Koalas at risk from climate change

In this June 30, 2006 file photo, an 8-month-old koala joey, left, clings to his mother, Adori, at Sydney's Taronga Zoo, as she perches in her tree while eating fresh eucalyptus leaves. A researcher says koala numbers are under threat from carbon pollution in the atmosphere because the greenhouse gas saps nutrients from eucalypt leaves with are the animals\' only source of food. (AP Photo/Rick Rycroft)