Extinction risk from climate change

The extinction risk of climate change is the risk species have of becoming extinct due to the effects of global warming.

The scientific consensus in the IPCC Fourth Assessment Report is that "Anthropogenic warming could lead to some impacts that are abrupt or irreversible, depending upon the rate and magnitude of the climate change.""There is medium confidence that approximately 20-30% of species assessed so far are likely to be at increased risk of extinction if increases in global average warming exceed 1.5-2.5°C (relative to 1980-1999). As global average temperature increase exceeds about 3.5°C, model projections suggest significant extinctions (40-70% of species assessed) around the globe."

In one study published in "Nature" in 2004, between 15 and 37% of known plant and animal species will be extinct or heading for eventual extinction by 2050.cite journal | author = Thomas, C.D. | coauthors = Cameron, A.; Green, R.E.; Bakkenes, M.; Beaumont, L.J.; Collingham, Y.C.; Erasmus, B.F.N.; Siqueira, M.F.D.; Grainger, A.; Hannah, L. | year = 2004 | title = Extinction risk from climate change | journal = Nature | volume = 427 | issue = 6970 | pages = 145–148 | doi= 10.1038/nature02121 | url = http://www.mnp.nl/bibliotheek/digitaaldepot/20040108nature.pdf |format= PDF | accessdate = 2008-04-15] More properly, changes in habitat by 2050 will put them outside the survival range for the inhabitants, thus committing the species to extinction.

The abstract states:

Climate change over the past 30 years has produced numerous shifts in the distributions and abundances of species and has been implicated in one species-level extinction. Using projections of species' distributions for future climate scenarios, we assess extinction risks for sample regions that cover some 20% of the Earth's terrestrial surface. Exploring three approaches in which the estimated probability of extinction shows a power-law relationship with geographical range size, we predict, on the basis of mid-range climate-warming scenarios for 2050, that 15−37% of species in our sample of regions and taxa will be 'committed to extinction'. When the average of the three methods and two dispersal scenarios is taken, minimal climate-warming scenarios produce lower projections of species committed to extinction (18%) than mid-range (24%) and maximum-change (35%) scenarios. These estimates show the importance of rapid implementation of technologies to decrease greenhouse gas emissions and strategies for carbon sequestration.

Other researchers, such as Thuiller "et al.",cite journal | author = Thuiller, W. | coauthors = Araújo, M.B.; Pearson, R.G.; Whittaker, R.J.; Brotons, L.; Lavorel, S. | year = 2004 | title = Biodiversity conservation: Uncertainty in predictions of extinction risk | journal = Nature | volume = 430 | pages = 1 | doi = 10.1038/nature02716] Araújo "et al."cite journal | author = Araújo, M.B. | coauthors = Miguel B.; Whittaker, Robert J.; Ladle, Richard J.; Erhard, Markus | year = 2005 | title = Reducing uncertainty in projections of extinction risk from climate change | journal = Global Ecology & Biogeography, | volume = 14 | issue = 6 | pages = 529–538(10) |url=http://www.ingentaconnect.com/content/bsc/geb/2005/00000014/00000006/art00004 | doi = 10.1111/j.1466-822X.2005.00182.x] , Person "et al.", [cite journal | last = Pearson | first = Richard G. | coauthors = Richard G. Pearson, Wilfried Thuiller, Miguel B. Araujo, Enrique Martinez-Meyer, Lluıs Brotons, Colin McClean, Lera Miles, Pedro Segurado, Terence P. Dawson and David C. Lees | title = Model-based uncertainty in species range prediction | journal = Journal of Biogeography | volume = 33 | pages = 1704–1711 | date = 2006 | url = http://www.will.chez-alice.fr/pdf/PearsonJBI2006.pdf |format= PDF | accessdate = 2008-04-15 | doi = 10.1111/j.1365-2699.2006.01460.x] Buckley and Roughgarden, [cite journal | author = Buckley, L. B | coauthors = Roughgarden | year = 2004 | title = Biodiversity conservation: Effects of changes in climate and land use | journal = Nature | volume = 430 | url=http://www.nature.com/nature/journal/v430/n6995/abs/nature02717.html | doi =10.1038/nature02717] and Harte "et al." [cite journal | author = John Harte | coauthors = Annette Ostling, Jessica L. Green & Ann Kinzig | year = 2004 | title = Biodiversity conservation: Climate change and extinction risk | journal = Nature | volume = 430 | url=http://www.nature.com/nature/journal/v430/n6995/abs/nature02718.html | doi =10.1038/nature02718] have raised concern regarding uncertainty in Thomas "et al."'s projections; some of these studies believe it is an overestimate, others believe the risk could be greater. Thomas "et al." replied in Nature [cite journal | author = Thomas, C.D | coauthors = Cameron, A.; Green, R.E.; Bakkenes, M.; Beaumont, L.J.; Collingham, Y.C.; Erasmus, B.F.N.; Siqueira, M.F.D.; Grainger, A.; Hannah, L. | year = 2004 | title = Biodiversity conservation: Uncertainty in predictions of extinction risk/Effects of changes in climate and land use/Climate change and extinction risk (reply) | journal = Nature | volume = 430 | url=http://www.nature.com/nature/journal/v430/n6995/full/nature02719.html | doi:10.1038/nature02719] addressing criticisms and concluding "Although further investigation is needed into each of these areas, it is unlikely to result in substantially reduced estimates of extinction. Anthropogenic climate change seems set to generate very large numbers of species-level extinctions." On the other hand, Daniel Botkin "et al." state "... global estimates of extinctions due to climate change (Thomas et al. 2004) may have greatly overestimated the probability of extinction..." [cite journal |last=Botkin |first=Daniel B. |coauthors="et al." |year=2007 |month=March |title=Forecasting the Effects of Global Warming on Biodiversity |journal=BioScience |volume=57 |issue=3 |pages=227–236 |doi=10.1641/B570306 |url=http://www.imv.dk/Admin/Public/DWSDownload.aspx?File=%2FFiles%2FFiler%2FIMV%2FPublikationer%2FFagartikler%2F2007%2F050307_Botkin_et_al.pdf |accessdate= 2007-11-30]

Mechanistic studies have documented extinctions due to recent climate change: McLaughlin "et al." documented two populations of Bay checkerspot butterfly being threatened by precipitation change.cite journal |last= McLaughlin |first= John F. |coauthors= "et al." |date= 2002-04-30 |title= Climate change hastens population extinctions |journal= PNAS |volume= 99 |issue= 9 |pages= 6070–6074 |doi= 10.1073/pnas.052131199 |url= http://www.nd.edu/~hellmann/pnas.pdf |format= PDF |accessdate= 2007-03-29] Parmesan states, "Few studies have been conducted at a scale that encompasses an entire species" [cite journal |last= Permesan |first= Camille |date= 2006-08-24 |title= Ecological and Evolutionary Responses to Recent Climate Change |journal= Annual Review of Ecology, Evolution, and Systematics |volume= 37 |pages= 637–669 |doi= 10.1146/annurev.ecolsys.37.091305.110100 |url= http://cns.utexas.edu/communications/File/AnnRev_CCimpacts2006.pdf |format= PDF |accessdate= 2007-03-30] and McLaughlin "et al." agreed "few mechanistic studies have linked extinctions to recent climate change."

References

External links

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