Over the past 200 years human beings have poured more than two trillion metric tons of carbon dioxide into the atmosphere. As ‘The Changing Sea’ illustrates, carbon dioxide isn’t just changing the climate on land, it’s transforming the ocean in ways that haven’t been seen for millions of years. Is mass extinction the inevitable fate of the future sea? Are we willing to form a new partnership with the ocean and its creatures? If not, then our future and the future of thousands of species may hang in the balance. Narrated by David Suzuki. Co-produced by Merit Motion Pictures and CBC’s ‘The Nature of Things’, in association with National Geographic’s International and Science Channel (USA).