|
|
|
How long will the world's grain, fish and water last?
Loaves and fishes
Mar 19th 1998
From The Economist print edition
Will there be enough of them?
HOW long will the world's resources last? The answer depends on whom you ask. Among the prophets of doom was Thomas Malthus, who argued 200 years ago that the world's population was increasing geometrically but food supplies only arithmetically, so unless population growth was checked, the food would run out. More recent doomsters include the Club of Rome, an international think-tank which in the 1970s gave warning of an impending scarcity of vital minerals; and a host of modern-day environmentalists, who are worried about the demands on resources made by a world that is not only getting ever more populous but also steadily richer. Such predictions, however humourless, often make the headlines. By contrast, the prophets of abundance, who insist that no crisis is looming, get little media coverage. They are irrepressibly, sometimes irritatingly, optimistic. So far, they have also almost always been right.
Since 1950 the world's population has more than doubled, but food output has more than trebled. True, there have been famines, but they were brought about by catastrophes such as civil wars and droughts, not the world's innate inability to feed itself. Contrary to predictions, vital commodities such as coal and copper remain abundant. Oil reserves, which in the 1970s were thought to be in danger of running out, have grown mightily since then. For the past few decades the trend in prices of most widely used minerals and metals has been downwards, reflecting a faster increase in supply than in demand.
Now the debate is about to enter a new phase. Over the next few decades the prophets of doom and abundance will turn their attention to three resources�grain, fish and water�which are particularly important to developing countries. This time proving the doomsters wrong may prove trickier.
Catch as catch can
Take them in turns, starting with fish. The world's fish harvest has risen from 49m tonnes in 1965 to over 110m today, but in recent years some worrying trends have emerged. Much of the recent increase has come from farmed fish. Among the catches of wild fish from the sea, fewer have been of high-value species (such as cod and haddock) and more of less desirable kinds (such as anchovy and pilchard). According to the United Nation's Food and Agriculture Organisation�not a body given to hysteria�around 60% of the world's various commercial fish stocks are now being harvested near or beyond sustainable levels.
The decline in stocks has caused strife between otherwise peaceful nations. Canada and Spain had a serious row about Greenland halibut a few years ago, and the Malaysian navy has killed Thai fishermen suspected of illegal fishing. As rich countries have depleted their stocks of fish, they have imported growing quantities from developing countries, who now catch far more fish than they do (see chart 9). In 1995 fish exports from developing countries were worth $23 billion, more than their earnings from meat and cereal exports combined, according to calculations by the Washington-based International Food Policy Research Institute. But if overfishing continues it could hurt poor countries, because their people rely more heavily on fish for protein than do rich-world dwellers.
Fish, it would seem, are proving Malthus right. But overfishing is not so much the inevitable result of population growth as the outcome of perverse policies. Fishermen the world over have little incentive to conserve stocks. They know that if they do not take all the fish they can, others will. Governments are now trying harder to enforce restrictions on fishing, in some cases using satellites to track boats. But developing countries have neither the money nor the technology to regulate their millions of subsistence fishermen; and in rich and poor countries alike, rules are still widely flouted.
This so-called "tragedy of the commons" is made worse by the huge subsidies governments pay to keep their fishing industries afloat. One recent study puts worldwide fishing subsidies at $21 billion a year, a quarter of the industry's annual revenues. These subsidies help explain why the world's industrial fishing fleet has grown twice as fast as fish catches over the past 20 years and why, in spite of overcapacity in the industry, few fishing boats are being retired. Although most subsidies are paid out by governments in rich countries, they are having an increasing effect on fishing in developing countries. Many subsidised rich-world vessels are now fishing in the waters of poor countries, either illegally or after paying for licences.
Next, consider cereals, the main source of food for most of the world. In 1995 and 1996 grain prices rose rapidly and world cereal stocks fell to record lows, causing an upsurge of panic at the prospect of a world food crisis. Last year grain prices resumed the downward trend they had been maintaining over many decades. The blip, it seemed, was caused by a series of one-off events: unusual weather, the collapse of Russian agriculture, and reform of farm subsidies in America and Europe.
But some analysts fear there could be more trouble in store. The title of one recent scaremongering book by Lester Brown, an environmental campaigner, spells out one of their worries: "Who Will Feed China?" (W.W. Norton, 1995). In 50 years� time, they say, not only will the world's population have almost doubled, but many more people will be able to afford meat, which will make huge demands on the supply of cereals. To produce a kilo of beef, for example, takes an average of seven kilos of feedgrain. Between now and 2020, about 80% of the increase in demand for cereals is likely to be in developing countries.
