According to a report in The Independent, the experts, drawn from the Royal Society, Britain's national academy of scientists, said that 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.
They 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 said.
The area of land available to sustain each human being is "dangerously declining" because of soil degradation, according to the report.
According to Professor Sir David Baulcombe of Cambridge University, who led the study, the Government must be prepared to pay 2 billion pounds 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," he said.
"There's a very clear need for policy action and publicly-funded science to make sure this happens," he added.
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.