Global landmarks go dark for Earth Hour campaign

NEW YORK - New York's Empire State Building, Egypt's pyramids, London's Big Ben and Rio's Christ the Redeemer statue were among the world's most renowned monuments plunged into darkness for an hour on Saturday as part of a global campaign to raise awareness about climate change and its impact on the planet's vanishing plant and animal life.

The 13th edition of Earth Hour, organized by green group World Wide Fund for Nature, or WWF, saw millions of people across 180 countries turn off their lights at 8:30 pm to highlight energy use and the need for conservation.

The event comes after some of the most dire warnings yet on the state of Earth's natural habitat and species.