When we arrived at Kapawi Lodge deep in the Ecuadorian Amazon by aircraft and canoe in November 2005 we could see that the water level in the rivers was much lower than normal, 10 feet lower, leaving some docks high and dry. Amazonia, almost as large as the continental United States, had endured the worst drought in 40 years triggered by exceptionally warm waters off Africa that also spawned the New Orleans's hurricanes of 2005. Many people who live on the smaller rivers had not been able to leave by boat for supplies or medical help.

Amazonian residents and scientists are concerned that global warming along with deforestation will initiate a drying up of the world's largest rainforest that would in decades to come not only alter the climates of South America but also climates in the United States. Researchers at Duke University using NASA computer models predict that Amazonian deforestation would lower rainfall in northern Mexico and Texas in the critical agricultural seasons of spring and summer.

Almost 20% of Amazonia with a third of all the plants and animals on Earth has been cleared and is being deforested at the rate of about 25,000 square kilometers per year for agriculture, cattle ranching, and logging spurred by new highway development. Ultra high resolution satellite images show that an additional 25,000 square kilometers is degraded annually by selective logging of hardwood species such as mahogany. Selective logging involves building invasive roads for heavy equipment to reach the prized trees which drag down many other trees as they are being felled and removed.

The $40 billion Brazilian government plan, Advance Brazil, a vast network of highways and infrastructure in the Amazon basin, will open pristine rainforest to illegal logging, hunting, and mining, thus accelerating deforestation, pollution, and biodiversity loss. Once the forest is opened up and fragmented by logging and agriculture, drying ensues making forest fires more likely. Fires raged in the Brazilian State of Acre in September 2005, typically set by farmers to clear forests in the dry season. The millions of acres burned each year, deforestation, and fossil fuel burning put 550 million metric tons of carbon dioxide into the atmosphere annually placing Brazil among the top ten polluting countries.

Amazonia contains one-third of all carbon found in the Earth's land vegetation. The forest trees grow slowly because of the nutrient poor soils and half of the trees more than 4 inches in diameter are over 300 years old. This means that forest restoration could take hundreds of years. Field studies have shown that Amazon forests are not storing carbon as much as in the past due probably to the higher concentration of carbon dioxide, now 380 ppm up from the pre-industrial level of 280 ppm. The resulting changes in forest composition would affect other plants, animals, and energy flows in the ecosystem.

In the past three years the record destruction of the Amazon forest has been driven by soy bean farming and cattle ranching. Demand for beef free of mad cow disease has resulted in accelerated deforestation by cattle ranchers. Brazil is now the world's largest beef exporter at 1.9 million tons a year. Six times as much land has been cleared for cattle ranching than for crop land. Much of the forest clearing in the Brazilian state of Mato Grosso has been for soy beans which are shipped to China and Europe.

Continued forest destruction and fragmentation will have dire consequences for world climates and species diversity in Amazonia. Fragmentation alters species abundance and richness and degrades ecosystem processes. Studies in Kenya's Kakamega tropical forest have shown that it would take about 50 years following isolation for half the birds to become locally extinct in a forest fragment of 25,000 acres. Modeling and field studies have shown that leaving just 10% of the forest connected by corridors is below the threshold for the ultimate destruction of the natural forests of Amazonia. Nature reserves would have to be very large not only to protect biodiversity but to ensure that the climate is not inalterably changed. Once a critical threshold of forest destruction is reached, the rainforest climate, sustained largely by evapotranspiration from forest vegetation, would fail and ecosystems would crash leading to vast extinctions of plants and animals and major climate changes in the Americas.