The Impacts and Costs of Climate Change

The Impacts and Costs of Climate Change
Impacts at or above 3C temperature increase relative to pre-industrial levels:
* 22% of global ecosystems transformed: ecosystems lose between 7 and 74% of their extent
(Leemans and Eickhout 2003)
* Alpine species near extinction in Europe (Bugmann 1997)
* 60% loss of tundra ecosystem globally (Hare 2003/Malcolm et al 2002)
A recent publication has assessed the potential impacts on ecosystems (Thomas et al, 2004.). Using
projections of species' distributions for future climate scenarios, they assess extinction risks for
sample regions that cover some 20% of the Earth's terrestrial surface. Exploring three approaches they
predict, on the basis of mid-range climate-warming scenarios for 2050, that 15-37% of species in a
sample of regions and taxa will be 'committed to extinction'. When the average of the different
methods and dispersal scenarios is taken, minimal climate-warming scenarios produce lower
projections of species committed to extinction (18%) than mid-range (24%) and maximum change
(35%) scenarios. The table below shows the proportion of species extinction by area. It can be seen
that a step change in the number of species extinct occurs between the minimum and mid-range
climate change and also between the mid and maximum expected climate change for the majority of
sample regions.
Table 8. Projected percentage extinctions for different taxa and regions (simplified from
Thomas et al, 2004)
Taxon Region Number With dispersal No dispersal
of species
directly
assessed
Minimum Mid-range Maximum Minimum Mid-range Maximum
expected climate expected expected climate expected
climate change climate climate change climate
change change change change
Mammals Mexico 96 5 8 24 26
Queensland 11 16 77
South Africa 5 0 0 69
Birds Mexico 186 4 5 - 9 8 -
Europe 34 - - 7 48
Queensland 13 12 85
South Africa 5 - 0 - - 51 -
Frogs Queensland 23 13 68
Reptiles Queensland 18 9 76
South Africa 0 50
Butterflies Mexico 41 7 7 13 19
South Africa 4 0 78
Australia 24 7 23 33 16 35 54
Other invertebrates South Africa 10 0 85
Plants Amzonia 9
Europe 192 6 7 8 18 22 29
Cerrado 163 66 75
South Africa 243 38 52
Proteaceae
All species 11 19 33 34 45 58

AEA Technology Environment, August 2005

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Watkiss, Paul; Downing, Tom; Handley, Claire & Butterfield, Ruth. The Impacts and Costs of Climate Change. Oxford, England. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc29337/. Accessed April 17, 2014.