The Environment Ministry reported late Thursday that the rate of Amazon destruction dropped 20 percent between August 2006 and July 2007. The report came the same day an environmental group warned that climate change together with deforestation could wipe out or severely damage nearly 60 percent of the Amazon forest by 2030.

The Brazilian ministry report, citing preliminary figures, showed the rainforest lost 4,333 square miles - an area twice as big as Delaware - during the 12 months ending in July. In the prior 12-month period, 5,420 square miles were lost.

Joao Paulo Capobianco, the ministry's executive secretary, attributed the drop to increased enforcement of environmental regulations. He also cited lower prices of soybeans and the strengthening of Brazil's currency, which make it less profitable to clear forest to grow the crop.

"The numbers are very positive, but we are not celebrating," Capobianco told the O Estado de S. Paulo newspaper. "We are still very far away from the government's goal which is zero deforestation."

At the U.N. climate change conference in Bali on Thursday, the World Wide Fund For Nature released a less sanguine outlook for the rainforest.

It said logging, livestock expansion and worsening drought are projected to rise in the coming years and could result in the clearing of 55 percent of the rain forest. If rainfall declines by 10 percent in the Amazon, as predicted, an additional 4 percent could be wiped out.

Noting the threat of climate change and deforestation, it said major loss of the Amazon rainforest would make it impossible to keep global temperatures from reaching catastrophic levels.