The slow burn.
The classic view of desertification is of wind-battered landscapes, denuded and rubbed raw by sand, with towns and villages transformed into dustbowls. And it's easy to find this face of desertification in the Sahel, the transition zone in Africa between the Sahara in the north and the savannahs of the south.
For decades, the creeping sands have edged southwards, changing the ecological balances and installing in this part of Africa a seemingly inexorable process of desertification. Cities such as N'Djamena, the capital of Chad, appear to have shrivelled to a dry husk over the past 20 years, thanks to a combination of human activity and rainfall shortages.
It's an extraordinary phenomenon that appears to call for an extraordinary response. And we appear to have one: the Great Green Wall, a project developed by the African Union to plant a belt of trees 15 kilometres wide stretching almost 8,000 kilometres across the width of Africa from Djibouti in the east to Senegal in the west. Using native trees such as figs, acacias and gum bdellium, the wall will slow down wind erosion, improve river infiltration, create habitats for wildlife and provide energy resources and foodstuffs, say its proponents.
But for some reason, desertification fails to capture the minds and motivation of the international community. Although donors pledged 96million [euro] (84million [pounds sterling]) for the Great Green Wall earlier this year, this is a long way off the estimated 2.4billion [euro] required to complete the project. This may be because the process of desertification is painfully slow and its consequences often imperceptible.
But it's a vast, widespread phenomenon. According to the UN's Convention to Combat Desertification (UNCCD), the livelihoods of more than one billion people are threatened by desertification, and those of 1.5 billion depend on degrading land. A third of all crops are cultivated on land affected by desertification, it says, and 12 million hectares of land are lost to it every year. According to CARI, a France-based NGO, every day, 4,200 hectares of valuable land is lost to erosion and 83,000 hectares of new degraded land is created.
More than two thirds of land in continental Africa is desert or strongly degraded, and desertification is a key factor affecting development in Djibouti, Ethiopia, Kenya and Somalia, where millions of people currently depend on emergency aid. Three quarters of drylands in Latin America are affected by desertification and 83 per cent in Western Asia, where all dryland ecosystems are officially classified as vulnerable.
Europe is far from exempt: most of Greece is either semi-arid or sub-humid according to UNESCO, while up to 35 per cent of Spain is at significant risk of desertification. Already, three quarters of Spain is categorised as arid, semi-arid or dry sub-humid, according to the Spanish National Action Programme to Combat Desertification. Vast areas in the communities of Murcia, Andalucia and Valencia are slowly turning into desert. Globally, the cost of desertification is estimated at about 100billion [euro] per year. For some countries, the impact is equivalent to eight per cent of annual GDP--enough to negate growth and stall development.
The impact of desertification is clear enough, so you would think that it would be straightforward for the international community to agree on a strategy to combat it and then throw its political weight behind it. The problem is that few people working in the field can even agree on a definition of what it is. The subject overlaps with so many areas--drought and famine, for example--and calls to mind the observation of the naturalist John Muir that 'when one tugs at a single thing in nature, he finds it attached to the rest of the world'.
Soil erosion has contributed significantly to the albedo effect on snowy mountaintops, says Dr Jayne Belnap of the US Geological Survey's Southwest Biological Science Center. Dust created by the erosion settles on the snow and absorbs more sunlight, causing the snow to melt more quickly. 'It comes down in a great "whoosh" and there's a lot less late-season water for farmers and fish,' she explains. At the same time, dust from the Sahara, laden with fungi, has been cited as a cause of coral death in the Caribbean.
For these reasons, no single international body can achieve an overview and provide leadership. More than 800 NGOs are officially accredited to UNCCD, but desertification has not obviously been integrated into wider policies such as water security or climate change. 'Most development aid agencies and NGOs, although well meaning, are causing confusion and greater future problems and suffering,' says Allan Savory, president of the Savory Institute, which works to restore grasslands through a holistic approach.
In a speech to the UN this autumn, Patrice Burger, director of CARl, said: 'We deal with blindness and indifference about land degradation while the process is at work on every continent and threatens our common future. Desertification is primarily a leprosy of the earth, destroying under our feet what we, and furthermore our children, will be in the greatest need of tomorrow.'
So what is desertification? The French scientist Andre Aubreville is thought to have coined the term during the 1940s, and the UNCCD defines it as 'land degradation in arid, semiarid and dry sub-humid areas resulting from various factors, including climatic variations and human activities'.
Essentially, desertification has many causes and is, in effect, the catch-all term for a wider phenomenon of land degradation, the causes of which include erosion, drought, overgrazing, flooding, other agricultural and bio-industrial activities, and salinisation.
