Suppose you’d been invited to go into the ring with Muhammad Ali at his prime, for a 15-round bout. You’d almost certainly have said, “No thanks.”

Climate change: down for the count.

Photo: iStockphoto

But what if you had no choice? Say someone had a gun to your head, and you’d be killed if you didn’t comply? What would you do? One option would be to cower in the ring, letting Ali pound you senseless. But another approach might be to go for it: bob and weave, dance and waggle — give it your best shot, maybe even have a little fun. And hope this guy’s talk of “hospitalizing a brick” is all bluster. After all, you have no choice.

This is the situation we find ourselves in with climate change. We have a nasty battle in front of us, and we have no choice but to fight it. The only question is what attitude we take into the ring.

By now most Americans know that climate change is what’s for dinner for the foreseeable future. They also know what will be on the plate — a heaping serving of doom and gloom. NASA’s James Hansen, one of the world’s leading climate scientists, has said that if we don’t take radical action to reduce global greenhouse-gas emissions in the next decade, our children will be living on a planet unrecognizable to us.

Elizabeth Kolbert of The New Yorker concludes her book Field Notes From a Catastrophe with this chilling comment: “It may seem impossible to imagine that a technologically advanced society could choose, in essence, to destroy itself, but that is what we are now in the process of doing.”

As Hansen, Kolbert, and many other leading thinkers are striving to make clear, climate change seems to be the most pressing issue ever to face humanity. But the problem is that humans, and Americans in particular, can’t be galvanized into action by “the sky is falling” scenarios, even if they’re true. We tend not to believe them, partly because we have such a history of overcoming predictions of doom with technology or luck (population, Y2K, and ozone-layer destruction, for example), and partly because we can’t imagine the scope of a challenge like this. The Black Death killed off a third of Europe, but that was in 1348; we don’t have the experience, or social memory, of real catastrophe.

To solve this problem, we need to entirely reengineer our energy infrastructure — which is to say our societies — in order to cut greenhouse-gas emissions 90 percent by century’s end. It will be the greatest challenge humanity has ever faced. But there’s another way to look at climate change. It is an opportunity on the scale of the Enlightenment or the Renaissance, a rare chance to radically change the face of society forever. Such wholesale societal change is within our ability: we have done it before.

When Europe emerged from the Dark Ages, it moved from a period of irrational superstition — when mythology, not reason, ruled people’s lives, and fear, not optimism, was the operating principle of the day — into an age of reason and rationality. The movement was traumatic, but ultimately it improved every aspect of people’s lives, from medicine to law, science to government.

Like the Enlightenment, tackling climate change will require a century-long revolutionary mobilization of society’s intellect, finances, mores, vision, government, and technology. And the payoff, the promise of overcoming this challenge, is not just a safe, stable, and livable world. It is a planet from which the barriers to utopia are substantially removed.

In a highly efficient planet running on clean energy (which is a world that has solved the climate problem), most existing pollution will be gone, and many of the obstacles to solving other problems — poverty, starvation, access to clean or any water, disease — will be significantly reduced. Wars will be less likely without the need to fight over scarce resources like oil or water. The health risks associated with contemporary energy generation and usage — mercury in our blood, acid destroying our lakes and forests, diesel fumes in our lungs, and toxic smog in our cities — will decrease significantly, if not vanish altogether. And the environment — on which much of our wealth is based — will be able to rebound and flourish when the stresses of mining, drilling, and clearcutting are replaced with cleaner, renewable options.

My favorite sport is white-water kayaking. When faced with an especially difficult section of river, I will scout the run, examining all the obstacles from the bank, planning a safe route through the rocks, holes, and churning waves. At some point, though, most kayakers get tired of scouting. Anxious to tackle the challenge, we want to get in our boats and go.

As Americans, we have scouted this climate problem to death. Yes, we are frightened by the immensity of the problem. But this is the opportunity of a lifetime, maybe of a species.

Like the leaders of the Enlightenment, who viewed themselves as courageous, able, and hopeful, Americans are ready to engage climate change frontally, right now. Because we have no choice on the matter, we might as well relish — even enjoy — the fight.