Impact of multiple small and persistent threats on extinction risk

Kaitlin Kimmel, Michael Clark, David Tilman

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


Many species may face multiple distinct and persistent drivers of extinction risk, yet theoretical and empirical studies tend to focus on the single largest driver. This means that existing approaches potentially underestimate and mischaracterize future risks to biodiversity. We synthesized existing knowledge on how multiple drivers of extinction can interact to influence a species’ overall extinction probability in a probabilistic model of extinction risk that incorporated the impacts of multiple drivers of extinction risk, their interactions, and their accumulative effects through time. We then used this model framework to explore how different threats, interactions between them, and time trends may affect a species’ overall extinction probability. Multiple small threats together had potential to pose a large cumulative extinction risk; for example, 10 individual threats posed a 1% extinction risk each and cumulatively posed a 9.7% total extinction risk. Interactions among drivers resulted in escalated risk in some cases, and persistent threats with a small (1%) extinction risk each decade ultimately posed large extinction risk over 100 (9.6% total extinction risk) to 200 years (18.2% total extinction risk). By estimating long-term extinction risk posed by several different factors and their interactions, this approach provides a framework to identify drivers of extinction risk that could be proactively targeted to help prevent species currently of least concern from becoming threatened with extinction.

Original languageEnglish (US)
Article numbere13901
JournalConservation Biology
Issue number5
StatePublished - Oct 2022

Bibliographical note

Funding Information:
We thank F. Isbell, N. Haddad, S. Hobbie, C. Lehman, and P. Reich for their insightful comments on these ideas. K.K. was funded by the Pim Postdoctoral Fellowship. M.C. was funded by the Wellcome Trust, Our Planet Our Health Programme (Livestock, Environment and People [LEAP], award 205212/Z/16/Z). For the purpose of open access, the author has applied a CC BY public copyright license to any author accepted manuscript version arising from this submission.

Publisher Copyright:
© 2022 Society for Conservation Biology.


  • concurrent extinction drivers
  • efectos sinérgicos
  • extinction theory
  • impulsores de la extinción concurrente
  • long-term extinction probability
  • marco probabilístico
  • probabilidad de extinción a largo plazo
  • probabilistic framework
  • synergistic effects
  • teoría de la extinción

PubMed: MeSH publication types

  • Journal Article
  • Research Support, Non-U.S. Gov't


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