LONDON (AP) — In Paris, the Eiffel Tower went dark. In London, a kaleidoscope of famous sites switched off their lights — Tower Bridge, Big Ben, Piccadilly Circus, the London Eye.~~SNIP~~It lasted for just an hour and its power is purely symbolic. But in countries around the world, at 8:30 p.m., people were switching off their lights for Earth Hour, a global call for international unity on the importance of addressing climate change.