Why alarmed astronomers are now looking at Earth

On the morning of January 18, 2003, Penny Sackett, then director of the Australian National University’s Mount Stromlo Observatory, outside Canberra, received a worrying email from a student at the facility.

The forest fires that had appeared on the horizon the day before they were approaching quickly. Astronomers were considering the possibility of evacuating the site, the student wrote.

All but one of Mount Stromlo’s eight telescopes were destroyed that day, along with millions of dollars’ worth of equipment that engineers had built to observatories around the world. The fires also destroyed 500 homes in Canberra and killed four people.

The incident was an early warning for Astronomy: forest fires, exacerbated by climate change, were becoming a problem for their field. Since then, other observatories have been damaged or threatened by fires and other extreme weather eventsand changing atmospheric conditions made astronomical research from the ground difficult.

Such incidents drew attention to the planet’s plight, and now a growing number of astronomers are coming together to fight climate change. In 2019, professionals and students founded a global organization called Astronomers on Planet Earth.

Astrobites, a journal run by graduate students in the field, published “Climate Change for Astronomers: Causes, Consequences, and Communication,” a collection of articles detailing researchers’ personal experiences with climate change. climate crisis, their impact on their work, and how they could use their scientific authority to make a difference. Other astronomers raise awareness in classrooms, incorporating the Earth’s climate into their research, or they abandoned science and became full-time activists.

Travis Rector, astronomer at the University of Alaska Anchorage and founder of Astronomers on Planet Earthsaid that “people are often surprised to learn that astronomers are dedicated to climate change.”

And he added: “But there is a very strong overlap between the science of astrophysics and the science of climate change. We understand more than anyone that the Earth is our only home.”

The modern scientific understanding of greenhouse gases is based in part on studies of Venus, a suffocated planet by carbon dioxide gas that traps heat.

At more than 800 degrees Fahrenheit, Venus is hot enough to melt lead, as well as the few probes that managed to land on its surface.

By comparing Earth’s atmosphere to others, Raissa Estrela, an astrophysicist at NASA’s Jet Propulsion Laboratory, came to appreciate her own planet even more. Star characterizes the atmospheres of exoplanets using techniques that it also uses to map plastics and other pollutants on Earth.

“We have this beautiful diversity of life that took us more than 2.5 billion years to achieve,” he says. Now, in just a few hundred years, humans have altered Earth’s hard-won atmosphere and endangered their biodiversity only.

Anna Cabré, an independent oceanographer, abandoned her original career as a cosmologist in part because the work was too abstract. “There is not much contact with reality,” she admits.

Since then, he has used his experience in mathematics and programming to study how global warming could affect marine animals and ocean circulation patterns, and to design an interactive map to assist in international climate negotiations. “It is the theory of hope through action. “I am doing my bit,” she says.

Peter Kalmus, a climate scientist at the Jet Propulsion Laboratory, began his career searching for gravitational waves in the Universe. “I felt a lot of anxiety about not dedicating my talents to doing something to stop global warming,” he said. After a few years of research in astrophysics, he went on to study the physics of clouds and, later, to use climate models to examine the risks of extreme heat. He also became an outspoken climate activist and was arrested for his protest tactics. “I’m still a little angry because, because the political leaders “They don’t do enough to stop global warming, I felt forced to leave Astrophysics and become a climate scientist,” he warned.

Global warming also had more subtle effects on Astronomy. The goal of telescopes is to collect as much light as possible to obtain detailed views of the night sky. But this delicate work is easily disturbed by the atmospheric turbulencethe irregular movement of air that increases as temperatures rise.

In 2020, a team of scientists analyzed long-term weather data from the Paranal Observatory in Chile’s Atacama Desert and found that climate-related research complications were increasing.

“It was the first time we did something like this and, at first, my colleagues were not very happy,” explained Faustine Cantalloube, an exoplanet researcher at the French National Center for Scientific Research who led that study. Some astrophysicists worried that the results suggested that Paranal was not a good place to astronomical observations. He further commented that the increase in news coverage and public awareness of climate change in recent years has facilitated debate on climate-related issues.

To preserve their ability to study stars, astronomers strive to reduce their carbon footprint. A study carried out in 2022 estimated that observatories, satellites and other physical infrastructure on which Astronomy depends annually release 1.2 million metric tons of greenhouse gasesequivalent to what would free up the electricity consumption of 230,000 American homes in one year.

The National Science Foundation’s National Optical and Infrared Astronomy Research Laboratory (NOIRLab) estimates that its facilities and activities emit 12,500 tons of these gases, equivalent to 2,500 American homes.

In Australia, the energy cost of supercomputing, which astronomers use to run simulations and process data, is the biggest contributor to the sector’s emissions. A study published in April revealed that the journey of air travel of researchers to Astronomy conferences in 2019 was greater than the distance between the Earth and the Sun.

In 2022, the American Astronomical Society announced a new task force tasked with reducing the sector’s carbon footprint by 50 percent over the next decade. Their efforts include improving options to attend conferences virtually and observe through remote telescopeschanges that began to occur organically during the coronavirus pandemic.

NOIRLab employees also put together a plan to cut their trips in half by 2027. The money saved would be used to invest in more efficient infrastructure, such as double-glazed windows. In Chile, NOIRLab plans to install a solar battery system that would charge during the day and power the entire Gemini South telescope, and about 60 percent of the Rubin Observatory, at night.

A decade ago, Bernadette Rodgers, former head of scientific operations of NOIRLab’s Gemini South, made a significant change: He left his position and moved to Oregon, where he runs a youth climate activism group called SustainUS.

Rodgers admitted that some scientists consider it irresponsible to get involved in political issues, but argued that “the physical world does not listen to politicians. Follow your own laws.”

That human emissions are altering the Earth’s carbon cycle “is established science,” Rodgers added. Stating this outright does not jeopardize scientific credibility.

Translation: Patricia Sar