Deforestation Means Larger Carbon Footprint For Brazilian Beef

Beef production in Brazil, the world's second-largest producer, leads to greater carbon emissions than previously thought. Because cattle ranches are heavily responsible for deforestation, beef from the Brazilian Amazon carries perhaps the highest carbon footprint of any beef in the world, according to a new study (Environ. Sci. Technol., DOI: 10.1021/es103240z).

Beef ranches account for about 70% of the cleared forest in the Brazilian Amazon, says Christel Cederberg of the Swedish Institute of Food and Biotechnology, in Gothenburg. She and her colleagues wanted to calculate the carbon footprint of the beef that came from these pastures.

Cederberg's team started with results from a 2006 agricultural census: Over the previous 20 years, cattle ranches had caused the destruction of more than 20 million hectares of Amazonian forest. The researchers then developed a way to calculate beef's share of the greenhouse gas emissions due to removing trees, by accounting for the share due to crops and timber, and by averaging the emissions over the 20-year time scale.

The result: deforestation due to cattle ranching produces more than 700 kg of CO₂ per kilogram of carcass weight. Since only 72% of the carcass is edible, that amounts to nearly a ton of carbon per kilogram of meat, the researchers calculated.

But only 6% of Brazilian beef comes from ranches created by deforestation, which means the carbon footprint of Brazilian beef varies enormously based on where it is raised, Cederberg says. As a result, just 6% of the country's beef accounts for 60% of its beef industry's carbon footprint.

Cederberg argues that Brazil's carbon footprint for beef should take deforestation into account. By most estimates, beef exported from Brazil carries a footprint of 28 kg of CO₂ per kilogram of beef, which accounts for greenhouse emissions from cow digestion and manure, and from the fuel used to raise the animals. Cederberg calls those estimates "misleading" because adding in deforestation's effects makes the the country's beef footprint shoot up to 72 kg, more than double the world average for beef.

"I would expect that a good fraction of the companies that buy Brazilian beef in the European Union would buy less after seeing the higher footprints," says co-author Roland Clift, an emeritus professor of environmental technology at the University of Surrey, in the U.K.

This study is the first to quantify how much deforestation adds to Brazilian beef's carbon footprint, says Tara Garnett, who runs the Food Climate Research Network at the University of Surrey, and who was not involved with the study. "Since global demand for meat is rising rapidly, it's a big concern."

Chemical & Engineering News

ISSN 0009-2347

Copyright © 2011 American Chemical Society