Wheat, corn and rice prices have more than doubled in the past two years. Global cereal demand is projected to increase by 75 per cent between 2000 and 2050, and global meat demand is expected to double. Global cereal reserves have fallen to their lowest levels for 30 years, and oil prices have more than tripled since the start of 2004.
Food riots are not uncommon. Higher incomes, urbanisation and changing preferences are raising domestic consumer demand for high-value products and shifting consumption from grains to meat and diary. Throw climate change and high energy prices into the mix and we have a conundrum.
Historically, the answer was to bring more land under cultivation. This solved issues of population growth and market expansion.
Increasingly, in more densely populated parts of the world, the land frontier is closing. In other areas, pressure on food supplies is driving expansion into marginal areas, rainforests, wetlands, peat lands, savannahs and grasslands, meaning further loss of biodiversity.
The relationship between climate change and agriculture is a two-way street. Climate change is increasing production risks in many farming systems. Factors such as changes in temperature, precipitation, carbon dioxide fertilisation, climate variability and surface water runoff will all affect productivity.
In the 1960s the solution was a Green Revolution, based on high input systems sustained by new seed varieties, pesticides and fertilisers. Evidence is mounting that the productivity of many of these systems cannot be sustained, and is being undermined by pollution, salinisation, soil degradation and pest and weed build-up.
Today almost 2 billion hectares and 3 billion people are affected by significant levels of land degradation. So the Green Revolution won't give us the get-out-of-jail-free card. We are losing land as quickly as we can find new areas to farm.
Costs are also becoming a constraint. The price of fertiliser is going through the roof, due to global demand and rising energy prices. Two fertilisers of choice for Australian cereal crops have recently hit $1600 a tonne, more than double the price 12 months ago. The herbicide Round-up has gone from $4 a litre last October to $13 today. Even the cost of tractor tyres is expected to rise as costs of raw materials and production increase.
The unequal distribution of food, and conflict over control of the world's dwindling natural resources, present major political and social challenges to governments and policymakers. They are likely to reach crisis status as climate change advances and world population expands from 6.7 billion to 9.2 billion by 2050.
How do we increase agricultural productivity and yet protect the natural assets that underpin future production?
We've got to look at ecological, energy and water systems as a whole to appreciate the impact, or footprint, of our food on our natural resource base.
We need science that enhances sustainability whilst maintaining productivity. To do this, we desperately need improved understanding of the landscapes in which we farm.
Traditionally, food prices do not include the cost of environmental damage. The natural resource base (land, water, biodiversity) for agriculture continues to suffer. We can't afford to keep running down the systems that feed us.
As long as the cost of maintaining and improving the natural resource base in agricultural systems is not included in the price of food, farmers will never be able to farm sustainably and profitably. This may mean dearer food, but it will also mean ensuring we can continue to produce enough food.
We need market and trade policies that remove perverse subsidies. Rewarding the provision of ecosystem services is a good start. With a market for these services, farmers will not only be paid for the goods they produce but for the services they deliver through management of healthy landscapes, rivers, wetlands and estuaries.
Agriculture exploits the natural resource base. The nutrients in our food were once part of an ecosystem, but farming doesn't have to be an endless cycle of more synthetic inputs to offset land degradation.
Advances are being made in tapping nutrient sources that do not depend on fossil fuels but there is more to be done. We need biological substitutes for agrochemicals and biocontrols of pests and pathogens. We must address agricultural production as an agro-ecosystem that is part of the larger-scale ecosystem. New crop and forage species bred for specific conditions will be important.
In an industry where inputs are increasingly expensive and climates continually variable, surviving is all about both precision and resilience. There are serious deficiencies and problems with our scientific understanding of the ecology of the rehabilitation process in many ecosystems and the environmental impacts of specific actions on the farm.
We can't afford to keep ignoring the need for the research and development of farming systems that integrate productive land uses into the landscape in a way that is compatible with ecological, hydrological and biogeochemical processes.
Investment in publicly funded agricultural research in many industrialised countries has stalled or declined, and has become a small proportion of total spending on science. Spending public funds on research that the private sector can undertake profitably, such as developing novel seed varieties, doesn't make sense. Public investments in science to address environmental shortcomings that have ramifications for society at large do.
Agriculture is not just about putting things in the ground and then harvesting them. It is increasingly about the social and environmental variables that will determine the future capacity of agriculture to provide for eight billion or nine billion people in a sustainable manner.
Agriculture is facing its greatest challenge yet. In a nutshell, global agricultural production must be increased substantially to meet rising demand, but it must be achieved with a decreasing impact on the natural resources and environment at a time when energy costs will continue to rise.
It is possible to create resilient agricultural systems, to have healthy and productive landscapes. It isn't easy, but it is essential. The present path of agricultural science is unlikely to achieve development goals for global food production and security whilst improving or maintaining the condition of the natural resource base and global environment.
Now is not the time for Australia to turn its back on the rest of the world and allow our investment and international commitment in agricultural science to decline further. This country has a tradition of leadership in agricultural science, and has much to contribute to this global problem.
The challenge of producing more food by farming without harming the natural resource base and environment in an era of increasingly expensive fertiliser, pesticides and energy, coupled with the spectre of climate change, is formidable. It is a wake-up call to our civilisation.
Dr John Williams is Commissioner of the NSW Natural Resources Commission, a commissioner to the Australian Centre for International Agricultural Research and former chief of CSIRO Land and Water.
Fiona McKenzie is a senior policy analyst with the Wentworth Group of Concerned Scientists.
This is an edited extract of a paper published in Australasian Science.