The Week: Advertising news - Ad blackout for Earth Hour

The famous Coca-Cola sign at London's Piccadilly Circus will be switched off for only the third time since the Second World War as part of a global campaign supporting action against climate change.

The sign will go dark from 8.30pm to 9.30pm on Saturday 28 March to support WWF's Earth Hour. The charity is calling on a billion people across the world to do likewise and turn off their lights to reinforce the importance of reducing carbon emissions.