The Third Science Conference of the Large-scale Biosphere-Atmosphere Experiment in Amazonia (LBA) convened from 27-29 July 2004 in Brasilia, Brazil.

Marina Silva, Brazil’s Minister of the Environment, opened the meeting, which was attended by over 700 scientists from around the world. LBA has been called the largest international environmental research project ever. It began in 1998 and is expected to continue through 2006. It studies the interaction between the Amazon rainforest and regional and global weather patterns and involves more than 1,000 scientists and specialists from over 100 research institutions.
Among the research results presented during the Third LBA Conference were studies concerning the effects of deforestation on the Amazon River and greenhouse gas emissions. Researchers involved with this study found that deforestation is hurting the tributaries that feed the Amazon River and could threaten the river’s main trunk if the trend is not reversed. This four-year study suggests that many of the Amazon’s 7,000 tributaries are drying up and fertilizers and pesticides have greatly altered their ecosystems, although researchers found little harm along the Amazon River itself. One of the researchers, Reynaldo Victoria of University of Sao Paulo, said “to save them [tributaries], we only have to follow the law,” which orders farmers not to interfere with the forest within the riparian zones – 165 feet (50 meters) – of any river bank.
Scientists from Brazil’s National Institute of Amazon Research said about 400 million tons of carbon dioxide-equivalent were emitted in 2003 — 60 percent more than one estimate by other scientists at the conference. Philip Fearnside, a researcher at the Institute, said “It’s emitting much more than it is absorbing.” He pointed to the need to include methane gas emissions from rotting trees by hydroelectric dams, for example, in his challenge to the view that the Amazon is a small net producer of oxygen. Brazil is expected to publish its inventory of emissions soon, as required by the Kyoto Protocol of the United Nations Framework Convention on Climate Change. Many scientists expect that the inventory will cite 300 million tons for Brazil’s total emissions, which would make it one of the world’s top ten polluting states. Fearnside’s figure would move it up to one of the top five polluting states.
Studies from the Institute of Amazon Research also suggest that about two thirds of carbon dioxide-equivalent produced annually in Brazil come from logging and burning of the Amazon. Researchers from the University of Sao Paolo suggested that the Amazon forest is currently able to absorb greenhouse gases generated by burning parts of the forest, but that will change if deforestation continues to accelerate.
Links to further information

Large Scale Biosphere-Atmosphere Experiment in Amazonia
3rd LBA Conference website
Deforestation Puts Amazon River At Risk, Scientists Say, UN Wire story, 30 July 2004
Deforestation threatens Amazon river, scientists warn, ENN news story, 30 July 2004
Amazon fires change weather, speed deforestation, ENN news story, 28 July 2004
Amazon burning makes Brazil a leading polluter, ENN news story, 20 July 2004
Estimates of Amazon’s greenhouse gas too low, ENN news story, 30 July 2004
Amazon Burning Makes Brazil One of Top 10 Polluters, UN Wire story, 20 July 2004
Burning in Amazon Linked to Accelerating Global Warming, UN Wire story, 20 July 2004