Human Touch

The primary contributors to the sharp rise in global temperatures are humans in a sea-ice region of the Arctic Ocean, scientists have observed polar bears stalking, killing and eating other polar bears. Many species of plants across the middle and higher latitudes of the northern hemisphere are now flowering earlier than a few years ago. Migratory birds in Europe, Asia and Australia are arriving early. And the population of Emperor Penguins in parts of Antarctica has dropped by half over the past 50 years.