Today's global population is around six billion people, and our dominant form of agriculture is based on using synthetic chemical inputs to produce high-yielding monocultures. Crops such as corn, wheat and soya are grown to be processed into foods for people, or for animals that then suffer short, miserable lives in factory conditions, before being fed to people as well.
According to population experts, by 2050 there will be nine billion of us. If our government-agreed target on greenhouse gas (GHG) is to be met, we will also have cut emissions by 80%. Oil and phosphate supplies, on which much modern agriculture is heavily dependent, will be tow. Climate change will present all kinds of challenges - with extreme and unpredictable weather events, increased flooding and drought. How can we meet the challenge of feeding more people in what will undoubtedly be a more resource-constrained and 'climate-difficult' future?
The current picture
Farming, food, forestry and land use change are together responsible for a third of total GHG emissions according to the International Panel on Climate Change (IPCC). Particularly in developed countries, a significant proportion of agricultural GHG emissions are nitrous oxide (N20), arising from the manufacture and use of artificial nitrogen fertiliser - N20 is around 300 times more powerful a GHG than CO2. However, the most significant GHG emissions associated with agriculture come from converting forests and permanent grassland to cropland, because this releases carbon stored in the soil.
Taking account of carbon stored in soil is vitally important when assessing the environmental impact of agriculture. Globally our soils are a carbon sink that hold more than five times as much carbon as all our forests. Organic farming, with its reliance on pasture rotation, grazing manure and compost to build fertility, generally stores more soil organic matter (and therefore carbon) than intensive farming, with its reliance on synthetic fertiliser. But because intensive systems currently dominate global systems, our soil is not sequestering as much carbon as it easil, could - Professor Pete Smith from the University of Aberdeen, who lead the agriculture work for the IPCC, estimates that better soil management could take around 4,000 million tons of CO2 out the atmosphere; a 'no brainer' he says in terms of trying to cut our GHG emissions.
Historically, the environmental cost of intensive agriculture has been justified by the high yields that such systems have produced. The policy of maximising food production has its origins in the food shortages caused by World War II. And modern methods do produce a lot of food; global increased yields have seen food production more than double since 1950 - all be it by an increasing inefficient use of non-renewable resources (oil at mineral phosphates, for example), and at huge cocost to our soil, water, wildlife and environment.
The problem is that much of this food has been produced in the developed world, with the help of subsidy that has the effect of reducing global prices - sometimes below the cost of production. Exporting these subsidised surpluses has frequently had the effect of making it impossible for farmers in developing countries to sell what they produce at a reasonable price. Intensive farming has gone hand in hand with increased control of the food chain by a smaller number of large companies (although many thriving small and artisan producers are increasingly bucking this trend).
Farmers in the global South haven't been able to compete on price, so have been encouraged, often through active development policy, to rely on growing cash-crops for export in order to earn enough to buy the food they need to eat. Today, while there is more than enough food in the world to feed us all comfortably, around one billion people in the developing world are going hungry each day.
If change to our food and farming systems is needed in the wake of the 'perfect storm of population growth, climate change, diet related ill-health and diminishing resources, what should it look like? The bio-tech and agribusiness sectors have not been slow to suggest that even more intensification of agriculture, based on new technology such as genetic modification (GM), is the only way to guarantee higher yields.
The aphorism that only GM and high-input farming can drive high-yields is accepted by many policy makers. However, this assumption isn't backed up by evidence. In recent years several studies have started to examine how yields in organic and low-input systems compare to intensive systems of farming. In 2006 a paper by Catherine Badgley found that, while yields from organic systems in temperate regions were typically 9% less than in non-organic systems, in. tropical regions, organic agriculture can increase yields by over 50%, with the possibility of more than doubling the production of some types of food. A report in 2006, by the UN Conference on Trade and Development (UNCTAD), based on 114 studies in Africa, found that organic agriculture could increase yields by up to 116% - more than double.
Combined with ecological, environmental and social benefits, the report was clear that these yields meant organic agriculture in the developing world could guarantee both food supply and equitable development.
This evidence is backed by Gathuru Mburu, the director of the Institute for Culture and Ecology (ICE) in Kenya, who has been working with communities in the Lari Division of central Kenya to move away from farming tea for export, and towards using indigenous seeds and plant varieties to organically farm food for consumption. 'The community was growing tea, in order to sell it and then buy food,' Mburu explains. 'But they weren't receiving enough income to cover their costs, because the price was controlled by the global market. We've encouraged them to take control by growing food to eat.' In 18 months since they started the project, the 100 or so households have produced enough surplus to sell at the local market; this in a time when 10 million Kenyans are heading towards famine brought on by the failure of the (intensively farmed, non-indigenous) maize crop.