A study shows that even astronomy is affected by the consequences of global warming: At many telescope locations around the world, the climatic changes caused by global warming could adversely affect astronomical research. This emerges from an analysis of regional trends based on high-resolution climate models. The increase in temperature and atmospheric water content could therefore lead to a clouded view and technical problems. The researchers say that the local effects of climate change should now be taken into account when choosing the location and the technical equipment for planned astronomical facilities.
Temperatures are rising and the weather is becoming increasingly crazy: the consequences of anthropogenic climate change are extremely complex and, as is well known, are affecting mankind in many different ways. However, one might think that those who deal with distant worlds are not affected by these problems. But that is not the case, explain the researchers led by Caroline Haslebacher from the University of Bern. Because the possibilities of astronomical observations with ground-based telescopes are influenced by atmospheric conditions. The quality of the insights into the cosmos depends crucially on the clarity of the atmosphere above a telescope. That is why the locations are selected very carefully, especially for large-scale projects: The astronomical facilities are often built at high altitudes, so that there are fewer layers of atmosphere between them and their intended targets in space. Many telescopes are also specifically erected in arid regions, where clouds and humidity less often impair the view of the night sky.
The climate change factor has not been taken into account so far
However, in view of the long planning phases and running times of astronomical facilities, the question arises as to how stable the conditions at such locations actually are in times of climate change, say the researchers. “Although telescopes usually have a lifespan of several decades, the atmospheric conditions are only taken into account when choosing a location for a short period of time. As a rule, this is the last five years - too short to capture long-term trends, let alone map future changes due to global warming," says Haslebacher.
The international research team has therefore now dedicated itself to the task of showing this long-term perspective in a well-founded manner. For their study, the scientists examined the development of astronomical observation conditions at eight locations - from Hawaii to the Canary Islands, Chile, Mexico, South Africa and Australia. Most of them either already house telescopes or are candidates for the next generation of facilities. To assess climate development at these locations, the scientists use the latest information from high-resolution global climate models.
It's getting less favorable at the locations
As they report, the projections, which extended up to the year 2050, show that an increase in temperature and atmospheric water content can be expected at all locations examined. The extent to which these changes can lead to individual impairments must be assessed individually, but the effects could be significant: "For these variables, the model projects an increasing trend at all locations, resulting in poorer astronomical observation conditions compared to the current ones will lead,” the researchers write. Specifically, there could be a loss of observation time and a loss of quality in the data.
Apparently, not only increasing atmospheric impairments play a role, but also technical ones: “Nowadays astronomical observatories are designed for the current site conditions and have only few possibilities for adjustment. Possible consequences of the climatic conditions for the telescopes are therefore an increased risk of condensation due to a higher dew point or poorly functioning cooling systems, which can then lead to more air turbulence in the telescope dome," says Haslebacher.
As the team emphasizes, the fact that the possible effects of climate change were not taken into account was not due to negligence on the part of those responsible, but was previously due to the limited accuracy of forecasts. “It is the first time that such a study has ever been possible. Thanks to the higher resolution of the global climate models developed as part of the Horizon 2020 project PRIMAVERA, we were able to study conditions in different locations around the globe very precisely - something we could not do with previous models," says co-author Marie -Estelle Demory from ETH Zurich.
In conclusion, Haslebacher sums up: "Our study now clearly shows that anthropogenic climate change must be taken into account when selecting the location for next-generation telescopes, and when building and maintaining astronomical facilities," says the scientist.
Source: University of Bern, specialist article: Astronomy & Astrophysics, doi: 10.1051/0004-6361/202142493