Amazon Drought Worst in 100 Years

BRASILIA, Brazil, October 24, 2005 (ENS) - Manaus, capital of the state of Amazonas, and the entire eastern region of the state are suffering the worst drought in more than a century. A government scientist who calls it an "atypical" drought says it is chiefly caused by warmer ocean temperatures.

Scientist Carlos Nobre, of the National Institute of Space Research (INPE), said, "When it comes to the Rio Negro, in Manaus, this drought has no parallel in the last 103 years. That is, since 1902, when the level of the Rio Negro began to be measured," he said.

In the eastern part of the region, this is the worst drought in the last 50 or 60 years, he estimates. The governor of Amazonas state has declared a crisis due to the drought.


A deforested floodplain with a diminished river marks human interference with the once abundant ecosystem. (Photo courtesy Greenpeace)
The Amazon River floodplains have dried up and people are walking and using bicycles on areas in which canoes and riverboats used to be the only means of transport, Greenpeace Amazon campaigners have observed.

"Large boats have become stuck in the dry mud and the landscape is covered with thousands of rotting dead fish, which are attracting dozens of vultures," Greenpeace said.

The drought is caused by three factors, Nobre told the Brazilian state news agency - the warming of the Atlantic Ocean, reduction in arboreal transpiration, and the smoke emitted by forest burnings.

"The chief reason is the warming of the Northern Tropical Ocean, which is up to two degrees warmer than average," he said.

"The water induces considerable rainfall in the region, as well as an upward movement - common in places where it rains a lot. And everything that rises must fall. This air, which descends upon the Amazon region, interferes with cloud formation," he says.

"This explains the great extension, gravity, and duration of this quite atypical drought."

Deforestation has wiped out 17 percent of the rainforest that once blanketed the Brazilian Amazon, Nobre pointed out. Now wildfires are crackling through the unusually dry forest, destroying thousands of hectares.

Nobre, who holds a doctorate in meterorology from the Massachusetts Institute of Technology, is senior scientist at INPE. He was director of INPE's Center for Weather Forecasting and Climate Studies from 1991 to 2003.

A member of the Brazilian Academy of Sciences, Nobre's research interests lie in tropical meteorology, climate modeling, and biosphere-atmosphere interactions. He is president of the International Geosphere Biosphere Program and program scientist for the Large Scale Biosphere-Atmosphere Experiment in Amazonia.

This experiment is designed to create the new knowledge needed to understand the climatological, ecological, biogeochemical, and hydrological functioning of Amazonia, the impact of land use change on these functions, and the interactions between Amazonia and the Earth system.


Carlos Nobre is director of the Centro de Previsão do Tempo e Estudos Climáticos, CPTEC, Brazil's center for weather forecasting and climate studies. (Photo courtesy U. Miami)
"Brazil is one of the most vulnerable countries to climate changes in the world because of its invaluable biodiversity," said Nobre. "If the Amazon loses more than 40 percent of its forest cover, we will reach a turning point from where we cannot reverse the savannization process of the world's largest forest."

The other two factors are less important in determining the intensity of the drought, said Nobre. He concurs that prolonged droughts cause plants to transpire less, curtailing the water cycle.

Nobre cites studies showing that smoke from the forest burnings "can also interfere with cloud formation during the dry season."

Carlos Rittl, Greenpeace Brazil's climate campaigner, said, "This drought and its effects are really shocking. Towns are lacking food, medicines and fuel because boats cannot get through."

Greenpeace warns that a cycle created by the combined affects of global warming and deforestation could cause the "collapse" of the Amazon rainforest.


The Amazon River is being reduced to a trickle in places. The people of the Amazon rely on the river and its tributaries for everything from food to transportation. (Photo courtesy Greenpeace)
"If the landscape I've seen this week is a sign of things to come, we're in serious trouble," Rittl said. "We risk losing the world's largest rainforest, the network of rivers and invaluable and varied life it sustains, much of which we haven't even discovered or researched."

Greenpeace is calling on governments to take urgent action to stop deforestation of the Amazon and commit to the massive reductions in carbon dioxide emissions needed to protect the Earth's biodiversity and millions of people who are at risk from the impacts of climate change and ancient forest destruction.

Burning of fossil fuels emits carbon dioxide, the principal greenhouse gas, which traps the Sun's heat close to the planet, raising the surface temperature of both land and sea.

Amazonian deforestation and fires account for more than 75 percent of Brazil's greenhouse gas emissions and place it among the top four contributors to global climate change, Greenpeace says.

On Thursday, Greenpeace campaigners in Madrid linked the city's Queen Sofia Museum with deforestation of the Amazone and sealed it off with yellow crime scene tape. The action was prompted by Greenpeace's discovery that the museum's newly opened extension was built using timber bought from companies involved in the illegal logging of the Amazon rainforest.