This weekend, cities, businesses, and individuals around the world switched off or dimmed their lights for an hour to raise awareness about climate change. The event, called “Earth Hour,” started in Sydney, Australia, last year; organizers say that this year it spread to about 380 cities and towns in 35 countries, temporarily extinguishing non-essential lights and darkening landmarks around the world, including the Sydney Opera House and the Golden Gate Bridge. Internet search engine Google even switched its homepage background from white to black to mark the event. Aside from awareness-raising, the event did save a modest amount of energy in some areas. But that wasn’t necessarily the point. “The main point is not to make a significant dent in climate change, but to demonstrate the need for people to take leadership on their own to address this problem,” said Richard Moss of the World Wildlife Fund.