Mankind will continue to be fed and fuelled through the age of climate change if we make the right choices, writes Patrick Cunningham
HUMANITY IS often seen as facing four great challenges: population growth, food shortages, energy supply and climate change. Each is indeed a major challenge requiring policy innovation and intervention, but the issues are inextricably linked, and indeed can be said to represent the four elements of a single challenge - that of sustainability.
Population growth in poor countries is the main factor testing food production systems to new limits. Food production increasingly depends on finite energy resources through higher fertiliser inputs and mechanised production.
The increasing use of fossil energy (largely coal and gas) in turn is inexorably changing the climate. And to complete the circle, this climate change reduces the globe's food production capacity.
Despite this stark scenario, it is not inevitable that one day the planet will be unable to feed its population. While less than one third of the globe is dry land, and less than one third of this is farmed, global agriculture nevertheless has the capacity to feed us all, now and into the future. But this will only happen if the correct policy decisions are made and implemented.
Population growth may cease during this century. At the moment population is increasing at slightly more than 1 per cent per annum globally. It has, however, stabilised in the developed world. By 2050, three-quarters of current developing countries are expected to have stabilised their populations, and global population may level off at between nine and 10 billion people - 50 per cent more of us than there are today.
That is a substantial number of extra people to feed and diets are changing as the world is getting richer. But cereals remain the key to global food security. They supply most of the calorie needs of humans, and also provide most of the feed stock from which much of the meat and milk in the world is produced.
With a range of technologies, led by developments in genetics and breeding, we have increased grain yields more than sixfold in six decades.
Irish winter wheat yields are now the highest in the world, having averaged 9.4 tonnes per hectare in the first six years of this century. This is the same as this year's estimated average maize yield in the US.
With new breeding technologies, yield increases will continue, while crop protection from insects, diseases and weeds will become cheaper and more effective.
Oil is running out and the price has rocketed. In response, biofuels are being promoted in developed countries, meaning land that could be used for food production is being devoted to energy production instead.
In the US this year 33 per cent of the corn crop will go to ethanol production. Recent research shows that the net energy yield from corn-based bioethanol is modest, and that it also adds to the global climate change problem.
In addition, the demand for food or feed grains for conversion to ethanol is partly responsible for escalating food grain prices (wheat and rice up threefold since 2000, corn twofold).
This chain of consequences falls hardest on the poorest. FAO, the Food and Agriculture Organisation of the United Nations, estimates that an additional 50 million people joined the ranks of the hungry in 2007 as a result of high food prices.
After five decades in which the number and percentage of hungry people in the world had been declining, the last two years has seen a dramatic worsening in global food security. Cereal stocks, at 409 million tonnes, are at their lowest level in 30 years.
Nitrogen fertiliser, the most critical input in increasing production, is mostly derived from natural gas, and its cost has been increasing even faster than that of food.
Against this increasingly critical background, FAO estimates that global food production will need to double by 2050 - mainly in developing countries, where more than 95 per cent of the projected population increase will occur.
This challenge can be met - the world can feed its people. But poor countries cannot meet this challenge on their own. They need assistance, but the current response of the developed world is inadequate.
While the problem is growing, the level of assistance poor countries receive from the rich countries of the world has been static in real terms for many years. The proportion of official development assistance given for agricultural purposes has declined from 17 per cent in 1980 to just 3 per cent in 2006.
While official aid is only part of the answer, it is clear that both the scale and targeting of assistance to the poorest countries is totally inadequate for the challenges they now face.
On both fronts, Ireland's record is good. The ODA budget for this year is over €900 million, five times larger than it was a decade ago. It is also well directed - focusing on health, education and agriculture in nine of the poorest countries in the world, seven of them in Africa. The impact of climatic change is becoming clearer each year. Predictions to 2080 show reductions in food production potential in poor tropical countries as land productivity is reduced by desertification.
The largest impact is expected to be in the Indian subcontinent, where cereal production capacity could drop by 20 per cent. Elsewhere in Asia, and also in Africa, production could drop by 4-8 per cent. In contrast, higher CO2 levels and warmer conditions would increase cereal yields in the developed world.
The gulf between rich and poor would thus be made even wider. To avoid catastrophic consequences of climate change in our world, a reduction of 80 per cent in fossil energy use in developed countries is required. The policy choices are clear and the world can do the right thing.
Targeted agricultural assistance to the developing world coupled with sharp reductions in fossil fuel consumption in the developed world is what is required.
The largest challenges in human existence face us in the coming generation.
• Dr Patrick Cunningham is chief scientific adviser to the Government. He will be delivering a paper on this topic to the Agricultural, Biotechnology International Conference (ABIC) in Cork next week