Biodiversity loss

This article is about the current and recent reduction in biological diversity caused by human activities. For biodiversity loss in geologic timeframes, see extinction event. For extinction or decrease of animals from ecological communities, see defaunation.
Summary of major environmental-change categories that cause biodiversity loss. The data is expressed as a percentage of human-driven change (in red) relative to baseline (blue), as of 2021. Red indicates the percentage of the category that is damaged, lost, or otherwise affected, whereas blue indicates the percentage that is intact, remaining, or otherwise unaffected.[1]

Biodiversity loss happens when plant or animal species disappear completely from Earth (extinction) or when there is a decrease or disappearance of species in a specific area. Biodiversity loss means that there is a reduction in biological diversity in a given area. The decrease can be temporary or permanent. It is temporary if the damage that led to the loss is reversible in time, for example through ecological restoration. If this is not possible, then the decrease is permanent. The cause of most of the biodiversity loss is, generally speaking, human activities that push the planetary boundaries too far.[1][2][3] These activities include habitat destruction[4] (for example deforestation) and land use intensification (for example monoculture farming).[5][6] Further problem areas are air and water pollution (including nutrient pollution), over-exploitation, invasive species[7] and climate change.[4]

Many scientists, along with the Global Assessment Report on Biodiversity and Ecosystem Services, say that the main reason for biodiversity loss is a growing human population because this leads to human overpopulation and excessive consumption.[8][9][10][11][12] Others disagree, saying that loss of habitat is caused mainly by "the growth of commodities for export" and that population has very little to do with overall consumption. More important are wealth disparities between and within countries.[13]

Climate change is another threat to global biodiversity.[14][15] For example, coral reefs—which are biodiversity hotspots—will be lost by the year 2100 if global warming continues at the current rate.[16][17] Still, it is the general habitat destruction (often for expansion of agriculture), not climate change, that is currently the bigger driver of biodiversity loss.[18][19] Invasive species and other disturbances have become more common in forests in the last several decades. These tend to be directly or indirectly connected to climate change and can cause a deterioration of forest ecosystems.[20][21]

Groups that care about the environment have been working for many years to stop the decrease in biodiversity. Nowadays, many global policies include activities to stop biodiversity loss. For example, the UN Convention on Biological Diversity aims to prevent biodiversity loss and to conserve wilderness areas. However, a 2020 United Nations Environment Programme report found that most of these efforts had failed to meet their goals.[22] For example, of the 20 biodiversity goals laid out by the Aichi Biodiversity Targets in 2010, only six were "partially achieved" by 2020.[23][24]

This ongoing global extinction is also called the holocene extinction or sixth mass extinction.

