Extinction risk from climate change

This article is about data on extinction of plant or animal species due to climate change. For speculation about human extinction due to climate change, see Climate change and civilizational collapse.
The impact of three different climate change scenarios on local biodiversity and risk of extinction of vertebrate species[1]

There are several plausible pathways that could lead to an increased extinction risk from climate change. Every plant and animal species has evolved to exist within a certain ecological niche.[2] But climate change leads to changes of temperature and average weather patterns.[3][4] These changes can push climatic conditions outside of the species' niche, and ultimately render it extinct.[5] Normally, species faced with changing conditions can either adapt in place through microevolution or move to another habitat with suitable conditions. However, the speed of recent climate change is very fast. Due to this rapid change, for example Ectotherm cold-blooded animals (a category which includes amphibians, reptiles and all invertebrates) may struggle to find a suitable habitat within 50 km of their current location at the end of this century (for a mid-range scenario of future global warming).[6]

Climate change also increases both the frequency and intensity of extreme weather events,[7] which can directly wipe out regional populations of species.[8] Those species occupying coastal and low-lying island habitats can also become extinct by sea level rise. This has already happened with Bramble Cay melomys in Australia.[9] Finally, climate change has been linked with the increased prevalence and global spread of certain diseases affecting wildlife. This includes Batrachochytrium dendrobatidis, a fungus that is one of the main drivers of the worldwide decline in amphibian populations.[10]

So far, climate change has not yet been a major contributor to the ongoing holocene extinction. In fact, nearly all of the irreversible biodiversity loss to date has been caused by other anthropogenic pressures such as habitat destruction.[11][12][13] Yet, its effects are certain to become more prevalent in the future. As of 2021, 19% of species on the IUCN Red List of Threatened Species are already being impacted by climate change.[14] Out of 4000 species analyzed by the IPCC Sixth Assessment Report, half were found to have shifted their distribution to higher latitudes or elevations in response to climate change. According to IUCN, once a species has lost over half of its geographic range, it is classified as "endangered", which is considered equivalent to a >20% likelihood of extinction over the next 10–100 years. If it loses 80% or more of its range, it is considered "critically endangered", and has a very high (over 50%) likelihood of going extinct over the next 10–100 years.[15]

The IPCC Sixth Assessment Report projected that in the future, 9%-14% of the species assessed would be at a very high risk of extinction under 1.5 °C (2.7 °F) of global warming over the preindustrial levels, and more warming means more widespread risk, with 3 °C (5.4 °F) placing 12%-29% at very high risk, and 5 °C (9.0 °F) 15%-48%. In particular, at 3.2 °C (5.8 °F), 15% of invertebrates (including 12% of pollinators), 11% of amphibians and 10% of flowering plants would be at a very high risk of extinction, while ~49% of insects, 44% of plants, and 26% of vertebrates would be at a high risk of extinction. In contrast, even the more modest Paris Agreement goal of limiting warming to 2 °C (3.6 °F) reduces the fraction of invertebrates, amphibians and flowering plants at a very high risk of extinction to below 3%. However, while the more ambitious 1.5 °C (2.7 °F) goal dramatically cuts the proportion of insects, plants, and vertebrates at high risk of extinction to 6%, 4% and 8%, the less ambitious target triples (to 18%) and doubles (8% and 16%) the proportion of respective species at risk.[15]

  1. ^ Cite error: The named reference Strona2022 was invoked but never defined (see the help page).
  2. ^ Pocheville, Arnaud (2015). "The Ecological Niche: History and Recent Controversies". In Heams, Thomas; Huneman, Philippe; Lecointre, Guillaume; et al. (eds.). Handbook of Evolutionary Thinking in the Sciences. Dordrecht: Springer. pp. 547–586. ISBN 978-94-017-9014-7.
  3. ^ "Climate Change". National Geographic. 28 March 2019. Retrieved 1 November 2021.
  4. ^ Witze, Alexandra. "Why extreme rains are gaining strength as the climate warms". Nature. Retrieved 30 July 2021.
  5. ^ Van der Putten, Wim H.; Macel, Mirka; Visser, Marcel E. (2010-07-12). "Predicting species distribution and abundance responses to climate change: why it is essential to include biotic interactions across trophic Levels". Philosophical Transactions of the Royal Society B: Biological Sciences. 365 (1549): 2025–2034. doi:10.1098/rstb.2010.0037. PMC 2880132. PMID 20513711.
  6. ^ Cite error: The named reference Buckley2012 was invoked but never defined (see the help page).
  7. ^ "Summary for Policymakers". Climate Change 2021: The Physical Science Basis. Working Group I contribution to the WGI Sixth Assessment Report of the Intergovernmental Panel on Climate Change (PDF). Intergovernmental Panel on Climate Change. 9 August 2021. p. SPM-23; Fig. SPM.6. Archived (PDF) from the original on 4 November 2021.
  8. ^ Cite error: The named reference Maxwell2018 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference :0 was invoked but never defined (see the help page).
  10. ^ Pounds, Alan (12 January 2006). "Widespread Amphibian Extinctions from Epidemic Disease Driven by Global Warming". Nature. 439 (7073): 161–167. Bibcode:2006Natur.439..161A. doi:10.1038/nature04246. PMID 16407945. S2CID 4430672.
  11. ^ Cite error: The named reference IPBES was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference :9 was invoked but never defined (see the help page).
  13. ^ Caro, Tim; Rowe, Zeke; et al. (2022). "An inconvenient misconception: Climate change is not the principal driver of biodiversity loss". Conservation Letters. 15 (3): e12868. Bibcode:2022ConL...15E2868C. doi:10.1111/conl.12868. S2CID 246172852.
  14. ^ "Species and Climate Change". IUCN Issues Brief. IUCN. October 2021.
  15. ^ a b Cite error: The named reference AR6_WGII_Chapter2 was invoked but never defined (see the help page).