Started in 2007 by WWF and partners as a symbolic lights-out event in Sydney to raise awareness of climate change, Earth Hour is now one of the world's largest grassroots movements for the environment. Held every year on the last Saturday of March, Earth Hour engages supporters in more than 190 countries and territories, all taking action to ensure a brighter future for people and the planet.
Earth Hour has also gone far beyond the symbolic action of switching off - it has become a catalyst for positive environmental impact, driving major legislative changes by harnessing the power of the people and collective action.
Earth Hour is open-source and we welcome everyone, anyone, to take part and help amplify our mission and impact.
In 2007, we encouraged people around the world to switch off their lights to call attention to climate change. More than a decade later, the climate crisis remains, made worse by another urgent threat: the rapid loss of biodiversity and nature.
Natural systems are vital for all our futures – and yet, the rate of global loss of nature during the past 50 years is unprecedented in human history. Nature not only provides us food, water, clean air, and other services worth over US$125 trillion a year – it is also one of our strongest allies against the climate crisis.
Today, Earth Hour aims to increase awareness and spark global conversations on protecting nature, tackling the climate crisis, and working together to shape a brighter future for us all.
Every year, we countdown together across the globe to celebrate Earth Hour and take one iconic action: switch off the lights.
But it is so much more than that. It is a symbol of unity. It is a symbol of hope. It is a demonstration of the power of collective action for our future and the planet's.