Population Growth, Land and Water Limits and Climate Change Forcing a Radical Rethinking of Agriculture; GM Crops, Aquaculture, Drylands and Saline Agriculture
Population growth, limits to arable land and fresh water, and climate change have “profound implications” for the ability of agriculture to meet this century’s demands for food, feed, fiber, and fuel while reducing the environmental impact of their production.
Meeting these challenges will depend on the acceptance and use of contemporary molecular techniques, as well as the increasing development of farming systems that use saline water and integrate nutrient flows, according to a perspective piece by an international team of scientists from academia, the private sector, and government, published in the 12 February issue of the journal Science, which is focused on Food Security.
|“There is a critical need to get beyond popular biases against the use of agricultural biotechnology and develop forward-looking regulatory frameworks based on scientific evidence.”|
|—Federoff et al.|
The research team, led by Nina Federoff, science and technology adviser to Secretary of State Hillary Clinton, notes that the impacts of climate change on agriculture and human health are already apparent. They point to the 2003 heat wave in Europe, which caused just a 3.5°C rise in the average summer temperature, but killed 30,000 to 50,000 people. Gaining much less attention was the resulting 20% to 36% decrease in the yields of grains and fruit that summer.
But if the climate scientists are right, summers will be that hot on average by mid-century, and by 2090 much of the world will be experiencing summers hotter than the hottest summer now on record. The yields of our most important food, feed, and fiber crops decline precipitously at temperatures much above 30°C. Among other reasons, this is because photosynthesis has a temperature optimum in the range of 20° to 25°C for our major temperate crops, and plants develop faster as temperature increases, leaving less time to accumulate the carbohydrates, fats, and proteins that constitute the bulk of fruits and grains.
Widespread adoption of more effective and sustainable agronomic practices can help buffer crops against warmer and drier environments, but it will be increasingly difficult to maintain, much less increase, yields of our current major crops as temperatures rise and drylands expand. Climate change will further affect agriculture as the sea level rises, submerging low-lying cropland, and as glaciers melt, causing river systems to experience shorter and more intense seasonal flows, as well as more flooding.—Federoff et al.
The authors suggest that a serious reevaluation of the existing regulatory framework in the light of accumulated evidence and experience with genetically modified crops is needed. Such an assessment should encompass protein safety, gene stability, acute toxicity, composition, nutritional value, allergenicity, gene flow, and effects on non-target organisms. This would establish a foundation for reducing the complexity of the regulatory process without affecting the integrity of the safety assessment, they said.
A public facility within the USDA with the mission of conducting the requisite safety testing of GM crops developed in the public sector is also essential, they suggest.
However, it is not at all a foregone conclusion that our current crops can be pushed to perform as well as they do now at much higher temperatures and with much less water and other agricultural inputs. It will take new approaches, new methods, new technology—indeed, perhaps even new crops and new agricultural systems.
Aquaculture is part of the answer...Another part of the answer is in the scale-up of dryland and saline agriculture.
...The heart of new agricultural paradigms for a hotter and more populous world must be systems that close the loop of nutrient flows from microorganisms and plants to animals and back, powered and irrigated as much as possible by sunlight and seawater.—Federoff et al.
This perspective piece was developed from the authors’ presentations during a September 2009 workshop titled “Adapting Agriculture to Climate Change: What Will it Take?” which was held under the auspices of the Office of the Science and Technology Adviser to the US Secretary of State.
N. V. Fedoroff, D. S. Battisti, R. N. Beachy, P. J. M. Cooper, D. A. Fischhoff, C. N. Hodges, V. C. Knauf, D. Lobell, B. J. Mazur, D. Molden, M. P. Reynolds, P. C. Ronald, M. W. Rosegrant, P. A. Sanchez, A. Vonshak, and J.-K. Zhu (2010) Radically Rethinking Agriculture for the 21st Century. Science Vol. 327. no. 5967, pp. 833 - 834 doi: 10.1126/science.1186834