One of the most critical issues todays world needs to address is climate change. Whilst revising for my AS geography exams, I took the time to purchase and watch Al Gores: An Inconvenient Truth.
If you have yet to see this, then I would advise watching it. It completely changed my perspective of climate change - I wasn't a skeptic beforehand, but now I know i'll never be one. Hard, solid evidence is provided which really emphasises the destruction we are causing to our planet.