The researchers, led by David Tilman, an ecology professor at the University of Minnesota, said that the practice of clearing more land to increase the area available for food production – as practiced in many poorer nations – significantly increases the amount of carbon dioxide and nitrogen in the environment.
They examined several different strategies for meeting growing food demand, and measured the likely environmental impacts of each. These involved increasing the productivity of existing cropland, increasing the amount of land used for food production, or a combination of the two.
“Agriculture’s greenhouse gas emissions could double by 2050 if current trends in global food production continue,” Tilman said. “Global agriculture already accounts for a third of all greenhouse gas emissions.”
Tilman and his colleagues found that if current land clearing rates in poorer nations were to continue, more than 1bn hectares of land would be cleared by 2050 – whereas using technologies to improve yields could reduce land clearing to about 0.2bn hectares, with fewer greenhouse gas emissions and less nitrogen use.
“Attainment of high yields on existing croplands of underyielding nations is of great importance if global crop demand is to be met with minimal environmental impacts,” they wrote.
Tilman said: “Our analyses show that we can save most of the Earth’s remaining ecosystems by helping the poorer nations of the world feed themselves.”
The full paper is available online here.