A new study (Velasco et al. 2021) predicts truly dire consequences from the synergistic interactions of global climate change and thermohaline circulation collapse on amphibians. Under a high carbon emissions scenario, temperate zone amphibians are predicted to show the lowest proportion of range loss. In contrast, Indomalayan, Afrotropical and Neotropical amphibians are highly vulnerable to even small levels of warming and they reach median range losses larger than 50% as early as the 2030s and more than 75% by the end of the century. If one adds in the impact of the Atlantic meridional overturning circulation (AMOC), the effect is magnified. Very large range attractions occur soon after additional freshwater is added and suitable areas for amphibians shrink throughout the century. Even if freshwater addition stops about midcentury, consequences of AMOC are persistent in simulations. Effects will be strongly nonlinear but decreased in richness could be as great as 70 - 80% over much of the earth, especially the Neotropics. The authors argue that the impact of a substantial weakening of AMOC might be extensive across many clades and biogeographical regions.
