Effects of Global Warming We're already experiencing some changes: ice has melted, animal populations have shifted, precipitation has increased. What else may be in store if trends continue? Find Out More The Global Fish Crisis: Still Waters After thousands of years of living in balance as a wild food source for humans, so many giant bluefin tuna now have been hauled out of the Mediterranean that the population is in danger of collapse. Can the Bluefin Be Saved? Photo Gallery: Polluted Oceans Learn how we are hurting the largest habitat on Earth with these photos of ocean pollution, from the devastating effects of oil spills to the dangers of dumping. View Photos of Polluted Oceans