Trouble has already arrived for the 800m people in developing countries who are chronically undernourished. But their problem is poverty rather than an overall shortage of food supplies: if all the world's grain were distributed evenly, there would be more than enough for everyone's needs. But will overall supplies continue to keep up with demand?
There are some unsettling signs. The technologies of the "green revolution" that dramatically boosted grain supplies in the 1960s and 1970s�irrigation, farm chemicals and higher-yielding strains of cereals�appear to be running out of steam. The growth in cereal yields in developing countries has slowed down from 3% a year in the 1970s to around 2% in the 1980s and 1990s. In Asia vast tracts of irrigated land have become either waterlogged or too salty to support crops. Many insects and fungi are developing resistance to chemical pesticides.
There are only two ways to increase grain output: by taking more land into production or by boosting yields. The first may well be possible: of the estimated 3.3 billion hectares of land thought capable of supporting agriculture, only around 750m hectares is used today. But the land not currently under cultivation is generally less fertile, and converting it to agriculture would mean clearing huge areas of forests and prairies, causing environmental destruction on an unprecedented scale.
Clearly a further boost in yields is the better bet. Applying existing technologies to farms in poor countries will do some good, as it has done in the Brazilian Amazon. Beyond that, it is up to scientists to devise strains of cereals with even higher yields. Their job should have become easier thanks to biotechnology, a powerful new tool in plant breeding. Unlike conventional plant breeding, biotechnology allows scientists to pinpoint useful traits in plants (such as resistance to drought or disease) with great speed. It also allows them to transfer genes from entirely different organisms, such as bacteria, into plants (see article). For now, it seems that the best reason for disbelieving the prophets of doom is that man's scientific ingenuity has always found solutions in the past. It may be nerve-wracking to rely on that, but there is no real alternative.
The main problem with water, the third item on the list, is the lack of it in some parts of the world. All but 1% of the water on earth comes in the form of either salty seas or ice locked up in glaciers. Evenly distributed, that tiny share of fresh water would be ample to cover all conceivable human needs for the next century at least; but like grain, it is unevenly spread. Africa, Asia and Europe have far less fresh water per head of population than North and South America (see map). In 1990, 20 countries suffered chronic water scarcities (that is, their yearly supply was less than 1,000 cubic metres of water per head), most of them in North Africa and the Middle East. By 2025, the World Bank expects the number to rise to 34. The conventional wisdom now is that the wars of the next century will be over water.
Cut and dried
Many cities, including Mexico city, Bangkok and Jakarta, have been subsiding in recent decades as underground aquifers have been drained by growing populations. More than half of China's 600 cities suffer water shortages. In parts of the North China plain, water tables are falling by as much as a metre a year. Iraq, Turkey and Syria squabble over the use of the Tigris and Euphrates rivers, and Israel and its neighbours have a long-running argument over the Jordan river.
Cities are also being forced to rely on ever more expensive sources of water as local ones become depleted or polluted. Amman in Jordan is now pumping water uphill from 40 kilometres away, and Mexico city has a similar scheme. The technology for converting sea water to fresh water is well established, but the cost is prohibitive. And no one has yet cracked the economics of another much-touted idea: towing icebergs to the Middle East.
A cheaper and more attractive solution to the shortages is to reduce demand for water. In developing countries irrigation accounts for 80% of water use, but most of the water just drains away. Part of the blame lies with the huge subsidies that governments pay towards irrigation. Farmers in developing countries, just like city households connected to water mains, pay only a small fraction of the cost of supplying that water. In Bangladesh, Nepal and Thailand, according to the Asian Developing Bank, water charges collected amount to less than a tenth of the cost of supply. Raising water charges would encourage conservation without necessarily cutting back food production by much. Farmers would have an incentive to invest in technologies that use water more efficiently. One example is drip irrigation, a system pioneered in Israel's Negev desert that directs a small amount of water precisely to the root of each plant.
The loudest opposition to such changes will come from the people who benefit most from the present system: comfortable landowners rather than peasant smallholders. Only here and there�for example, in a few cities in China�are politicians serious about raising water prices. To tackle water scarcity requires political courage, which is why, on that subject, this survey sides with the prophets of doom.
previous article
|
next article
Source: The Economist
CONTENT COPYRIGHT The Economist. THIS CONTENT IS INTENDED SOLELY FOR EDUCATIONAL PURPOSES.
mongabay.com users agree to the following as a condition for use of this material:
This site contains copyrighted material the use of which has not always been authorized by the copyright owner. Such material is made available in an effort to advance understanding of environmental issues. This constitutes 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit. If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner.
If you are the copyright owner and would like this content removed from mongabay.com, please contact me.
|
