Global warming changes how we see the sky

The atmosphere above a telescope is an important factor in how much an astronomer can see in the sky. For this reason, the locations of observatories are carefully picked. Usually, high elevation, desert, and remote areas are preferred. 

Now, a team of scientists led by the University of Bern and the National Centre of Competence in Research (NCCR) PlanetS has investigated how climate change might impact astronomical observation. 

“Even though telescopes usually have a lifetime of several decades, site selection processes only consider the atmospheric conditions over a short timeframe. Usually over the past five years – too short to capture long-term trends, let alone future changes caused by global warming,” explained study lead author Caroline Haslebacher.

The research shows that observatories in Hawaii, the Canary Islands, Mexico, Chile, South Africa, and Australia will probably experience rises in temperature and atmospheric humidity by 2050. These changes could make observing the cosmos more challenging.   

“Nowadays, astronomical observatories are designed to work under the current site conditions and only have a few possibilities for adaptation. Potential consequences of the climatic conditions for telescopes therefore include a higher risk of condensation due to an increased dew point or malfunctioning cooling systems, which can lead to more air turbulence in the telescope dome,” said Haslebacher. 

This problem was not something that was simply overlooked, the scientists say, but available technology didn’t allow climate change to be taken into account when many observatories were built.

“This is the first time that such a study has been possible. Thanks to the higher resolution of the global climate models developed through the Horizon 2020 PRIMAVERA project, we were able to examine the conditions at various locations of the globe with great fidelity – something that we were unable to do with conventional models. These models are valuable tools for the work we do at the Wyss Academy,” said study co-author Marie-Estelle Demory.

“This now allows us to say with certainty that anthropogenic climate change must be taken into account in the site selection for next-generation telescopes, and in the construction and maintenance of astronomical facilities,” said Haslebacher.

The study is published in the journal Astronomy & Astrophysics. 

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By Erin Moody , Earth.com Staff Writer