The crisis that hit world financial markets in 2008 caused greenhouse gas emissions to dip slightly the following year, experts have calculated.
But the decrease was less than half that previously predicted, and highlights the growth in carbon dioxide emissions from developing nations.
Over the past 100 years, the increase in carbon dioxide levels has been attributed to emissions produced by the burning of fossil fuels.
Scientists believe that those emissions are closely tied to economic growth, so they had expected the global financial crisis to have some impact. Exactly how big the impact would be wasn't clear.
Now, an international group of researchers from the Global Carbon Project report a decrease of 1.3 per cent, much smaller than they expected, according to their report in the journal Nature Geoscience.
Just a year ago, the researchers had estimated that the financial crisis would cause emissions to drop by 2.8 per cent, roughly equivalent to the amount that emissions had been increasing each year.
GDP impact overestimated
The disparity arose because the International Monetary Fund overestimated the impact that the financial crisis would have on global gross domestic product (GDP), says Pep Canadell, executive director of the Global Carbon Project, and a research scientist in CSIRO Marine and Atmospheric Research.
"Our forecasts are as good as the quality of the forecast of global GDP," he said.
Canadell also points out that the financial crisis did not affect all countries equally. While carbon dioxide emissions dropped in 2009 in places like North America, Europe and Japan, they increased substantially in China and India.
Looking ahead, the researchers note that the International Monetary Fund is projecting an increase of global GDP by 4.8 per cent in 2010, which will lead to an increase in global emissions of at least three per cent this year.
Drop in deforestation emissions
The researchers also point out that the regrowth of forests in temperate regions has overcompensated for carbon dioxide emissions from land conversion outside the tropics. "In the temperate world, we're now planting more trees that we are cutting down," says Canadell.
In fact the scientists estimate that global emissions from deforestation and other land use change seem to be lower now than in the 1990s.
"A recent decrease in land use change emissions would be consistent with the reported downward trends of deforestation detected from satellite data in the Brazilian Amazon and Indonesia," they write.