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| Human World on Nov 24, 2011

Global demand for food could double by 2050, study says

A new analysis suggests that the global environment would benefit if wealthier nations taught poorer nations how to increase crop yields.

Global food demand could double by 2050, and agricultural practices around the world need to change in order to avoid environmental challenges, according to a new analysis reported this week (November 21, 2011) in the journal Proceedings of the National Academy of Sciences (PNAS). The analysis suggests that richer nations will need to help poorer nations learn to grow higher-yield crops, in contrast to clearing more farmland, in order to keep environmental effects to a minimum as global population moves from 7 billion today to a projected 9 billion by 2050.

Scientists David Tilman and Jason Hill of the University of Minnesota (UMN) and colleagues found that producing the amount of food needed by 2050 has the potential to cause significant increases of the levels of carbon dioxide and nitrogen in the environment. That increase, in turn, could cause the extinction of numerous species.

Their study also indicates that if poorer nations continue current practices, these nations will clear a land area larger than the United States (two and a half billion acres) by 2050. But if richer nations help poorer nations to improve yields, that number could be reduced to half a billion acres. 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.

Global food demand could double by 2050.

These scientists point out that options for growing more food include increasing productivity on existing agricultural land, clearing more land, or a combination of both. To minimize environmental effects, they feel, the option of increasing productivity might be best.

They also consider various scenarios in which the amount of nitrogen use, land cleared, and resulting greenhouse gas emissions differ. Tilman said:

Agriculture’s greenhouse gas emissions could double by 2050 if current trends in global food production continue. This would be a major problem, since global agriculture already accounts for a third of all greenhouse gas emissions.

Saran Twombly, program director in the National Science Foundation (NSF)’s Division of Environmental Biology, which funded the research, said:

Ever increasing global demands for food pit environmental health against human prosperity.

Twombly added:

These assessments show that agricultural intensification, through improved agronomic practices and technology transfer, best ensure the latter with minimal costs to the former.

The results challenge wealthy nations to invest technologically in under-yielding nations to alter the current global trajectory of agricultural expansion. Identifying the economic and political incentives needed to realize this investment is the critical next step.

The research shows that adopting nitrogen-efficient “intensive” farming can meet future global food demand with much lower environmental effects, vs. the “extensive” farming practiced by many poor nations, which clears land to produce more food. For example, in 2005, crop yields for the wealthiest nations were more than 300 percent higher than yields for the poorest nations. Hill said:

Strategically intensifying crop production in developing and least-developed nations would reduce the overall environmental harm caused by food production, as well as provide a more equitable food supply across the globe.

Bottom line: A new analysis reported this week (November 21, 2011) in the journal Proceedings of the National Academy of Sciences (PNAS) suggests that global food demand could double by 2050. The analysis looked at environmental effects that would occur from various farming practices. It suggests that clearing more land for agriculture will cause more damaging effects than increasing crop yields on existing acreage.

How many hungry in a world with 7 billion?