Some scientists favour a genetically modified solution
The world's food production needs to double by 2050 to feed the world's growing population.
But over this period, climate change, reduced access to water and changing land use are likely to make growing crops harder rather than easier.
Scientists are trying to find new ways of using fewer resources to produce more food.
Dr Chris Atkinson, head of science at East Malling Research in Kent, UK, said that in the next few years the UK would not be able to rely on imports of cheap food.
"A number of places where the UK sources food, like southern Spain, Greece and Italy, are going to find it very difficult in the next 50 years to continue to produce the levels of food they currently do," he said.
"That's in part due to the predictions of the scarcity of water in those parts of Europe."
The work at East Malling Research has focused on refining traditional agricultural techniques. But Dr Atkinson believes that GM technology will eventually be needed to produce enough food to feed the world.
"The concept of using tools like GM to improve water use efficiency are a reality. It is a matter of whether people want to accept that technology," he explained.
Scientists try to boost crop yield
Currently, many people refuse to accept the technology - particularly in Europe, where it is effectively banned.
Professor Bob Watson, chief scientist at the Department for Environment Food and Rural Affairs (Defra), believes that food production has to be doubled over the next 50 years.
That can only be done by developing all relevant technologies - including GM.
"We need science and technology to [find] ways to double food production over the next 50 years in a way that is environmentally sound," he said.
Professor Watson said there were a number of key issues which needed to be tackled.
One of the most important was how to reduce greenhouse gas emissions from farming, such as methane from rice production and nitrogen oxide from use of fertilisers.
He added that thought also needed to be given to how agricultural systems should be adapted to a changing climate.
The government's chief scientist, Professor John Beddington, has set up a food strategy task force to answer these very questions.
He has also commissioned a "foresight study" into food and farming, due out next year.
BBC News understands it will highlight concerns that the UK's agricultural research has been cut back by 70% since the 1980s. Professor Ian Crute, the former director of Rothamsted Research, is among those involved in producing the report.
"Over the last 20 years or so, we have been extremely complacent. We have really eroded our capability in research and development focused on agriculture and food," he said.
"Having wound it down over the last 20 years, we have to really begin to wind it back up again. We have to invest in skills, our research and development.
"If we are to get this increase in efficiency we just have to make these investments. I think it is quite urgent."
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