The price of wheat, as well as that of rice, corn and other crops, has dramatically risen in recent times.

Scientists are pondering a new "green revolution," half a century after the first one, to solve a growing food shortage that has reached crisis proportions in some countries.

American consumers are experiencing the trickle-down effects of the lack of food. People in Haiti, Mexico, Guinea, Mauritania, Morocco, Senegal, Uzbekistan, Yemen and other countries have taken to the streets in recent weeks and months to protest the rising costs of food. An official with the World Food Program yesterday called it a "silent tsunami" of world hunger.

The causes are many, including rising fuel prices, the diversion of land to grow biofuel instead of food crops and droughts in Australia, one of the world's main producers of wheat. Additionally, the global population is growing, notably in places such as India and China, where increasing prosperity has allowed more people to buy more and finer food.

Many people look to science to ease the pinch — after all, it worked once before.

Between the 1940s and 1970s, major advances in food technology — such as chemical fertilizers and pesticides, improved seed varieties, better irrigation and farm technology — led to huge gains in the amount of food the world's farmers were able to grow. This "green revolution" caused crop yields in Mexico, Asia and other areas of the world to shoot up, protecting many people from starvation.

Although some of these technologies were found to have drawbacks — for example, chemical fertilizer can deplete the soil of nutrients and pollute water — the green revolution undeniably saved lives.

The question is: Can science do it again?

Another green revolution

"Absolutely, science is going to play a key role," said Kent Bradford, director of the Seed Biotechnology Center at the University of California, Davis. "The fact is that the reason we have been able to have food and [have] not had these shortages for the last 40 years is in fact the green revolution and the technologies that went with it. If we are really going to make a quantum leap, raise the yield thresholds significantly, then probably biotechnology is going to help."

Researchers around the world at sites like the International Rice Research Institute in the Philippines and the International Maize and Wheat Improvement Center (CIMMYT) in Mexico are studying how to improve crops and farming techniques to address worldwide hunger. By breeding staple crops such as wheat, rice, maize, and soy to be more pest- and weed-resistant, more nutrient-rich and high-yielding, they hope to offer more nutrition per acre of farmed land.

Science can also provide new tools to increase crop production, such as an optical sensor to scan crops in order to customize fertilizer to plants' needs.

"I can't ask a plant how it feels, but I can sense it with optical sensors," said CIMMYT researcher Bram Govaerts. "This is a perfect example of how instead of throwing away the green revolution techniques, we can rationally apply them. That technology already exists."

Other tools, such as a multi-use, multi-crop machine, could also make a huge difference, Govaerts said. The technology allows farmers to plant many different crops under many different conditions. The result would not only increase the variety of nutrients farmers eat, but would allow them to farm more sustainably, since land growing a single crop is more susceptible to disease and soil degradation than land on which different crops rotate.

In addition to new technologies, experts say simple changes in agricultural practices could also accomplish a lot.

"In my opinion, if we have another green revolution it's going to be because people very seriously address the issue of soil management," said Matthew Reynolds, a CIMMYT wheat physiologist. "That could really give a quantum leap in productivity."

Conventional farming techniques, such as plowing, which is traditionally used to disrupt the growth of weeds, break down soil's healthy structure and biological processes, he said. By reducing plowing, and keeping the straw residue on fields after crops are harvested, the soil could support much larger yields.

Battle over biotechnology

Some scientists think the key to truly ending world hunger lies in genetically manipulating crops to provide boons that nature cannot match.

Already crops such as Bt corn, which produces its own insecticide, and Roundup Ready crops, which are resistant to the commonly-used herbicide Roundup, are sold by the U.S. company Monsanto on the domestic market, though they are banned in Europe.

Golden Rice is a type of rice engineered by Ingo Potrykus of the Institute of Plant Sciences at the Swiss Federal Institute of Technology and Peter Beyer of the University of Freiburg to produce beta-carotene, a source of vitamin A. The scientists intended to distribute the rice seeds free to subsistence farmers in vitamin A-deficient areas, but this plan was opposed by critics of genetically-engineered crops such as Greenpeace. The crop is not yet available.

Proponents of genetically-modified (GM) organisms say that in order to solve the world's hunger issues, we must embrace these kinds of scientific interventions into nature.

"If we are really going to raise the yield thresholds significantly then probably biotechnology is going to help. For example, if we can make wheat and rice more like corn, the plants could be more productive," UC-Davis's Bradford said. The photosynthesis process in corn allows the crop to thrive with less water. "It would be very complicated to do, but it may be possible."

Or, he suggested, scientists may be able to engineer plants so they are more nutritious for humans.

"Grain sorghum is a very important crop in Africa," Bradford said. "Unfortunately, its protein is relatively undigestible — the nutrient is inefficiently metabolized. There is work in trying to modify sorghum so the protein is more digestible. That would be a huge bonus."

But many people question the wisdom of dabbling in complicated natural processes that we don't fully understand.

"I think using genetically-engineered crops would not only not solve the situation, but it would continue to put the food supply at risk," said Ryan Zinn, campaign coordinator for the Organic Consumers Association, a non-profit organization. "When you're messing with the crop's genome, you run the risk of opening Pandora's box. What people don't realize is that the FDA does not test these crops. They've been out on the market, they're not labeled, and they've got some potentially significant human health consequences."

These consequences may include a reduction in nutrients or inclusions of harmful pesticides, he said.

Defenders of GM crops say many of these fears are unfounded.

"Nobody can point to a single thing to say there's been unintended health consequences," Bradford told LiveScience. "While it's always possible, it's also possible that breeding crops could have unintended health consequences. It's a matter of balancing risks and benefits. The risks are exceedingly small, but the benefits are tangible."

Superfood

Even some of biotechnology's biggest fans are skeptical that scientists could ever create a superfood to cure all the world's hunger problems, such as a daily pill with all the nutrients a person needs.

"I don't really see getting your complete nutrition from some kind of single food," Bradford said. "Why would anybody want to? It would be boring to just eat a pill."

Science is closer than you may think to some radical solutions, though.

Researchers are hard at work on animal-free meat. Scientists, such as Henk Haagsman, a professor of meat science at Utrecht University in the Netherlands, are growing synthetic meat with the help of animal stem cells. When fed with glucose, amino acids, minerals and growth factors, the stem cells can grow into muscle tissue, which the researchers say tastes a lot like ground meat.

Though it may sound far-fetched, proponents of so-called cultivated meat say this could be a key to solving world hunger problems.

"The benefits could be enormous," said Jason Matheny, the director of New Harvest, a non-profit organization that funds research on in vitro meat. "The demand for meat is increasing worldwide … With a single cell, you could theoretically produce the world's annual meat supply. And you could do it in a way that's better for the environment and human health. In the long term, this is a very feasible idea."

Long-term solutions

This week United Nations Secretary-General Ban Ki-moon announced the formation of a U.N. task force to address the problem of mass hunger and food shortages. The Secretary-General stressed the importance of economic aid in the short term to deal with the crisis, but discussed the need for scientific advances in the long term.

"Whatever the factors are, the overall amount of food consumption has gone up, relative to the amount of supply, and we need to find a way to deal with that," said Farhan Haq, a spokesperson for Ban Ki-moon. "What's needed is trade and investment being used to bring about a green revolution — technologies that can improve agricultural productivity, particularly across Africa, but in general as well."