In 2007 Sydney started the first ever Earth Hour event, by persuading as many businesses and individuals as possible to switch off their lights.
This year the city was almost completely engulfed in darkness; over two million individuals and more than two thousand businesses took part.
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Business Secretary Vince Cable says the party plans to double the number of employers offering apprenticeships to young people.
A study suggests people who are obese fall into six types including heavy drinking males, young healthy females and those in poorest health.
Ed Miliband will announce the plan to crack down on exploitation which he says is driving immigration of low skilled workers and poor wages.