Climate change in the UKOTs an overview of the ... - JNCC - Defra

• Warmer and drier conditions are partially
responsible for reduced forest productivity
and increased forest fires in
the Mediterranean Basin.
Projections
• The long-term prospect is for continued
warming as the influence of greenhouse
gases increases over time. A
2005 study by WWF found that a global
temperature increase of 2°C is likely to
lead to a corresponding warming of 1°C
to 3°C in the Mediterranean. Temperatures
are likely to be higher inland than
along the coast and the largest increase
will take place during the summer
(Giannakopolous et al., 2005).
• Precipitation trends are uncertain, but
some models suggest an increase of
up to 10 per cent in winter precipitation
and a decrease of 5 to 15 per cent in
summer precipitation by the latter half
of the 21st century (Karas, 2000).
• As climate changes in the region, the
frequency of extreme weather - heat
waves and droughts - will increase.
Droughts are likely to be longer.
Implications and possible future
impacts
• As early as 1990, the United Nations
Environment Programme (UNEP)
warned that the Mediterranean would
be one of the first regions to feel the
impact of climate change on water
resources. Water is already scarce in
some parts of the region and a
decrease in precipitation could make
existing problems even worse. Water
quality could also be affected. Higher
temperatures and evaporation would
cause an increase in salinity of lakes
and reservoirs. Sea level rise would
increase saltwater intrusion into
aquifers and estuaries (Karas, 2000).
• The areas that are prone to desertification
are likely to increase, as will the
severity of desertification in existing dry
lands (Karas, 2000).
• There may be a reduction in production
and crop yields in the southern part of
the Mediterranean basin. Desertification,
increased fire risk, spread of pests
and diseases in the region, and
changes in global markets could affect
agriculture to varying degrees (Karas,
2000).
• Warmer temperatures in northern
Europe could encourage people there
to take domestic holidays, rather than
travel to the Mediterranean (Giannakopolous
et al., 2005). This would
adversely affect the economy of the
Mediterranean.
Variations in precipitation due to climate
change are likely to accelerate erosion on the
eastern side of St. Helena. The Great Wood
(shown here) was originally populated by
gumwood trees endemic to St Helena. The
whole forest has been destroyed as timber
was used for firewood and the bark for
tanning leather. Domesticated animals
roamed free grazing on new growth. Low
rainfall and the south-easterly winds are now
instrumental in changing the exposed
woodland soil to parched low-grade sand/clay
with low levels of nutrient. Heavy rains can
increase the erosion rate; drought retains the
conditions for further wind based erosion.
Credit: Vince Thompson, St Helena National Trust
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