If you didn’t turn the lights off on March 28th, please be aware that you had missed the ninth Earth Hour, an annual energy-saving, sustainability-driven initiative held by WWF globally. On this day all the households, communities, businesses and nonprofits are encouraged to switch the lights off to save the planet’s energy resources. 

Over 170 countries, more than 1,200 landmarks and nearly 40 UNESCO world heritage sites participated in the initiative, according to the chair, board of directors, Earth Hour Global, Sudhanshu Sarronwala. Iconic Empire State Building in New York city, the Eifel Tower in Paris, Sydney Harbour Bridge, Hong Kong’s skyline along Victoria Harbour, Taiwan Taipei 101 tower, Dubai’s Burj Khalifa, as well as Kuala Lumpur’s Petronas Twin Towers went dark on Saturday for an hour to support the cause.

Nearly 100 businesses in the U.S. only participated in the event and encouraged their customers to join in too. Among them were Timex, Verizon, IKEA,ING, Fairmont Hotels, Hilton Hotels, HSBC, Philips, The Body Shop, Volvo Construction, H&M and Sony Mobile, as Sustainable Life Media reports.

Additionally to the climate change awareness campaign in the international press and social media, WWF also launched a direct fundraising effort on Twitter. In collaboration with Havas Media’s mobile marketing agency Mobext, WWF developed a dedicated donating platform. Activist can still connect their Twitter account to the #TweetMyPower app, sync their credit cards, and «tweet» their donations to the environmental organization Change Climate Change.

Sudhanshu Sarronwala, head of Earth Hour Global, admits a clear evolutional makeover of the initiative from an auction to an action. He says:

“Earth Hour started with an ordinary action—switching off one’s lights—and placed the power to act in the hands of ordinary people who wanted strong climate action. Technology’s evolution helps us to do that on an even bigger scale. Be it a tweet, a digital signature or an online donation, technology empowers anyone anywhere to take action on our globe’s biggest environmental challenge.”

Alternatively, donations can be made directly through Earth Hour Blue, a WWF’s crowd funding and crowd sourcing platform. In 2014, the site raised nearly $60,000 to fund climate change-related projects in over 162 participating countries. Besides the Earth Hour initiative, the nonprofit encourages sustainability activists to take action and support other WWF’s socially and environmentally led causes online.

Next year the Earth Hour will be celebrated on March 19, 2016, as always at 8.30-9.30 pm local time.