Study links lower carbon emissions to recession

By Doyle Rice, USA TODAY

Worldwide emissions of carbon dioxide, widely blamed as the chief cause of global warming, dropped from 2008 to 2009, largely because of the global economic slowdown, according to a study released Sunday. It was the first decline since the late 1990s.

The study, published in the journal Nature Geoscience, is part of the annual carbon budget update from the Global Carbon Project, a group of emissions experts and economists from several international environmental organizations.

The emissions decrease of 1.3% from 2008 to 2009 was directly related to the economic crisis, says study lead author Pierre Friedlingstein of the University of Exeter in the United Kingdom. "There is a close link between the world's gross domestic product and emissions of carbon dioxide," he says.

Over the past century, human activities, primarily the burning of fossil fuels such as coal, gas and oil, have added increasing amounts of carbon dioxide into the Earth's atmosphere. Production of cement also contributes a tiny amount of carbon to the air.

The 2009 drop was less than half of what was expected, says Friedlingstein, partly because the drop in global GDP was less than expected. The total of 30.8 billion tons of carbon dioxide was the second highest in human history, just below the 2008 emissions.

The study projects that if the economic recovery proceeds as expected, global fossil fuel emissions will increase by more than 3% in 2010, approaching the high emissions growth rates observed from 2000 to 2008.

Last year's worldwide decrease included significant regional differences. The largest decreases occurred in Europe, Japan and North America: 6.9% in the United States, 8.6% in the U.K., 7% in Germany, 11.8% in Japan and 8.4% in Russia. The study notes that some emerging economies recorded substantial increases in their total emissions, including 8% in China and 6.2% in India.

Each country reports its own emission totals to the United Nations, says Friedlingstein. China remains the top emitter of carbon dioxide from the burning of fossil fuels, followed by the USA, India, Russia and Japan.

Is the emissions drop entirely a result of the economic crisis? No, says Dan Lashof, director of the Natural Resources Defense Council climate center, who was not part of the study. "The decreases in emissions for the big countries were larger than their GDP decline," he says. "It's not just the recession."

Lashof says concerted efforts to limit and reduce carbon emissions and invest in clean energy in countries such as Germany and the U.K. could be paying dividends.

The fact that fewer trees are being cut down in some parts of the world is also good news. "We found global emissions from deforestation have decreased through the last decade by more than 25%, compared to the 1990s," says study co-author and Global Carbon Project executive director Pep Canadell. Cutting down trees and clearing forests — known as deforestation — releases carbon dioxide into the atmosphere as the trees rot and are burned.