Imagine a giant asteroid on a direct collision course with Earth. That is the equivalent of what we face now [with climate change], yet we dither.

Source: "Why I Must Speak Out About Climate Change." TED2012. Feb. 2012. Conference Presentation. Additional Information: This quote by top climate scientist James Hansen means that climate change, a.k.a. global warming, poses a dire and urgent threat to the planet and to humanity, but we are wasting the time we have left by not doing anything to stop it. The quote is from Hansen's 2012 TED Talk in which he shares sobering data and insightful insights on the subject of climate change. Watch the full TED Talk here: James Hansen - Why I Must Speak Out About Climate Change