John Doerr's emotional presentation at the TED conference has put climate change on Silicon Valley's agenda, pushed Silicon Valley giants such as Apple to become green, and given moral force to the opportunistic enthusiasm of investors for clean tech startup ideas. We could discuss these issues, and show the Kleiner Perkins partner's full 20-minute presentation. But we won't. Instead here's the clip you want to see, the point at the end of his talk when the legendary investor — wondering whether he'll be able to face his daughter with a clean conscience in twenty years — chokes up. The clip, after the jump.