Supplementary material from "Mapping co-benefits for carbon storage and biodiversity to inform conservation policy and action"

Integrated high-resolution maps on carbon stocks and biodiversity that identify areas of potential co-benefits for climate change mitigation and biodiversity conservation can help facilitate the implementation of global climate and biodiversity commitments at local levels. However, the multi-dimensional nature of biodiversity presents a major challenge for understanding, mapping and communicating where and how biodiversity benefits coincide with climate benefits that are more simply represented by a single parameter, carbon, and new integrated approaches are needed. Here, we (a) present a new high-resolution map of global above- and below-ground carbon stored in biomass and soil, (b) quantify biodiversity values using two complementary indices (BIp and BIr) representing proactive and reactive approaches to conservation, and that integrate local diversity and ecosystem intactness, and regional ecosystem intactness across the broader area supporting a similar natural assemblage of species to the location of interest) and (c) examine patterns of carbon-biodiversity overlap by identifying 'hotspots' (20% highest values for both aspects). The western Amazon basin, central Africa and southeast Asia capture the last strongholds of highest local biodiversity and ecosystem intactness worldwide, while the last refuges for unique biological communities whose habitats have been highly deteriorated across their range are mostly found in the tropical Andes and central Sundaland. There is 38% and 5% overlap in carbon and biodiversity hotspots, for proactive and reactive conservation, respectively. Alarmingly, only around 12% and 21%, respectively, of these hotspot areas are formally protected. This highlights that a coupled approach is urgently needed, focusing on unprotected, degraded ecosystems, particularly in the Neotropics and Indomalayan realms, and retention of the remaining highly intact areas to help achieve both climate and biodiversity global targets.This article is part of the theme issue ‘Climate change and ecosystems: threats, opportunities and solutions’.