Astronomy also has to do with climate change

The Paranal Observatory in Chile: Climate change can affect astronomical observations. (Image: ESO / S. Brunier)

You’re not looking at the universe for once – a group of astronomers is now campaigning for climate protection with a series of publications. In it, the scientists show how astronomical research influences the climate crisis – and vice versa. They show how they themselves cause greenhouse gas emissions through their work and technical equipment. They also explain how climate changes can have a negative impact on the observatory operations.

Many astronomers are certainly particularly aware of the explosive nature of current developments on our planet, because atmospheric and climatic conditions are an important subject of studies in planetary research. At this year’s – virtual – annual conference of the European Astronomical Society, the topic of terrestrial climate change evidently caused intense discussions among the participants: As the Max Planck Institute for Astronomy in Heidelberg (MPIA) reports, this gave rise to the idea of ​​developing the to take a closer look at the direct connection between astronomical research and the climate crisis. The scientists involved have now published the results in six articles in the journal Nature Astronomy. With this campaign you want to make it clear that everyone – including scientists – is affected by the consequences of anthropogenic climate change and that they bear responsibility and can do something.

How an astronomical institute pollutes the climate

If you want to reduce emissions, you should first clarify where they actually occur in your own life and the respective activity, explain the astronomers. “We astronomers are also responsible for emissions from fossil fuels. So we first have to find out where the emissions come from. Then it emerges how we can take measures at the institute level, at the level of the astronomical community as a whole, or at the level of society as a whole, which lead to a substantial reduction, ”says Knud Jahnke from the MPIA. In one of the articles in the series, he and his colleagues have now worked out the CO2 emissions their institute and the work of its employees caused in 2018.

The bottom line was that they produced 18 tonnes of carbon dioxide per year for research activities alone. For comparison: this is almost twice as much as the current average per capita carbon dioxide emissions in Germany. This is also far from the target that the government is targeting for the year 2030 with 6.8 tons per person. The researchers found that two factors make up by far the largest share of emissions: the numerous intercontinental flights to attend conferences or to carry out observation programs at observatories in North and South America, and the power consumption of the supercomputers.

As part of the article, the researchers also give recommendations on how astronomical institutes could reduce their emissions. One of them is the relocation of supercomputers to locations where electricity is mainly generated from renewable sources. Since the computers need strong cooling, locations in climatically favorable regions make sense – Iceland would be a good choice, say the scientists. The other measure is to drastically reduce research-related flights.

Comparison: virtual and conventional conferences

Another part of the article shows how important international conferences are in this context and that enormous savings are possible. In it, the authors compare the last two annual meetings of the European Astronomical Society: The 2019 meeting in Lyon was still a conventional on-site conference, with many of the 1200+ participants arriving by plane. Due to the corona crisis, this year’s meeting was completely different: Due to the global pandemic, it was designed as a virtual event with almost 1,800 participants.

It is of course clear that online meetings cause comparatively few emissions. But the extent of the savings that the researchers have worked out seems impressive: The virtual conference of 2020 caused less than a thousandth of the carbon dioxide emissions of the on-site meeting of 2019. The pressures of circumstances have now also forced astronomers to experiment with online formats, the scientists say. However, they emphasize that virtual meetings also have disadvantages: While online versions can be easily organized for some conference formats, there is currently no effective substitute for personal networking, which is also important.

“A climate-friendly solution could be to have a conference at several locations at the same time, so that all participants can travel by train in a relatively climate-friendly way. The plenary lectures would then take place online. But personal contacts between the scientists would be possible at each of the separate conference locations, ”says the first author of this article, co-author Leonard Burtscher from the University of Leiden.

How climate change affects astronomical observations

In another article in the series, the authors look from the emissions in their area to the consequences of climate change for astronomical research. They show how the changes can affect the quality of astronomical observations. As an example, they have chosen the Paranal observatory of the European Southern Observatory in Chile, which is about 2600 meters high. As they report, weather data shows that the average temperature at the site has increased by 1.5 degrees Celsius over the past four decades.

This development leads to more frequent difficulties in cooling the telescopes, the researchers say. As they explain, the domes of the Very Large Telescope (VLT) on Paranal must be cooled to the expected night temperatures during the day in order to avoid air turbulence when the dome is opened at sunset, because the eddies would disrupt the observations. The previous cooling system is now increasingly unable to guarantee complete cooling, which means that impairments in the quality of observation are unavoidable, the researchers report.

Another aspect that significantly affects the performance of the Paranal is the characteristics of the atmosphere above the observatory. For example, the very low humidity at the location is decisive for infrared observations. In other observations, air movements play an important role as they can deflect the incident light. In this context, the researchers emphasize that the Paranal lies under a jet stream layer, the characteristics of which are influenced by the El Niño climatic phenomenon. In the future, disruptive effects could become more and more frequent, because as climate change progresses, an increase in the frequency and strength of El Niño events can be expected over the next few decades. When building the Extremely Large Telescope (ELT) within sight of Paranal, the effects of the changing climate must now be taken into account, say the researchers. As a precaution, one should also factor in particularly serious climatic changes on the Paranal, which threaten if mankind does not get the problem under control.

With the articles now published, the astronomers hope to focus on the climate crisis in a somewhat unusual way. “As astronomers, we are very fortunate to be able to do fascinating research. But with our unique perspective on the universe, we also have a responsibility to make our colleagues and the general public aware of the catastrophic consequences of anthropogenic climate change for our planet and our society, ”concludes co-author Faustine Cantalloube from the MPIA.

Source: Max Planck Institute for Astronomy, selected specialist articles: Nature Astronomy, doi: 10.1038 / s41550-020-1202-4; Nature Astronomy, doi: 10.1038 / s41550-020-1207-z; Nature Astronomy, doi: 10.1038 / s41550-020-1203-3

Recent Articles

Related Stories

Stay on op - Ge the daily news in your inbox