In a video message, UN Secretary-General Ban Ki-moon, said: “This year's Earth Hour comes at a pivotal moment. Last December, all the world's Governments came together to adopt the Paris Agreement on climate change. This is a historic achievement for people and the planet – but only if we follow through on the promises made.”

Organized by the World Wildlife Fund (WWF), Earth Hour encourages individuals, companies, organizations and Governments to switch off their lights for one hour at 8:30 p.m., local time worldwide, to focus attention on people-driven solutions to protecting the planet and building a bright, sustainable future.

 Ban notes that the world is now entering a new era of opportunity. “Together, we can create the low-emissions future the world needs for sustainable development and a life of dignity and stability for all. Earth Hour reminds us that we all have a role to play.”

First launched in 2007, Earth Hour has become an annual event, mobilizing hundreds of millions of individuals to participate and growing to become the world's largest grassroots movement for the environment.

According to the WWF, the UN family will join the thousands of homes, offices, skylines and monuments that will go dark to put the spotlight on the issues facing the planet, and to inspire millions across the world to live more sustainably. At least 178 countries and territories are expected to take part in this year's celebrations.

So far over 366 landmarks are confirmed and will be turning off on the night of Earth Hour including iconic sites such as the Brandenburg Gate, Empire State Building, Sydney Opera House, the Roman Colosseum and Marina Bay Sands.

Amongst participating countries this year 90 are taking actions to achieve impact during Earth Hour through digital interactions, engaging local communities and raising awareness, adds the WWF.