A CLEAR pattern of ecological change triggered by global warming is already emerging, according to a worldwide review. And it can be seen from the polar wastes to the tropical oceans.
Butterflies, birds and other highly mobile species are moving to new habitats to survive. But creatures that can鈥檛 move, such as corals, are suffering. 鈥淭he implications of such large-scale, consistent responses to relatively low average rates of climate change are large,鈥� says Gian-Reto Walther of the Institute of Geobotany at the University of Hanover in Germany, who led the study. 鈥淭he projected warming for the coming decades raises even more concern.鈥�
Butterflies, which can flit cross-country, are proving to be among the most sensitive indicators of global warming. Across North America and Europe they have shifted their range northwards by up to 200 kilometres. Plants lag behind, and larger animals are often hemmed in by cities and highways.
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Another visible consequence of warming is the early arrival of spring. This is an almost universal phenomenon, says Walther. Plants are blossoming, eggs hatching and frogs spawning earlier. In Britain, spring butterflies are appearing an average of six days earlier than they did two decades ago.
In many cases these shifts are causing ecological chaos. Migrating birds are arriving in Europe too late to produce offspring during the height of the caterpillar season, for example.
The disruption has hit wilderness areas everywhere. In places, the planet is blooming. Mosses stretch across previously bare ground in Antarctica. But since 1998 an estimated 16 per cent of the world鈥檚 coral reefs have died from bleaching, triggered by record temperatures.