Peter Kalmus, a climate scientist at NASA’s Jet Propulsion Laboratory, began his career searching for gravitational waves in the universe.

“I started feeling a lot of anxiety that I wasn’t committing my talents to doing something to stop global heating,” said Dr. Kalmus, who stressed that he spoke for only himself, not his employer. After a few years of research in astrophysics, he pivoted to studying the physics of clouds and, later, to using climate models to examine the risks of extreme heat. (Dr. Kalmus has also become an outspoken climate activist who has been arrested for his protest tactics.)

“I’m still kind of angry that, because of policymakers not doing enough to stop global heating, I felt compelled to leave astrophysics and become the climate scientist,” he said.

Rising Risks

Telescopes must be built in places that are high, dry and removed from cities’ light pollution, and they have often ended up in fire-prone places like mountaintops and forests. So it came as no surprise, in 2013, when a fire reached Australia’s Siding Spring Observatory, a sister facility to Mount Stromlo that’s located in a national park in New South Wales.

By then, astronomers had learned some lessons. Employees had maintained the grounds at Siding Spring to keep vegetation away from telescope domes. Flames destroyed some infrastructure, but most of the observatory was spared.

“Bushfires are a normal part of Australia’s life,” said Céline d’Orgeville, director of the Advanced Instrumentation and Technology Center, a state-of-the-art facility that opened at Mount Stromlo three years after the 2003 disaster. “But in recent years, it’s been clear that the frequency and the severity of the fires has increased significantly.”

In 2022, a wildfire destroyed multiple buildings at Kitt Peak Observatory in Arizona. And fires aren’t the only danger: In 2020, the giant Arecibo telescope in Puerto Rico collapsed, in part because of repeated stress from hurricanes, according to a 2022 forensic investigation commissioned by the National Science Foundation.

“People have become acutely aware that they actually have to account for climate change when they’re going to choose new sites,” Ms. d’Orgeville said.