'Double food output to stop world starving,' say scientists

Royal Society wants green revolution to deal with global population rise of 3 billion

Global food production needs to be increased by between 50 and 100 per cent if widespread famine is to be avoided in the coming decades as the human population expands rapidly, leading scientists said.

A second "green revolution" is needed in agriculture to feed the extra 3 billion people who will be added to the existing population of 6 billion by 2050.

The experts, drawn from the Royal Society, Britain's national academy of scientists, believe that a variety of short-term and longer-term measures will have to be adopted urgently if agricultural production is to meet the demands made by the growth in human numbers.

They cite the original green revolution of the 1960s when new crop varieties, greater use of agro-chemicals, and a change in farming practices led to a dramatic increase in food production: it leapt from 1.84 billion tonnes in 1961 to 4.38 billion tonnes in 2007. But scientists accept that this increase came at great environmental cost, and the Royal Society report warns that a second green revolution has to be based on a sustainable increase in global food production without a significant expansion in the area of land turned over to farming.

"There is insufficient water to support an increase in the cultivated areas, and the environmental consequences of increasing cultivated areas are undesirable. Additional production will have to take place without further damage to [the environment]," the Royal Society report says. The area of land available to sustain each human being is "dangerously declining" because of soil degradation, the report says.

Professor Sir David Baulcombe of Cambridge University, who led the study, said that the Government must be prepared to pay £2bn over a period of 10 years to fund research into ways of boosting food production around the world. "We need to take action now to stave off food shortages. If we wait even five to 10 years, it may be too late. Biological science has progressed in leaps and bounds in the last decade and UK scientists have been at the head of the pack when it comes to topics related to food crops," Professor Baulcombe said.

"In the UK, we have the potential to come up with viable scientific solutions for feeding a growing population, and we have a responsibility to realise this potential. There's a very clear need for policy action and publicly-funded science to make sure this happens," he said.

The Royal Society report says that a range of measures, from new ways of managing crops – such as changes to the way they are irrigated – to the introduction of GM varieties that are drought-resistant or salt-tolerant, will all have to be called upon to boost food production.

"There is no panacea for ensuring global food security. Science-based approaches introduced alongside social science and economic innovations are essential if we're to have a decent chance of feeding the world's population in 40 years' time," Professor Baulcombe said.

"Technologies that work on a farm in the UK may have little impact for harvests in Africa," he said.