By THOMAS L. FRIEDMAN — The New York Times.

Tapajós National Forest, Brazil

No matter how many times you hear them, there are some statistics that just bowl you over. The one that always stuns me is this: Imagine if you took all the cars, trucks, planes, trains and ships in the world and added up their exhaust every year. The amount of carbon dioxide, or CO2, all those cars, trucks, planes, trains and ships collectively emit into the atmosphere is actually less than the carbon emissions every year that result from the chopping down and clearing of tropical forests in places like Brazil, Indonesia and the Congo. We are now losing a tropical forest the size of New York State every year, and the carbon that releases into the atmosphere now accounts for roughly 17 percent of all global emissions contributing to climate change.

It is going to be a long time before we transform the world’s transportation fleet so it is emission-free. But right now — like tomorrow — we could eliminate 17 percent of all global emissions if we could halt the cutting and burning of tropical forests. But to do that requires putting in place a whole new system of economic development — one that makes it more profitable for the poorer, forest-rich nations to preserve and manage their trees rather than to chop them down to make furniture or plant soybeans.

Without a new system for economic development in the timber-rich tropics, you can kiss the rainforests goodbye. The old model of economic growth will devour them. The only Amazon your grandchildren will ever relate to is the one that ends in dot-com and sells books.

To better understand this issue, I’m visiting the Tapajós National Forest in the heart of the Brazilian Amazon on a trip organized by Conservation International and the Brazilian government. Flying in here by prop plane from Manaus, you can understand why the Amazon rainforest is considered one of the lungs of the world. Even from 20,000 feet, all you see in every direction is an unbroken expanse of rainforest treetops that, from the air, looks like a vast and endless carpet of broccoli.

Once on the ground, we drove from Santarém into Tapajós, where we met with the community cooperative that manages the eco-friendly businesses here that support the 8,000 local people living in this protected forest. What you learn when you visit with a tiny Brazilian community that actually lives in, and off, the forest is a simple but crucial truth: To save an ecosystem of nature, you need an ecosystem of markets and governance.

“You need a new model of economic development — one that is based on raising people’s standards of living by maintaining their natural capital, not just by converting that natural capital to ranching or industrial farming or logging,” said José María Silva, vice president for South America of Conservation International.

Right now people protecting the rainforest are paid a pittance — compared with those who strip it — even though we now know that the rainforest provides everything from keeping CO2 out of the atmosphere to maintaining the flow of freshwater into rivers.

The good news is that Brazil has put in place all the elements of a system to compensate its forest-dwellers for maintaining the forests. Brazil has already set aside 43 percent of the Amazon rainforest for conservation and for indigenous peoples. Another 19 percent of the Amazon, though, has already been deforested by farmers and ranchers.

So the big question is what will happen to the other 38 percent. The more we get the Brazilian system to work, the more of that 38 percent will be preserved and the less carbon reductions the whole world would have to make. But it takes money.

The residents of the Tapajós reserve are already organized into cooperatives that sell eco-tourism on rainforest trails, furniture and other wood products made from sustainable selective logging and a very attractive line of purses made from “ecological leather,” a k a, rainforest rubber. They also get government subsidies.

Sergio Pimentel, 48, explained to me that he used to farm about five acres of land for subsistence, but now is using only about one acre to support his family of six. The rest of the income comes through the co-op’s forest businesses. “We were born inside the forest,” he added. “So we know the importance of it being preserved, but we need better access to global markets for the products we make here. Can you help us with that?”

There are community co-ops like this all over the protected areas of the Amazon rainforest. But this system needs money — money to expand into more markets, money to maintain police monitoring and enforcement and money to improve the productivity of farming on already degraded lands so people won’t eat up more rainforest. That is why we need to make sure that whatever energy-climate bill comes out of the U.S. Congress, and whatever framework comes out of the Copenhagen conference next month, they include provisions for financing rainforest conservation systems like those in Brazil. The last 38 percent of the Amazon is still up for grabs. It is there for us to save. Your grandchildren will thank you.