This is the VOA Special English Development Report, from http://voaspecialenglish.com

On March twenty-seventh at eight thirty at night, all the lights were shut off at the Tokyo Tower in Japan. The Brandenburg Gate in Berlin, Germany went dark. So did the Eiffel Tower in Paris, France. The Empire State Building in New York City shut off all its lights. So did buildings in other cities around the world. The lights stayed off for one hour for an event called Earth Hour. The observance was organized by a conservation group, the World Wide Fund for Nature, also known as the World Wildlife Fund.

For the fourth year, people were urged to turn off their lights for one hour to call attention to the issue of climate change. The group says climate change is one of the greatest threats facing wildlife and nature. The first Earth Hour was held in two thousand seven in Sydney, Australia. Organizers said more than two thousand businesses and two million people took part.

Since then, Earth Hour has grown into an international event.

People in more than four thousand cities in eighty-eight countries took part last year. Organizers said more than one hundred countries and territories promised their official support this year. This was the first Earth Hour for countries including Kuwait, Qatar, Kosovo, Madagascar, Nepal, Cambodia and Panama. At least nineteen of the fifty American states took part in the two thousand ten Earth Hour observance. The event organizers said that one of the last states to join was Missouri.

Governor Jay Nixon shut off the lights in the dome of the state capitol building. He said when it comes to saving energy and money, big changes start with small steps like turning out the lights.

Did you turn off your lights to observe Earth Hour? Do you think about what the organizers call your "environmental footprint," and try to reduce harmful effects?

Is climate change a concern for you?

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