Climate change and biodiversity loss ranks highly among the challenges our society faces as rates of both processes currently exceed boundaries that are considered safe for humanity. One proposed approach for mitigating the biodiversity and climate crisis is maintaining and restoring 50% of terrestrial land area as intact natural ecosystems by 2050. The ‘nature needs half’ movement has garnered considerable attention because promoting intact natural ecosystems is critical for maintaining biodiversity and for achieving scalable climate solutions. Climate change imparts unique challenges for conserving the planet’s biodiversity. If the past is prologue, we can expect that species will respond idiosyncratically to ongoing climate changes. This poses a challenge to conservation frameworks that rely on static boundaries defined by protected areas. Here we examine potential climate driven shifts in the distribution of the planet’s terrestrial ecoregions and its implications for a global conservation framework. ‘Nature needs half’ is based on 846 global terrestrial ecoregions ranked by the extent to which they contain protected area and natural habitat. Using a climate analog approach, we examine the extent to which climate driven shifts in the distribution of these ecoregions affects representation by the current global protected area network.
Results/Conclusions
Under a +2C and +4C warming scenario, global patterns of multivariate climatic dissimilarity showed a latitudinal gradient with higher values in tropical and sub-tropical regions and a general decline in dissimilarity towards high latitudes. At the scale of biomes, tropical and Mediterranean biomes showed the highest climate dissimilarity whereas montane grasslands showed the lowest. Approximately 3% and 16% of terrestrial land surfaces are projected to have novel climates for the +2C and +4C scenarios respectively. Under the +2C scenario, the protected area status at the biome scale was projected to remain fairly stable. However, within each biome there is the potential for notable shifts in the distribution of specific ecoregions resulting in substantial losses (and gains) in their protected status. These patterns are further exacerbated under a +4C scenario. Overall, our results raise questions about our ability to assess representation within a static global protected area network given the potential dynamic distribution of the planet’s ecoregions.