It seemed the fate of farmers rested almost entirely on vagaries of seasons, weather and markets. These dominated the prayers of the faithful come Sunday morning, and the church was always full. Years later, interviewing farmers in foreign fields, I realised how little I really knew of the intricate, invisible, imperative machinery underpinning the success of the First World farming enterprise: infrastructure and information, policy and process, systems and science. Sometimes it's only in their absence that such things come into view. ''Why don't you warehouse grain from the good years for the hungry ones?'' Because we have no silos, no safe storage, and no money to build them, explains the Afghan farmer. Similarly, precious water is lost from ancient underground karez systems because of the lack of resources to reconstruct and better regulate them. In Africa, as rains vanish, soils diminish and traditional crops fail, ''why not diversify, try new ones?'' That would require new seed - and the knowledge to nurture it. In other places, such as the lush highlands of Papua New Guinea, crops might thrive. But impoverished farmers have no roads to get their produce to town markets. Instead the town stores offer anaemic, expensive, imported fruit and vegetables to undernourished populations.

These are parables of food insecurity, footnotes in a narrative which looms as a horror story as the global population heads towards an anticipated 9 billion by 2050. The converging threats of population growth, climate change, volatile markets and unsustainable use of resources are now being shouted loud by leading scientists urging governments to work together to transform the way food is produced, distributed and consumed. They want food on the table at international forums - on the agenda, not the buffet. There is, they insist, little time to waste in ushering in a new agricultural revolution, one which echoes the bumper yields of 1960-90, but without the associated environmental costs. ''The next 60 years will require as much food as we have ever produced in human history,'' says Dr Megan Clark, chief executive of Australia's CSIRO and one of the high-powered coterie of scientific leaders spearheading the international food production reform effort. In the same time frame, climate change threatens to erode productivity, with more frequent devastating droughts and floods forecast by the Intergovernmental Panel on Climate Change.

Producing and distributing food through merely ratcheting up the scale and pace of existing systems is no solution. ''You've got agriculture now contributing on average around 25 per cent of greenhouse gas emissions - through land clearing, fertilisers etc,'' Dr Clark says. More of the same risks a self-defeating spiral. Complicating the landscape further are issues of equity and access. Already a billion people go hungry on a planet with sufficient food for all. Another billion put their health at risk by eating too much. ''I don't think there is a full appreciation of the challenge,'' Dr Clark says. To remedy that, the challenge has been starkly articulated by Dr Clark and 12 other eminent scientists who form the Commission on Sustainable Agriculture and Climate Change, headed by Britain's chief scientist, Professor Sir John Beddington. In a policy paper published yesterday in the journal Science, they identify strategies they say will not only feed the future, but have the capacity to harness agriculture as a mechanism to haul back dangerous emissions through techniques that absorb carbon dioxide rather than releasing it. The blueprint has seven priorities: integrating global and national policies; increasing investment; sustainable intensification; helping the most vulnerable; reshaping consumption around health; reducing waste; sharing information. At the heart of it all is sustainability. ''Alternative agricultural practices, tailored to different regions, show promise for reducing greenhouse gas emissions and maintaining or improving yields despite extreme weather,'' they say.

They cite projects in Niger where agroforestry across 5 million hectares has benefited more than 1.25 million households, sequestered carbon and boosted grain yields. In Denmark, using a combination of approaches (including optimised breeding and feeding, improved use of nitrogen in manure, less fertiliser and changes in tillage) agricultural emissions have fallen by 28 per cent while productivity has increased. Local innovations include collaborations between the CSIRO and irrigators on the Murrumbidgee River, who now receive bespoke scientific advice on precisely how much water to put on their crops and when via SMS messages. ''We're finding that in many areas we used to over water, leaching the soil of nutrients,'' Dr Clark says. ''Technologies like this can be scaled right around the world as people get mobile phones.'' In other projects, scientists are exploring growing biofuel crops to restore degraded land; rice varieties for Asia which produce two crops in a season; and developing drought-tolerant root crops to meet changing conditions in the Pacific. The Science paper observes that despite the scientific momentum, the demographic writing on the wall and grassroots support for a greener revolution, action has been ''slow to materialise''. It echoes another report released this week. An investigation into the international response to the continuing drought in the Horn of Africa found that the deaths of tens of thousands of people could have been avoided. Scientific early-warning systems forecast the emergency back in August 2010, but a full-scale response was not launched until July 2011.

''The truth is that science, technology, innovation and creativity are providing the tools for us to win the battle against hunger,'' observed former Nigerian president (and farmer) Olusegun Obasanjo in an article this week. ''What is needed now is to put the products of these scientific advances, together with the necessary financial and non-financial support, into the hands of farmers.''