The impact of climate change on astronomical observations

TL;DR

This study examines how climate change influences key weather parameters affecting astronomical observations at Cerro Paranal, analyzing long-term trends and climate projections to assess future impacts on observational quality.

Contribution

It provides a comprehensive analysis of long-term climate data and projections to evaluate climate change effects on astronomical observation conditions.

Findings

Long-term increase in temperature and humidity at Paranal.

Projected worsening of atmospheric turbulence and wind conditions under climate change scenarios.

Identification of climate trends relevant for future astronomical site planning.

Abstract

Climate change is affecting and will increasingly affect astronomical observations. In this paper, we investigated the role some key weather parameters play in the quality of astronomical observations, and analysed their long-term trends (longer than 30 years) in order to grasp the impact of climate change on current and future observations. In this preliminary study, we specifically analysed four parameters, the temperature, the surface layer turbulence, the wind speed at the jetstream layer and the humidity. The analyses is conducted with data from the Very Large Telescope (VLT), operated by the European Southern Observatory (ESO), located at Cerro Paranal in the Atacama desert, Chile, which is one of the driest places on Earth. To complete the data from the various sensors installed at Paranal, we used the fifth generation and 20th century European Centre Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis of the global climate, ERA5 (from 1980 to now) and ERA20C (from 1900 to 2010), which we interpolated at the Paranal observatory location. In addition, we also explored climate projections in this region, using the Coupled Model Intercomparison Project Phase 6 (CMIP6) multi-model ensemble, under the worst-case climate change Shared Socio-Economic Pathways (SSP5-8.5) scenario. Further investigation is needed to better understand the underlying mechanisms of change, as well as to assess the severity of the impact.