Historical weather data for climate risk assessment

Abstract

Weather‐ and climate‐related hazards are responsible for monetary losses, material damages, and societal consequences. Quantifying related risks is, therefore, an important societal task, particularly in view of future climate change. For this task, climate risk assessment increasingly uses model chains, which mainly build on data from the last few decades. The past record of events could play a role in this context. New numerical techniques can make use of historical weather data to simulate impacts quantitatively. However, using historical data for model applications differs from using recent products. Here, we provide an overview of climate risk assessment methodologies and of the properties of historical instrumental and documentary data. Using three examples, we then outline how historical environmental data can be used today in climate risk assessment by (1) developing and validating numerical model chains, (2) providing a large statistical sample which can be directly exploited to estimate hazards and to model present risks, and (3) establishing “worst‐case” events which are relevant references in the present or future. The examples show that, in order to be successful, different sources (reanalyses, digitized instrumental data, and documentary data) and methods (dynamical downscaling and analog methods) need to be combined on a case‐by‐case basis.

Understanding and managing connected extreme events

“…For instance, the adaptive pathway approach 80 recognizes that the 'decision space' can be highly sensitive to climate change, political or financial resources, or other contexts, and may exhibit qualitative jumps at certain 'tipping point' thresholds 81 . Storylines and scenario-planning methods about potential large-impact events allow for the engagement of stakeholders and the public in identifying crucial factors, chains of causality and 'tail risks' through a collaborative process unencumbered by the usual focus on quantification 71,82,83 . Stress testing explores the 'impacts space' associated with connected extremes' imprint on a given sector or location, highlighting where impact sensitivities are largest in response to slight changes in physical drivers 84,85 .…”

Early instrumental meteorological measurements in Switzerland

“…In our study we have compiled information on more than 300 station records from Switzerland prior to 1864. The inventory is added to the global registry of the Copernicus Data Rescue Services (Brönnimann et al, 2018b), and the images are published at the open-access repository Zenodo (https://doi.org/10.5281/zenodo.3066836). Two examples illustrate the usefulness not only of the digitised data, but also of the images provided, for reconstructing daily weather as far back as the 18th century.…”

Construction of the REACHES climate database based on historical documents of China

“…However, the majority of these records was scattered around the world and owned by individual investigators or institutions. Recently, efforts have been made to compile the documentary data into databases such as Euro-Climhist 25 , TAMBORA 26 , and TEMPEST 27 mainly in central Europe and England. There appears to be no consistent endeavor in Asia to systematically compile all those records into a coherent database.…”