As part of an annual tradition to raise awareness of climate change, millions of people in more than 190 countries will turn off their lights for one hour on Saturday.

The annual celebration known as Earth Hour was launched in Sydney, Australia in 2007 by the World Wildlife Fund and its partners.CNNAmerican.

The nonprofit organization calls Earth Hour “the world’s largest grassroots movement for the environment.”

According to the Global Fund for Nature, the goal of Earth Hour is to raise awareness about protecting nature and solving the climate crisis.

Since its launch in 2007, the initiative has helped drive action on the ground. WWF Uganda created its first “Earth Hour forests” in 2013, and Argentina used the campaign to pass a bill in the Senate to protect 8.4 million acres of marine areas.

In order to participate in the campaign, the lights must be switched off between 8.30pm and 9.30pm on Saturday in each participant’s time zone.

Famous landmarks such as the Empire State Building in New York and the Willis Tower in Chicago have their lights turned off.

According to the WWF, turning off the lights is a “symbolic” way to raise awareness about climate change.

In a statement, the organization said that in the face of biodiversity loss and accelerating climate change, an hour without lights “takes us out of our daily routines and allows us to reflect on the one home we all share.”

The organization encourages participants to use the lights-out time to “do something positive for our planet,” such as reading an article or listening to a podcast about biodiversity or climate change, spending time outdoors reconnecting with nature, or sharing information about climate change. Local with friends, family or politicians.