism and racism, which have easier faces to conjure up than carbon. But if we hold fast to those things that have marked our world as ‘specially beautiful, then we have a chance. For all who love Vermont, winter may be chief of all.