To tread more lightly on the planet, our diets must change

Published on Friday 9 May 2008 21:00

AT NO time in history has the pace and scale of change in our diet been faster than the past 50 years. Consumer choice has increased massively, but choice is part of the problem, not part of the solution. Waste, overconsumption and unhealthy diets are rife. We cannot go on like this.

What troubles analysts today is that this time there are at least eight features of the 20th-century food revolution whose fundamentals are now under threat.

The first is the energy crisis. The price of oil has been over $100 per barrel for two months, having risen steadily for a year. Some 95 per cent of food products are oil-dependent – agricultural productivity gains rely on fertilisers and mechanisation. The first rush to biofuels as substitute oil is now looking thin and if land goes to biofuels, that means less land for food.

Secondly, world food commodity prices are rocketing. Most of this increase is due to rising prices of imported coarse grains and vegetable oils – those which feature most heavily in biofuel production.

Thirdly, world population is rising rapidly – from 6.6 billion in 2007, it will be 9.1 billion by 2050. This raises the fourth problem, labour: with a seemingly unstoppable rise in urbanisation, who will be the rural labour force?

The fifth fundamental is land. Available productive land depends on sea levels, drainage and investment and climate change is likely to change which areas of land can grow most.

But the politics will probably centre on national "footprints". By the 1990s, each US citizen had a notional 1.9 hectares of cropland and pasture land from which to be fed – in China, it was just 0.4ha per person. Land availability has dropped significantly since. And a recent UK study showed consumers actually use food as though they have six times more food-producing land and sea available to them than they do.

The sixth fundamental is water. Globally, of all drinkable freshwater, households use 10 per cent, industry 20 per cent and agriculture 70 per cent. Today, 92 per cent of humanity has a relative sufficiency of drinkable water but by 2025 this will be 62 per cent.

The notion of "embedded water" is likely to be as important as greenhouse gas emissions. There is talk of labelling foods for their water consumption: to produce 1kg of grain-fed beef requires 15 cubic metres (15,000l) of water; a 250ml glass of beer uses 75l of water; a glass of apple juice takes 190l. A 150g hamburger takes a staggering 2,400l.

The seventh threat is already high on the agenda: climate change. The Stern Report on Climate Change found agriculture was responsible for 14 per cent of greenhouse gas emissions. The food and drink sector accounts for 20 per cent to 30 per cent of the various environmental impacts of the most common forms of European consumption; the most significant sectors being meat and dairy.

The eighth fundamental is what is known as "nutrition transition". As people become more affluent, they change their diets, eating more sugars, soft drinks, meat and dairy products. This in turn is associated with a shift in disease patterns – a rise in chronic conditions such as heart disease, cancer, diabetes and obesity. A diet heavy in meat has a far greater impact than a plant-based diet.

Each of these eight fundamentals poses a serious challenge to world food capacity. But the truth is that they are linked. Should humans stop treating the planet as a limitless resource? Definitely yes. But, hooked onto global growth, can we develop a way of consuming which treads lighter on the Earth?

The solutions all depend on whether we want more of the same diet and lifestyle or are prepared to change.

If everyone eats meat and dairy diets like the US or Europe, the world continues walking into a crisis. But if we eat less of these, and farm differently, there is room for manoeuvre. The pressure is thus likely to be on consumers to change.

The Scottish Government is right to be taking a holistic approach to food by considering the economic, environmental and social aspects of food together is essential. But it must not underestimate the scale of the challenges ahead. Food is built into our culture and economy, so there is no short fix – no omelette can be made without breaking eggs!

&#149 Tim Lang is a professor at the Centre for Food Policy, City University, London and a member of the Sustainable Development Commission.