**3.2.10 Climate change and ecosystems**

Beyond the year 2050, climate change may be the major driver for biodiversity loss globally. It was projected by Fischlin *et al.* (2007a) that approximately 20 to 30% of plant and animal species assessed so far would likely be at increasingly high risk of extinction should global mean temperatures exceed a warming of 2 to 3 °C above pre-industrial temperature levels (Fischlin *et al.,* 2007b). The uncertainties in this estimate, however, are large: for a rise of about 2 °C the percentage may be as low as 10%, or for about 3 °C, as high as 40%, and depending on biota(Parry 2007a) (all living organisms of an area, the flora and fauna considered as a unit) the range is between 1% and 80%. As global average temperature exceeds 4 °C above pre-industrial levels, model projections suggested that there could be significant extinctions (40-70% of species that were assessed) around the globe.
