From an Antarctic research base and the Great Pyramids of Egypt to the Empire State Building in New York and the Sears Tower in Chicago, illuminated patches of the globe went dark today for Earth Hour, a campaign to highlight the threat of climate change.

Time zone by time zone, nearly 4,000 cities and towns in 88 countries joined the event sponsored by the World Wildlife Fund to dim nonessential lights from 8:30 p.m. to 9:30 p.m. The campaign began in Australia in 2007 and last year grew to 400 cities worldwide.

Honolulu was among the cities participating, and did so for the second consecutive year.

In announcing Honolulu's participation earlier this week, Mayor Mufi Hannemann asked residents to turn off lights and other unnecesssary electrical devices for one hour at 8:30 p.m. today.

Honolulu Hale and the Municipal Building were among city facilities with lights minimized or entirely dark tonight.