Cities around the world were marking Earth Hour on Saturday night by turning off the lights in a call for global action on climate change. Beginning in Sydney in 2007, Earth Hour has spread to more than 180 countries, with tens of millions of people joining in. Top tourist sites in coal-reliant Poland turned off their lights at 8:30 p.m. in solidarity with global Earth Hour action calling for better climate protections. In Poland's capital city, Warsaw, the spired landmark Palace of Culture and Science turned off its night illumination, along with some churches and Old Town walls, all popular tourist venues. In the southern renaissance city of Krakow, which sees millions of tourists from around the world each year, the central vaulted Cloth Market and the 14th-century red brick St. Mary's Basilica al turned off its lights as well.

In Hong Kong, major buildings along Victoria Harbour turned off their non-essential lights at 8:30 p.m. and the city's popular tourist attraction known as the Symphony of Lights was canceled. Over 3,000 corporations in Hong Kong signed up for Earth Hour 2019, according to the WWF Hong Kong website. Iconic skyscrapers including the Bank of China Tower and the HSBC Building in Central, the city's major business district, switched off their lights in response to the global movement. n Taipei, Taiwan's capital, the island's tallest building, Taipei 101, joined surrounding buildings in shutting off the lights as part of the Earth Hour event.

In France the Eiffel Tower's lights shut off Saturday night along with landmarks in other countries across the world, including the Acropolis hill in Greece, the Houses of Parliament and the London Eye in the United Kingdom, also descended into darkness briefly to mark this year's Earth Hour.

It is estimated that millions of people were expected to have participated in the event across over 180 countries. The World Wildlife Fund or WWF said in a statement that it hopes the effort will motivate international leaders to take more action to combat climate change.  "We're the first generation to know we are destroying our planet," WWF said in a statement. "And we could be the last that can do anything about it," the organization added.

The Earth Hour gesture calls for greater awareness and more sparing use of resources, especially fossil fuels that produce carbon gases and lead to global warming. With the entire world in relative unison Earth Hour is making an enormous difference, and over the next century, the accumulated saved energy will be astonishing.