An ambitious plan to put more than 10 percent of Brazil's Amazon forest beyond the grasp of loggers and agribusiness could slash carbon emissions by 1.1 billion tons by mid-century, according to a study released on Wednesday.

Deforestation in the tropics accounts for 20 percent of global emissions of CO2, making it the second largest driver of global warming after the burning of fossil fuels.

Amazonia alone accounts for nearly half of those emissions, and 65 percent of the Amazon forest is in Brazil.

Researchers at the Federal University of Minas Gerais in Brazil and the Woods Hole Research Centre in Massachusetts calculated that the areas pegged for protection under the Amazon Region Areas Program (ARPA) stock some 4.6 billion tons of carbon, equivalent to 20 times the annual emissions of Germany.

The ARPA network, slated for completion in 2012, would cover 12 percent of Brazil's tropical forests.

They then estimated how much carbon would be released into the atmosphere over the next four decades if the designated areas were not protected — a total of some 1.1 billion tons of CO2.

The report was presented in Bonn at the UN Convention on Biological Diversity, where more than 6000 representatives from 191 countries have gathered to map out a plan for saving the planet's flora and fauna.

Whether these carbon emissions can be avoided depends a lot on enforcement in the nature reserves, experts say.

"Brazil is trying to battle illegal logging, but as long as the demand for the wood remains strong, they have a very hard time doing anything about it," said Saskia Richartz, policy director for biodiversity at Greenpeace.

Brazil's new environment minister, Carlos Minc, took up his functions on Tuesday in a government increasingly split over how to balance preservation and development in the Amazon rainforest.

Minc, the 56-year-old former environment secretary for the state of Rio de Janeiro, replaces a highly respected minister, Marina Silva, who unexpectedly stepped down early this month after losing a series of inter-ministry fights over the future of the Amazon.

The rate of deforestation in Brazil's Amazon forest declined for the third consecutive year in 2007, but has again increased during the first half of this year, according to studies based on satellite photos.

More than 11 224 square kilometres of Brazil's tropical forest disappeared last year.

AFP