Food security today is both an issue of food supply, as in whether food is physically available, and one of economic access, as in people can actually afford to buy that food. Economic access is probably an even bigger problem to global food security than supply.

At the heart of this issue is the struggle to find a balance in food prices so that prices are both high enough for rural farmers to make a profit, and low enough for urban consumers to afford the food that the farmers send to market. One of the best ways to tackle this issue is for governments to cooperate with international agreements that ensure currencies are valued properly and barriers to trade are reduced.

Agriculture is a terrific sector for investment. Return on investment in agriculture routinely exceeds 10 percent, much better than your average stock or bond. However, investment in agriculture has decreased much over the past decades and remains low because these returns are "public goods." In other words, they benefit the entire country, not just a particular individual or corporation. That is why agricultural investment is still an extremely important job for governments and NGOs.

Africa needs investment most of all. Climate change poses extreme danger for global food security. The crop that will be hurt most by higher average temperatures and more variable rainfall will be maize in sub-Saharan Africa. This is the very region that already has the lowest yields and which contributed the least to adding carbon dioxide to the atmosphere. There is a moral duty to invest heavily in this area to improve maize varieties that better tolerate drought and heat, and an economic duty to prevent conflict stemming from food insecurity and keep markets open.

Global food prices have been increasing recently. Some say China's demand for food is one reason for this. However, a major reason that food prices spiked so suddenly, particularly for rice, was likely because major rice exporters panicked and stopped exporting. This created an artificial fall in supply. Meat and biofuel demand are driving the engine of global food demand, and so far trade has oiled the machine and kept all cylinders running smoothly.

The amount of grain needed to fill one tank of ethanol for a large SUV could feed one person for one year. To its credit, the Chinese government has been less enthusiastic than the US about maize-based ethanol, and recently only supports using secondary crops like sweet potatoes and cassava as an ethanol feedstock.

China has done a remarkable job of transforming its agricultural sector in the last 40 years. Rice yields have doubled and maize yields have nearly quadrupled since the mid-1960s. China has shown, definitively, that the key to economic and industrial growth is the foundation of a strong and productive agricultural sector.

When labor is freed from highly productive farms, the factories begin to produce, and the ports begin to export. Countries today that still try to develop a service-based economy without first developing a strong agricultural foundation, and are floundering in the process, can learn from China's experience.

But China is also faced with food security threats, which today are mainly environmental, like the lack of water for irrigation, and the enormous overuse of fertilizers that are poisoning rivers and harbors, and demographic. The average age of a Chinese farmer is 60 and he or she works a farm, by hand, that is on average less than one thousandth the size of the average US farm.

As these farmers grow even older, China will face an enormous, socially transformational challenge. It will either have to convince millions of young people to give up a life in the city to work small farms just like their grandparents did, or they will have to massively consolidate and mechanize croplands so they can produce a larger amount of food using far fewer farmers. Neither option will be easy.

The article was compiled by Global Times reporter Wang Zhaokun based on an interview with Chris Fedor, researcher at the Center for Food Security and the Environment of Stanford University. opinion@globaltimes.com.cn