Why you should care
You know about the impact of climate change on rainforests and oceans. But the picture isn’t complete without the delicate web of life being slowly parched in the world’s deserts and drylands.
We often picture climate change drying up rainforests, oceans and other hotbeds of biodiversity. But what happens to regions that are already dry? Far from barren, deserts and drylands sustain a surprising variety of animal species, as well as human life — but not for long, if global temperatures continue to rise. Climate change and human activity are disturbing these delicate ecosystems, and new research shows it could have serious environmental, human and economic consequences.
Up to 20%
Amount of the world’s drylands that are degraded
Economic losses associated with this drylands degradation
Climate change-induced drought, overgrazing and unsustainable farming practices lead to a loss of vegetation, which in turn further parches arid lands by exposing infertile lower soil layers that are less able to support agriculture and wildlife — a process known as desertification . A U.N.-backed report released by the Economics of Land Degradation (ELD) in September found that up to one-fifth of drylands are degraded, resulting in estimated economic losses of about $40 billion per year.
A Somali man leads his drought-stricken camels to a water point northwest of Somalia’s capital Mogadishu in 2011. (Reuters/Thomas Mukoya)
But as we approach 2014 – the halfway point in the U.N.’s Decade for Deserts and the Fight against Desertification – desertification remains largely invisible in the conservation agenda. It get little press and is rarely addressed by policymakers.
Despite its low priority, desertification exacts a steep human cost. Drylands, which occupy roughly 40 percent of the Earth’s land area, are home to two billion people, mostly in developing African nations. According to the ELD report, annual global losses of arable land can reach 10 million hectares per year, an area roughly the size of Austria. Poor productivity in arid regions also makes them less attractive to investment, which excludes them from development.
Land degradation: A reduction in the economic value of ecosystem services and goods derived from land as a result of human activity or natural biophysical evolution, according to a U.N. report.
Desertification: Vegetation loss parches arid lands, exposing infertile lower soil layers that can’t support agriculture or wildlife.
Although the poor suffer most from desertification, we may all end up feeling its impact. The decline in arable land renews concerns about the world’s ability to feed a booming population. The U.N.’s Food and Agriculture Organization predicts that the demand for food will increase 60 percent by 2050, which will require an additional 120 million hectares of agricultural land. That’s a farm the size of South Africa.
The good news? Adopting sustainable land management — such as crop rotation, which involves growing different crops in succession in the same field – could increase world crop supplies by an estimated 2.3 billion tons, worth $1.4 trillion. Managed grazing practices – such as letting livestock graze on only one portion of pasture while allowing others to recover – might also help, the report added.
Wildlife in these regions is also on the decline. Last Tuesday, the Wildlife Conservation Society and Zoological Society of London reported that half of the species historically found in the Sahara Desert are approaching extinction, most likely due to desertification and overhunting. Seven out of 14 species historically found in the Sahara, the world’s largest tropical desert, are regionally extinct or confined to 10 percent or less of their historical range. The lion, African wild dog and a type of antelope called the bubal hartebeest have vanished entirely from the region. Other species have fared only slightly better. Only the Nubian ibex still inhabits most of its historical range, but it’s still classified as vulnerable.
Violence and instability across the region contribute to a lack of studies, which makes it hard to pinpoint the exact cause of the wildlife decline, but desertification and overhunting are the most likely culprits, researchers say.
“The Sahara serves as an example of a wider historical neglect of deserts and the human communities who depend on them,” conservation biologist and study leader Sarah Durant said in a statement.
This may be our last opportunity to put deserts back on the radar. The longer we treat them as invsible, the more likely they actually will vanish – and the desert communities and ecosystems along with them.