Britain is to commit itself to a massive increase in domestic food production to feed the population in the next 40 years, The Independent on Sunday has learnt. The UK will announce tomorrow that it intends to "play a full part" in meeting a United Nations target of raising food production by 70 per cent by 2050.

The surge in homegrown crops and meat – which has echoes of the Dig for Victory campaign of the Second World War – is needed to cope with rising global population levels and crop failures and water scarcity caused by climate change.

British officials are increasingly concerned that food supplies will come under strain as a result of rocketing demand from newly prosperous and powerful nations such as China and India. Self-sufficiency has fallen in recent years, and only about 60 per cent of the food British people eat comes from the UK.

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Tomorrow, the Secretary of State for the Environment, Hilary Benn, will set out the scale of the problem and challenge farmers to raise output rapidly while cutting greenhouse gases. In the search for a new green revolution, he will say new research is needed to develop new crop breeds and techniques. Manufacturers, retailers and households will be urged to cut current massive levels of waste. Households can help by growing more food in back gardens and allotments.

Civil servants described the new food strategy as a "wake-up call" for farmers, retailers and the public.

Farmers who have long criticised the Government for taking a relaxed attitude towards food security will welcome the focus on domestic production. Wildlife groups, however, fear that further agricultural intensification will hit wildlife. Ripping out hedgerows, growing crops on meadows and dousing fields in pesticides and fertilisers have badly affected farmland birds and animals in the past 50 years.

Numbers of farmland birds such as skylarks, yellowhammers and corn buntings have almost halved and many wildflowers have been left on the brink of extinction. Most of England's hedgerows have been lost since 1947.

The Government's new approach is set out in a new document, the UK Food Security Assessment. It says that Britain's position is currently favourable because agricultural production has risen in recent years, with Britain a major exporter of wheat and barley. But it warns that rising population pressures and a likely worsening environmental picture will pose serious challenges in coming decades.

In a list of challenges to UK food security are the changing climate, floods, drought, soil erosion, water scarcities and the breakdown of ecosystems. Global temperatures may rise two to three degrees in the next 50 years, threatening large-scale crop failure in Africa.

"The Government is monitoring the climate risks to harvests and the potential for more volatility in supplies and prices. We will also examine any implications for animal disease and food safety," the document said. "Other areas of climate-change impacts on our food will include further pressure on fish products from increasing ocean acidification; supply strains on water-reliant crops such as fruit from the Mediterranean; and the impacts of increasing episodes of coastal flooding and erosion."

Droughts and rocketing demand last year sparked riots across developing countries such as Haiti after food prices rose by 40 per cent in 2007. In Britain, years of cheap food ended, with prices rising back to 1997 levels. British households still spend on average less than 10 per cent of their income on food, compared with 70 per cent in many developing countries.

The new document says that while Britain is relatively well placed for food security, countries from which we import may be in a much worse position. It adds that Britain should help to take pressure off global food supplies by raising production.

The UN Food and Agriculture Programme believes food production must rise by 70 per cent on 2005-7 levels to cope with a world population forecast to hit nine billion in 2050. On the risk of wildlife destruction, a government source said: "We are obviously hoping it's not going to lead to that. The central message is we have got to produce more using less and not trash our wildlife."

Last year the Department for the Environment, Food and Rural Affairs (Defra) said that the agrarian revolution must be done sustainably, or else future generations would inherit depleted natural resources and, ultimately, dwindling food.

Professor Tim Lang, a commissioner for land use on the Government's Sustainable Development Commission, warned: "We are facing a mounting crisis in securing global food supplies, with climate change, rocketing oil prices and growing demand all placing a strain on traditional supply chains."

Britain was wholly self-sufficient in food before the start of the Industrial Revolution in the 18th century. Self-sufficiency sank to a record low of 30 per cent before the Second World War, when the Government was forced to increase production rapidly by bringing more areas under the plough and exhorting people to grow their own fruit and vegetables.

After the Dig for Victory campaign, production drifted back downwards, before nudging up to the current level of 62 per cent. Imports are mainly plants that have to be grown in hotter countries such as bananas, oranges, tomatoes, tea and coffee.

In a speech to the Fabian Society last year, Mr Benn – who will launch the new policy at the massive Thanet Earth greenhouse complex in Kent tomorrow morning – said: "UK farming is doing all right overall. We are more self-sufficient now than we were before and after the Second World War, and we have shown during wartime what we can do to raise production when we need to.

"But to look at our food security in this way is only to think about art of the problem. Rather, we should look to maintain the security of our sources of supply. And if we want to avoid too much demand chasing not enough world supply, then we need to help to create a stable food market which can meet global demand for future generations."

Groups such as the Council for the Protection of Rural England, the Soil Association and the RSPB are concerned that Britain will opt for massive single-crop farms, turning many areas of the country into monocultures dubbed "green concrete" for their impact on wildlife.

The RSPB said: "It is important that concerns about food security are not used as an argument to decrease the sustainability of production. For long-term food security, we must consider our impacts on the environment and ensure we do not cause lasting damage to biodiversity and the ecosystem."