WASHINGTON (Reuters) - The current carbon market actually encourages cutting down some of the world's biggest forests, which would unleash tonnes of climate-warming carbon into the atmosphere, a new study reported on Monday.

Under the Kyoto Protocol aimed at stemming climate change, there is no profitable reason for the 10 countries and one French territory with 20 percent of Earth's intact tropical forest to maintain this resource, according to a study in the journal Public Library of Science Biology.

The Kyoto treaty and other talks on global warming focus on so-called carbon credits for countries and companies that plant new trees where forests have been destroyed. Trees and other plants absorb carbon dioxide, a greenhouse gas emitted by petroleum-fueled vehicles, coal-fired power plants and humans.

At this point, there is no credit for countries that keep the forests they have, the study said.

"The countries that haven't really been the target of deforestation have nothing to sell because they haven't deforested anything," said Gustavo Fonseca, one of the study's authors.

PERVERSE INCENTIVE

"So that creates a perverse incentive for them to actually start deforesting, so that in the future, they might be allowed to actually cap-and-trade, as they call it: you put a cap on your deforestation and you trade that piece that hasn't been deforested," Fonseca said in a telephone interview.

The countries most at risk for this kind of deforestation, because they all have more than half their original forests intact, are Panama, Colombia, Democratic Republic of Congo, Peru, Belize, Gabon, Guyana, Suriname, Bhutan and Zambia, along with the French territory of French Guiana.

These places need a system of credits to involve them in the "global deforestation avoidance market," said Fonseca, of the World Bank's Global Environment Facility.

Under this kind of system, these countries could agree to keep deforestation rates below the global average and get credit for how much below the average they are, Fonseca said.

These market mechanisms are still being worked out and are likely to be debated at a series of international meetings on climate change this year at the United Nations, in Washington and in Bali, Indonesia.

Besides curbing greenhouse gas emissions, this system could offer other benefits that intact forests provide, according to Russell Mittermeier, a study co-author and president of the environmental group Conservation International.

Intact forests protect watersheds, encourage pollination and preserve biodiversity, Mittermeier said by telephone.

Mittermeier said perhaps 20 to 25 percent of world carbon emissions come from the destruction of tropical forest, but this issue is not at the center of the global warming discussion.

"People are talking a lot about vehicle emissions, industrial emissions, biofuels and recycling," Mittermeier said. "Forests were barely in there and yet forests are ... perhaps the major contributor" to global climate change.