Earth Hour won't suffer for a lack of gimmicks. Servers wearing glow-in-the-dark necklaces will sell eco-tinis at bars and restaurants in Phoenix. A local yoga house in Michigan will offer sessions by lamplight, and the Sheraton Hotel in Chicago will have check-in by candlelight. Watching the lights wink off in major metropolitan areas might look impressive, but it's worth asking: What's the point? As Roberts himself notes, the energy saved by turning off your lights for an hour "won't make an enormous difference." So, if it won't cut carbon emissions, why bother then with Earth Hour, or Earth Day or Earth Live, last year's daylong concert for the environment?
Because climate change is essentially a political problem, and the language of politics is symbolism. Just because an act is symbolic doesn't mean it empty.