Continental-scale assessments of 21st century global impacts of climate change on biodiversity have forecasted range contractions for many species. These coarse resolution studies are, however, of limited relevance for projecting risks to biodiversity in mountain systems, where pronounced microclimatic variation could allow species to persist locally, and are ill-suited for assessment of species-specific threat in particular regions. Here, we assess the impacts of climate change on 2632 plant species across all major European mountain ranges, using high-resolution (ca. 100 m) species samples and data expressing four future climate scenarios. Projected habitat loss is greater for species distributed at higher elevations; depending on the climate scenario, we find 36-55% of alpine species, 31-51% of subalpine species and 19-46% of montane species lose more than 80% of their suitable habitat by 2070-2100. While our high-resolution analyses consistently indicate marked levels of threat to cold-adapted mountain florae across Europe, they also reveal unequal distribution of this threat across the various mountain ranges. Impacts on florae from regions projected to undergo increased warming accompanied by decreased precipitation, such as the Pyrenees and the Eastern Austrian Alps, will likely be greater than on florae in regions where the increase in temperature is less pronounced and rainfall increases concomitantly, such as in the Norwegian Scandes and the Scottish Highlands. This suggests that change in precipitation, not only warming, plays an important role in determining the potential impacts of climate change on vegetation

To meet the ambitious objectives of biodiversity and climate conventions, countries and the international community require clarity on how these objectives can be operationalized spatially, and multiple targets be pursued concurrently 1 . To support governments and political conventions, spatial guidance is needed to identify which areas should be managed for conservation to generate the greatest synergies between biodiversity and nature's contribution to people (NCP). Here we present results from a joint optimization that maximizes improvements in species conservation status, carbon retention and water provisioning and rank terrestrial conservation priorities globally. We found that, selecting the top-ranked 30% (respectively 50%) of areas would conserve 62.4% (86.8%) of the estimated total carbon stock and 67.8% (90.7%) of all clean water provisioning, in addition to improving the conservation status for 69.7% (83.8%) of all species considered. If priority was given to biodiversity only, managing 30% of optimally located land area for conservation may be sufficient to improve the conservation status of 86.3% of plant and vertebrate species on Earth. Our results provide a global baseline on where land could be managed for conservation. We discuss how such a spatial prioritisation framework can support the implementation of the biodiversity and climate conventions.

Integrated high-resolution maps of 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. A new integrated approach to biodiversity is therefore 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 (c) examine patterns of carbon–biodiversity overlap by identifying 'hotspots' (20% highest values for both aspects). Our indices integrate local diversity and ecosystem intactness, as well as regional ecosystem intactness across the broader area supporting a similar natural assemblage of species to the location of interest. 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 greatly reduced 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% of these proactive and reactive hotspot areas, respectively, are formally protected. This highlights that a coupled approach is urgently needed to help achieve both climate and biodiversity global targets. This would involve (1) restoring and conserving unprotected, degraded ecosystems, particularly in the Neotropics and Indomalaya, and (2) retaining the remaining strongholds of intactness. This article is part of the theme issue ‘Climate change and ecosystems: threats, opportunities and solutions’.

We provide a global, spatially explicit characterization of 47 terrestrial habitat types, as defined in the International Union for Conservation of Nature (IUCN) habitat classification scheme, which is widely used in ecological analyses, including for quantifying species' area of Habitat. We produced this novel habitat map for the year 2015 by creating a global decision tree that intersects the best currently available global data on land cover, climate and land use. We independently validated the map using occurrence data for 828 species of vertebrates (35152 point plus 8181 polygonal occurrences) and 6026 sampling sites. Across datasets and mapped classes we found on average a balanced accuracy of 0.77 (+0.14 SD) at Level 1 and 0.71 (+0.15 SD) at Level 2, while noting potential issues of using occurrence records for validation. the maps broaden our understanding of habitats globally, assist in constructing area of habitat refinements and are relevant for broad-scale ecological studies and future IUCN Red List assessments. Periodic updates are planned as better or more recent data becomes available.

paragraph 64 65To meet the ambitious objectives of biodiversity and climate conventions, countries and the 66 international community require clarity on how these objectives can be operationalized spatially, 67and multiple targets be pursued concurrently 1 . To support governments and political conventions, 68 spatial guidance is needed to identify which areas should be managed for conservation to generate 69 the greatest synergies between biodiversity and nature's contribution to people (NCP). Here we 70 present results from a joint optimization that maximizes improvements in species conservation 71 status, carbon retention and water provisioning and rank terrestrial conservation priorities globally. 72We found that, selecting the top-ranked 30% (respectively 50%) of areas would conserve 62.4% 73 (86.8%) of the estimated total carbon stock and 67.8% (90.7%) of all clean water provisioning, in 74 addition to improving the conservation status for 69.7% (83.8%) of all species considered. If 75 priority was given to biodiversity only, managing 30% of optimally located land area for 76 conservation may be sufficient to improve the conservation status of 86.3% of plant and vertebrate 77 species on Earth. Our results provide a global baseline on where land could be managed for 78conservation. We discuss how such a spatial prioritisation framework can support the 79 implementation of the biodiversity and climate conventions. 80 81 82(SDGs), the United Nations Framework Convention on Climate Change (UNFCCC) and the CBD 97 emphasize that habitat conservation and restoration should contribute simultaneously to 98 biodiversity conservation and climate change mitigation 4 . Recent analyses of conservation 99priorities for biodiversity and carbon have spatially overlaid areas of importance for both assets, 100effectively treating the two goals as to be pursued separately (e.g. 6,9 ). However, multi-criteria 101 spatial optimization approaches applied to conservation and restoration prioritisation have shown 102 that carbon sequestration could be doubled, and the number of extinctions prevented tripled, if 103 priority areas were jointly identified rather than independently 10,11 . Yet, no comparable 104 optimization analyses exist at a global scale. 105A number of recent studies have attempted to map spatial conservation priorities on land 12 , 106relying on spatial conservation prioritisation (SCP) methods . However, these approaches are 107 limited, in that: they (i) are limited by geographic extent 22 or focus on only a subset of global 108 biodiversity, notably ignoring either reptiles or plant species, which show considerable variation 109 in areas of importance compared to other taxa 18,19 ; (ii) focus on species representation only, rather 110 than reducing extinction risk, as per international biodiversity targets, and often ignore other 111 dimensions of biodiversity, e.g. evolutionary distinctiveness 20,21 ; (iii) do not investigate the extent 112 to which synergies between biodiversity and NCPs, such as carbon seq...