The earth’s climate is changing. The Greenland ice sheet, where the rate of melt is more rapid than expected, is one of the indicators scientists use to find out how quickly global temperatures are rising. Scientists have found human activity significantly contributes to global warming. Unless emissions of greenhouse gases such as carbon dioxide are quickly reduced, scientists predict potential losses of up to 30 percent of plant and animal species and a 1.4-meter rise in sea level by 2100. (© AP Images)