'Desertification is the name given to the slow but steady conversion, by humanity, of seasonal rainfall grasslands and savannahs to ultimately degraded condition resembling true deserts,' says Savory, who estimates that desertification now affects about two thirds of the world's land area. 'Desertification is an ancient problem, having led to the demise of many civilizations regionally, and now it poses a global threat.'
Puzzlingly, the UNCCD excludes what we might think of as classical desert from its definition. 'People think of sand dunes encroaching on villages, and that does happen,' says Dr Zafar Adeel, director of the UN University Institute for Water, Environment and Health (UNU-IWEH). 'But hyper-arid areas are excluded from the convention--and that does seem illogical. The UNCCD's founding fathers also took the view that few people live there, but that is also not logical--significant numbers of people live there.'
However you define it, desertification equates to a persistent long-term loss of land productivity and is, Adeel points out, a global problem. 'You get land degradation on all five continents,' he says.
'It's a serious and pressing problem, particularly as it cuts across so many issues, such as food security, climate change and population growth,' says Dr Lindsay C Stringer, co-director of the Sustainability Research Institute at the University of Leeds. 'There's the way land is managed, combined with the types of crops that are grown, local decision making and rules that determine who has access to land. On top of that, you have political-economic processes that can frame things such as how much fertilisers cost, as well as global trade rules that contribute to decisions on what is grown where. You have a global political-economic system that shapes the way people live to a certain degree. That all makes it really difficult to address the issue.'
Stringer herself feels that land degradation is a more accurate description of the phenomenon than desertification. 'There's no real consensus, so scientists tend to pick just what they want to do, and they will tend to stress perspectives to serve their own interests, such as lost biological productivity or lost economic potential. It makes desertification a difficult problem to solve if you can't define it or measure it.'
Even if a definition of desertification is elusive, the consequences are clear. 'People in drylands get politically marginalised,' says Adeel. 'They tend to fall behind in terms of quality of life and be worse off in terms of income and infant mortality.' According to a report published by UNU-IWEH, the number of people at risk of displacement due to severe desertification, particularly in sub-Saharan Africa and Central Asia, will exceed 50 million during the next ten years.
'Desert encroaching on the land bordering the desert is just a part of the story,' says Fenke Elskamp, Oxfam's associate country director in Niger. 'There are places where the desert is advancing, compromising production and destroying wells, and that leads to social consequences, such as people leaving.'
When it comes to the causes, all the usual suspects are present, from anthropogenic climate change to natural weather trends and agricultural practices. 'It's closely related to climate change,' says Adeel. 'But desertification, in turn, contributes to the reduction of carbon sequestration.'
The deep interplay between these factors unsettles some observers. The overlap with food security is clear enough in countries such as Niger, where desertification degrades the natural-resource base for animal and vegetal production. A major drought hits Niger almost every five years, says Oxfam, and the intervening years also see pockets of drought. 'It isn't drought as such that is a disaster but the fact that people are vulnerable and have no alternative options to cope with disaster,' says Elskamp.
'Drought and desertification force nomads and pastoralists to look for different grazing areas, to even change their annual trekking routes,' she continues. 'They move southwards earlier in the year and large herds of cattle enter agricultural areas, where there is a potential farmer-livestock conflict when herds enter the fields and destroy crops. This happens every year, and the conflicts become more and more violent.'
Separating the causes, however, can be so complex as to risk missing the point, argues Belnap. 'The causes are so interactive it's always going to be a muddle,' she says. 'It makes more sense to ask whether we are prepared to adapt and to work with it all the time.'
Studies have suggested where the problems lie. Like-for-like comparisons between the fortunes of grasses planted in different environments has shown the varying impacts of humans and climate change. 'In national parks, we're seeing a loss of grasses to climate change. On rangeland that is grazed, the loss is even more significant,' says Belnap. 'The best we can hope to do is get the grass loss on rangeland down to the level of national parks.'
And land degradation doesn't just happen in Africa and the Middle East. Belnap argues that Iceland provides the worst example of desertification she has seen, a legacy of the early settlers, who grazed sheep and ponies, turning birch forest into exposed black rock. And in Spain, the causes range from climate change to the over exploitation of resources by farmers.
The implications of such soil death, argues Belnap, mean there is no going back. 'We can undo a lot of things, but getting soils back is pretty much beyond our ability,' she says. 'Once the soil is gone, it takes about 1,000 years to grow a centimetre. If we lose the soils through erosion, we have lost the fundamental productivity of the system. The birds, bunnies, deer, raptors--we lose the whole show.'
