The event was tried in Sydney a year ago and now it goes global. A month ago, a similar event in the U.K. saved statistically insignificant 0.1% of the energy, despite loud and hysterical threats by the London bishop, Richard Anti-Christ Chartres.
Tonight, the officials in many cities, including Atlanta, Phoenix, San Francisco, Montreal, Toronto, Bangkok, Dubai, Tel Aviv, Bogota, Buenos Aires, Caracas, Mexico City, Ottawa, Warsaw, Copenhagen, and Dublin, joined the activists. The Chicago skyline will probably disappear, too. All Czech cities, towns, and villages unanimously rejected the idea. TVs will likely be on, too: Sexy Pistols are on TV NOVA since 8 p.m. ;-) India won't join, either.
Incidentally, the believers who will replace light bulbs by candles should know that a candle produces as much CO2 as a 20W light bulb powered by average energy sources during the same time. Five candles replace the CO2 output of a 100W light bulb.
Last February, Jiří Hájek, the spokesman for the Prague Castle described a similar 5-minute event well:
You talk in categories of holocaust deniers which is clearly absolute nonsense. If you were right, we could return to the trees and deny the whole civilization. The 'five minutes without power' campaign is a ridiculous political event and people who believe these warnings are naive. We can't see obscurantism [in Czech: darkism] in natura frequently but this is an example.