The Amazonian tropical forests have been disappearing at a fast rate in the last 50 y due to deforestation to open areas for agriculture, posing high risks of irreversible changes to biodiversity and ecosystems. Climate change poses additional risks to the stability of the forests. Studies suggest “tipping points” not to be transgressed: 4° C of global warming or 40% of total deforested area. The regional development debate has focused on attempting to reconcile maximizing conservation with intensification of traditional agriculture.

The study estimated, for the first time, the greenhouse gas emissions associated with cattle raising in Brazil, focusing on the period from 2003 to 2008 and the three principal sources: 1) portion of deforestation resulting in pasture establishment and subsequent burning of felled vegetation; 2) pasture burning; and 3) bovine enteric fermentation. Deforestation for pasture establishment was only considered for the Amazon and Cerrado. Emissions from pasture burning and enteric fermentation were accounted for the entire country.

Next week, thousands of participants from governments, the private sector, non governmental organizations, and other stakeholders will gather in Brazil at a United Nations (UN) summit to secure political and economic commitments for sustainable development and to address new and emerging challenges. These objectives recall the 1992 UN Conference on Environment and Development, also held in Rio de Janeiro. Although political progress toward these goals has stagnated, in the intervening 20 years science and technology have moved on.