The importance of non-climatic factors in climate risk assessments for ecosystems

High-impact events driven by weather extremes, such as large-scale drought-induced mortality, crop failure, mega-fires, and widespread tree mortality are expected to intensify under climate change in many regions. While the importance of climate change in increasing the frequency or intensity of many such events has been demonstrated by climate attribution studies, non-climatic factors such as landscape structure and composition, diversity, biotic agents, disturbance history, etc., shape ecosystem resistance and ability to recover from such events.

Quantifying the role of non-climatic factors on observed impacts is challenging, since they are often of second order importance, given the signal of weather extreme anomalies. Nevertheless, quantifying the importance of such non-climatic factors and how they are influenced by human activities is crucial to anticipate potential loss of resistance/resilience and to support effective adaptation strategies to ongoing climate change. Here, we discuss the importance of non-climatic factors for climate risks based on historical events and show how the ecoclimatic event framework can be adapted to support the attribution of climatic vs. non-climatic factors in climate risk assessments for ecosystems.