Online version: PDF - DTIE

022
UNIT 1: WHERE DO WE STAND? THE STATE OF THE GLOBAL ENVIRONMENT
prevent it blowing away. But if this vegetation cover is stripped away, the soil
becomes vulnerable. Erosion induced by human activities like agriculture, grazing,
deforestation, burning or bulldozing is the most serious form of soil degradation.
In extreme cases the surface soil can be blown or washed away right down to the
bedrock.
Salination is the result of water logging due to over-irrigation or flooding. When
the water runs off again, it leaves salt deposits in the soil. This significantly
reduces yield and can, in the long run, make the land unsuitable for cultivation.
There are several causes of land degradation:
• Both modern and traditional agricultural methods – intensive farming,
overgrazing, and shifting cultivation, extensive cultivation of marginal
lands, poor land management, the use of inappropriate technology –
are without doubt the most significant;
• Deforestation is another. UNEP estimates that over 20 acres of forests
are destroyed every day for timber and fuel;
• Long and continuous droughts, water scarcity and subsequent
desertification have destroyed vast areas of land, especially in Africa
and Asia;
• Forest fires are important causes of land degradation in Asia, the
Pacific and the Mediterranean;
• Significant areas have been degraded through industrial practices.
Land contamination in and around former industrial sites worldwide –
gas works and metal smelters, for example – are giving rise to highprofile
environment liability legal actions.
Calorie intake per capita
kilocalories/day
S
E
C
T
I
O
N
1
3,600
Calorie intake
has generally
increased over
the past two
decades but
there were
downturns in
both Europe and
Central Asia (as a
result of political
upheaval) and in
West Asia (as a
result of war)
during 1990-95
3,400
3,200
3,000
2,800
2,600
2,400
2,200
2,000
1975 1980 1985 1990 1995
Source: compiled by UNEP GRID Geneva from FAOSTAT 1997 and WRI, UNEP,
UNDP and WB 1998
Europe and
Central Asia
North America
Latin America
and the
Caribbean
Africa
West Asia
Asia and the
Pacific
World