Amazon deforestation rate slashed

The rate of deforestation in the Brazilian Amazon has fallen by almost half over the past year, according to government data. The figures are only preliminary and need to be confirmed with satellite data, but indications are that the estimate of a 47.5 per cent decline in lost forest area in the period August 2009 and August 2010 is close to the mark.

Deforestation of tropical forests is a major contributor to greenhouse emissions worldwide. Forest loss adds billions of tonnes of carbon to the atmosphere every year around 15 per cent of total human-related emissions.

The Brazilian government remote-sensing agency Instituto Nacional de Pesquisas Espaciais (INPE) said the area of forest burned over the period fell below 2300 square kilometres, compared to 4375 sq km for the previous year. Burning is the main form of clearing for farm expansion and the figures show the area lost to fire remains concentrated in the agricultural states of Pará and Mato Grosso.

Caution must be attached to the figures. The monitoring system that produces the figures only detects fires of 25 hectares or more and does not account for forest cleared or degraded from illegal logging. Farmers may be burning off in smaller parcels to avoid detection, and the economic downturn may have slowed agricultural land demand only temporarily.

However, a forest scientist at the US Woods Hole Research Center, Daniel Nepstad, says that some large soybean and beef processors have committed not to buy products from newly-deforested areas and this has helped slow deforestation. He also says a combination of legal penalties and growing carbon market incentives for forest preservation have forced “a very big change in the attitude of ranchers and farmers”.

A satellite expert with the Carnegie Institution for Science at Stanford University, Greg Asner, told Science Magazine: “I think the results are pretty strong for a big additional decrease in deforestation. I do not doubt that the trend is real.”

If so, then the rate of Amazon deforestation has been reduced by as much as 90 per cent since 2004.

A separate Stanford University study offers an indication of just how big clearing forest for agriculture has been in recent decades. More than half a million square miles of new farmland was created in the developing world between 1980 and 2000, and 80 per cent came from clearing tropical forests, study leader Holly Gibbs said.

The study, published in the Proceedings of the National Academy of Sciences, also noted that big agribusinesses are replacing small farmers in Brazil and Indonesia, making it easier for enforcement authorities to clamp down on clearing.

Science Magazine, Stanford Report 2/9/10