A combination picture shows the imperial Schoenbrunn Palace before Earth Hour and during Earth Hour in Vienna

A combination picture shows the imperial Schoenbrunn Palace before Earth Hour (top) and during Earth Hour in Vienna March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Leonhard Foeger (AUSTRIA – Tags: SOCIETY ENVIRONMENT)