Every year, we add 78 million people to the world’s population – equivalent to a new USA every 4 years. Demographers, mathematicians and environmentalists have been warning for years that the world’s population will eventually hit a natural limit. In part one of this series, I looked at five reasons to be optimistic about our chances of feeding a population of 10 billion. In part two, I look at five major challenges.
1) The climate changes everything
For a select and privileged few countries, a warming climate will do wonders for their agriculture. Greenland’s farmers are already enjoying a growing season that is two weeks longer and 1.3C warmer than it was 50 years ago. They are the exception however. For warmer countries, more heat isn’t such a good thing. Southern Africa as a whole is 1C warmer than 50 years ago, and summer rainfall has declined by 20% (pdf). That’s an observable trend, and the consequences are already being felt.
Climatic change isn’t uniform, and some parts of Africa have warmed faster. The tea-growing highlands of Kericho, Kenya, are now 3.5C warmer. That kind of change is disruptive to agriculture. Rains come later, or not at all, or all at once. Seasons change, and farmers don’t know when to plant any more. Weather is more extreme, meaning more crops are lost to drought, floods, or storms.
And it’s not just Africa, as Russia’s drought last year proved. The Chinese Academy of Agricultural Sciences anticipated a 5-10% fall in grain production by 2030. Britain has followed the driest March for 50 years with what is likely to be the hottest April on record, and it’s too early to tell what this will do for our wheat crop. Will it ripen early for a bumper harvest, or dry out in the fields? An unpredictable climate throws food production up in the air.
2) Water shortages
Linked to climate change is the issue of water. A changing climate moves rainfall patterns, and produces more extreme weather. But even without climate change to contend with, the world’s agricultural systems have a water problem. The planet has a fixed amount of water circulating its hydrological cycles, so it’s not that we’re running out of water per se. The issue is not the amount of water, but where it is and whether or not it is accessible to us.
For example, huge reserves of fresh water are locked up in glaciers. The glaciers melt into rivers, which are diverted for irrigation. As the earth warms, glaciers are melting faster in summer than they can be topped up by snow in winter. The result is a depleting resource. China’s Urumqi river irrigates thousands of acres across Xianjiang, but the glacier that feeds the river is 1C warmer than in 1962, and has declined by 20%.
More water is locked up in groundwater aquifers. Some of these are replenished by rainfall, but can be pumped for irrigation faster than they are topped up. In drier areas, they are often a vestige of a wetter past, meaning it is a one-time only store. Saudi Arabia is a case in point. Their agriculture has been entirely dependent on an aquifer which is now gone, and the wheat harvest has fallen by two thirds since 2007. The World Bank estimates that 175 million Indians and 130 Chinese are fed from unsustainable aquifer use.
3) The ground beneath our feet
The plough was one of history’s greatest inventions, paving the way for human settlement and a diversification of employment that allowed art and culture to blossom. We owe a lot to the plough, but it may also play a part in our undoing. Ploughing rips into the soil and tears away the vegetation that keeps it together. Year after year, it reduces the soil’s fertility and leaves it dry and dusty, at which point it can simply blow away.
The US ‘dust bowl’ is the most famous example of widespread erosion, when drought and unsustainable farming devastated the Great Plains States. A similar scenario is brewing in China, where grasslands in the Northwest and Inner Mongolia have been turned over to intensive farming, but it’s a worldwide problem. The first global soil survey in 1991 found that 7.5 million square miles of land had already been degraded, a third of all arable land.
4) Oil dependency
It is an often-repeated fact that ten units of fossil fuel energy go into our food for every unit of calorific energy we get back. Whether it breaks down quite that neatly I couldn’t say, but our agricultural system is certainly dependent on oil to an extraordinary degree. Tractors plough and combines harvest. Machines spray and irrigate. Grain is dried and processed industrially, and shipped thousands of miles by boat and truck for consumption in a genuinely global marketplace. Oil is needed at every stage, and it is a finite resource.
The amount of oil used in agriculture is falling in some areas. It takes 12 gallons of fuel to produce one tonne of US grain today, against 33 in 1973. But in other areas it is growing. Food consumed in Britain today has travelled 50% further than it did in the 1970s. More and more countries have mechanised their agriculture – delivering higher yields, but accelerating oil depletion and erosion in the process.
It is likely that oil production has already peaked. It has certainly hit a plateau, if not gone into decline. The global food network cannot function without cheap oil, and the oil spike in 2008 demonstrates how closely the price of food is tied to the price of oil.
5) Protectionism, self-interest and bad politics
At a time of crisis, it would be nice to think that the world would be able to pull together and cooperate. Global food reserves and crisis response mechanisms might have been a good place start. Instead, the food crisis of 2008 prompted a rush to secure food supplies on a unilateral basis, every country for itself.
One particular phenomenon is land leasing, where a country with a shortage of arable land leases large tranches of it from a country with a surplus. Deals have proliferated across Africa, as Middle Eastern and Asian countries have snapped up the rights to agricultural produce across vast estates. Saudi Arabia has leased land in Ethiopia. South Korea has a share of Sudan. Madagascar even considered leasing a river to the Saudis. The details of these deals are often sketchy, and how they will pan out for the host country is yet to be seen. There result could well be situations where a native population is going hungry while the country remains an exporter of food, with obvious implications for political stability.
We know plenty of the things we need to do to improve self sufficiency and grow more food, but we don’t do them because of our self interest. Subsidies are the most obvious, and the most immoral. We know that if we dismantled the US and EU agricultural subsidies, farmers in poorer countries would be able to compete in their own local markets. It is a vital measure for future food production and famine prevention, but every attempt to redress the injustice has been thwarted by lobbyists, on both sides of the Atlantic.
Those are five reasons why it is highly unlikely that the world can support 10 billion people,and there are more reasons besides. I haven’t mentioned peak phosphorus, or the hazards of monoculture and our over-reliance on a very few food crops. But there are also things we can do, as I explained in part one of this two part series.
I’ve presented both sides here to show that we need an honest, big-picture discussion on our world food system. We can’t cherry pick movements or developments we like, and use them to justify either our optimism or pessimism. We cannot allow either complacency or despair to stop us acting.
Can the world feed 10 billion people? I don’t know. But I know that starvation is a terrible way to die, and that we should do everything within our power to try.