As a group, architects are without question among the most enthusiastic supporters of sustainable initiatives around. It should therefore be welcome news to many architects that National Geographic has released its latest documentary on climate change, Before the Flood, for free on Youtube, Facebook, Twitter--pretty much everywhere.

Presented by Hollywood superstar and recently-appointed UN Climate Ambassador Leonardo DiCaprio, the documentary is perhaps the most ambitious film about climate change since Al Gore's 2006 An Inconvenient Truth. Throughout the course of the 90-minute film, DiCaprio travels the globe to see the damage wrought by the early signs of irreversible climate change, from melting glaciers, to dying coral reefs, to flooding cities. Speaking to world leaders including Barack Obama and The Pope, as well as a whole host of climate scientists, DiCaprio's aim is not so much to convince viewers of the existence of climate change, as with An Inconvenient Truth, but instead to investigate just how far down the wrong path we've traveled, and whether there is any hope for humanity to save itself.