But Belnap is equally unsettled by the way in which this trend will reverberate through ecosystems and across continents. 'If we give away the potential of the system, then what's left is unpalatable, with vast ramifications downstream,' she says. 'You get dust, with all the implications that has for human health. For me, that is the biggest issue of all.'
The task of slowing down or reversing desertification appears daunting. 'To expect the one billion hungry people in the world to exploit the Earth's soil in a circumspect and thoughtful way is a big ask,' says Luc Gnacadja, executive secretary of the UNCCD. 'Wouldn't we all try to squeeze every last drop of goodness from the soil to survive? Almost any means would seem to justify this end, including tapping non-renewable water resources or depleting soils.
'It's not simple or easy,' he continues. 'A lot of people involved are very, very poor and you aren't just going to waltz in and say they have to lose their animals. We're just going to have to learn there are better ways to graze and crop. It's really a question of people thinking it isn't important.'
Many observers believe that the ingenuity and determination of local farmers is vital. This kind of 'barefoot science' is considered to be as important as anything 21 st-century technology or development agencies can offer. In some areas of the planet, local people have been doing their best to reverse trends themselves.
'The solution lies in accepting a reality that we have refused to face for decades: everywhere, the most effective and sustainable solutions are those from rural family systems still present, and whose resilience is exceptional,' says Burger. 'Farmers and breeders have selected the proposed innovations for years and are experts in the development of their territories, where they know how to produce in places in which most of us couldn't survive.'
Farmers in several densely populated parts of Niger have protected and managed on-farm trees since the mid-1980s. A report by Both Ends, an agency founded by Dutch environmental groups, found that this re-greening stretched to five million hectares--about 200 million new trees, an unprecedented number for an African tree-planting project.
In the Maradi region of Niger, the number of tree species has grown from a handful in 1985 to 35 in 2006. Farmers in project areas have reported benefits: early in the rainy season, they say, the high tree density protects crops against strong winds, and during the food shortages of 2005, infant mortality was close to nil.
A separate project, named DESIRE and funded by the European Commission and UNCCD, investigated 18 hotspots, talked to communities to see what policies they used to combat desertification, and tested them to see if they could work. 'Most international projects focus on [the] scientific angle. We decided to employ a holistic approach, to understand the limitations and dangers local people faced, and devise potential solutions with them,' says Professor Coen Retsima, a soil-quality specialist at Wageningen University in the Netherlands. 'Solutions differ from site to site. Desertification has many faces, but the methodology is key. We tried to combine scientific knowledge with local traditional knowledge.'
Retsima and his colleagues quickly established that the problematic areas were often located where access to information and different techniques to deal with land degradation was limited or impossible. 'It's difficult for land users to know what's going on outside their specific area--elsewhere in the country or region,' he says. 'Knowledge exchange is important: letting people know about different techniques that address the same problem.'
Farmers and pastoralists are also wary of radical change, which results in a reluctance to try innovative approaches. 'They're often hesitant and it's difficult to convince them to try a totally new way of farming,' Retsima says. 'It would be good to try some innovative products. There are all kinds of products--new fertilisers, soil amendments--and many of them are being used widely in the USA, Australia and Europe. These may be ingredients that keep golf courses and sports fields green. They can be expensive, but they can sometimes be very cheap.'
There remain many challenges. Tree planting under harsh climatic conditions is difficult, and survival rates of saplings are often less than 20 per cent. Oxfam believes it's difficult to say whether the Great Green Wall will provide a solution in the Sahel. 'It may be partly true that many farmers may know solutions for fighting desertification, but that they lack financial means or support,' says Elskamp. 'But not all farmers know solutions. Most people who are affected by droughts are the most vulnerable people in society who have no alternative options.'
Yet others put a case, in some circumstances, for less intervention. Professor Robert Webb of the University of Arizona argues that we may just have to live with it. 'We're not going to go back to a pre-Columbian landscape. Restoration and recovery are something of a fallacy. We're seeing a directional change. We won't replace what we've lost with what went before. It will be something completely different.'
Webb believes that we should leave landscapes to recover fertility themselves. His studies in the Mojave Desert suggest that without human intervention, plants in a denuded landscape take an average of 85 years to recover, and that soil compaction recovers within 125 years.
Despite the formidable obstacles, Adeel argues that there are grounds for optimism. 'One of the tricks we've missed is that we have failed to make the economic argument,' he says. 'If we show the rewards of investing, then that will help our case with policymakers. I'm cautiously optimistic that people recognise the scale of the problem.'
The same argument goes for the farmers and communities affected by desertification, says Retsima. 'People need to be able to make a living out of the land,' she says. 'You can suggest ways to reduce degradation, but if they won't benefit the land user then they won't adopt them.'
