Earth Hour Tonight: What Time? What's the Point?
Millions will turn off the lights for Earth Hour. Is it a bright idea?
(See before-and-after Earth Hour pictures from past years.)
The organizers behind the fifth annual Earth Hour urge people to turn off lights and other nonessential appliances in a symbolic show of support for action against climate change and for energy conservation in general.
In 2010, 128 countries and territories took part in Earth Hour. Eighty-nine national capitals participated, as did nine of the world's ten biggest cities, thousands of other communities, countless businesses, and hundreds of millions of individuals, according to WWF, the international conservation nonprofit, which organizes Earth Hour.
Earth Hour 2011 may be even larger, thanks in part to promotion by world leaders such as United Nations Secretary-General Ban Ki-moon.
"Let us join
