Effects of Climate Change
Climate change will bring more intense and unpredictable impacts
that will be felt across the world. For example, sea level rise
threatens the existence of some island states and puts millions of
people at risk from flooding. Temperature increases, drought and
flooding will affect people's health and way of life, and cause the
irreversible loss of many species of plants and animals. The
economic, human and environmental costs are likely to be huge and
could create political tension within and between countries,
exacerbating regional instability.
The specific effects of climate change will vary greatly from place
to place. Agricultural production in some countries is expected to
benefit through increased rainfall and longer growing seasons. But
there is a high risk of serious threats to populations throughout
the world, particularly the poor who have the fewest resources for
adapting to such major changes. Water resources for drinking and
irrigation will be affected by reduced rainfall, or as water
resources in coastal areas are exposed to salinisation as sea
levels rise. Diseases such as malaria will spread to previously
unaffected areas, and crops will fail as conditions change.
People's lives will be put at risk from increased frequency of
droughts and flooding, and extreme storm events. Many major cities
are located in low-lying areas and could face profound economic
consequences as sea level rise makes them increasingly prone to
flooding.
Widespread ecological impacts of climate change are reported to be
visible in every part of the world and in every ecosystem. It is
possible that reports have underestimated the scale of future
impacts on ecosystems because ecosystem changes appear to be driven
most strongly by changes in extreme weather rather than average
conditions. The high rate of change is exacerbating the
effects.
The website of the Northwest Climate Group www.snw.org.uk/climate (external
link) contains information on how climate change will affect
the NW of England. The Environment Agency's website www.environment-agency.gov.uk (external
link) provides a Flood Map to enable people to find out areas
that could be affected by flooding from rivers and the sea, and how
they can receive early warnings of floods.
Future trends
Mathematical climate models are complex and their absolute accuracy
depends on the accuracy of a large number of influencing factors or
variables. There are also several 'unpredictables' that could
influence the outcome, such as collapse of the Greenland and West
Antarctic Ice Sheets, changes to the Gulf Stream current, and
effects associated with reduced 'global dimming'.
Average global temperatures are likely to rise by 1.4-5.8'C during
this century, but there is some uncertainty about the sensitivity
of the climate to increasing levels of greenhouse gases. An
emerging consensus suggests that to avoid the worst impacts, global
temperature rise needs to be limited to 2'C.