The heatwaves and forest fires that swept through the Mediterranean this summer gave Europeans a grim lesson in the dangers of climate change. But many experts are just as worried about a longer-term affliction: desertification.
An often irreversible process, desertification is a growing problem in Europe – especially in Spain where about one-fifth of the country is already affected.
“Desertification is one of the world’s big four environmental areas of concern, together with climate change, biodiversity loss and pollution,” said Elias Symeonakis, an expert on the subject at Manchester Metropolitan University. “We depend on those areas that are degrading . . . for our food and our population. Once they are degraded, there is not much you can do.”
Desertification can conjure up romantic images of sand dunes. In fact, the process is more banal. It refers to the degradation of land in dry areas that makes it unproductive and infertile.
The main cause is often human action, such as overfarming and excessive irrigation, which erodes soil and drains aquifers. The problem exists on a daunting scale in Spain, where agriculture has steadily industrialised and three-quarters of the landmass is already generally dry or semi-arid.
“Spain is the EU country at greatest risk of desertification,” Teresa Ribera, deputy prime minister and minister for the environment, told the Financial Times. She said the government was planning to set out a national strategy this autumn, its first in 13 years.
Regions in Spain’s south-east and east are among Europe’s worst affected, partly because they are cut off from the more temperate north by mountain ranges. But desertification is also happening in Italy and Greece. The crisis is graver still in north Africa, in the Palestinian territories and in Mozambique. In the US, overuse of water, combined with recent droughts, is steadily drying up the American West.
In Spain, about 20 per cent of land is already desertified, largely for historical reasons such as the destructive mining and overfarming that followed the change of use of land expropriated from the Catholic church in the 18th and 19th centuries.
Satellite imagery shows that a further 1 per cent of Spanish territory is actively degrading because of intensive agricultural practices, although a greater area is indirectly affected, too.
“It is like a black hole,” said Gabriel del Barrio, a researcher at the state-run Arid Zone Experimental Station in Almería, one of the most affected areas. “This 1 per cent endangers the countryside for kilometres around it . . . using up water and causing other damage.”
He added that, contrary to a common misapprehension, desertification does not signify the advance of the desert. “The Sahara, for example, is a very mature system,” he said. “Instead, this is about the non-sustainable overuse of natural resources that are replenished very slowly, if at all.”
In contrast to any pristine Saharan sands, desertified lands such as the Sierra de Gádor in Almería have thin soil lightly covered by vegetation. Meanwhile, rapidly desertifying territory in the east of Spain can appear lush and green because of water commandeered from a much wider region. The industrialization of agriculture and intensive irrigation have helped increase Spain’s income from agriculture almost 50 per cent in the decade to 2020. But agriculture uses almost seven times as much water as all Spanish homes.
About a quarter of the country’s aquifers are overexploited, according to the EU. Modelling by Jaime Martínez Valderrama at Alicante university indicates that the soil for wheat and sunflower crops in Córdoba province could be exhausted in six decades.
Spain has been renowned for olive oil exports since Roman times. But while the crop traditionally requires little to no irrigation, it is now often grown in high-density orchards where the plants resemble bushes and can be machine harvested. While more productive, this needs more water.
Industry groups say more efficient irrigation systems have enabled agriculture to reduce its water use this century. Even so, over the past decade the sector’s consumption has climbed again.
“It’s an old saying: ‘The more water, the sweeter the fruit’,” said Vicente Andreu Pérez, a senior researcher on desertification at Spain’s National Research Council. “But we can’t increase agricultural profits indefinitely. Everything has a limit and if we arrive at the limit in this case we won’t be able to go back.”