Surviving Global Warming by Migrating Mere Meters ... or Even Millimeters
Suggitt, A.J., Gillingham, P.K., Hill, J.K., Huntley, B., Kunin, W.E., Roy D.B. and Thomas, C.D. 2011. Habitat microclimates drive fine-scale variation in extreme temperatures. Oikos 120: 1-8.
In an effort designed to illustrate these facts, Suggitt et al. recorded temperatures in numerous micro-sites at two locations where the vegetation was relatively homogenous (the Lake Vyrnwy Royal Society for the Protection of Birds reserve in Wales, and High Peak in the Peak District National Park in England) in September 2007 and January 2008, as well as in numerous micro-sites within three different habitat types (woodland, heathland and grassland) located within Skipwith Common in North Yorkshire, UK, in September 2008 and January 2009.
The seven scientists report that "thermal differences between habitats, and slope and aspects, were of the same order of magnitude as projected increases in global average surface temperatures," and they indicate that in some cases, microclimate variation exceeded estimates of warming under all of the IPCC's emissions scenarios, "which range from 1.1 to a 6.4°C rise in global mean temperatures (IPCC, 2007)."
Suggitt et al. write that "these large temperature differences provide opportunities for individual organisms that are able to move short distances to escape unfavorable microclimates," and, hence, that "populations may shift microhabitats (slopes, aspects and vegetation density) in response to inter-annual variation in the climate." Thus, they say their results indicate that "the incorporation of habitat and topographical information is essential for species that (a) have some level of flexibility in their habitat associations, and (b) are at least partially limited by temperature extremes," bearing witness to the fact that in the real world of nature, the 'bioclimate approach' or 'climate envelope' modeling are not adequate for describing how different species will respond to future changes in climate, such as the global warming that is predicted by state-of-the-art climate models.
IPCC. 2007. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom.