6 segments
President Obama is in Copenhagen, and the climate change negotiations may hinge on how much emissions oversight China will agree to. Washington Post environmental reporter David Fahrenthold has the latest; and Lucia Green-Weiskel, at the summit, works in Beijing on emissions verification issues. Also: rewriting the diagnostic manual for mental illness; math at local community colleges; and your reasons to love NYC.

Check out a map of the holiday markets happening this weekend!