Astronomers reveal what to do themselves to prevent our planet from chasing unlivable Venus

Astronomy is not immediately very climate friendly. And that has to change. But how?

The earth is warming rapidly and the consequences of this are being experienced in many places on earth. Glaciers are melting, sea levels are rising and wildfires prompted by heat and drought are spreading ruthlessly around them. This climate crisis is not ignoring astronomers either. And they also know better than anyone how a climate can get out of hand. The consequences of this are visible to this day, for example, on the widely studied, red-hot and unlivable planet Venus, which, by the way, is believed to have once been a good place to be, just like on Earth. And although the Earth is fortunately not yet heading for the temperatures we measure on Venus – the surface temperature averages 464 degrees Celsius – researchers warned that if we do not reduce our emissions a third of the world’s population could be faced with unlivable temperatures within fifty years. Reason enough to be economical on our planet and our climate. Because any astronomer can tell you, a second earth has not yet been found, let alone within travel range.

Hand in your own bosom
Limiting emissions and temperature rise is therefore of vital importance. And in a special section of the magazine Nature Astronomy astronomers put their hands into their own bosom in this regard. Because astronomy can – no, it should – be greener too.

Astronomers contribute to global emissions in different ways, German researchers show after calculating the emissions of their research institute in 2018. Every astronomer at it Max Planck Institute for Astronomy (MPIA) in Heidelberg turned out to be responsible for about 18 tons of CO2 emissions on average – and then only research activities were considered. That is almost twice as much as the average German. The emissions can mainly be traced back to intercontinental flights to conferences and also telescopes in North and South America. In addition, the electricity consumption of supercomputers that the astronomers use for data analysis and simulations also plays a role.

Supercomputers and computer language
Although these supercomputers are often necessary to be able to conduct research, astronomers can be a bit more careful with them, says Leiden astronomer Simon Portegies Zwart, who also wrote about this in the special appendix of Nature Astronomy publishes. For example, when using supercomputers, one should not simply go to full capacity. “If necessary, you should of course use the entire supercomputer to do sums,” he explains Scientias.nl. “But then you have to know what you are doing and what the consequences are. So: run a supercomputer to the last chip, but only do that if it is really necessary. ” In addition, according to Portegies Zwart, astronomers can also reduce their ecological footprint by taking a critical look at their computer language. “Don’t program in Python if you want to do large calculations,” he urges his colleagues. The latter will be difficult for many astronomers. “I myself am a big fan of Python,” admits Portegies Zwart. “It’s a great language; easy to learn, but not very optimal. ” The computer language – which is used to give a computer instructions – is quite energy-consuming. Portegies Zwart illustrates this with an example. “In a normal car you have to fill up the tank about every 1000 kilometers. If you were to compare such a car with a (more energy-efficient, ed.) Third-generation language, you could compare Python with a car with which you have to refuel every ten kilometers. ”

Wanderlust
Portegies Zwart is not the only Dutch astronomer to put his hand in his own bosom. Colleague Leonard Burtscher does the same. In his contribution to the special section of Nature Astronomy he and colleagues examine the impact that the travel-loving nature of astronomers has on the climate. To this end, he compared the emissions of the European astronomy conference that was held in Lyon in 2019 with the conference that was – out of necessity – organized virtually in 2020. The latter conference turned out to be accompanied by no less than 3000 times (!) Less CO2 emissions. Although the researchers had expected that the emissions from the most recent conference – because no one took the plane, but everyone at home crawled behind the laptop – would be smaller, the results did surprise Burtscher. “We found that the difference was so big,” says Burtscher Scientias.nl. “Because it is always said that the internet is a major CO2 polluter.” On closer inspection, this turns out to be not so bad, although half of the emissions of the virtual conference can be attributed to internet use. The other half is for the electricity consumption of laptops.

Looking more critically
Judging from his research, Burtscher therefore thinks it would not hurt if astronomers take a critical look at their travel behavior. “I’m not saying we should stop flying, but we should do it a lot less,” he says. “I can do without offline conferences myself, but I already have my network of colleagues all over the world, because I used to fly a lot – like everyone else. I would consider it unfair to deny younger scientists the opportunity to get to know other scientists personally and thus make new colleagues and friends. I think a good personal relationship is necessary in order to be able to work together professionally. In principle, you can also build such a relationship online, but it is certainly more fun offline. And if we make the personal relationships more on our own continent (after all, there are enough scientists to work with!) Then we can just take the train and the journey itself will no longer be an environmental problem. If you do have to get to know that famous scientist from Japan, you go there for six months or so to really work together and not for a conference of just one week. ”

Consideration
It all sounds very logical, yet in astronomy little account is taken of the climate. “For COVID-19 we sometimes traveled several times a year to other continents,” says Burtscher. “My PhD student flew to Chile last year to be able to do observations only for a few nights. There was no other way. ” And once there, it doesn’t get any better. “Large observatories – including in Chile, for example – still run mainly on fossil energy (…) And that while we (astronomers, ed.) Should actually know how serious the climate crisis is.”