If you were caught off guard by the sudden darkness in your city, you're probably wondering what Earth Hour means and what it has to do with you.
"There's never been a more critical moment in the fight", said Terry Macko, senior vice president of marketing and communications at World Wildlife Fund.
It is an environmental movement organized by the "World Wide Fund for Nature" was inaugurated in Sydney, Australia in 2007 as a light-off event.
That is the goal of Earth Hour, to show that if every single person turns off a light, then we can see buildings, towns, cities, countries and the entire world united by the same cause.
Skylines around the world fell dark on Saturday night to mark the tenth Earth Hour.
Despite the terror attack in Westminster on Wednesday, the Houses of Parliament and Big Ben are joining more than 270 landmarks across the United Kingdom in switching off the lights for conservation charity WWF's Earth Hour.
This year it turns a decade old and monuments like Big Ben, The Gherkins, The Eiffel Tower, Sidney Opera House and Bangkok Grand Palace will be on a total black-out for an hour! "Earth Hour is a way for people around the globe to commit to reducing their impact on climate and show support for climate efforts", said Jonathan Koehn, regional sustainability coordinator for the City of Boulder.
Spikes in food prices and extinctions (one-in-six species on the planet are already threatened, though climate change is only one factor driving this mass die off) are likely in the near future. "We hope our Travel with Purpose Contest will inspire others to learn more about climate change and energy conservation".
Earth Hour is described as "60 minutes to protect the planet", a show of solidarity with Earth by choosing to unplug.
Mr Seruiratu also called on Fijians to join the rest of the global community to take action and start small in the battle against climate change.
David Zucchino, a Durham resident and contract writer for the New York Times, said he believes that this event is important because it gets people to pay attention to just the environment for an hour.