World population growth could spur food shortage

U researchers say farming practices will have to change.

by Megan Nicolai

Global food demand could double by 2050, according to a new projection released by University of Minnesota researchers Monday.

This could severely increase the amount of environmental pollutants and threaten extinction for many species, according to the findings of David Tilman, regents professor of Ecology in the College of Biological Sciences, and his colleagues.

According to United Nations demographers, the worldâÄôs population could reach 9.3 billion by 2050. The worldâÄôs total population is already at or nearing 7 billion, based on varying reports from the U.N. and the U.S. Census Bureau.

As poorer nations increase their populationsâÄô annual incomes in future decades, there will be a large increase in demand for animal products like meat and dairy, said Jason Hill, an assistant professor in the UniversityâÄôs College of Food, Agricultural and Natural Resource Sciences, As a result, demand for grain crops to feed livestock will also increase, he said.

Tilman and Hill, along with another University researcher Belinda Befortand, and Christian Blazer âÄî a University of California, Santa Barbara professor âÄî co-authored an article that summarized their findings and the potential risks of current international agricultural practices.

âÄúItâÄôs long been known that thereâÄôs more that we can do to ensure that thereâÄôs a sustainable food supply for the future,âÄù Hill said. âÄúBut in this paper we put some hard numbers behind the claims.âÄù

Thirty-five percent of all greenhouse gas emissions come from agricultural processes, compared with 20 percent from automobile emissions, Tilman said. But the effects could be decreased by improving agricultural practices in poorer countries, he said.

For example, in nations like the United States, farmers control fertilizer use based on the specific needs of different areas of land. This could easily be adopted by farmers with smaller areas of land in poor countries, Tilman said.

According to the article, agricultural techniques in richer nations can increase crop yield and reduce the amount of pollution emitted. Crop yields for the wealthiest nations were more than 300 percent higher than yields for the poorest nations in 2005, the article said.

Traditionally, farmers in developing countries would simply clear more land when attempting to grow more food. But that technique does nothing to increase crop yield, Tilman said. The technique also accounts for a large portion of agricultural greenhouse gas emissions and threatens certain species of animals with extinction, Tilman said.

But he said industrialized agriculture techniques require a large amount of farmer education and often come with larger costs up front.

If current agricultural techniques continue, the article stated, critical levels of nitrogen and carbon could be released into the environment and excessive use of fertilizer could contaminate groundwater.

If current levels of land clearing continue, more than 2.5 billion acres of land would be cleared by 2050, an area the size of the United States. But if new processes are adapted, that amount could be reduced to half a billion acres, Tilman said.

âÄúItâÄôs not an emergency, but itâÄôs not something we can wait until 2050 to start doing,âÄù Tilman said. âÄúBy that time, we will have the environmental damage done, and weâÄôll have lots of people with very substandard diets around the world.âÄù