Martin Hickman: We can still feed ourselves, but for how much longer?

Rocketing food prices, millions going hungry, rioters ransacking warehouses... The Government wants to guard against this happening in Britain.

It happened abroad, though, last year, when a combination of circumstances conspired to send the price of food out of the reach of the world's poor.

Britain was not immune: inflation for a typical basket of UK groceries hit 19 per cent last May, prompting complaints that shoppers hit by rising inflation and energy bills were struggling to buy everyday food.

The 2008 food crisis sent a jolt around the world. It was felt even in the Department for Environment, Food and Rural Affairs (Defra) around the corner from the Houses of Parliament.

Officials realised, in a globalised world where Britain imports much of its food, the interconnection of the global food system might one day hit the UK as dramatically as did the recent crisis in the financial system.

The Secretary of State for the Environment, Hilary Benn, has become increasingly mindful of the need to plan for a secure food supply in the coming years.

For more than a decade, the Government pursued a laissez-faire food policy. It didn't much matter where supplies came from, so long as British farmers made money; Britain was wealthy enough to import. It has worked, albeit at a cost to wildlife and animal welfare from intensive agriculture.

Supermarkets brim with an extraordinary range of food that would strike envy into a medieval king. Food is highly affordable and Britons spend an average of 9 per cent of household income on food, compared with 16 per cent in 1984.

But the system is hugely wasteful. At least a quarter of fresh produce is wasted because of the high standards for keeping food set by supermarkets. Households waste a third of the food they buy and an average family bins food worth £610 every year.

At the same time, faced with an abundance where previous generations have faced dearth, Britons are becoming obese.

Ministers are now aware that the banquet must come to an end. Climate change is threatening to lower crop yields in the southern hemisphere, as the global population is predicted to rise from six billion to nine billion by 2050. Consumers in the populous emerging powerhouses of China, India and Brazil are eating a more calorific diet, heavier in energy-intensive meat and dairy.

The US biofuels policy, aimed at reducing its reliance on Middle Eastern oil, is exacerbating the strain.

Despite these forces, there is cause for optimism. The UK's Food Security Assessment points out that there is enough food to feed everyone in the world, even now. The United Nations Food and Agriculture Organisation (FAO) estimates that one billion people are undernourished, while 1.6 billion adults, mostly in the West, are overweight.

Britain is 60 per cent self- sufficient. Of the things that can be grown here, we produce three-quarters of what we consume. The Government wants farmers to increase production while using fewer resources, but is unsure how: this is the big question arising from its new strategy.

Growing more, says Defra, will not just help us to feed ourselves but will also relieve pressure on global supplies. With future wars likely to break out over scarce natural resources, helping the world to feed itself is not merely nutritional self-interest; it is also a geopolitical imperative. Britain has plenty of food. But complacency is no longer an option.