Identifying the World's Most Climate Change Vulnerable Species: A Systematic Trait-Based Assessment of all Birds, Amphibians and Corals

Abstract

Climate change will have far-reaching impacts on biodiversity, including increasing extinction rates. Current approaches to quantifying such impacts focus on measuring exposure to climatic change and largely ignore the biological differences between species that may significantly increase or reduce their vulnerability. To address this, we present a framework for assessing three dimensions of climate change vulnerability, namely sensitivity, exposure and adaptive capacity; this draws on species’ biological traits and their modeled exposure to projected climatic changes. In the largest such assessment to date, we applied this approach to each of the world’s birds, amphibians and corals (16,857 species). The resulting assessments identify the species with greatest relative vulnerability to climate change and the geographic areas in which they are concentrated, including the Amazon basin for amphibians and birds, and the central Indo-west Pacific (Coral Triangle) for corals. We found that high concentration areas for species with traits conferring highest sensitivity and lowest adaptive capacity differ from those of highly exposed species, and we identify areas where exposure-based assessments alone may over or under-estimate climate change impacts. We found that 608–851 bird (6–9%), 670–933 amphibian (11–15%), and 47–73 coral species (6–9%) are both highly climate change vulnerable and already threatened with extinction on the IUCN Red List. The remaining highly climate change vulnerable species represent new priorities for conservation. Fewer species are highly climate change vulnerable under lower IPCC SRES emissions scenarios, indicating that reducing greenhouse emissions will reduce climate change driven extinctions. Our study answers the growing call for a more biologically and ecologically inclusive approach to assessing climate change vulnerability. By facilitating independent assessment of the three dimensions of climate change vulnerability, our approach can be used to devise species and area-specific conservation interventions and indices. The priorities we identify will strengthen global strategies to mitigate climate change impacts.

Thermal-safety margins and the necessity of thermoregulatory behavior across latitude and elevation

“…Thus, water balance and temperature are not easily dissociated in this group, and safety margins of amphibians are dependent on hydration. Our estimates of sensitivity to warming based on site-specific thermal-safety margins among amphibians gives a very different estimate of warming vulnerability than approaches using species-level variables such as climate occupancy or habitat specialization (2).…”

“…macrophysiology | operative temperature | climate sensitivity P redicting the organismal responses to climate change-a global priority-requires an understanding of the physiological, behavioral, ecological, and evolutionary factors that constrain where species can live (1,2). Macrophysiological analyses that predict large-scale patterns in the vulnerability of ectotherms to climate warming often invoke the concept of the "thermal-safety margin" (3)(4)(5)(6), which measures the difference between a species' maximum tolerance to heat and the warm air temperatures it regularly experiences.…”

Climate change and pollution speed declines in zebrafish populations

“…In contrast, cyp19a1a (and cyp19a1b) plays the pivotal role in the production of estrogen, ultimately controlling sexual phenotype in zebrafish (41) and in all animals exhibiting environmental/temperaturedependent sex determination/differentiation (18). The long-term impacts of global environmental change on wildlife species will depend upon niche specificity, plasticity, and dispersal (70); dependence on environmental cues, ecological interactions (including sex-determining mechanisms), physiological tolerance, and adaptive capacity (71), each underpinned by genetic diversity (13,14). Sexual reproduction has the potential to promote genetic diversity in populations by accelerating the production of novel genotypes and limiting the accumulation of deleterious mutations (72)(73)(74)(75).…”

Geographical variation in species' population responses to changes in temperature and precipitation

“…Gaining a full understanding of the processes by which climate change impacts populations is essential not just to develop improved assessment of risk [13], but also to inform adaptive conservation management [14,15]. Recent evidence has highlighted that climate change will directly drive population change and extinction primarily through altered species interactions [12,16].…”