Neil deGrasse Tyson's Cosmos episode on climate change was really compelling. The planet Venus is a great example of what could happen and the importance of balance.
Brian Cox believes that nuclear fusion research would be the best source of energy right now, whereas Neil believes either artificial photosynthesis or solar farms would be able to power our civilization millions of times over.
Algae is the best producer of oxygen purely because of the surface area - trees only account for 20-30% of all oxygen.
