Recent protests over food prices underline a key message from a new report about the potential dangers of neglecting agricultural research.
The ousting of Tunisia's president last week, and unrest in other nations such as Algeria and Sudan, has many causes — but rising food prices have been one of the underlying themes.
At one level, the problem of food scarcity can be told simply. There are seven billion of us on Earth, of whom probably two billion are underfed. Two billion more people are due to join the planet by 2050. Food security is not just a huge problem — some now argue it is the central problem facing humanity.
Hunger has a daunting array of causes. These include the scarcity of water and other agricultural inputs; soil erosion and the spread of salinity; and the tightening grip of climate change.
But one important part of what shapes the story of food and hunger is agricultural research — or the lack of it. The Green Revolution that began in the 1960s, which produced high-yield varieties of wheat allowing India, for example, to become a net exporter of grain, was a high point in the history of such research.
Many feel that a low point has now come, and that we are reaping the harvest of a tragic two decades of neglected agricultural science. This situation needs to be reversed.
Hunger's global reach
International reports on food security have been appearing in abundance over the past two months. , , , 
Most recent is a report, 'The Future of Food and Farming: Challenges and choices for global sustainability', launched this week by the British government and written by its Foresight think tank, in consultation with researchers from 34 countries from across the developed and developing worlds.
The report provides a uniquely broad view of what causes food scarcity, identifying the factors that make up a complex political, social, economic and scientific web.
And it includes less obvious causes of hunger, such as the distressing fact that nearly a third of the food that is grown is wasted, for example by spoiling through poor storage.
It also conveys the sheer scale of the problem, demonstrating that food scarcity will eventually affect us all, even those of us whose bellies are full. Because, as we have seen in Tunisia and elsewhere, hunger leads to civil unrest and migration, and because farming, as it is currently practised, is destroying key resources and emits too much greenhouse gas.
Guilty by omission
In the sphere of research, many omissions have contributed to hunger. The report points out that existing innovations have not reached many of those who could benefit from them. In Africa, if these alone were implemented, productivity could rise as much as three-fold.
But three-fold, in only a few regions, is not enough.
New knowledge is essential. Yet for most countries, research into agriculture and fisheries is a low priority, says the report, and studies have now correlated the previous two-decade apathy with today's slowdown in productivity gains.
The report offers no support for 'knee-jerk' commentary seeking obvious scapegoats for hunger, such as the failure to adopt genetically modified crops, or the politics of food distribution. There is no single cause to rail against, and there is definitely no single solution.
And it makes clear that every approach must be harnessed in the quest for a new food system that "needs to change more radically in the coming decades than ever before, including during the Industrial and Green Revolutions".
Investing in research is one of the report's "key priorities". It points out that modellers agree that the science and technology yet to be done will be "one of the most critical drivers" of future food supply: "These challenges will require solutions at the limits of human ingenuity and at the forefront of scientific understanding," it says.
A priority for research
To achieve the required levels of research investment, says the report, more incentives must be provided for research into public goods that benefit low-income countries. New models of research funding are necessary. And research funders from the public, private and third sectors should sort out their differences and coordinate better.
The question is: can this report, and the others, propel hunger to the top of the political agenda? Calestous Juma, professor of international development at Harvard University, and author of a recent book on African food production , argues that the crucial step is getting heads of state to wantto solve the problem.
But achieving this degree of political will is hard, if only because hunger has the biggest impact on those who are in the weakest position to influence policy.
Agriculture, of course, competes for research funding with health, and other pressing problems, some of which have celebrated champions. But the need for research into food supplies supersedes every other need, since successfully producing and distributing food is a precondition for tackling other social problems.
Funders must reconsider their priorities. Researchers have a lot of catching up to do. And whatever its political justification, the unrest in Tunisia and elsewhere underlines the potential price of failure.
Foresight. The Future of Food and Farming: Challenges and choices for global sustainability (The Government Office for Science, 2011)
 Worldwatch Institute. State of the World 2011: Innovations that Nourish the Planet (Worldwatch Institute, 2011)
 Cirad: Agrimonde. Scenarios and Challenges for Feeding the World in 2050 (Editions Quae, 2010)
Calestous Juma: The New Harvest: Agricultural Innovation in Africa (Oxford University Press, 2010)