GLOBIO contains a regression equation relating changes in global mean temperature increase (GMTI) to MSA. As species responses differ per biome, the equation is different for each of 14 biomes. The figure shows three examples. In GLOBIO, climate change is set to only affect natural and semi-natural areas.
The treatment of climate change is different from that of the other drivers, as the available empirical evidence is limited to areas that are already experiencing significant impacts (such as the Arctic and montane forests). The cause–effect relationships for climate change are based on model studies.
The models EUROMOVE and IMAGE were used to predict the proportion of remaining plant species and the proportion of stable area of biomes respectively, as a function of global mean temperature increase (GMTI). Stable groups of plant species occurring within a biome (EUROMOVE), or stable areas for each biome (IMAGE), are considered proxies for MSA.
For each biome a linear regression equation was estimated to relate cause and effect, i.e. GMTI and the MSA proxy. For each biome, the regression-equation was selected that predicts the smallest effects, either from EUROMOVE or from IMAGE, yielding conservative estimates.