Two questions: what bids do I hear for Guyana’s rainforest—and why is Harrison Ford having a patch of his chest hair ripped off with what looks like duct tape?

The answer to the second is simpler. In a 30-second video produced for Conservation International, Ford, looking not at all Indiana-y, lies on his back while a woman in white applies goop to his chest and covers it with a cloth. Ford intones that “every year, tropical forest equal to an area the size of England disappears. That’s a jungle the size of Manhattan lost every four hours. Saving forests is more than helping wildlife survive. It combats climate change, and allows people to continue getting the fresh water and food and medicines they need from healthy forest ecosystems.” As the woman secures the cloth, Ford tells us that “every bit of rainforest that gets ripped out over there”—cue the cloth ripping off his chest hair—“really hurts us over here.”

“Save the rainforest!” never went away as an environmental cause, and has been a front-burner issue since at least 1992, when the Earth Summit was held in Rio de Janeiro in part to highlight the importance of the Amazon rainforest to mitigating climate change. (The Earth Summit was where the first President Bush signed a climate treaty committing the U.S. to reducing greenhouse gases. Oh well.)

But as scientists do the math and despair of countries controlling their emissions of carbon dioxide before it’s too late, the importance of rainforests has grown. Burning and clearing tropical forests emits some 20 percent of the world’s greenhouse gases every year, more than all the cars, trucks and airplanes combined. But virtually all the money pouring into projects aimed at stabilizing the climate is going into alternative energy; less than 1 percent of the investments in the global carbon market created by the Kyoto Protocol is going to preserve tropical forests.

This is where Guyana comes in. The South American country still has some 80 percent of its original Amazon forest cover. At a press conference organized by Conservation International this week, President Bharrat Jagdeo basically asked the world, “what am I bid to keep it that way?”

Or, to quote him, “we are willing to place almost our entire rainforest, which is larger than England, under the supervision of an international body to ensure compliance” with standards of sustainable forestry, which basically mean preserving the forest’s ability to absorb and store carbon dioxide. (Guyana’s forests store 250 to 400 tons or more of CO2 per hectare, for a total of hundreds of millions of tons. For comparison, energy use in all the homes in the U.S. caused the emission of about 300 million tons of CO2 in 2000.)

How much will it cost? The market will determine that, but economists estimate about $10 per ton of CO2. If the world wants to preserve, say, 500 million tons of CO2 in Guyana’s forests, it will cost $5 billion.

Worth it? That depends on what other methods of carbon sequestration cost, but it’s in the ballpark for other forms of forest sequestration and way cheaper than geologic storage, though cost estimates vary widely, as Figure 6 in this report shows.

As things now stand, the Kyoto Protocol says countries can claim carbon credits (which can be applied toward the amount they have to reduce their CO2 emissions) only if they replant or restore degraded or deforested areas. According to the concept of avoided deforestation, although a mature forest is not absorbing as much carbon from the atmosphere as when it was young, it is still storing a huge amount that we better keep out of the atmosphere. Countries with lots of intact forest could, in theory, blackmail the world: "want to keep rising oceans out of the lobbies of your high-rises and away from the pricey condos along your coasts? Pay up."

Let the bidding begin.