  1. ^ a b Bradshaw CJ, Ehrlich PR, Beattie A, Ceballos G, Crist E, Diamond J, et al. (2021). "Underestimating the Challenges of Avoiding a Ghastly Future". Frontiers in Conservation Science. 1. doi:10.3389/fcosc.2020.615419.
  2. ^ Ripple WJ, Wolf C, Newsome TM, Galetti M, Alamgir M, Crist E, et al. (November 13, 2017). "World Scientists' Warning to Humanity: A Second Notice". BioScience. 67 (12): 1026–1028. doi:10.1093/biosci/bix125. hdl:11336/71342. Moreover, we have unleashed a mass extinction event, the sixth in roughly 540 million years, wherein many current life forms could be annihilated or at least committed to extinction by the end of this century.
  3. ^ Cowie RH, Bouchet P, Fontaine B (April 2022). "The Sixth Mass Extinction: fact, fiction or speculation?". Biological Reviews of the Cambridge Philosophical Society. 97 (2): 640–663. doi:10.1111/brv.12816. PMC 9786292. PMID 35014169. S2CID 245889833.
  4. ^ a b Cite error: The named reference CBD-2010 was invoked but never defined (see the help page).
  5. ^ Kehoe L, Romero-Muñoz A, Polaina E, Estes L, Kreft H, Kuemmerle T (August 2017). "Biodiversity at risk under future cropland expansion and intensification". Nature Ecology & Evolution. 1 (8): 1129–1135. Bibcode:2017NatEE...1.1129K. doi:10.1038/s41559-017-0234-3. ISSN 2397-334X. PMID 29046577. S2CID 3642597. Archived from the original on April 23, 2022. Retrieved March 28, 2022.
  6. ^ Cite error: The named reference Allan-2015 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Walsh-2016 was invoked but never defined (see the help page).
  8. ^ Stokstad E (May 6, 2019). "Landmark analysis documents the alarming global decline of nature". Science. doi:10.1126/science.aax9287. For the first time at a global scale, the report has ranked the causes of damage. Topping the list, changes in land use—principally agriculture—that have destroyed habitat. Second, hunting and other kinds of exploitation. These are followed by climate change, pollution, and invasive species, which are being spread by trade and other activities. Climate change will likely overtake the other threats in the next decades, the authors note. Driving these threats are the growing human population, which has doubled since 1970 to 7.6 billion, and consumption. (Per capita of use of materials is up 15% over the past 5 decades.)
  9. ^ Pimm SL, Jenkins CN, Abell R, Brooks TM, Gittleman JL, Joppa LN, et al. (May 2014). "The biodiversity of species and their rates of extinction, distribution, and protection". Science. 344 (6187): 1246752. doi:10.1126/science.1246752. PMID 24876501. S2CID 206552746. The overarching driver of species extinction is human population growth and increasing per capita consumption.
  10. ^ Cafaro P, Hansson P, Götmark F (August 2022). "Overpopulation is a major cause of biodiversity loss and smaller human populations are necessary to preserve what is left" (PDF). Biological Conservation. 272. 109646. Bibcode:2022BCons.27209646C. doi:10.1016/j.biocon.2022.109646. ISSN 0006-3207. S2CID 250185617. Archived (PDF) from the original on December 8, 2023. Retrieved December 25, 2022. Conservation biologists standardly list five main direct drivers of biodiversity loss: habitat loss, overexploitation of species, pollution, invasive species, and climate change. The Global Assessment Report on Biodiversity and Ecosystem Services found that in recent decades habitat loss was the leading cause of terrestrial biodiversity loss, while overexploitation (overfishing) was the most important cause of marine losses (IPBES, 2019). All five direct drivers are important, on land and at sea, and all are made worse by larger and denser human populations.
  11. ^ Crist E, Mora C, Engelman R (April 21, 2017). "The interaction of human population, food production, and biodiversity protection". Science. 356 (6335): 260–264. Bibcode:2017Sci...356..260C. doi:10.1126/science.aal2011. PMID 28428391. S2CID 12770178. Retrieved January 2, 2023. Research suggests that the scale of human population and the current pace of its growth contribute substantially to the loss of biological diversity. Although technological change and unequal consumption inextricably mingle with demographic impacts on the environment, the needs of all human beings—especially for food—imply that projected population growth will undermine protection of the natural world.
  12. ^ Ceballos G, Ehrlich PR (2023). "Mutilation of the tree of life via mass extinction of animal genera". Proceedings of the National Academy of Sciences of the United States of America. 120 (39): e2306987120. Bibcode:2023PNAS..12006987C. doi:10.1073/pnas.2306987120. PMC 10523489. PMID 37722053. Current generic extinction rates will likely greatly accelerate in the next few decades due to drivers accompanying the growth and consumption of the human enterprise such as habitat destruction, illegal trade, and climate disruption.
  13. ^ Hughes AC, Tougeron K, Martin DA, Menga F, Rosado BH, Villasante S, et al. (January 1, 2023). "Smaller human populations are neither a necessary nor sufficient condition for biodiversity conservation". Biological Conservation. 277: 109841. Bibcode:2023BCons.27709841H. doi:10.1016/j.biocon.2022.109841. ISSN 0006-3207. Through examining the drivers of biodiversity loss in highly biodiverse countries, we show that it is not population driving the loss of habitats, but rather the growth of commodities for export, particularly soybean and oil-palm, primarily for livestock feed or biofuel consumption in higher income economies.
  14. ^ "Climate change and biodiversity" (PDF). Intergovernmental Panel on Climate Change. 2005. Archived from the original (PDF) on February 5, 2018. Retrieved June 12, 2012.
  15. ^ Kannan R, James DA (2009). "Effects of climate change on global biodiversity: a review of key literature" (PDF). Tropical Ecology. 50 (1): 31–39. Archived from the original (PDF) on April 15, 2021. Retrieved May 21, 2014.
  16. ^ "Climate change, reefs and the Coral Triangle". wwf.panda.org. Archived from the original on May 2, 2018. Retrieved November 9, 2015.
  17. ^ Aldred J (July 2, 2014). "Caribbean coral reefs 'will be lost within 20 years' without protection". The Guardian. Archived from the original on October 20, 2022. Retrieved November 9, 2015.
  18. ^ Ketcham C (December 3, 2022). "Addressing Climate Change Will Not "Save the Planet"". The Intercept. Archived from the original on February 18, 2024. Retrieved December 8, 2022.
  19. ^ Caro T, Rowe Z (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.
  20. ^ Bank EI (December 8, 2022). Forests at the heart of sustainable development: Investing in forests to meet biodiversity and climate goals. European Investment Bank. ISBN 978-92-861-5403-4. Archived from the original on March 21, 2023. Retrieved March 9, 2023.
  21. ^ Finch DM, Butler JL, Runyon JB, Fettig CJ, Kilkenny FF, Jose S, et al. (2021). "Effects of Climate Change on Invasive Species". In Poland TM, Patel-Weynand T, Finch DM, Miniat CF (eds.). Invasive Species in Forests and Rangelands of the United States: A Comprehensive Science Synthesis for the United States Forest Sector. Cham: Springer International Publishing. pp. 57–83. doi:10.1007/978-3-030-45367-1_4. ISBN 978-3-030-45367-1. S2CID 234260720.
  22. ^ United Nations Environment Programme (2021). Making Peace with Nature: A scientific blueprint to tackle the climate, biodiversity and pollution emergencies. Nairobi: United Nations. Archived from the original on March 23, 2021. Retrieved March 9, 2021.
  23. ^ Cite error: The named reference Cohen-2020 was invoked but never defined (see the help page).
  24. ^ "Global Biodiversity Outlook 5". Convention on Biological Diversity. Archived from the original on October 6, 2021. Retrieved March 23, 2023.