Investigators:

• Dr. Daniel Odermatt, Eawag, CH
• Dr. Iestyn Woolway, Bangor University
• Dr. Caren Binding, Environment and Climate Change Canada
• Dr. Elisa Calamita, Eberhard Karls University Tuebingen

In Earth and climate science, tipping points are critical thresholds at which a system reorganises, often abruptly or irreversibly. Tipping elements are components of the Earth system that are susceptible to approaching such a tipping point in the course of global or regional environmental change. The potentially severe consequences of tipping elements and their potential feedback to climate warming have made tipping elements a priority topic in climate reporting in recent years (e.g., IPCC assessment reports). RESETlakes (2024-2027) is a new project funded by the European Space Agency (ESA), which aims to explore the use of satellite Earth observation (EO) data for the assessment of potential tipping points in lakes.

The theory of tipping systems states that ecosystems approaching a tipping point feature common response patterns, such as the delayed recovery from disturbances referred to as critical slowing down, flickering, or a shift in state and variance. Such patterns can be identified in all kinds of long-term monitoring data, including EO products. ESA’s Climate Change Initiative (CCI) datasets were developed for this very purpose. They include lake water level and extent, surface water temperature, ice cover and thickness, and water-leaving reflectance, covering (with some exceptions) the years 1992-2022. We combine analyses of past response patterns in the CCI products with lake and Earth system models. In doing so, we can detect lakes having already reached tipping points, as well as anticipate those lakes vulnerable to future tipping based on climate change scenarios.