Closing the Gap in German Loss and Damage Data. The Importance of Heat- and Drought-related Extreme Events

This study summarizes the results of the project "Costs due to climate change impacts in Germany" commissioned by the Federal Ministry of Economics and Climate Protection and therefore aims to find answers to questions from three areas:

• How do climate change-related damages arise, which of the numerous complex cause-effect relationships of climate change are suitable for calculating damages at all, and how can they be recorded or broken down?
• What damage has already been caused by extreme weather events in Germany in the past?
• What damages can be expected for Germany by 2050 as climate change progresses?

In addition to an overall overview of the monetary damages of past extreme weather events, incurred damages of selected events, especially the heat and drought summers of 2018 and 2019, as well as the flash floods and floods of July 2021, are examined in detail, as they show a clear link to climate change: Studies have shown that heat waves like the one in 2019 would statistically occur in Germany about every 150 years without climate change, but with the change in climate that is already occurring, they can occur every 15-30 years. An influence of climate change was also demonstrated for the devastating flash floods on the Ahr and Erft rivers in July 2021.

The present study shows that since 2000, at least €145 billion in damages have occurred in Germany due to climate change-related extreme events, of which more than €80 billion in the years since 2018 alone. However, this figure only represents a lower limit of the actual damages, as many impact channels of climate change are difficult to monetize (e.g., losses of biodiversity or recreational value). Another new aspect of the present study is that indirect damages along value chains were included in the analysis.