Climate change: Alpine landslide risk may increase with climate warming

The area affected by landslides during extreme rainfall events in the Austrian Alpine forelands could increase by 45% with a global warming of 4°C above current levels, according to an article published online in Communications Earth & Environment. Limiting warming could reduce the extent of areas affected by landslides, and planting climate-resilient forests could further mitigate the increased landslide hazard.

Landslides are a major natural hazard, and there are uncertainties about their occurrence in a warmer climate. Heavy rainfall in the Austrian Alpine forelands triggered more than 3,000 landslides in June 2009, which resulted in a local state of emergency requiring the evacuation of houses, and cost the state of Styria, Austria, more than €13 million in damages. Climate change is projected to increase rainfall over the Alps and is likely to increase future landslide hazards.

To investigate how landslide extreme events, similar to the Austrian landslides of 2009, could unfold under climate warming and land-use changes, Douglas Maraun and colleagues simulated a range of different rainfall levels under various climate warming scenarios in south eastern Austria. The authors found that the area in this region affected by landslides could increase by 45% in a 4°C warmer world. Additionally, they found that if warming is limited to 1.5°C — as set out under the Paris agreement — the affected area may only increase by up to 10%, and increases in landslide hazards could be fully compensated for by replacing agricultural land in critical areas and spruce forests with climate-resistant forests in this region.

The findings highlight the relevance of climate mitigation, and the co-benefits of proactive land management for adapting forests to climate change and reducing landslide hazards.