More than 80 Chinese cities plan to take part in "Earth Hour", an international event in which households and businesses are to turn off unessential electrical devices for an hour, starting at 8:30 pm on Saturday.

Volunteers and students of the No 1 Middle School in Hanshan county, East China's Anhui province, display a painting on Friday promoting the Earth Hour movement. [China Daily]

The number is more than twice as large as it was in 2010, according to the China branch of the World Wildlife Fund, an environmental group.

This year, the campaign encourages participants to "go beyond the hour", and to commit themselves to taking steps to protect the environment far into the future, according to Andy Ridley, co-founder and executive director of the Earth Hour movement.?

Using the campaign's official website, netizens can indicate their own locations and make recommendations on ways to protect the environment. By Friday night, more than 113,000 netizens had gone online to show their support.

Earth Hour has also garnered support from popular websites in China, including sohu.com, sina.com.cn, qq.com and 163.com.

A famous Chinese entertainment website, mosh.cn, has arranged for a jazz concert to take place from 8:30 to 9:30 pm on Saturday. And an event called "Take Pictures of Your City for Earth Hour" has been organized by the users of renren.com, a social networking service site in China.

Many renowned stars and celebrities have made video clips in support of the movement. Li Bingbing, an actress who was named Ambassador of Earth Hour last year, has committed to being a vegetarian for 100 days every year.

And the well-known band Yu Quan wrote and recorded an Earth Hour theme song, Turn Off the Light, which calls on the public to "make small changes" to make the world a better place.

Li Yuchun, a well-known singer, said she has promised that disposable food containers will no longer be used either by herself or by those who work in the studio where she records.

The Chinese dairy company Mengniu said it will increase the use of "green" packages, and will double the number of milk cartons it recycles. Baidu, the most popular search engine in China, also pledged to reduce the amount of office waste it throws away by 30 percent. The clothing brand Marcassne plans to replace from 15 percent to 20 percent of its cotton fabric with organic cotton.

Responding to the movement's call, many local governments have shown their commitment to the cause. Hangzhou, Wenzhou and 11 other cities in East China's Zhejiang province will build 30 water-protection sites; 10 billion yuan ($1.5 billion) will be invested in planting 340 million trees in Dalian, in Northeast China's Liaoning province; and more than 50,000 bicycles will be made available to the public for rental in Chengdu, capital of Southwest China's Sichuan province.

"This is an excellent opportunity for us to make a small contribution to the cause of environmental protection and to spend an hour in peace, thinking about how we can make the world a better place for our children," said a netizen who goes by the name woshininanine in a comment posted to sina.com.cn.

This year, 131 countries and regions will take part in Earth Hour.