Advances in high-yield agriculture have prevented the equivalent of 590 billion metric tonnes of carbon dioxide (CO2) from escaping into the air, say two Stanford University Earth scientists.
The yield improvements reduced the need to convert forests to farmland, a process that typically involves burning of trees and other plants, which generates CO2 and other greenhouse gases.
Researchers estimate that if not for increased yields, additional greenhouse gas emissions from clearing land for farming would have been equal to as much as a third of the world’s total output of greenhouse gases since the dawn of the Industrial Revolution in 1850.
“Our results dispel the notion that modern intensive agriculture is inherently worse for the environment than the more ‘old-fashioned’ way of doing things,” said Stanford Earth’s Jennifer Burney, postdoctoral researcher with the Programme on Food Security and the Environment at Stanford who led the study.
Burney said agriculture currently accounts for about 12 percent of human-caused greenhouse emissions.
“Every time forest or shrub land is cleared for farming, the carbon that was tied up in the biomass is released and rapidly makes its way into the atmosphere, usually by being burned,” she said, according to a Stanford Earth release.
“Yield intensification has lessened the pressure to clear land and reduced emissions by up to 13 billion tons of carbon dioxide a year,” added Burney.
Added Steven Davis, study co-author and postdoctoral researcher at the Carnegie Institution at Stanford, “We find that funding agricultural research ranks among the cheapest ways to prevent greenhouse gas emissions.”
These findings will be published online by the Proceedings of the National Academy of Sciences.