Worst Amazon Drought in 40 Years Linked to Global Warming

October 19, 2005
Reporting by Roddy Scheer

Researchers believe that rising sea temperatures in the North Atlantic, possibly as a result of human-induced climate change, are primarily responsible for the worst drought in the Amazon in four decades. Brazilian officials have declared 16 cities within the country's Amazonas region to be disaster areas due to the effects of the two-month-long drought.

Droughts in South America are often the result of El Nino weather patterns warming ocean surface temperatures, in turn leading to evaporation and then dry, cloudless high pressure systems. But even though this is not an El Nino year, scientists are measuring some of the highest ocean temperatures on record. While these warmer ocean temperatures are no doubt intensifying tropical hurricanes, they also might be responsible for the Amazon's drought.

"If the warming of the North Atlantic is the smoking gun, it really shows how the world is changing," says Dan Nepstadt of the Woods Hole Research Institute, which has been monitoring the link between ocean temperatures and the drought.

"The Amazon is a canary in a coalmine for the Earth. As we enter a warming trend we are in uncertain territory," he adds.

Researchers also believe that the extensive and on-going deforestation throughout the Amazon is playing a role in the drought, as cutting down trees reduces moisture in the air and allows increased penetration of sunlight onto previously canopy-covered land.

Meanwhile, residents of affected areas now must walk miles to find food and medicines, as river transportation is non-existent and many small local farms have no water to irrigate their crops. No doubt the millions of people affected will welcome the rainy season in two more months, but the intensity of the drought may leave them worried about the prospects for next year, not to mention the next generation.