Carbon dioxide is often thought of as one of the main causes of global warming. But scientists are finding new ways to turn CO2 into a useful resource. We see how fast-growing seaweed can be used to absorb vast amounts of carbon dioxide through photosynthesis, and how the CO2 is then used to make plastics and methane gas. What's the secret behind this miraculous new technique? Here's a clue: microorganisms. Tune in and see the latest scientific attempts to turn "trash into treasure."