The second option is for developed countries to pay trillions of dollars to finance a green energy revolution in developing countries. This is politically unthinkable: Can anyone sanely imagine the U.S. Congress appropriating hundreds of billions of dollars for China, an economic competitor?

The final possibility is for developed countries to compel developing countries to reduce emissions by taxing the carbon content of their exports. Countries like China depend on export-driven economic growth, so a carbon tariff would surely get their attention, but in a very bad way—retaliation in kind would be almost assured. That would launch a global trade tariff war of the sort that exacerbated the Great Depression. That is the last thing the ailing global economy needs.

Of all three possibilities, the smart money is on global inaction. “Doing something” about global warming doesn’t come cheap—the International Energy Agency estimates it would cost $45 trillion to halve emissions by 2050—and there is no precedent for international burden sharing of this magnitude for anything short of a world war. History implies that a global response to global warming is impossible. Current climate diplomacy certainly suggests as much.

That’s not a cause for despair. There is ample evidence that the benefits of economic growth unhindered by costly emissions controls surpass the deleterious effects of global warming. According to World Bank estimates, nearly 2 billion people in developing countries rely on dung, wood and charcoal to heat their homes and cook their food. For the impoverished, a coal-fired power plant giving them access to affordable energy would be a blessing. We can afford to let the climate be.

William Yeatman is an energy policy analyst at the Competitive Enterprise Institute and a contributor to Globalwarming.org.