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The Persistence of Species
Volume 13, Number 24: 16 June 2010

In his 26 April 2007 testimony before the Select Committee of Energy Independence and Global Warming of the U.S. House of Representatives entitled "Dangerous Human-Made Interference with Climate," NASA's James Hansen stated that life in alpine regions is "in danger of being pushed off the planet" in response to continued greenhouse-gas-induced global warming. Why? Because that's what all the species distribution models of the day predicted at that time. Now, however, a set of new-and-improved models is raising some serious questions about Hansen's overly zealous contention, as described in a "perspective" published in Science by Willis and Bhagwat (2009).

The two researchers - Kathy Willis from the UK's Long-Term Ecology Laboratory of Oxford University's Centre for the Environment, and Shonil Bhagwat from Norway's University of Bergen - raise a warning flag about the older models, stating "their coarse spatial scales fail to capture topography or 'microclimatic buffering' and they often do not consider the full acclimation capacity of plants and animals," citing the analysis of Botkin et al. (2007) in this regard.

As an example of the first of these older-model deficiencies, Willis and Bhagwat report that for alpine plant species growing in the Swiss Alps, "a coarse European-scale model (with 16 km by 16 km grid cells) predicted a loss of all suitable habitats during the 21st century, whereas a model run using local-scale data (25 m by 25 m grid cells) predicted persistence of suitable habitats for up to 100% of plant species [our italics]," as was shown to be the case by Randin et al. (2009), and as we describe in a bit more detail in our Editorial of 23 Sep 2009. In addition, the two Europeans note that Luoto and Heikkinen (2008) "reached a similar conclusion in their study of the predictive accuracy of bioclimatic envelope models on the future distribution of 100 European butterfly species," finding that "a model that included climate and topographical heterogeneity (such as elevational range) predicted only half of the species losses in mountainous areas for the period from 2051 to 2080 in comparison to a climate-only model."

In the case of the older models' failure to consider the capacity of plants and animals to acclimate to warmer temperatures, Willis and Bhagwat note that "many studies have indicated that increased atmospheric CO2 affects photosynthesis rates and enhances net primary productivity - more so in tropical than in temperate regions - yet previous climate-vegetation simulations did not take this into account." As an example of the significance of this neglected phenomenon, they cite the study of Lapola et al. (2009), who developed a new vegetation model for tropical South America, the results of which indicate that "when the CO2 fertilization effects are considered, they overwhelm the impacts arising from temperature," so that "rather than the large-scale die-back predicted previously, tropical rainforest biomes remain the same or [are] substituted by wetter and more productive biomes." This phenomenon is described in considerably more detail in our recent book (Idso and Idso, 2009), where we additionally review the findings of many studies that demonstrate the tremendous capacity for both plants and animals to actually evolve on a timescale commensurate with predicted climate change in such a way as to successfully adjust to projected warmer conditions.

"Another complexity," however, as Willis and Bhagwat describe it, is the fact that "over 75% of the earth's terrestrial biomes now show evidence of alteration as a result of human residence and land use," which has resulted in "a highly fragmented landscape" that has been hypothesized to make it especially difficult for the preservation of species. Nevertheless, they report that Prugh et al. (2008) have "compiled and analyzed raw data from previous research on the occurrence of 785 animal species in >12,000 discrete habitat fragments on six continents," and that "in many cases, fragment size and isolation were poor predictors of occupancy." And they add that "this ability of species to persist in what would appear to be a highly undesirable and fragmented landscape has also been recently demonstrated in West Africa," where "in a census on the presence of 972 forest butterflies over the past 16 years, Larsen [2008] found that despite an 87% reduction in forest cover, 97% of all species ever recorded in the area are still present."

Clearly, the panic-evoking extinction-predicting paradigms of the past are rapidly giving way to the realization they bear little resemblance to reality. Earth's plant and animal species are not slip-sliding away - even slowly - into the netherworld of extinction that is preached from the pulpit of climate alarmism as being caused by CO2-induced global warming.

Sherwood, Keith and Craig Idso

Botkin, D.B., Saxe, H., Araujo, M.B., Betts, R., Bradshaw, R.H.W., Cedhagen, T., Chesson, P., Dawson, T.P., Etterson, J.R., Faith, D.P., Ferrier, S., Guisan, A., Hansen, A.S., Hilbert, D.W., Loehle, C., Margules, C., New, M., Sobel, M.J. and Stockwell, D.R.B. 2007. Forecasting the effects of global warming on biodiversity. BioScience 57: 227-236.

Idso, C.D. and Idso, S.B. 2009. CO2, Global Warming and Species Extinctions: Prospects for the Future. Science and Public Policy Institute, Vales Lake Publishing, LLC, Pueblo West, Colorado, USA.

Lapola, D.M, Oyama, M.D. and Nobre, C.A. 2009. Exploring the range of climate biome projections for tropical South America: The role of CO2 fertilization and seasonality. Global Biogeochemical Cycles 23: 10.1029/2008GB003357.

Larsen, T.B. 2008. Forest butterflies in West Africa have resisted extinction ... so far (Lepidoptera: Papilionoidea and Hesperioidea). Biodiversity and Conservation 17: 2833-2847.

Luoto, M. and Heikkinen, R.K. 2008. Disregarding topographical heterogeneity biases species turnover assessments based on bioclimatic models. Global Change Biology 14: 483-494.

Prugh, L.R., Hodges, K.E., Sinclair, R.E. and Brashares, J.S. 2008. Effect of habitat area and isolation on fragmented animal populations. Proceedings of the National Academy of Sciences USA 105: 20,770-20,775.

Randin, C.F., Engler, R., Normand, S., Zappa, M., Zimmermann, N.E., Pearman, P.B., Vittoz, P., Thuiller, W. and Guisan, A. 2009. Climate change and plant distribution: local models predict high-elevation persistence. Global Change Biology 15: 1557-1569.

Willis, K.J. and Bhagwat, S.A. 2009. Biodiversity and climate change. Science 326: 806-807.