Get ready for a candlelight hour from 8:30 pm to 9:30 pm tonight.

Spend the hour gazing the moon and the stars or at a torch-lit party, or walk in to one of the many restaurants that offer special candle-lit dinners. Or use the hour to meditate or do a bit of soul-searching.

Just one hour of darkness for us could make a world of difference to the environment.

We have learned to take energy for granted without realizing how it benefits us every minute of the day, and of course night. We sit in well-lit air-conditioned homes and offices, using computers and countless labor-saving appliances. We enjoy the comforts of modern society without thinking about the consequences of our actions on the environment.

The Earth Hour, initiated by World Wide Fund for Nature (WWF) in 2007, unites the whole world on the last Saturday of March to save energy and reduce carbon emission. People across the world volunteer to turn off non-essential lights - unnecessary neon signs and decorative lights, TV sets and other electronic devices - for one hour.

WWF's goal is to help shift the world to a low-carbon economy to reduce global warming. As WWF says, Earth Hour is a reminder to us that planet Earth is our home and we should reduce the impact of our energy system on that planet.

Billions of people in more than 130 countries are expected to turn off their lights on Saturday evening to signify their fight against climate change, which is happening faster than predicted.

People in China, too, observe Earth Hour. People in 33 Chinese cities turned off their lights for an hour last year. This year, millions of Chinese are expected to turn off their lights and electronic devices for an hour on Saturday.

China's leadership has joined the fight against climate change in its own way. In 2009, the State Council, China's Cabinet, pledged to reduce carbon emission for every unit of GDP by 40-45 percent by 2020 from the 2005 level. Last year, the National Development and Reform Commission, the country's top planning body, said a pilot program to test the impact of an emission cap on growth would be started in one sector or city before expanding it to other sectors and cities. And addressing the National People's Congress on March 5 this year, Premier Wen Jiabao vowed to improve energy efficiency and curb pollution and carbon emission.

None of these commitments would have been possible without public support, which will be seen during Earth Hour on Saturday. We know that solutions to environmental problems are there. And those solutions will become easier if we work together.

We hope the Earth Hour is not a one-time event but will open the door to sustainable energy programs.

With that hope in mind, let's enjoy 60 minutes in the dark.