Authorities have recorded an estimated 3 per cent drop in energy use in Sydney's central business district during Earth Hour.
Hundreds of landmarks from Berlin's Brandenburg Gate to the Great Wall of China went dark on Saturday night as part of a global effort to highlight climate change.
It's back - and bigger than ever. Tim Elliott reports on a global idea that was born in Sydney.
Photos from around the country.
Debra Jopson The lights went out around the globe like a Mexican wave in a football stadium at the weekend, as successive settlements observed Earth Hour.
Peter Hannam The Great Barrier Reef will be irreversibly damaged by climate change in just 16 years, according to leading reef researcher Ove Hoegh-Guldberg.
Peter Hannam The lights go off - but Earth Hour organisers are urging participants to make a bigger switch.
Peter Hannam Convert 60 minutes of near darkness into a permanent shift in household energy use - that's the Australian goal of Earth Hour on Saturday.
The Loaded Dog
Earth Hour proved a truly explosive topic when we asked readers if they would join in the anti-global warming campaign.
Dermot O'Gorman In just over a week, thousands of cities across the globe will dim their lights at 8.30pm for an hour, joining in the world's largest voluntary environmental action: Earth Hour.
Households have helped drive up the share of power production from renewables in Australia, but it still trails far behind the ambitious plans of other developed countries, writes Ben Cubby.
Esther Han Last April, Lily Morrissey crammed a small camera, a camcorder and a laptop into her backpack and embarked on a worldwide adventure to document solutions to environmental problems.
Earth Hour is increasingly making a mark in Asia and in developing countries far beyond its Sydney origins, writes Ben Cubby.
Jonathan Swan IN THE bush behind their Castle Hill home, twins Freya and Imogen Wadlow have been poisoning privet, the weed that strangles their gum and wattle trees.
CAROLINE MARCUS SYDNEY plunged into darkness for a good cause last night, doing its unlit bit for a record Earth Hour effort around the globe.
Peter Fray Climate change is not having an easy 2010.
Nick Galvin ORGANISERS of Earth Hour are claiming that this year's event has been the most successful yet, with 126 countries and more than 4000 cities and towns taking part in the global protest.
Ben Cubby Earth Hour will take place on March 31, with the aim of attracting more than 1.3 billion people and becoming the biggest environmental event ever.
Ben Cubby The national green star rating system for office buildings is having one important side effect - those that are energy efficient are becoming much more valuable than those that are not.
Ben Cubby In a warehouse made from recycled straw, heated by solar panels and cooled by rainwater tanks, Claire Gordon patiently collects second-hand books about saving the world.