Brazilian President Luiz Inacio Lula da Silva signed a decree Friday creating a fund that will seek donations from developed countries to help protect the Amazon rain forest and combat global warming.

Officials say the fund could raise as much as US$21 billion by 2021 for projects promoting alternatives to rain forest destruction, protecting nature preserves and developing scientific and technological advances to protect the environment.

"Brazil will certainly assume its responsibility to preserve the Amazon, to combat global warming," Silva said at a ceremony at Brazil's National Development Bank, which is charged with administering the fund.

But even as he sought to attract foreign money, Silva took a swipe at international concerns over Brazil's stewardship of the world's largest remaining tropical wilderness.

Other countries "talk as if they own the Amazon, but we know what it represents to humanity and to Brazil. And what needs to be done will be done," he said.

Environment Minister Carlos Minc said the fund is essential for promoting a new development model for the impoverished region, covering nearly 60 percent of the nation.

"Our war isn't against last month's deforestation numbers, it's against a model that leaves people impoverished and the destroys the rain forest," Minc said.

Environmentalists said the fund may be more important for what it symbolizes than how much money it eventually raises.

"This is the first time Brazil is accepting the link between global warming and preserving the forest," said Sergio Leitao, director of public policies for Greenpeace Brasil. "For a long time, Brazil was violently opposed to this, insisting fossil fuel was to blame. That's true, historically speaking, but today forests play an important role."

Logging and burning in the Amazon releases an estimated 400 million tons of carbon dioxide into the atmosphere every year, accounting for up to 80 percent of Brazil's greenhouse gases — and making the country one of the world's highest sources of emissions.

Leitao also said Brazil may have a hard time raising much money for the fund during a global economic downturn, at least until it can demonstrate serious progress in the fight against Amazon destruction.

Norway recently offered US$500 million over five years to protect the world's forests. Brazil, which is home to nearly 70 percent of the Amazon, is likely to get at least some of that money.

Eduardo Bandeira de Mello, chief of the National Development Bank's environmental department, said the fund could attract as much as US$1 billion during its first year.

"This US$21 billion figure (by 2021) is based on the fund's potential to attract donations, not on expected donations," Mello said.

A recent study by the environmental group Imazon estimates that the Amazon loses the equivalent of one and a half football fields of forest cover every minute to logging, ranching and farming.

About 20 percent of the Amazon rain forest, an area larger than Western Europe, has been destroyed.