The Green Revolution wasn’t green enough

For someone of my generation, growing up under postwar food rationing, the idea that food would always be plentiful and cheap seemed about as likely as a portable phone that you could carry around with you.

For many of us the dire predictions of Thomas Malthus were all too credible. Malthus had advanced the dismal theory that human populations would always grow faster than their food supply. It meant you could forget all your grand ideas about progress. Every social advance was destined to be brought to nothing by famine.

The singular achievement of the agronomist Norman Borlaug, who died at the weekend, was to take away this age-old fear, at least for those of us in the rich West.

In a crop-breeding programme that won him the Nobel Peace Prize, he developed a clutch of wheat varieties with remarkably short stems. As a young farming journalist I remember writing about one of the first to appear in Britain, a diminutive variety called Hobbit.

Compared with the taller traditional wheats, the short-strawed types shifted a higher proportion of plant sugars into the seedhead or ear of the plant, where the grains were formed. In this way they were capable of producing dramatically higher yields. But to achieve them they needed huge amounts of chemical fertiliser. Borlaug once remarked that “if the high-yielding wheat and rice varieties are the catalysts that ignited the revolution, chemical fertiliser is the fuel that powered its forward thrust”.

His Green Revolution led to a near-doubling of wheat yields in India and Pakistan during the late 1960s. Altogether more than a billion people are believed to have been saved from starvation as a result of the new varieties.

Over the past 30 years Western governments have poured subsidies into the development of so-called high-yield grain production. One early result was the notorious grain mountains of the 1970s and 1980s which, far from alleviating hunger, did much to undermine the development of food production in poor countries. Borlaug intended his methods to be used for the benefit of people across the planet. Instead they were seized on by industrial countries with the wealth to pay for expensive seeds and fertilisers. Where they were used in developing countries, this often came at the cost of a crippling debt burden.

Today Borlaug’s ideas underpin the global food system. Three quarters of the world’s cultivated land is sown to grain crops and oilseeds. Most are dependent on massive amounts of oil energy in the form of nitrate fertilisers, pesticides, diesel fuel and heavy machinery.

Though the Green Revolution has undoubtedly given the world more food, it has brought with it worrying consequences. An investigation into agriculture funded by the World Bank concluded that the benefits have been unevenly distributed. Equally disturbing, the revolution has led to widespread environmental damage that may reduce the planet’s capacity to feed future generations.

No less than 1.9 billion hectares of farmland has been degraded by modern grain-growing techniques. Growing annual grain crops such as wheat over lengthy periods inevitably leads to soil damage. The land must be ploughed and cultivated each year, and for long periods is left bare, a condition that seldom arises in nature. Stripped of vegetation cover, the soil’s organic matter starts to burn up or oxidise, releasing carbon into the atmosphere and adding to the greenhouse gas burden. The process is hastened by heavy inputs of chemical fertiliser and pesticides. With the loss of organic matter the soil’s structure is weakened so it becomes unstable and subject to erosion, either by wind or rainfall.

Around the world soils are eroding at a faster rate than at any time in history. Each year the weight of soil washing downstream in rivers is estimated at four tonnes for every man, woman and child on the planet. For all our technology, civilisation continues to depend on a few centimetres of topsoil. At this rate of loss the future for humanity is grim.

For all the high hopes of the 1960s, it is hard to see Borlaug’s system as more than a partial success. Its weakness is its reliance on a handful of annual crops that cannot be grown without massive inputs of fossil fuel. The sustainable methods called for in the World Bank report will almost certainly make greater use of perennial crops — principally grassland — to feed livestock.

One of the consequences of the grain surpluses produced by the Green Revolution is that more than half the world’s cereal crops are now fed to animals. Cattle, which as ruminants are adapted to grazing pastures, are now routinely confined to yards, or “feedlots”, and fed on grains. There is mounting evidence that beef and dairy foods produced this way are less healthy than those same foods produced from grazing animals. One unfortunate consequence of Borlaug’s breakthrough is that we are now degrading croplands on a global scale to produce meat and dairy products that are inferior to those we used to get from pasture.

While Borlaug’s revolutionary wheats run mainly on oil, the world’s grasslands — which are mostly made up of perennial species — are truly solar-powered. Once established perennial plants maintain their root systems from year to year. So they do not need the fertilisers and chemicals required for plants grown from seed each time. Unlike grains, grasslands will give us a secure and sustainable source of meat and milk. And as part of a mixed farming system, clover-rich pastures provide a non-chemical way of building up fertility on crop land.

But there is another more pressing reason for turning away from Borlaug’s grains and making more use of the world’s neglected grasslands. The shift to industrial grain production has added hugely to the level of greenhouse gases in the atmosphere. Properly managed grassland could reverse the process.

Grasslands that are grazed rotationally are able to capture large amounts of atmospheric carbon dioxide and lock it up safely in soil organic matter. Australian researchers estimate that if the world’s pasture farmers managed their grazing in this way, the amount of carbon captured could easily exceed total annual emissions. This will be the real Green Revolution. It could restore, not just our food supply, but the health of the planet.

Graham Harvey, the author of The Carbon Fields: How Our Countryside Can Save Britain.