Light pollution. satelite trains and radio frequency interference. The invading civilization. All of these pose threats to ground-based astronomy. But did anyone ever think that global climate change could wreak havoc on observatories? It turns out that the answer is “yes”.

We are all familiar with predictions about global climate change. It will make hot places warmer, cold places cooler, and it will bring wilder weather to places all over the planet. Economically, its effects are already making a dent in world trade and are changing the living conditions of millions of people. And it will inevitably change astronomy and the places where astronomers do their work.

Observatories need clean, dry air

Observations from ground-based telescopes are incredibly sensitive to local atmospheric conditions. Most observatories are located well above sea level. Less atmosphere to look at means better astronomical data.

And there are other factors too. For example, the observatories on the Big Island of Hawaii sit on top of a 4,000-meter volcano. Infrared-sensitive instruments, like those at the Subaru and Gemini observatories, work very well there. This is because there is very little water vapor in the air at high altitudes, and near-infrared light can leak out.

Many telescopes are also built in deserts, which also have less cloudy nights and lower water vapor content. Those are observation sites that are much more sensitive to climate change. The wildest conditions will adversely affect observatories long before the end of the useful life of their instruments.

Back when these places were planned and built, selection committees only looked at short-term atmospheric analyzes (like five years or so of weather data). They also used older climate models to project future conditions at the sites. As astronomy faces the challenges of global climate change, it looks like it will have to improve its site selection criteria and look to longer-term climate predictions.

That is the conclusion reached by a team of researchers, led by Caroline Haslebacher of the University of Bern and the National Center of Competence in Research (NCCR) PlanetS. They analyzed environmental conditions at various sites around the world. The group also discussed the site selection process for each facility. Team members recommend that planners use longer time frames and newer climate models to predict weather conditions in new locations.

Astronomy in the age of climate change

So how will things change for astronomy in the age of anthropogenic climate change? For one thing, global warming has the effect of putting more water into the atmosphere. To be specific, major astronomical observatories from Hawaii to the Canary Islands, Chile, Mexico, South Africa, and Australia will experience an increase in temperature and atmospheric water content by 2050. Those changes will affect observing time and data quality. that they get get.

“Today’s astronomical observatories are designed to function in today’s site conditions and only have some room for adaptation,” said Haslebacher, lead author of the study. “Potential consequences of weather conditions for telescopes therefore include an increased risk of condensation due to a higher dew point or malfunctioning cooling systems, which can lead to more air turbulence in the dome. of the telescope.

It is likely that technology and observing practices at current facilities can be adapted to these conditions in the short term. However, for future observatories, planners should use better atmospheric models in site selection criteria. Haslebacher points out that improving the data is the key to avoiding the degradation of ground-based astronomy.

“Although telescopes typically have a lifespan of several decades, site selection processes only take atmospheric conditions into account for a short period of time. Typically over the last five years, too short to capture long-term trends, let alone future changes caused by global warming,” he said.

What’s next for astronomy?

The failure of previous planners to take into account the effects of climate change was not simply an oversight. They had to plan with the information they had. Study co-author Marie-Estelle Demory (Wyss Academy, University of Bern, Switzerland) notes that state-of-the-art climate models are incredibly important for future observing sites.

“Thanks to the higher resolution of global climate models developed through the Horizon 2020 SPRING project, we were able to examine conditions in various locations around the world with high fidelity,” he said. “This is something we couldn’t do with conventional models. These models are valuable tools for the work we do at Wyss Academy.”

Global climate change is not going to go away. It’s something we’ll all have to deal with for decades to come. For astronomers, it is another challenge to face. The silver lining is that the data is there to help, according to Haslebacher. “This now allows us to say with certainty that anthropogenic climate change must be taken into account in site selection for next-generation telescopes and in the construction and maintenance of astronomical facilities,” he said.

This article was originally published on universe today by Carolyn Collins Petersen. Read the original article here.