Advances in high-yield agriculture over the latter part of the 20th century have prevented massive amounts of greenhouse gases (GHG) from entering the atmosphere, equal to 590 billion metric tons of carbon dioxide, says a new study from Stanford University published in the proceedings of the National Academy of Sciences.

If not for increased yields, additional GHG emissions from clearing land for farming would have been equal to as much as a third of the world’s total output of GHG since the dawn of the Industrial Revolution in 1850, according to Stanford researchers.

The researchers also calculated that for every dollar spent on agricultural research and development since 1961, emissions of the three principal GHG – methane, nitrous oxide and carbon dioxide – were reduced by the equivalent of about a quarter ton of carbon dioxide.

This is considered a high rate of financial return compared to other approaches to reducing the gases.

To evaluate the impact of yield intensification on climate change, the researchers compared actual agricultural production between 1961 and 2005 with hypothetical scenarios in which the world’s increasing food needs were met by expanding the amount of farmland rather than by boosting yields.

“Our results dispel the notion that modern intensive agriculture is inherently worse for the environment than a more ‘old-fashioned’ way of doing things,” says Jennifer Burney, lead author of the study.

The American Meat Institute announced the release of the study Wednesday.

For more information, go to http://www.pnas.org/content/early/2010/06/14/0914216107.abstract.