What is unique today is the rate and extent of deforestation globally. Earlier in this century, forests covered around 40 percent of the Earth's total land area. Today, that forest cover is down to 27 percent - a loss of roughly one third. In developing regions, where population pressures have forced accelerated clearing of forests for agriculture and fuelwood, that loss is estimated to be nearer one-half. As forests are cleared, not only is the Earth's ability to absorb carbon reduced, but the carbon retained in the trees is also released into the atmosphere.
Forests also help stabilize local and global weather.
Large-scale deforestation is linked to changes in weather patterns, as well as to soil erosion and siltation of rivers. Increased flooding in India and Bangladesh is now believed to be caused by deforestation in the Himalayan Mountains, where many of the sub-continent's rivers begin. Recent disastrous floods in China and Honduras are also linked to deforestation. The specific reasons for deforestation vary by region, but the underlying cause is simple - increasing numbers of people, and increasing demand for wood products. By far the greatest cause of forest loss was clearing for agricultural purposes in developing regions.