Posted on January, 03 2003

Two articles published in this week's issue of the scientific journal Nature provide evidence that global warming is forcing plants and animals to shift their ranges and affecting the timing of spring-related events such as egg-laying and migrations. These studies provide strong evidence that climate change is already affecting living systems. They are also consistent with two reports already released by WWF — Global Warming and Terrestrial Biodiversity Decline and Habitats at Risk — that show the effect of global warming on species migration and ecoregions. By looking for a climate "fingerprint" — an overall pattern in studies of a wide range of plants and animals — the two Nature articles show that recent biological trends match climate change predictions. In their article, Camille Parmesan and Gary Yohe, from the University of Texas and Wesleyan University, respectively, present the results of a meta-analysis of studies of more than 1,700 species, including plants, insects, birds, amphibians, and mammals. This analysis revealed significant range shifts averaging 6.1 km per decade towards the poles, as predicted in a warmer world. They also found that spring has advanced by 2.3 days per decade, as evidenced by earlier frog breeding, bird nesting, first flowering, tree-bud burst, and arrival of migrant birds and butterflies. According to the authors, this analysis "generates ‘very high confidence’ (as laid down by the Intergovernmental Panel on Climate Change (IPCC)) that climate change is already affecting living systems". Terry Root from Stanford University, together with co-workers from the American Bird Conservancy, Stanford University, Michigan State University, NASA, and Costa Rica's Monteverde Cloud Forest Preserve and Tropical Science Center, also found a temperature-related "fingerprint" in species from molluscs and mammals to grasses and trees. The changes are most marked at high latitudes and high altitudes, where the largest temperature changes are predicted. The study also found a marked shift towards earlier spring events. According to the authors, the result of their study "strongly suggests that a significant impact of global warming is already discernible in animal and plant populations". They also warn that "the synergism of rapid temperature rise and other stresses, in particular habitat destruction, could easily disrupt the connectedness among species and lead to a reformulation of species communities, reflecting differential changes in species, and to numerous extirpations and possibly extinctions". For further information: Martin Hiller Communications Manager, WWF Climate Change Programme Tel: +41 79 347 2256 (mobile) E-mail: mhiller@wwfint.org