The problem, argues Stringer, is that land degradation isn't easily pigeon-holed. 'In terms of actual scientific and traditional knowledge reaching the attention of policy makers, there's a real bottleneck. So it isn't always painted as an urgent issue at national or international levels,' she says. 'It's a cross-cutting problem that is addressed in different ways by different ministries--environment, water, agriculture--and they don't always talk to each other.
'It's often viewed as something that happens in the background,' she continues. 'But sooner or later, it will give us an unexpected shock. It's complex, there's no flood, or hurricane that wipes out a whole area. It's a creeping problem that builds up.'
Belnap believes that governments and decision makers haven't yet understood the implications. She jokes that the UN should sell dust credits as it does carbon credits. 'Politicians don't get it,' she says. 'Essentially we're talking about dirt. It's not sexy. It requires a lot of education. Most people still think that their food is made in a grocery store. There's no going back. There are no natural systems left, so we need to decide how to manage these systems. I don't see apocalypse as a result. I just see mediocrity.'
Desert and dryland areas (% of total land area)
Percentage of population in dryland areas
Land area suffering from human-induced degradation (%)
GLOBAL DERSERTIFICATION RISK
This map provides a startling illustration of the extent to which the remaining inhabitable land on Earth is threatened with desertification. Large parts of the Middle East and Central Asia appear to be on the verge of becoming desert, while tire majority of those areas in Australia that aren't classified as desert face at least a moderate risk. Note, too, tire virtually continuous band of red that stretches across Africa from Senegal in the west to Djibouti in the east--the planned location of the Great Green Wall. The biggest surprise might be the level of risk faced in the western USA
SOURCE: US Department of Agriculture
Is overgrazing a fallacy?
Overgrazing is widely cited as a key factor in desertification and tends to be addressed by removing livestock from the affected land.
However, Allan Savory, president of the Savory Institute and chairman of the Africa Centre for Holistic Management in Zimbabwe, argues that livestock should be encouraged to graze. He contests the widely held belief that in regions with only seasonal rainfall, more people and more animals mean overgrazing, fewer trees and, eventually, desertification. Animals, he points out, have the capacity to break the surface, compact the land and return plant material into the soil, and so help the land to recover.
Desertification, Savory explains, has two prime causes. The first is a lack of adequate grazing and disturbance of grasslands that, along with fire, leads to gradual chemical oxidation, decreasing soil-covering litter and the exposure of soil between plants. The second is overgrazing and overbrowsing of plants, resulting from too few animals that had become too static.
Desertification, he continues, occurs when the available rainfall in such environments becomes less effective. 'In reality, the rain is what it has always been in such environments--erratic' he says. 'The soil is the world's greatest reservoir of fresh water. However, when human actions decrease plant bulk--and, in particular, soilcovering litter from annually dying plant parts--the rain falling on such lands is lost, mainly to evaporation from the soil surface"
There is no option, he argues, other than to deploy livestock or large herbivores as a tool. 'It's neither exaggeration nor drama to state that the fate of humanity and civilization hangs on the slender thread of rapidly spreading the knowledge of how to correctly manage livestock, so that they reverse desertification, and to do away with any need to burn grasslands. The one luxury we don't enjoy in combating desertification and climate change is time.'
With its history of widespread land degradation and recurring droughts, Ethiopia often springs to mind when considering desertification. According to the Global Mechanism, a subsidiary of the UNCCD, Ethiopia continues to lose 62,000 hectares of forest and woodland a year, 30,000 hectares to water erosion, with another two million hectares severely damaged. All forms of land degradation occur in Ethiopia--water and wind erosion, salinisation and alkalinisation--and more than 85 per cent of the land is classified as at least moderately degraded.
Nevertheless, there are signs of hope. The Ethiopian government and the World Food Programme operate a programme known as MERET, which translates as 'land' in Amharic. initiatives to support communities suffering from chronic food insecurity include reforesting barren hillsides, restoring springs and ponds, and rebuilding and refurbishing agricultural terraces.
The programme is set up as a food-for-work scheme--participants receive three kilograms of wheat per day of work. In the decade since it began, more than 8,500 watersheds--such as ditches, dams and terraced hillsides--have been constructed, and 400 million tree seedlings planted. As a result, farmers are able to grow grains, fruits and vegetables in locations where the rain had previously washed away the topsoil. The UNCCD reports that during the 2008-09 droughts, these areas withstood the seasonal rain shortages without any major setbacks. The project, the UNCCD concludes, isn't a panacea, 'but it has shown that holistic approaches to food security can improve the lives of thousands of food-insecure people'.
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|Title Annotation:||DOSSIER: Desertification|
|Date:||Dec 1, 2011|
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