In the heart of the Amazon, a group of lumberjacks is pioneering the sustainable exploitation of the world's biggest rainforest doing their part to combat global warming.

Donning the orange helmet of the Flona Tapajos conservation unit, Marcelo Castro thrust into the forest with his colleagues, picked out a tree from a government list and ignoring the sticky humidity, powered up his chainsaw.

The 26-meter (85-foot) tree moaned before crashing loudly to the ground. But thanks to Castro's precise cuts into the trunk, the falling timber caused only minimal damage to the surrounding forest.

Two hours later, government inspector Carlito Lira noted the tree's type, origin and serial number, but also the name of the man delivering the wood into town and his truck's license plate number.

Trees cut down in this part of the forest, in the western part of Para state, are transported to the port of Santarem an hour away before crossing the Amazon during a days-long journey aboard a ship to reach the Atlantic and arrive in Europe with the guarantee they were not cut down illegally.

The government has yielded 32,000 hectares (79,000 acres) of the Tapajos National Forest to the cooperative, demanding environmental and social management in exchange, with 15 percent of the profits going to local communities.

The cooperative works on 1,000 hectares (2,470 acres) each year, where it can cut down pre-selected trees. The zone is then left untouched for 30 years so that the forest can regenerate.

The Amazon has been dubbed the lungs of the earth for its ability to transform dangerous carbon dioxide gas into oxygen.

Created four years ago, the cooperative counts 60 lumberjacks. It has won a government prize for "sustainable trade" and a two-million-dollar contract with a lumber company.

"Our main challenge is to work in a sustainable way so that our children can realize this vision," said cooperative president Sergio Pimentel.

Para University specialist Lia Melo hailed this type of exploitation because it "has no impact on the climate and protects the forest, with limited and selective forestry. The workers' presence in the region guarantees that nobody will set a fire."

Tapajos was a good example that should be followed unlike that of clandestine cattle farmers and lumberjacks who are inflicting unparalleled damage and deforestation on the Amazon, she said.

But such projects are expensive and require training.

The Pimentel cooperative was launched with a fund of 800,000 dollars as part of a joint Brazil-Germany project.

Such initiatives, still few and far between, will be at the heart of UN-sponsored climate talks in Copenhagen December 7-18, since the destruction of the planet's major forests releases huge amounts of carbon-dioxide trapped in its vegetation into the atmosphere.

This accounts for some 20 percent of the greenhouse gases blamed for global warming.

"In order to fight deforestation, you have to show inhabitants that the forest has a value," said local environment official Gustavo Podesta.

"We will only reach that goal when we find a way for the inhabitants to earn more by exploiting it than destroying it."

Brazil is the fourth-biggest emitter of greenhouse gases in the world, largely because of the carbon released through the deforestation of its vast Amazon forest by ranchers and farmers.

It has vowed to offer a "voluntary" cut of up between 36 to 39 percent in greenhouse gas emissions against Brazil's forecast level of emissions in 2020, namely by reducing Amazon deforestation by 80 percent.

The remainder of the cuts would come from making efforts in farming, industry and improving energy efficiency.

But Brazil has asked that rich, developed nations help finance forest preservation, a stand that was also backed by a meeting of the 54-nation Commonwealth at the weekend.