Guarda su Altadefinizione. Could the bluish-green liquid sloshing around in a laboratory beaker save the world from climate change? The liquid is an algae-based bio-fuel, and scientist Steve Mayfield believes it is a sign that a post-carbon future is drawing closer. If we're going to avoid catastrophic climate change, we will need to move away from fossil fuels as quickly as possible. But which alternatives are the most promising?