The World Wildlife Fund (WWF) is urging people to vote against global warming tomorrow during its annual Earth Hour campaign. Participants are encouraged to show their support by turning off all non-essential electronics (lights in particular) in their homes and businesses for an hour between 8:30 and 9:30 p.m. local time (in each community).

The WWF hopes that one billion people (roughly 17 percent of the world’s population) in 82 countries and more than 2,100 cities will cut their energy usage during the hour; last year, some 36 million people in 35 countries and more than 370 cities lightened their electrical loads in solidarity, according to the organization. WWF Australia organized the first Earth Hour in 2007, at which time 2.2 million households and businesses participated. EnergyAustralia, a Sidney utility, estimates that initial event saved 48,760 kilowatt hours (the same amount of electricity needed to run more than 400,000 televisions for one hour) in its coverage areas.

The results of this year's Earth Hour will be presented to world leaders when they gather later this year in Copenhagen for the Global Climate Change Conference to negotiate a successor to the Kyoto Protocol, an international environmental treaty reached in 1992 to reduce greenhouse gas emissions through 2012.

United Nations Secretary-General Ban Ki-moon said in a statement that lights will be switched off at the UN's New York headquarters as well as at other U.N. facilities around the globe. The U.N. is participating in Earth Hour as part of an effort to mobilize support for December's Copenhagen conference.

Others, however, are skeptical Earth Hour will be little more than a symbolic gesture. Among them: David Solomon, a University of Chicago doctoral candidate in the graduate school of business who in 2007 wrote a research paper examining the effects of Earth Hour on New South Wales, Australia, electricity consumption. He concluded that, while polls reported 57 percent of Sydney participated, statewide electricity use declined by about two percent, "statistically indistinguishable from zero." Further, Solomon claims that event participants, when asked by pollsters how much energy they cut during the hour, "overstated their involvement by around 36 [percent]," meaning they didn't switch off nearly as many lights as they claimed to.

With reporting by Rachel Olfson

Image of Sydney before and during Earth Hour 2007 © hangingpixels