Impacts of climate change on the world's most exceptional ecoregions.
The current rate of warming due to increases in greenhouse gas (GHG) emissions is very likely unprecedented over the last 10,000 y. Although the majority of countries have adopted the view that global warming must be limited to <2 °C, current GHG emission rates and nonagreement at Copenhagen in December 2009 increase the likelihood of this limit being exceeded by 2100. Extensive evidence has linked major changes in biological systems to 20th century warming. The "Global 200" comprises 238 ecoregions of exceptional biodiversity [Olson DM, Dinerstein E (2002) Ann Mo Bot Gard 89:199-224]. We assess the likelihood that, by 2070, these iconic ecoregions will regularly experience monthly climatic conditions that were extreme in 1961-1990. Using >600 realizations from climate model ensembles, we show that up to 86% of terrestrial and 83% of freshwater ecoregions will be exposed to average monthly temperature patterns >2 SDs (2σ) of the 1961-1990 baseline, including 82% of critically endangered ecoregions. The entire range of 89 ecoregions will experience extreme monthly temperatures with a local warming of <2 °C. Tropical and subtropical ecoregions, and mangroves, face extreme conditions earliest, some with <1 °C warming. In contrast, few ecoregions within Boreal Forests and Tundra biomes will experience such extremes this century. On average, precipitation regimes do not exceed 2σ of the baseline period, although considerable variability exists across the climate realizations. Further, the strength of the correlation between seasonal temperature and precipitation changes over numerous ecoregions. These results suggest many Global 200 ecoregions may be under substantial climatic stress by 2100.
Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia. lbeaumon@rna.bio.mq.edu.au.
Linda J
LJ
Beaumont
Andrew
A
Pitman
Sarah
S
Perkins
Niklaus E
NE
Zimmermann
Nigel G
NG
Yoccoz
Wilfried
W
Thuiller
D017753:Ecosystem; D017752:Greenhouse Effect; D006801:Humans; D008954:Models, Biological
Nature. 2002 Jan 31;415(6871):512-4
11823856
Proc Natl Acad Sci U S A. 2005 Aug 2;102(31):10823-7
16043702
Science. 2010 Aug 20;329(5994):940-3
20724633
Trends Ecol Evol. 2008 Aug;23(8):453-60
18582986
Proc Natl Acad Sci U S A. 2007 Apr 3;104(14):5738-42
17389402
Trends Ecol Evol. 2008 Feb;23(2):79-86
18191281
Proc Natl Acad Sci U S A. 2009 Nov 17;106 Suppl 2:19723-8
19897732
Ecology. 2009 Oct;90(10):2657-63
19886474
Trends Ecol Evol. 2007 Jul;22(7):357-65
17478009
Trends Ecol Evol. 2009 Dec;24(12):686-93
19712994
Nature. 2009 Dec 24;462(7276):1052-5
20033047
Science. 2003 Jun 6;300(5625):1560-3
12791990
Nature. 2007 Aug 2;448(7153):550-2
17671497
Science. 2010 Sep 10;329(5997):1298-303
20829476
Science. 2007 Jul 6;317(5834):41-2
17615322
Nature. 2004 Jan 22;427(6972):332-6
14716318
Science. 2004 Mar 5;303(5663):1499-503
15001774
Proc Natl Acad Sci U S A. 2005 May 24;102(21):7465-9
15899975
Nature. 2003 Jan 2;421(6918):57-60
12511952
Science. 2010 Dec 10;330(6010):1496-501
20978282
Nature. 2004 Jan 8;427(6970):145-8
14712274