Astronomers spend their careers looking up at the sky, far from Earth, but now some astronomers say their field has to deal with the fact that observing the cosmos is contributing to the climate emergency on their home planet.
A new estimate of greenhouse gas emissions from all ground-based and space-based telescopes, in the journal natural astronomyclaims that the annual carbon footprint of astronomy research infrastructure equates to approximately 20 million metric tons of carbon dioxide.
“Just to give you an idea – 20 million tons of CO2 – this is the annual carbon footprint of countries like Estonia, Croatia or Bulgaria”, explains Jürgen Knödlseder, astronomer at IRAP, a laboratory of astrophysics in France.
He and colleagues at IRAP, including Annie Hughes and Luigi Tibaldo, came up with the idea to do this study while estimating their own institute’s greenhouse gas emissions.
“The only piece missing from our assessment was the fingerprint of the observational data,” says Knödlseder, whose own research, for example, relied on observations made with the Fermi Space Telescope gamma-ray telescope.
“No study had ever attempted to calculate the carbon emissions from the construction and operation of all the telescopes and space missions that astronomers use to make observations,” notes Hughes.
This is exactly what this research team set out to do. Data was sometimes difficult to obtain, but they did their best to approximate and account for greenhouse gas emissions associated with nearly 50 space missions and 40 ground-based telescope installations.
most prolific the transmitters were the largest and most expensive observatories, such as the new James Webb Space Telescope and the Square Kilometer Array, according to the report.
By dividing the total annual emissions by the number of astronomers in the world, the researchers figure that each astronomer’s share of the profession’s emissions is approximately 36 metric tons per year.
Knödlseder points out that this is the amount of emissions generated by driving an average car in France for 165,000 kilometres, or more than 100,000 miles.
And that’s only for the use of telescopes — it doesn’t include things like scientists’ trips to conferences, supercomputing power, and office heating. “For our lab, the total is actually about 50 tons of CO2 equivalent per year for an astronomer,” he says.
Hughes believes astronomers must lead by example when it comes to taking action to mitigate climate change. “If we as scientists don’t react to reports and warnings from our colleagues,” she says, “then it’s a bit like your dad telling you not to smoke, when he himself smokes. a cigarette. Why would you take his word seriously?”
The researchers urge space agencies and funders of astronomical research to commit to requiring an environmental assessment of every observing facility they support and to making them public.
Moreover, they say, until research can be made more sustainable, through measures such as renewable energy sources, one option to reduce emissions is to slow the pace of building new telescopes still larger and more sophisticated.
“Some of our colleagues are a little shocked by this idea,” says Tibaldo. “What we really think is that these options need to be on the table. The urgency we face is so great and we are clearly playing a part in it with our work.”
Astronomers hope other fields of science will be inspired to compile a similar global inventory of greenhouse gas emissions from their research infrastructure. “As far as I know,” says Knödlseder, “this is the first time that this type of study has been done in a research field.”
The study is important because it draws attention to astronomy’s contribution to climate change, says Travis Rector, an astrophysicist at the University of Alaska Anchorage who is one of the organizers of the Astronomers for Planet Earth group.
“I think the overall picture is clear that we have substantial emissions associated not only with the operations of our facilities, but also with construction,” Rector says. “And that’s something that we’ve been aware of for some time. And there are efforts to try to reduce the emissions associated with those.”
Already, some observatories are using solar power or are exploring greener energy options. A spokesperson for the National Science Foundation, a major funder of astronomy research, told NPR that “we have explored and implemented clean energy alternatives, such as installing solar panels in our Gemini North and South facilities, and we built the possibilities for future solar upgrades.” in buildings.”
Astronomers also discussed the climate impact of traveling to in-person professional conferences. During the pandemic, Rector notes, virtual conferences drew even more attendees than past events, suggesting there were previously unrecognized barriers to attendance.
“It has been an opportunity for us as a profession to think critically about how we do business,” says Rector. “Are there ways to do this that reduce our carbon emissions and make it more scientifically productive?”
Even though astronomy is a relatively small profession and may have less of an impact on the climate than some other human activities, he says, “that doesn’t give us the right to say, well, that’s not our problem. We recognize that we are – that we must also be part of the solution.”