It is thought that clearing and burning the rainforests may contribute as much as a quarter of the world's total human CO2 emissions. The rainforests form a band around the equator, of which the largest is located in the Amazon basin of South America, and occupies an area in size equal to half that of the U.S. Other major rainforested regions are found in western Africa, e.g. Congo, and in the South Pacific, e.g. Indonesia and the Philippines. According to one estimate (www.savetherainforest.org), only half the rainforests which now remain will exist by 2050, and there will be none left by 2060, such is their staggering rate of destruction. More than one and a half acres (about two football pitches worth) is lost each second of every day, which over a year translates into an area more than twice the size of Florida.
There is no single driver for rainforest destruction, but it is not simply a matter of poverty and overpopulation, although these are underlying issues. The ongoing actions mostly responsible are logging and agriculture. Thus, removing a felled tree causes more damage than merely the loss of the tree, as it is dragged out by tractors whose tracks break-up the soil such that it washes away in the heavy rainfall (up to 400 inches per year), which is intrinsic to a rainforest. Road building leads to further deforestation, and the problem is compounded by the fact that displaced farmers then use these access roads to get into the forest where they "slash and burn" to provide land for subsistence farming. Most of the timber that is cut by the loggers ends up being exported to rich countries where it is sold-on for sometimes hundreds of times the rate paid locally.
Pristine areas of rainforest are raised to the ground in order to provide land to grow cash crops, tree plantations and for grazing cattle. I recall watching a television programme entitled "Jungleburgers" some years ago, whose subject was the clearing of rainforest in South America to provide land on which cattle could be grazed as a raw material for the rising U.S. burger industry. This typifies the aspect that much of the crops of vegetables, wood and meat end up being sold to the wealthy industrialised nations, in some cases while the local population goes short of food. The intense nature of this agriculture, with its modern machinery, fertilisers and pesticides, denatures and drains nutrients from the soil, leaving it unfit and barren, at which point the whole process moves on to destroy further tracts of rainforest. It is the same consequence when poor farmers - "shifted" cultivators - are forced off their land by governments and large corporations, e.g. to grow coffee and sugar, and move onto forested land which they slash and burn, overcultivate and finally leave barren, whereupon they shift again.
In short, large scale agriculture, logging, building dams to provide hydroelectric power, mining and industrial development all contribute to forcing indigenous populations from their own lands. Indeed, shifted cultivators are now being blamed for up to 60% of tropical deforestation.
If the principally equatorial peoples are burning the rainforests to the extent of 25% of the global CO2 emissions that are engendered by humans on the one hand, and China, India and South American countries remain steadfast in an unprecedented programme of industrialisation fuelled by oil, gas and coal on the other (all of which will pump further CO2 into the atmospheric canopy), then our Kyoto pledges and milestones begin to appear puny and futile. Whatever actions the governments in the developed world decide upon (mindful that George Bush has stated that signing-up to Kyoto would "destroy the U.S. economy"), they are likely to be overwhelmed by emissions from the developing world.