Global Warming and Nature

Anyone who doubts global warming's potential to wreak havoc should check in with Mother Nature.

• Laura Tangley
• Aug 01, 2002

Anyone who doubts global warming's potential to wreak havoc should check in with Mother Nature. A recent study by an international team of scientists, which was published in Nature, found that the past three decades of warming have already spawned major changes in Earth's species and ecosystems, everywhere from polar land masses to tropical oceans.

One of the most obvious signs has been the earlier arrival of spring. Throughout North America and the United Kingdom, birds have been migrating an average of nine days earlier and plants have been flowering and unfurling their leaves five days sooner than they did in the 1960s. Other animals' distributions are changing. In Europe and North America, the ranges of 39 butterfly species have shifted up to 125 miles north over the past 27 years. In Canada, red foxes are moving northward, edging out native arctic foxes.

Worst off are species that cannot migrate. Throughout the tropics, warming-induced coral bleaching has intensified. The sheer number of such ecosystem changes "is alarming when you consider that even conservative estimates predict that climate will heat up at least two or three degrees more," says team member Eric Post, a biologist at Pennsylvania State University.