The global food crisis, which the World Food Program's Josette Sheeran calls "a silent tsunami," is devastating for the world's poor. But its more subtle impact on the world's rich nations such as Britain has powerful political consequences.

Take bacon, mainstay of the classic British breakfast of bacon and eggs. The country's herd of breeding pigs has halved in the past 10 years, and it fell by another 8 percent in the first three months of this year alone.

The reason is simple, according to Barney Kay, general manager of the National Pig Association, who said last week that with feed costs jumping 70 percent in the past 18 months, "on average pig producers are now losing about 26 pounds ($50) on every pig they produce. This equates to an industry loss of $390 million. That is not sustainable."

Britain has not been self-sufficient in food for nearly 20 years. Last year it imported about one-third of its food, with an import bill of $40 billion. Most of this, just over two-thirds, came from its partners in the European Union.

Britain's Department of the Environment, Food and Rural Affairs paints a rosy overall picture in its annual report, claiming that overall farm incomes have risen by 34 percent since 2000. It points out that Britain was the EU's third-largest producer of wheat and milk, its fourth-largest producer of beef and veal, and its top producer of lamb and mutton.

Like the United States and its European partners, British farming is highly efficient. DEFRA says that since 1973 the productivity of the British agriculture industry has increased by 52 percent and labor productivity has grown five-fold. Britain has the good rural roads and storage facilities that mean little of the crop is lost or wasted, and its use of inputs like water, fertilizer and pesticide has been dropping steadily even as output grows. DEFRA says that since 1973 the volume of production has grown by 20 percent while the amount of inputs used to produce the crops has fallen by 22 percent.

Britain does not suffer the problems faced by poor farmers in poor countries, but inflation in food prices still hurts the voters, and this worries the government. Its new chief scientific adviser, John Beddington, warned this month that food security and the rapid rise in food prices make up the "elephant in the room" that politicians must address urgently.

Prices of staple foods like rice, maize and wheat would continue to rise because of increased demand caused by population growth and increasing wealth in developing nations, he went on. Moreover, climate change would intensify the pressure on food supplies because of decreased rainfall in many areas and crop failures related to climate.

"The agriculture industry needs to double its food production, using less water than today," he told a government conference on sustainable development. "There is progress on climate change. But out there is another major problem. It is very hard to imagine how we can see a world growing enough crops to produce renewable energy and at the same time meet the enormous increase in the demand for food which is quite properly going to happen as we alleviate poverty."

There are three main reasons for the food crisis. The first is the old rule of supply and demand. There is more demand, not just from more mouths to feed but from the way that diets improve as people clamber out of poverty, and hundreds of millions of Chinese start wanting pork chops and hamburgers as well as rice. But while it takes 2 pounds of grain to produce 1 pound of chicken, 7 pounds of grain are needed to make 1 pound of beef. In 1962 there was just 8 pounds of meat in the average annual Chinese diet; by 2005 that figure was 80 pounds and rising. (The average Brit eats 160 pounds of meat a year, and the average American gets through 250 pounds a year.)

There is shrinking supply, not just from the steady erosion of arable land as new cities and factories are built in India and China, but also because of the soaring oil price. Oil is a key ingredient in food production, because it is one of the main sources of fertilizer and it powers the tractors that plow and seed and harvest the crops and take them to market.

The second main reason for the food crisis is ill-considered government action, from the $300 billion in subsidies paid to North American, European and Japanese farmers to the EU bans on genetically modified crops and the latest outbreak of food export bans and taxes imposed across the world as governments panic at the thought of food riots. The recent fashion for subsidizing biofuels in Europe and the United States has also distorted markets as farmers changed their crop plans in repose to the new price signals.

The third main reason is related to the biofuel problem. As a planet and as a human race, we simply do not run agriculture logically. Vast swathes of well-watered and fertile land, like Africa's Congo River basin, are woefully under-used. Huge regions whose crop yields are pathetically low, like East Africa and Central America, could become the world's breadbaskets if intelligent modern irrigation systems, like the drip systems the Israelis developed to make the Negev desert bloom, were installed.

This is not rocket science or something only rich countries can afford. India feeds 17 percent of the world population on 5 percent of the world's freshwater supply and 3 percent of its arable land, Lennart Bage of the U.N. International Fund for Agricultural Development likes to stress. The global food crisis is fixable, and with intelligent land management even the great British bacon-and-egg breakfast should be safe -- unless doctors apply health warnings to what has been called "a heart attack on a plate."