CLIMATE IMPACTS - The Skeptic Tank

May 1997
Over the last 200 years human activities, primarily the burning fossil fuels for energy, have
increased the amount of carbon dioxide in the atmosphere. This means that more heat is
trapped within the earth’s atmosphere enhancing the natural greenhouse effect.
The Intergovernmental Panel on Climate Change (IPCC) has projected that, if humankind
continues to alter the composition of the atmosphere, global average surface temperatures
could rise by between 2 and 3 degrees C over the next 100 years. This rate of climatic
change would be unprecedented and would cause major damage to ecological systems and
economies on a global scale.
United Kingdom
The 1996 Department of Environment report ‘Review of the Potential Effects of Climate
Change in the United Kingdom’ looks at the changing climate and sea level for the decades
of the 2020s and 2050s. It assumes a ‘business as usual’ scenario i.e. no major global
policies of greenhouse gas reduction being enacted. Under this scenario:
Temperatures are expected to increase at a rate of about 0.2° C per decade with slower
rates over the northwestern UK compared to the southeastern and in winter compared to
summer. The United Nation’s Advisory Group on Greenhouse Gases have said that a
temperature increase of beyond 1°C ‘could elicit rapid, unpredictable, and non-linear
responses that could lead to extensive ecosystem damage’.
Extremely warm seasons and years are expected to occur more frequently. A hot
summer such as 1995, currently about a 1-in-90 year event, is expected to occur about
three times per decade by 2060.
Annual precipitation (rain/snow/etc.) over the UK increases by about 5% by the 2030 and
10% by the 2060 with a modest increase in average intensity in all regions and for all
Average seasonal wind speeds increase over most of the country in both summer and
winter. The frequency of gales over the UK is calculated to increase by 30% by the
Global sea level rise, about 5cm per decade, will be exacerbated in the south and eastern
UK by sinking land.
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The report goes on to assess the likely impacts affecting the UK under the ‘business as usual’
 Soils will be at increased risk of drying out. Changes in soil moisture content would
have wide-ranging effects on cultivation, sowing and other crop production practices.
 Clay soils in southern Britain will be subject to more intense shrinkage in summer with
potentially severe implications for building foundations.
 Wetland areas will be at risk from drying out and peat soils will be lost at increasing rates
due to drying and wind erosion.
 It is predicted that soil erosion will increase throughout Britain.
 Much of the Grade 1 agricultural land in England and Wales may become saline
following sea level rise and therefore of limited use for agriculture.
Flora, fauna and landscape
 A 1°c increase in temperature may significantly alter the species composition in about
half of the nature reserves in the UK.
 There will be a significant movement of species northwards in response to rising
 Although the number of animal species (especially insects) is likely to increase, the
number of plant species may decrease. A substantial number of the 506 currently
endangered species may be lost e.g. mountain hare, ptarmigan, snow bunting and
 There is some threat of invasion by alien weeds, pests, pathogens and viruses. A known
serious threat is posed by the Hottentot fig which forms dense mats on coastal cliffs and
dunes and is almost impossible to eradicate.
 A 20-30cm increase in sea levels will affect mudflats and some salt marshes, including
some nature reserves that are important for birds.
 Climate change will occur too rapidly for many species to adapt in an evolutionary sense.
 Climate change would affect health both directly (heatwave induced deaths) and
indirectly (altered rates of infectious diseases and altered exposure to air pollutants).
 Food-borne and water-borne infective agents, as causes of diarrhoeal and dysenteric
infections, are likely to spread more readily in warmer and wetter conditions.
 The existing problems of urban air pollution would be exacerbated by climate change.
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Global impacts
Polar regions
The Polar regions are particularly sensitive to global climate change and it is predicted that
warming due to increased CO2 in the atmosphere will affect the poles first and most
According to the British Antarctic Survey, warming of Antarctica is of concern because of
the vast reserves of water contained within the ice sheets. Increased melting of this ice in
a warmer climate could contribute to global sea level rise.
The Antarctic climate has a crucial role in controlling oceanic currents. Any regional
changes in the Antarctic are likely to have dramatic effects on global weather systems.
The effects of relatively small changes in temperature are demonstrated on the Antarctic
Peninsula, where a warming of 0.5°C a decade has already been observed.
A 200 metre thick ice shelf joining James Ross Island to the Antarctic continent
collapsed in 1995, making the island circumnavigable for the first time in recorded
Neighbouring ice shelf Larsen A collapsed in 1995.
A recent Greenpeace expedition to the Antarctic Peninsula discovered huge cracks in
the Larsen B Ice Shelf leading to fears that it may also collapse.
Warming is also thought to be responsible for the collapse of the Wordie Ice Shelf
American scientists monitoring Adelie penguins in the region are concerned about the
huge decline in populations. Twenty-one colonies have become extinct in recent years
and overall populations have fallen by 40% since 1975. Warmer winters and
decreased sea ice cover affecting food sources are thought to be responsible.
 Forests will be affected by more frequent outbreaks and extended ranges of pests and
diseases. For example populations of insects such as bark beetles, the Siberian
silkworm and the spruce budworm could explode and devastate millions of hectares of
 Species composition of forests is likely to change. Entire forest types may disappear.
 There is already an increase in the frequency and intensity of fires.
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 Deserts are likely to become more extreme. With few exceptions they are projected to
become hotter but not significantly wetter.
 Temperature increase could be a threat to organisms that exist near their heat tolerance
Mountain regions
 There is already evidence of glacier retreat and models project that between one-third
and one-half of existing mountain glacier mass could disappear over the next 100
 A decrease in glaciers, permafrost and snow will affect hydrologic systems, soil
stability and related socio-economic factors.
 Species with climactic ranges limited to mountain tops are likely to become extinct.
Coastal systems
 A rise in sea level or changes in storms or storm surges will result in:
 The erosion of shores and associated habitat
 Increased salinity of estuaries and freshwater aquifers
 Altered tidal ranges in rivers and bays
 Increased coastal flooding
 Changes in these ecosystems would have major negative effects on freshwater supplies,
fisheries, bio diversity and tourism.
There may be increased risk of hunger and famine in some locations.
Many of the world’s poorest people are most at risk of increased hunger and famine.
The costs of adaptation strategies would create a serious burden for developing
Rising sea levels
 Increased vulnerability of some coastal populations to flooding and erosional land loss
 The 46 million people currently estimated to be at risk of flooding due to storm surges
would increase to about 92 million with a 50cm rise.
 A one metre rise would raise the figure to 118 million.
 Storm surges and flooding could threaten entire cultures. For these countries,
sea-level rise could force populations to migrate.
 Environmental refugees fleeing ecological disaster areas could have a unique and
destructive effect on human settlements forced to cope with the influx.
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 Impacts on human health are likely to be wide-ranging and mostly adverse, with
significant loss of life.
 Direct health effects include increases in mortality and illness due to an anticipated
increase in the intensity and duration of heatwaves.
 Increased extreme weather would cause a higher incidence of death, injury,
psychological disorders and exposure to contaminated water supplies.
 Indirect effects include increases in the potential transmission of diseases such as
malaria, dengue,yellow fever and some viral encephalitis.
 A temperature increase of between 3-5°C over the next 100 years could lead to a
potential 50-80 million additional annual cases of malaria globally.
 Some increases in infectious diseases such as salmonellosis, cholera and giardiasis
could occur as a result of higher temperatures and increased flooding.
For further information please contact the Greenpeace Press Office on 0171-865