SAO PAULO — A proposal to help farmers and ranchers in Brazil's vast Amazon rain forest is alarming environmental groups, who say it will speed destruction of the world's biggest natural defense against global warming.
The measure, which was being debated Tuesday in Brazil's Congress, would loosen restrictions on the amount of forested areas that can be legally cut and grant an amnesty to those who illegally felled trees before July 2008. It also would also reduce the strip along rivers that cannot be touched and would allow farmers to use hilltops.
Environmentalists say those changes would lead to flooding, silty rivers and erosion and say the full package would inflict severe damage on the rain forest, an area the size of the U.S. west of the Mississippi River that absorbs the greenhouse gas carbon dioxide.
About 20 percent of the Brazilian rain forest already has been destroyed, and 75 percent of Brazil's greenhouse gas emissions are estimated to come from forest clearing as vegetation burns and felled trees rot.
Farmers, though, feel betrayed by the tough rules imposed in the late 1990s. Two decades earlier, Brazil's military dictatorship, seeking to speed development, had encouraged them to enter the Amazon, offering them free land if they would clear up to 50 percent of their land of trees.
Environmentalists and farmers alike say Brazil's government is unable to adequately patrol the vast and inhospitable Amazon region to enforce the laws in any consistent manner.
Congressman Aldo Rebelo, who introduced the measure, said the current law makes it impossible for farmers to make a living and said that nearly nobody now complies with it.
"The environmental ministers are only looking at the environmental side, not mentioning any concern about that fact that almost 100 percent of farmers are illegal," he said. "Our concern is with the environment, but also with the situation of the farmers in our country."
Brazil's agricultural industry says the environmental laws keep the nation from meeting its economic potential. The country is the world's No. 2 producer of agricultural products while using just a third of its arable land and farmers say they could easily surpass the U.S. if they were not shackled by the laws.
Brazil's forest law now states that landowners in the Amazon must maintain standing forest on 80 percent of their property.
Rebelo's bill would remove or sharply drop that limit for farmers and ranchers who have no more than 990 acres (400 hectares) of land. Backers say the amnesty is justified because many farmers had cut trees well before the tighter limits were imposed.
Environmentalists say big farmers would just split their parcels to qualify for the exemption, and they say amnesty would set a bad precedent. Brazilian President Dilma Rousseff has said she would veto that part of the law if passed by Congress and, later, the Senate.
"The proposed amnesty upholds a long tradition in Brazil of legalizing the illegal. People believe they can deforest illegally because sooner or later all will be forgiven," said Philip Fearnside of the government's National Institute for Amazon Research.
Satellite images from Brazil's National Institute for Space Research indicated deforestation in the Amazon last year dropped to its slowest pace in 22 years.
Between August 2009 and July 2010, 2,490 square miles (6,450 square kilometers) of forest were lost, a 14 percent drop from the year before, and the least since 1988 when the agency began recording the destruction. It is down from a peak in 2004 when 10,723 square miles (27,772 square kilometers) were felled.
Last week, however, the government announced that 230 square miles (590 square kilometers) of deforestation were recorded in March and April, nearly six times more than in the same period last year.
Associated Press writers Marco Sibaja in Brasilia and Stan Lehman in Sao Paulo contributed to this report.