Author
Susannah E. O’Hanlon
Bio: Susannah E. O’Hanlon is an academic researcher from Anglia Ruskin University. The author has contributed to research in topics: Global warming & Biodiversity. The author has an hindex of 1, co-authored 1 publications receiving 619 citations.
Papers
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International Union for Conservation of Nature and Natural Resources1, University of the Witwatersrand2, BirdLife International3, Stony Brook University4, Museum für Naturkunde5, James Cook University6, Zhejiang University7, University of British Columbia8, Imperial College London9, University of Southampton10, Anglia Ruskin University11, Charles Darwin University12, University of Utah13, University College London14
TL;DR: This study presents a framework for assessing three dimensions of climate change vulnerability, namely sensitivity, exposure and adaptive capacity, and finds that high concentration areas for species with traits conferring highest sensitivity and lowest adaptive capacity differ from those of highly exposed species.
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 areaspecific conservation interventions and indices. The priorities we identify will strengthen global strategies to mitigate climate change impacts.
722 citations
Cited by
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TL;DR: Estimating a global mean extinction rate was synthesized in order to determine which factors contribute the greatest uncertainty to climate change–induced extinction risks and suggest that extinction risks will accelerate with future global temperatures.
Abstract: Current predictions of extinction risks from climate change vary widely depending on the specific assumptions and geographic and taxonomic focus of each study. I synthesized published studies in order to estimate a global mean extinction rate and determine which factors contribute the greatest uncertainty to climate change–induced extinction risks. Results suggest that extinction risks will accelerate with future global temperatures, threatening up to one in six species under current policies. Extinction risks were highest in South America, Australia, and New Zealand, and risks did not vary by taxonomic group. Realistic assumptions about extinction debt and dispersal capacity substantially increased extinction risks. We urgently need to adopt strategies that limit further climate change if we are to avoid an acceleration of global extinctions.
1,472 citations
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TL;DR: An analysis of threat information gathered for more than 8,000 species revealed that overexploitation and agriculture are by far the biggest drivers of biodiversity decline.
Abstract: The threats of old are still the dominant drivers of current species loss, indicates an analysis of IUCN Red List data by Sean Maxwell and colleagues.
1,180 citations
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TL;DR: It is found that most terrestrial ectotherms are insufficiently tolerant of high temperatures to survive the warmest potential body temperatures in exposed habitats and must therefore thermoregulate by using shade, burrows, or evaporative cooling and show why heat-tolerance limits are relatively invariant in comparison with cold limits.
Abstract: Physiological thermal-tolerance limits of terrestrial ectotherms often exceed local air temperatures, implying a high degree of thermal safety (an excess of warm or cold thermal tolerance). However, air temperatures can be very different from the equilibrium body temperature of an individual ectotherm. Here, we compile thermal-tolerance limits of ectotherms across a wide range of latitudes and elevations and compare these thermal limits both to air and to operative body temperatures (theoretically equilibrated body temperatures) of small ectothermic animals during the warmest and coldest times of the year. We show that extreme operative body temperatures in exposed habitats match or exceed the physiological thermal limits of most ectotherms. Therefore, contrary to previous findings using air temperatures, most ectotherms do not have a physiological thermal-safety margin. They must therefore rely on behavior to avoid overheating during the warmest times, especially in the lowland tropics. Likewise, species living at temperate latitudes and in alpine habitats must retreat to avoid lethal cold exposure. Behavioral plasticity of habitat use and the energetic consequences of thermal retreats are therefore critical aspects of species’ vulnerability to climate warming and extreme events.
874 citations
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Sapienza University of Rome1, International Union for Conservation of Nature and Natural Resources2, University of the Witwatersrand3, Microsoft4, University of Queensland5, Wildlife Conservation Society6, BirdLife International7, Norwegian Polar Institute8, James Cook University9, Conservation International10, Commonwealth Scientific and Industrial Research Organisation11, Stony Brook University12, Chinese Academy of Sciences13, Durham University14, National University of Singapore15, University of Melbourne16, Stellenbosch University17, Zoological Society of London18, University College London19, NatureServe20
TL;DR: In this article, three main approaches used to derive these currencies (correlative, mechanistic and trait-based) and their associated data requirements, spatial and temporal scales of application and modelling methods are described.
Abstract: The effects of climate change on biodiversity are increasingly well documented, and many methods have been developed to assess species' vulnerability to climatic changes, both ongoing and projected in the coming decades. To minimize global biodiversity losses, conservationists need to identify those species that are likely to be most vulnerable to the impacts of climate change. In this Review, we summarize different currencies used for assessing species' climate change vulnerability. We describe three main approaches used to derive these currencies (correlative, mechanistic and trait-based), and their associated data requirements, spatial and temporal scales of application and modelling methods. We identify strengths and weaknesses of the approaches and highlight the sources of uncertainty inherent in each method that limit projection reliability. Finally, we provide guidance for conservation practitioners in selecting the most appropriate approach(es) for their planning needs and highlight priority areas for further assessments.
808 citations
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TL;DR: This review critically assesses the variety of metrics commonly used to describe climate change in biodiversity-impact assessments covering local changes in climate averages and extremes, regional changes in the availability and position of climates, and the velocity of climate change.
Abstract: The 21st century is projected to witness unprecedented climatic changes, with greater warming often reported for high latitudes. Yet, climate change can be measured in a variety of ways, reflecting distinct dimensions of change with unequal spatial patterns across the world. Polar climates are projected to not only warm, but also to shrink in area. By contrast, today's hot and arid climates are expected to expand worldwide and to reach climate states with no current analog. Although rarely appreciated in combination, these multiple dimensions of change convey complementary information. We review existing climate change metrics and discuss how they relate to threats and opportunities for biodiversity. Interpreting climate change metrics is particularly useful for unknown or poorly described species, which represent most of Earth's biodiversity.
548 citations