LOS ANGELES – In the wake of mudslides, wildfires and hurricanes, Southern California elected officials joined the mayor of Puerto Rico's capital city on Sunday, promising to support each other in responding to climate emergencies.

The officials drew climate change connections in the struggles following Hurricane Maria in 2017, the worst recorded natural disaster in Puerto Rico history, and the Woolsey Fire that forced nearly 300,000 people from their homes last November and created conditions for mudslides Saturday night that closed a stretch of the Pacific Coast Highway near Malibu.

"We are here today in solidarity, saying we are all in this together," said Los Angeles council member Paul Koretz. "And in the next 10 years, together we must rise to the occasion, the greatest challenge humankind has ever faced, to create a safe and stable climate."

Climate change made both natural disasters worse, said Alex Hall, director of UCLA's Center for Climate Science. With continued use of fossil fuels, climate change makes hurricanes in Puerto Rico more severe and increases the frequency and devastation of California wildfires. Communities need to adapt to climate change and think about how to respond to challenges together, he said.

To prevent the worst consequences of global warming, an October report by the United Nation's climate change panel called for "rapid, far-reaching and unprecedented changes in all aspects of society." Tropical storms, wildfires, water scarcity, sea level rise and biodiversity loss are some of the risks of climate change, the report said.

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Carmen Yulin Cruz, the mayor of San Juan, the largest city in Puerto Rico, and a critic of President Donald Trump, attested to the ripple effects of climate change. Because the U.S. territory lost 50 million trees during Hurricane Maria, Cruz said urban flooding occurs whenever it rains.

With 40,000 families still relying on blue tarps over their homes, she said, a tropical storm can force 160,000 people to relocate to shelters.

More than 3,000 people were killed during Hurricane Maria, and suicide attempts have also gone up 70 percent since the storm, the mayor said.

"It's very important to know that you're not alone when you're going through this devastation," Cruz said.

Because Saturday night's mudslide blocked the way to the planned destination for Sunday's news conference, officials made their climate change declaration on the highway. Vegetation that would normally hold mud and water from Saturday's rainfall burned in recent wildfires, Koretz said.

Sunday's symbolic pledge marked the beginning of collaboration between Southern California and Puerto Rico, Koretz said. Officials will work together to create climate change response plans, he said. He said the relationship began with Cruz's request to see scarred areas burned by the Woolsey Fire, which ravaged 97,000 acres and destroyed more than 1,600 structures.

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Along with local elected officials, Cruz surveyed the rubble with families Sunday morning.

Koretz commended the Puerto Rican mayor for how she "stood up so bravely against the lunatic in the White House in defense of her people." The distance between Puerto Rico and Southern California, Koretz said, could help Los Angeles work on its plan to combat climate change beyond its borders.

"If it's not going to be done by the federal government, we've got to be doing it with our municipalities and our states," he said.