Land degradation causes $10 billion loss to South Asia annually
The environmental impact on the countries of the South by soil erosion and other forms of land degradation is all too familiar. A recent United Nations study shows the high economic cost of such land degradations to the South Asian countries.
By Maritin Khor
SOIL is one of the most vital of our natural resources. Together with water and air, it forms the very basis of life.
Indeed, there is a thesis, quite difficult to refute, that the rise and fall of civilisations in history can be linked to the quality and management of their soil and land.
For from the soil comes food and other crops and plants that provide medicine, clothing and so many other things we need for daily life.
And the retention of soil in its natural state and habitat prevents erosion, river silting and flooding.
When land is disturbed or degraded, the ecology is damaged. There can be rather serious effects in terms of soil erosion, loss of soil fertility and thus reduced plant growth or crop productivity, clogging up of rivers and drainage systems, extensive floods and water shortages.
Environmentalists are familiar with the above cause-and-effect scenario. City planners and water and soil policy makers have to deal with the problem. And ordinary people experience and live in dread of the bad effects.
But soil degradation and erosion is also an economic issue. The loss of soil and its effects cause tremendous losses to the economy. So much so that these costs may well outweigh the benefits of many development projects that give rise to the problem.
If only the economic costs of soil erosion (and other environmental ills) were easily calculable. Then planners and politicians would think twice or thrice before allowing activities and projects that damage the land.
A recent pioneering study sponsored by three United Nations agencies (FAO, UNDP and UNEP) estimated the severity and costs of land degradation in South Asia. Its shocking conclusion was that the countries (India, Pakistan, Bangladesh, Iran, Afghanistan, Nepal, Sri Lanka, Bhutan) are losing at least US$10 billion annually as a result of losses resulting from land degradation.
This was equivalent to 2% of the region's Gross Domestic Product, or 7% of the value of its agricultural output.
And yet this high enough figure is a gross underestimate, because it measures only the on-site effects (for instance, reduced agricultural production) whilst leaving out off-site effects (such as river silting, floods, landslides and road collapses). The study, published in 1994 as a report, 'Land degradation in South Asia', defined land degradation as 'the temporary or permanent lowering of the productive capacity of land.'
The types of degradation it assessed were:
* Soil erosion caused by water. This was the most widespread, affecting 83 million hectares, or 25% of all agricultural land in the region. In many areas of sloping land, for example in Nepal, it is severe, causing permanent loss of the land's productive capacity.
* Soil loss caused by wind, affecting 59 million hectares, or 40% of agricultural land in the region's dry zone.
* Soil fertility decline, due to lowering of soil organic matter and loss of nutrients, is substantial and widespread in the region. This is due primarily to the increased and incorrect use of fertilisers.
* Waterlogging, or the lowering in land productivity through the rise in groundwater close to or above the soil surface. This is caused by incorrect irrigation management.
* Salinisation, or soil degradation caused by increase of salt in the soil, is caused by incorrect irrigation management or intrusion of sea water into coastal soils arising from over-abstraction of groundwater. It is severe on irrigated lands of the dry zone. It reduces crop yield and in severe cases causes complete abandonment of agriculture.
* Lowering of the groundwater table, caused by over-extraction of groundwater.
The study found that altogether 140 million hectares, or 43% of the region's total agricultural land, suffered from one form of degradation or more. Of this, 31 million hectares were strongly degraded and 63 million hectares moderately degraded. The worst country affected was Iran, with 94% of agricultural land degraded, followed by Bangladesh (75%), Pakistan (61%), Sri Lanka (44%), Afghanistan (33%), Nepal (26%), India (25%) and Bhutan (10%).
The study concludes: 'Land degradation in the region is widespread and has reached a severe degree in many areas. Environmental "disaster areas" have occurred already, for example areas of severe and extensive salinisation in parts of the irrigated Indus and Ganges plains.
'Others are predicted, most notably the severe deforestation and water erosion in the mountain and hill areas of Nepal.' The most original and interesting part of the study is its assessment of the economic costs of land degradation. Total on-site annual losses were estimated at US$9.8 to 11 billion a year, or at least US$10 billion.
The breakdown according to types of land degradation was: water erosion US$5.4 billion; wind erosion US$1.8 billion; fertility decline US$0.6 - 1.2 billion; waterlogging US$0.5 billion and salinisation US$1.5 billion.
These economic losses were calculated through estimating either the loss of agricultural productivity or output; the cost of replacing soil nutrients (through additional fertiliser); or the costs of land reclamation and restoration.
The study says the losses are not only suffered by the present generation but future generations. Since soils have been a resource for the past 2,000 and more years, there is no reason to doubt that people will still depend on it for at least 2,000 years ahead.
The value of today's soil resources to future generations could be estimated to be at least today's user values multiplied by 2,000.
Although the study does not attempt to measure the long-term losses of the present land degradation it has assessed, a simplified calculation (without discounting to obtain net present values) would be that these losses, if permanent and not repaired, would add up to at least US$20,000 billion over the next 2,000 years!
The estimates of annual loss are understated because off-site costs (such as losses caused by river silting, floods, landslides and so on) have not been counted.
Moreover, there are other forms of degradation, such as deforestation, forest degradation and rangeland degradation, acid sulphate formation, soil pollution, soil destruction through mining and quarrying, urban encroachment onto agricultural land and effects of war.
The economic costs of these are not assessed in the study. If they were, the losses would have been much higher. According to the study, there are three types of factors causing land degradation in the region.
The first category comprises natural hazards, such as heavy rains and steep slopes that lead to soil erosion; soils that are strongly acidic that result in soil fertility decline and arid climates that contribute to salinisation and lowering of the water table. The second set are direct factors that are humanly caused. These include deforestation, overcutting of vegetation, overgrazing, improper crop rotation, non-adoption of soil conservation practices, unbalanced fertiliser use, mismanagement of canal irrigation and overpumping of groundwater.
The third factor comprises what the study calls 'underlying causes of degradation'. These are the basic socio-economic structures that give rise to the direct factors.
Among them are land shortage, inappropriate land tenure arrangements, severe economic pressures on farmers, poverty, and population growth.
Although the UN study covered only South Asia, its results have implications for other countries outside the region where land degradation is also a serious problem.
For instance, at a recent national environment conference in Malaysia, Dr Lim Jit Sai of the Agriculture Department revealed that there are 18.9 million hectares of potentially degradable land in the country, making up 57% of total land areas. According to him, the main activities causing soil degradation in Malaysia are mining, agriculture, logging and urban development.
The adverse effects of soil erosion are a loss of topsoil, decline in soil fertility, siltation of water reservoirs and waterways, increasing frequency of flash floods, degradation of water quality, loss of hydropower, damage to properties and loss of lives. It would be most useful if estimates could be of the economic losses from soil erosion and land degradation in other countries, similar or even broader in scope than the study carried out for South Asia.
Such economic cost estimates might make it easier for policy makers to appreciate the economic folly of activities that degrade the land and erode soil, upon which future development (and civilisations too) depend.
Martin Khor is the Director of Third World Network.