2011年4月22日是第42个世界地球日，今年的主题是“珍惜地球资源，转变发展方式”。

Students pose for the photo with a globe during a campaign to mark the World Earth Day in a middle school in Dexing, Jiangxi province April 19, 2011.
If the environmental movement has a high holiday, Earth Day is it.

The annual effort to raise public awareness¹ about the environment and inspire actions to clean it up marks its 41st anniversary on Friday, coinciding with（符合，一致） the Christian² Good Friday and Judaism's celebration of Passover.

In an effort dubbed³ "A Billion Acts of Green," organizers are encouraging people to observe Earth Day 2011 by pledging online at http://act.earthday.org/ to do something small but sustainable（持久的） in their own lives to improve the planet's health -- from switching to compact fluorescent⁴（荧光的） light bulbs to reducing the use of pesticides⁵ and other toxic⁶ chemicals.

"Millions of people doing small, individual acts can add up to real change," said Chad Chitwood, a spokesman for the umbrella group coordinating⁷ efforts.

There will be hundreds of rallies, workshops and other events around the United States, where Earth Day was born, and hundreds more overseas, where it is now celebrated⁸ in 192 countries.

In the United States the activities range from the premiere（首映式） of the new film from the director of "Who Killed the Electric Car?" (it's called "Revenge of the Electric Car") at the Tribeca Film Festival in New York to a discussion about creating a green economy in 12 cities along the Gulf⁹ Coast, where this time last year residents were reeling from the effects of the BP oil spill in the Gulf of Mexico.

In the years since the first Earth Day was celebrated in 1970 the environmentalist movement made great strides with passage of the Clean Air Act, Clean Water Act, the Endangered Species Act and other groundbreaking laws.

But the bipartisanship（两党合作） that marked the birth of Earth Day -- it was sponsored in Congress by a Wisconsin Democrat¹⁰ named Gaylord Nelson and a California Republican named Pete McCloskey -- is often missing in discussions about environmental policy today.

Efforts to fight climate change by regulating greenhouse gases, for instance, face fierce resistance from many Republicans and members of the business community, who dispute the science supporting global warming and warn new rules to regulate emissions¹¹ will kill jobs and raise energy costs.