The koala and its marsupial cousins are in serious danger of extinction because greenhouse gases are rendering the eucalyptus leaves they rely on nutritionally worthless, reports the Australian. "What we're seeing is that the staple diet of these animals is being turned to leather," a professor said. "Life is set to become extremely difficult for these animals."
Studies have found that increased carbon dioxide levels lowered the nutrients in eucalyptus leaves. The leaves are already so poor nutritionally that koalas need to spend most of their waking hours eating. The koala—whose numbers have already plummeted 99% over the last century—completely depends on eucalyptus to stay alive. Wallabies, possums, and gliders are also heavily reliant on the leaves.