Friday, December 20, 2013
Peak Oil, Check. Peak Gas, Check. Peak Food? What?
Food may run out long before the oil does.
A study by scientists at the University of Nebraska warns of "abrupt plateaus or declines" in industrial agricultural production.
As much as "31% of total global rice, wheat and maize production" has experienced "yield plateaus or abrupt decreases in yield gain, including rice in eastern Asia and wheat in northwest Europe."
The declines and plateaus in production have become prevalent despite increasing investment in agriculture, which could mean that maximum potential yields under the industrial model of agribusiness have already occurred. Crop yields in "major cereal-producing regions have not increased for long periods of time following an earlier period of steady linear increase."
The paper makes for ominous reading. Production levels have already flattened out with "no case of a return to the previous rising yield trend" for key regions amounting to "33% of global rice and 27% of global wheat production." The US researchers concluded that these yield plateaus could be explained by the inference that "average farm yields approach a biophysical yield ceiling for the crop in question, which is determined by its yield potential in the regions where the crop is produced."
They wrote:"... we found widespread deceleration in the relative rate of increase of average yields of the major cereal crops during the 1990–2010 period in countries with greatest production of these crops, and strong evidence of yield plateaus or an abrupt drop in rate of yield gain in 44% of the cases, which, together, account for 31% of total global rice, wheat and maize production."
Past trends over the last five decades of perpetually increasing crop yields were "driven by rapid adoption of green revolution technologies that were largely one-time innovations" which cannot be repeated. These include major industrial innovations such as "the development of semi-dwarf wheat and rice varieties, first widespread use of commercial fertilizers and pesticides, and large investments to expand irrigation infrastructure."
The study criticises most other yield projection models which predict compound or exponential production increases over coming years and decades, even though these "do not occur in the real world." It notes that "such growth rates are not feasible over the long term because average farm yields eventually approach a yield potential ceiling determined by biophysical limits on crop growth rates and yield."
Factors contributing to the declines or plateaus in food production rates include land and soil degradation, climate change and cyclical weather patterns, use of fertilisers and pesticides, and inadequate or inappropriate investment.
The new research raises critical questions about the capacity of traditional industrial agricultural methods to sustain global food production for a growing world population. Food production will need to increase by about 60% by 2050 to meet demand.