San Francisco's iconic Golden Gate Bridge and Transamerica Pyramid went dark for an hour Saturday night in observance of Earth Hour, a worldwide effort to call attention to global climate change. The lights went out on both bridge towers, the downtown office building and several other notable San Francisco buildings in support of the effort, which took place in a different political climate than in previous years.

New U.S. President Donald trump, in office since January, has called climate change "a hoax" and slashed proposed federal government spending for dealing with expected impacts in next year's budget.

But Trump's view appears to buck a worldwide trend, as 170 countries have joined the Earth Hour observance since it began in Australia in 2007.

Structures darkened around the world included the Empire State Building and the Brooklyn Bridge in New York, the Space Needle in Seattle, hotels on the Las Vegas Strip, the Eiffel Tower in Paris, the Sydney Opera House and the Acropolis in Athens.

Time for reflection

“Cities, companies and the American people need to pick up the mantle of leadership on climate action,” said Lou Leonard of the World Wildlife Fund, which helped organize the event. Earth Hour was not a protest against energy use, he said, but a reminder to humans to "stop, reflect and have a conversation." Leonard urged the world's "engaged citizens and responsible corporate leaders" to lead the battle against climate change if Trump declined, according to the San Francisco Chronicle newspaper.

Lights out

Other buildings in Northern California that turned off the lights at 8:30 p.m. Saturday included The Warfield theater, the Regency Ballroom and the 505 and 545 Sansome office buildings in San Francisco, as well as the headquarters of Hewlett-Packard in Palo Alto.

Just two days earlier, a state environmental agency voted to tighten vehicle tailpipe regulations and mandated autornakers to sell more zero-emission cars and trucks.

The vote set up a possible confrontation with Trump, who has indicated that he wants to weaken such state requirements.

Controversy

Yet even Earth Hour observances were not without controversy. The conservative Ayn Rand Institute in Irvine, Calif., said in a statement that Earth Hour would be better used for celebrating electricity, not the opposite. "Try spending a month shivering in the dark without heating, electricity, refrigeration ... or life-saving products that industrial energy makes possible,” the institute said.