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Starving polar bears are eating one another in the Arctic. Flowers are blooming too soon and die. The ice caps are melting so fast that rising water levels will threaten coastal towns along Florida within several decades. These are just a few examples of the serious consequences of climate change supported by a new analysis in Nature.
In the past three decades, average global temperatures have risen about 1 degree Fahrenheit (0.6 degree Celsius) and are projected to jump by about 3 degrees F (1. 7 degrees C) by the end of the century, says study lead author Cynthia Rosenzweig, who heads the Climate Impacts Group at NASA's Goddard Institute for Space Studies at Columbia University in New York City. "We've already seen that a relatively low amount of wanning," she says, "can result in a broad range of changes. " The unnatural warming caused by man-made greenhouse gases, especially carbon dioxide produced by cars and coal-powered plants, brings trouble for entire ecosystems. In North America alone, scientists have identified 89 species of plants, such as the American holly that have flowered earlier in the spring. In Spain, apple trees bloom 35 days ahead of schedule in response to the higher temperatures. Other wildlife, like the insects that use certain plants for food and the birds that feed on the insects, must then...