Students attend the Earth Hour campaign at a primary school in Lin'an, Zhejiang province, on March 28, 2015. Earth Hour, an initiative by the World Wildlife Fund that began in 2007, is a show of support for tougher action to confront climate change. On the last Saturday in March every year, people are asked to turn off lights for an hour from 8:30 pm local time.[Hu Jianhuan / For China Daily]