IMAGE DISTRIBUTED FOR WWF/EARTH HOUR GLOBAL - Combination photos. The Macau skyline can be seen before (top) and after (below) the population of the city observed Earth Hour on Saturday, March 23, 2013. Earth Hour Global is a worldwide event organized by the World Wide Fund for Nature (WWF) encouraging households and businesses to turn off their non-essential lights for one hour to raise awareness about the need to take action on climate change. The event is designed to highlight the impact climate change is having on people and nature. Millions of people in more than 150 countries are expected to take part. Earth Hour 2013 is being held on March 23, 2013 from 8:30 p.m. to 9:30 p.m. during participants' local time. (AP Images for WWF/Earth Hour Global)

Associated Press
IMAGE DISTRIBUTED FOR WWF/EARTH HOUR GLOBAL - Combination photos. The Macau skyline can be seen before (top) and after (below) the population of the city observed Earth Hour on Saturday, March 23, 2013. Earth Hour Global is a worldwide event organized by the World Wide Fund for Nature (WWF) encouraging households and businesses to turn off their non-essential lights for one hour to raise awareness about the need to take action on climate change. The event is designed to highlight the impact climate change is having on people and nature. Millions of people in more than 150 countries are expected to take part. Earth Hour 2013 is being held on March 23, 2013 from 8:30 p.m. to 9:30 p.m. during participants' local time. (AP Images for WWF/Earth Hour Global)
IMAGE DISTRIBUTED FOR WWF/EARTH HOUR GLOBAL - Combination photos. The Macau skyline can be seen before (top) and after (below) the population of the city observed Earth Hour on Saturday, March 23, 2013. Earth Hour Global is a worldwide event organized by the World Wide Fund for Nature (WWF) encouraging households and businesses to turn off their non-essential lights for one hour to raise awareness about the need to take action on climate change. The event is designed to highlight the impact climate change is having on people and nature. Millions of people in more than 150 countries are expected to take part. Earth Hour 2013 is being held on March 23, 2013 from 8:30 p.m. to 9:30 p.m. during participants' local time. (AP Images for WWF/Earth Hour Global)