Geography Reference
In-Depth Information
nature of the resource and many aspects of the associated human
environment.
The distinction between renewable and non-renewable resources
is important in this context. The former, such as soils, fresh
water, forests, and fi sheries, are regenerated by biological or
environmental processes and may be harvested indefi nitely
provided that the sustainable yield is not exceeded. But the
exploitation of such resources is increasing at a faster rate than
the world's population: since the 1950s, world demand for water
has tripled, catches of fi shes have quadrupled, and consumption
of food has increased six-fold. Technological innovations in
agriculture, water supply, forestry, and fi sheries have proved
capable of both increasing yields and exceeding sustainable yields,
which can lead to resource depletion and the degradation of whole
geo-ecosystems. There are often knock-on effects throughout
economic and political systems, as exemplifi ed by so-called
'Water Wars' in the Middle East and elsewhere, where upstream
abstraction of water from rivers and groundwater has led to
limited downstream supply. Reserves of non-renewable resources,
such as fossil fuels and metal ores, which are in limited supply
because of their slow rate of formation by geological processes,
may be depleted and exhausted (although recycling is possible
in some cases, notably metals). Technological change and/or
changing societal values may lead to an increase in exploitation
but they are also capable of increasing reserves, reducing usage
or creating substitutes, which reduce the rate of depletion
and decrease the likelihood of exhaustion. The exploitation of
renewable and non-renewable resources therefore raises issues
of production and consumption, management and sustainability,
conservation and preservation, all of which have important
geographical dimensions.
Several of these resource issues are exemplifi ed by the use
of groundwater in arid lands. On the one hand, technology
has created a productive landscape and has caused 'deserts
