Overview:Joshua Jackson investigates the one place on Earth where the impacts of climate change are most profound yet practically invisible: the oceans. Josh travels to Australia’s Great Barrier Reef to look at the devastating impacts of ocean warming on the world’s largest reef system, and he explores the predicted impact of ocean acidification. In the Philippines, he looks at the impact of climate change in a place where hundreds of millions of people rely on healthy reefs for food, income and protection from storms.