Academics are becoming increasingly concerned about the contribution they make to climate change, particularly through travel to conferences. Australian astronomers decided to put some hard numbers to this, conducting a review of the carbon emissions associated with their community as a first step to reducing them. Although only a tiny proportion of the overall human contribution to greenhouse gases, the findings show the field is disproportionately carbon-intensive and has plenty of room to improve.
Astronomers have made vital contributions to climate science. The discovery that Venus is hotter than Mercury (despite being further from the Sun) because of a runaway greenhouse effect was a wake-up call to study our own atmosphere harder. Observations showing the Sun has become slightly less active over the last 60 years have focused the blame for rising temperatures firmly on humanity's contribution. We understand our own atmosphere better using what we have learned on Mars.
Consequently, no one, least of all astronomers, is saying we should stop studying stars and other planets until the climate crisis is solved. On the other hand, a group of Australian scientists argue: “Just as in any other profession, astronomers have an obligation to reduce their carbon footprint to meet the necessary global requirements for limiting the effects of climate change,” in their contribution to the mid-term review of Australian astronomy's decadal plan.
The Australians calculate on arXiv that more than 15,000 tonnes of carbon dioxide equivalent emissions are released each year from the work activities of themselves and their colleagues. This, they note, is more than 19 tonnes per professional astronomer, including PhD students. The total is almost certainly an underestimate, because it includes only one major observatory (Murchison), which accounts for around 2,000 tonnes on its own, despite being half-powered by onsite solar panels. Other telescopes didn't respond to inquiries.
While flying to conferences gets most of the attention, (particularly for Australians who have so far to travel) the authors find it accounts for only 4,300 tonnes, compared to 6,800 to power supercomputers to crunch telescopes' vast computing output.
Professor Michael Murphy of Swinburne University, one of the paper's authors, told IFLScience getting supercomputers onto renewable energy is the easy part of the problem to address. Pressure for change can be applied to supercomputer hosts in many ways, but, Murphy notes, “we need to coordinate cultural change” to reduce conference flying in favor of teleconferences. Murphy's own university, which runs a supercomputer used by many astronomical teams, announced plans this week to switch to 100 percent clean power.
Meanwhile, a Canada-wide team has produced a paper titled Astronomy in a Low-Carbon Future discussing how and why astronomy should get its emissions down. “At the most basic level, astronomy exists to serve humanity’s quest for knowledge about its place and future in the universe,” the paper argues. “To ignore a clear and present threat to that place and that future would be irresponsible in the extreme.”
Murphy said UK astronomers are working on quantifying their own emissions, but he is not aware of other scientific fields conducting similar studies.