Activists are warning that a proposed revamping of Brazil's tough environmental law could roll back recent historic gains in the fight against Amazon deforestation by opening parts of the rainforest to farming and increasing impunity for violators.

Brazil's agricultural lobby, which has maintained a decade-long fight for changes to the country's Forest Code, contends the bill would make pragmatic changes to an overly strict law that is unfair to farmers and ranchers.

The bill was approved by Brazil's Senate in December and is expected to be easily passed by the lower house of Congress on Tuesday. It would then go to President Dilma Rousseff, who has said she opposes parts of the reform and has promised to use her line-item veto powers on the proposed legislation.

"If this passes it will be a disaster for the environment, it will clearly lead to more deforestation and create an amnesty for those who have broken the law," said Paulo Adario, coordinator of Greenpeace's Amazon campaign who in February won a United Nations' "Forest Hero" award. "I see only more destruction in the future if this becomes law."

Brazil says that beginning in 2008 it implemented a "shock and awe" approach to environmental protection, dropping hundreds of agents into areas where satellite monitoring spotted the most rampant destruction. Amazon deforestation slowed and hit its lowest recorded level from August 2010 through July 2011 when just 2,410 square miles (6,240 square kilometers) was felled. Scientists say, however, that nearly 20 percent of the Amazon has already been cleared.

The bill before the House would leave untouched a key protection that requires farmers and ranchers to preserve or replant trees on a percentage of their lands. In the Amazon the requirement is 80 percent, while it ranges from 35 percent to 20 percent elsewhere.

But environmentalists fear that other protections would be eroded and punishments weakened at just the wrong time.

The bill would allow smaller farmers and ranchers to work land closer to riverbanks and on hilltops, which activists say will lead to increased deforestation. The version of the bill being debated by the House scraps protections for riverbanks that were in the Senate version, including maintaining strips of forest 30 yards (27 meters) to 100 yards (91 meters) deep along waterways.

The legislation would also hand over power to individual states to determine how much area along rivers must be preserved as standing forest. Riverbanks are sensitive to erosion if deforested, leading to degraded land, silty waters and harmed wildlife. Environmentalists say that would be disastrous since many states in the Amazon are dominated by big agriculture and would likely allow farmers and ranchers to work land right up to a river's edge.

The overhaul also provides an amnesty from harsh fines on farms and ranches of any size that cleared more tree cover than legally allowed, but only for cutting before July 2008. These fines can reach more than $1 million for a single, moderate size ranch of 2,000 acres (800 hectares).

While they would be freed from penalties already levied, bigger landholders would still have to replant most of the land they cleared beyond legal limits or buy and preserve the same amount of forested land elsewhere to make up for what they cut.

The overall affect, however, would be to weaken the deterrent force of environmental legislation.

"If (the bill) is approved, it's signaling that environmental crimes pay, that they can be committed and there will be no punishment," said Adario, the Greenpeace activist.

Sen. Katia Abreu, who is also president of Brazil's National Agriculture and Livestock Federation, said things aren't as simple as environmentalists would like them to be.

She insisted the changes would help ease an unfair burden placed on farmers and ranchers who were once pushed by the government itself to clear the rainforest. Beginning in the 1960s, land was given away as long as 50 percent of a plot was cleared. Other incentives didn't end until the 1990s.

Now, some producers are being forced to replant land that was deforested when it was still legal to do so, she said.

She also argued that individual states know best how the land needs to be protected.

"We're in a democratic regime and we have to think about people," she said.

Brazil's Amazon is a region the size of the U.S. west of the Mississippi River, much of it wild and with little to no government presence.

No matter how tough Brazil's environmental laws may be, they cannot be uniformly enforced. The nation has about 1,300 federal environmental enforcement agents. That's a force about the size of the police department in Kansas City, Missouri.

"It's true Brazil can't police all of the Amazon, but the mere possibility that someone could be harshly punished is a deterrent. This bill would take much of that away," Adario said.


Associated Press writer Marco Sibaja in Brasilia contributed to this report.