The recent Earth Hour initiative on Saturday 28 March, aimed at raising awareness about climate change, say 4.7 million light bulbs were switched off in South Africa, according to the Earth Hour website.

This is equivalent to a 15% drop in power usage for lighting – the 400 megawatts are equivalent to half the energy output of one of the Koeberg Power Stations reactors, according to a IOL.com article.

Around 100,000 South Africans signed the petition and committed to switching off their lights between 8.30 and 9.30 pm on Saturday. Around the world, about 150 million participated. This is up from 2 million who participated in the first event in 2007.

Although critics have raised skeptical eye brows at the effectiveness of the initiative, saying that the reduction in carbon emissions was merely a drop in the ocean, and that burning candles might even have increased overall emissions.

“Even if a billion people turn off their lights this Saturday the entire event will be equivalent to switching off China’s emissions for six short seconds,” said Bjorn Lomborg, director of the Copenhagen Consensus Centre think-tank, quoted in the IOL article.

Earth Hour director, Andy Ridley, acknowledged that the amount of power saved from the hour would be negligible, but that the symbolic gesture, and the culmination of the efforts at the Copenhagen conference on climate change at the end of year. He said it was significant that countries like China, Brazil and India participated in the event.

Below is an image from Vr-Zone, showing the city lights in Canberra before and during Earth Hour last Saturday: