Agricultural innovation has long sustained the world's masses with an abundance of low-cost food, thanks to the success of the mid-20th century's Green Revolution, which brought industrialization and high-yield grains to India, Mexico and many other developing countries.

A prosperous global population however, has blazed the way for burgeoning new mouths to feed that, by 2050, will nearly double food demand. At the same time, farmers face unprecedented challenges of climate change, high oil prices driving demand for biofuels, and rising costs of land and water.

The 2008 surge in food prices portended ominous and volatile times ahead. Just recently the Food and Agriculture Organization of the United Nations warned of more food supply shocks in 2011.

While on his Asia tour in November, President Obama announced that the U.S. and India would create a partnership to "spark a second, more sustainable 'Evergreen Revolution'"—a sequel to the Green Revolution, an endeavor advanced previously by Nobel laureate Norman Borlaug.

This intention to improve global agricultural productivity and extend food security to Africa is welcomed by former U.S. Department of Agriculture Chief Scientist and Undersecretary for Research, Education and Economics Gale A. Buchanan. And if the president's plan is to have any "real, revolutionary" impact, he said, then it must capitalize on the value of genetically modified (GM) crops. In a November 11 keynote address at Sigma Xi's "Food Safety and Security: Science and Policy" symposium, Buchanan charted out several examples of how GM crops could improve agricultural productivity.

Advocates argue that GM crops could also play an indispensable role in addressing the world's most serious agricultural challenges like climate change.

"The world has got to accept genetically modified plants because not to is to fail to acknowledge one of the most important discoveries of the 21st century," Buchanan said.

Critics argue otherwise. Some environmental activists raise concerns about displacement of biodiversity, jeopardizing native plants through cross-pollination or effects on wildlife. The Organic Consumers Association is concerned about health risks and commodity price manipulation by corporate giants such as Monsanto. According to a position statement from the Union of Concerned Scientists, GM foods may pose harm to human health or the environment. The organization calls for thorough risk assessment before introductions of all biotechnology products. Others cite the lack of long-term data on these and other possible impacts.

David Tribe of the University of Melbourne disagrees. The food scientist and safety expert is co-creator of Academics Review, a Web site that seeks to clear confusion about GM food safety by responding to unsubstantiated anti-GM claims. "Technological innovation is being straitjacketed by excessive and scientifically unjustified precaution. By delaying our ability to respond in time to climate change, it's doing more harm than good," he says.

Yet, the disagreement goes beyond questions about GM crop's safety—they are really not what poor farmers in developing countries need. In Africa, for example, the tried-and-true technologies of the Green Revolution are still lacking, along with access to good roads and fertilizer.

Buchanan agrees there are alternative solutions by building food chain infrastructure and trade, but he adds: "If we are to address the problems affecting our future well-being on the planet, we have to be far more visionary."

"Classical genetics and plant breeding played a role in the first Green Revolution and will continue to be needed, but biotechnology that generates genetically modified organisms will play an increasing role in future green revolutions," he says.

7 GM crop strategies that may bolster an Evergreen Revolution

One strategy along these lines, drawn from a report published in January by the Council of Agricultural Science and Technology (CAST) and chaired by Buchanan, is to bioengineer major food crops to convert the sun's energy more efficiently. There are three types of photosynthesis, two of which are known as C3 and C4. Most plants rely on the C3 process, which uses carbon dioxide and fixes three-carbon compounds in a photosynthetic cycle, but a few have evolved the more efficient C4 variety, developing a competitive edge by fixing four carbons per cycle.

C4 plants, such as corn and sugarcane, are better able to survive hotter, more arid climates. So, enabling C3 crops such as wheat, rice and soy to use C4 pathways could provide similar advantages of less photorespiration, which leads to production of more biomass, yet releases less carbon into the atmosphere.

Another idea is to bioengineer major crops to fix nitrogen. Nitrogen is plentiful in the atmosphere but as a fertilizer it is expensive, because it is made using fossil fuels. Plus, using it can contaminate waterways. In soy and other legumes nitrogen fixation is an evolved trait allowing them to hold on to the element and return it to the soil. The feat of introducing nitrogen fixation into corn and sorghum—or other genes that allow a crop to require less nitrogen—alone would cut costs and pollution markedly as well as drive higher yields.

Bioengineering grain crops to produce seed without fertilization from pollen may also be an option. A cloning type of reproduction that doesn't rely on fertilization, called apomixis, introduced to crops would allow farmers to be able to save high-yield hybrid seed without to the necessity of annual interbreeding, according to University of Georgia professor Wayne Hanna. The plant scientist, who has been working on apomixis for a number of years with molecular geneticist Peggy Ozias-Akins, also at Georgia, says, "If one could clone the genetic mechanism [of apomixis] and introduce it to maize, rice and wheat, it would revolutionize food production."

Another strategy is to bioengineer major crops that can withstand heat, drought and salinity. Drought already accounts for about 40 percent of corn crop losses. And irrigation often brings high salt concentrations into soil adding more stress on the plants. GM crops that can tolerate heat, drought and salt would not only allow farmers to use land normally unsuitable for cultivation but also circumvent problems of growing population and climate shifts brought on by global warming.

Bioengineering plants that have greater resistance to pests and diseases has also been proposed because, although not new, the arms race against evolving pests and diseases continues. The introduction of ribonucleic acid interference (RNAi) genes is a promising new development that can lead to new ways of neutralizing viruses or killing insect larva.

Another plan is to boost plants' light-capturing capabilities. Despite millions of years of evolution, plants are still quite inefficient at the job. Most absorb only about 1 to 3 percent of light, whereas solar panels can typically capture 10 to 15 percent. But some plants can capture more photons because of energy-efficient genes, which has led scientists to seek ways of inserting those genes into food crops to increase crop yields exponentially.

Lastly, genetic modification offers new ideas for innovations with the latest coming from the study of plant phenotypes, or phenomics as well as floating ocean crops, or ocean farming. These represent another strategy—the most celebrated example of which is bioengineered algae that converts carbon dioxide waste from coal-fired plants to biofuel.