Scenarios of change in the realized climatic niche of mountain carnivores and ungulates.

Mountains are among the natural systems most impacted by climate change and mountain mammals are considered particularly imperilled, given their high degree of specialization to narrow tolerance bands of environmental conditions. Climate change mitigation policies, such as the Paris Agreement, are essential to stem the impact of climate change on natural systems. But how significant is the Paris Agreement to the survival of mountain mammals? Here we investigate how alternative emission scenarios will determine change in the realised climatic niche of mountain carnivores and ungulates in 2050. We based our predictions of future change in species niches based on how species have responded to past environmental changes, focussing on the probabilities of niche shrink and niche stability. We found that achieving the Paris Agreement's commitments would substantially reduce climate instability for mountain species. Specifically, limiting global warming to below 1.5°C would reduce the probability of niche shrinkage by 4% compared to a high emission scenario. Globally, carnivores will experience a greater niche shrinkage than ungulates, while ungulates will be more likely to shift their niche (i.e. face a level of climate change that might allow adaptation). We also found 23 species threatened by climate change according to the IUCN Red List which will suffer from a greater niche contraction compared to the other species we analysed (3% higher on average). We therefore argue that climate mitigation policies must be coupled with rapid species-specific conservation intervention and sustainable land-use policies, to avoid high risk of loss for already vulnerable species. This article is protected by copyright. All rights reserved.