Investigating climate change impacts in mountainous regions on the local level using a hybrid data approach - A case study of Neustift im Stubaital, Tyrol, Austria

Abstract

Mountains are among the most vulnerable to climate change. Few efforts have focused on developing concrete and transferable procedures for optimizing the complementarity of different data sources, although the value of combining multiple types of evidence for local climate change impact assessments is widely recognized. In response, this thesis proposes such a “Hybrid Approach”. Its use is illustrated by investigating local climate change impacts in Neustift im Stubaital, Tyrol, Austria. Following the proposed approach, agreements between different climate data sources (measured data from 9 different stations, the gridded observational dataset SPARTACUS, and the model-based dataset ERA5-Land) are analyzed. Because of its high temporal consistency and high agreement with the station data, SPARTACUS is used to calculate trends, which are complemented with trends derived from local knowledge (44 responses to surveys in the province of North Tyrol). The outcomes suggest that local knowledge and climate data agree on the main observed temperature and precipitation trends, which include an increase in annual temperature (2.48 °C, during 1961– 2023), the occurrence of extreme warm temperatures and heat waves, the duration of warm seasons, precipitation intensity, and the occurrence of extreme precipitation events. Climate change impacts, sometimes in combination with socio-economic factors, are also reported for other climate variables, landscapes, and environmental activities. For other climate variables, reported impacts include decreases in glacier length, snowfall (frequency, amount, and duration) and increases in storm frequency, wind strength and number of windy days. Impacts in the landscape include increases in soil temperature and flooding; decreases in soil humidity; longer growing seasons and earlier plant growth. Impacts resulting from both climate change and socio-economic factors include increases in erosion frequency, landslide frequency and grassland productivity; decreases in soil quality and crop productivity; and a shift of the tree line to higher elevations. Indirect effects of climate change on animals include livestock suffering from heat and increases in parasites; and the flourishing and distress of those wildlife species that can and cannot adapt to new conditions respectively. By reflecting the high variability and complex human-environment interactions at the local Alpine scale, the Hybrid Approach demonstrates its potential for meaningful impact assessments. Its transferable procedure allows for intercomparisons and the upscaling of hybrid, place-based information to climate research and policy.