Population, Food and the Environment
Tim Dyson


Editors Introduction
With the world's population set to increase to 9 billion in the next few decades, will there be a major food shortage in the future? Many commentators have argued that a crisis is looming in terms of world food production. Some say that, in order to increase food production, more wilderness will have to be brought into cultivation. In this feature, Tim Dyson, professor of population studies at the London School of Economics and Political Science, argues that such fears are exaggerated. He says that there has been little change in cultivated land area around the world, little loss of natural habitat and that food needs can be met through increasing yields within existing areas of cultivation. The world's growing population will not starve.

What is the true impact of population growth on biodiversity and world food production?

Tim Dyson: I read an article by the late American economist Julian Simon about the issue of biodiversity loss. Essentially, he was looking at statements that were made 20-25 years ago about how many species would be lost in the forthcoming quarter-century. Statements were made to the effect that maybe a quarter of all species on the earth would vanish if current rates of biodiversity loss continued in that period of time. The point of his article was to say that there was very little empirical basis for these statements: they reflected a massive exaggeration and represented opinion rather than anything that could be reasonably established. I suspect his conclusions were correct.

I myself have done quite a bit of work looking into statements along the following lines: the world's population is growing so much that we are going to run out of food; agricultural yields are in trouble; population is growing faster than the supply of food, not only for the world as a whole, but for the world's major regions. When you look at some of these statements, you find that their basis is hardly as strong as some might suspect. Basically, some sections of the environmental lobby wildly exaggerate specific points. It doesn't do their case any good in the long run. The problems that we face on this planet are serious enough without exaggerating and overstating them.

Do you think that there will be a world food shortage in the future?

Dyson: There are a number of prominent people scattered around North America and, to some extent, Europe who suggest that the world faces major food problems because there has been very substantial population growth. They suggest that agriculture faces increasing environmental production constraints and that we are not going to be able to produce enough food for the people who are going to come along.

Having looked at this situation in some depth over a period of years, I don't think that the situation is anywhere near as calamitous as is sometimes portrayed. I should immediately say that the world does face very significant food problems: there are several hundred million people in the world today who don't have enough food to eat. However, over recent decades things have been improving. Average levels of calorie and protein intake in most parts of the world have been increasing. Supplies of cereals and vegetables have been increasing. In most areas of the world, human diets have improved quite substantially. Diets have in general become more diverse. They have become richer in calories and richer in proteins. The one possible exception to this is sub-Saharan Africa.

If one looks into the future, the key issue is whether agricultural yields are going to continue to rise at reasonable rates. I see no reason to believe that they will not. I don't foresee any kind of major food crisis in the coming decades. There are major problems that we do need to address, but on balance things have been getting better. In terms of major world problems, I don't think food production should be at the top of the agenda--certainly not in comparison to the issue of climate change, which could be extremely serious. We should be able to produce enough food for the 9 billion people that there will be on the planet in a few decades time. Getting sufficient food to the poorest among the 9 billion is an issue. There will still be problems in that area in 20 or 30 years.

What methods can we use to provide more food for increasing populations?

Dyson: Speaking very crudely, there are 6 billion of us now and there are going to be 9 billion in a number of decades. So we need 50 percent more food. There are two ways of growing that food. You can either increase the area that is brought under cultivation or you can increase agricultural yields, that is output per hectare. For several reasons, agricultural area in the world as a whole is unlikely to expand in the next 20 to 30 years. One is that certain countries, such as India and China, are already using most of their agricultural land. In Western Europe and North America, recent decades have seen some decline in agricultural area. Land has been taken out of agricultural use because these areas have been producing more food than they can sell. Therefore, the amount of land brought into cultivation had to be reduced. In some other parts of the world, particularly sub-Saharan Africa, there has been very little change in agricultural yields and, with growing populations, the agricultural area has had to be expanded. That has generally been achieved by destroying savannah and forest environments. To go back to the world as a whole, then, there has probably been little change in the cultivated area overall.

More food can also be produced through increasing agricultural yields. Often the technologies that are employed to increase yields are controversial, but I think the scope for increasing agricultural yields is so very considerable that there is no real requirement to expand the cultivated area for the world as a whole. In other words, we should be able to meet the food demands that arise in the next 30 or 40 years, given the current areas of agricultural land, but through increased yields. Increased yields are one way of conserving nature, because otherwise you've got to chop down forests in order to grow more food: yields are key.

Should governments aim for population stabilisation?

Dyson: I think that there are many reasons for thinking that slower rates of population growth are easier for governments to deal with than faster rates of population growth: this applies to health, employment and education provision. If your population is growing faster, then your urban areas are also growing faster: cities will be expanding rapidly. While saying that I believe quite firmly that slower rates of population growth are beneficial in some senses, I would never try to justify a family-planning programme on those grounds. The main reason for family-planning programmes at the beginning of the twenty-first century is that every person, female and male, should have access to safe, effective and affordable contraception so they can control their fertility. The purpose is not to bring about population stabilisation: if people want to have ten kids, they can have ten kids. However, all the evidence is that once you give women the choice, they take it, so you bring about a reduction in the birth rate and the population eventually stops growing. If you look further into the future, at some point in the second part of the present century, the world's population will start to decline. That brings about a huge set of new challenges.

This feature was taken from an interview held at the London School of Economics and Political Science on 7 May 2002. Copyright the London School of Economics and Political Science.