Climate extremes and ecosystem disturbance feedbacks

 

Climate extremes have direct impacts on ecosystems, for example reduced productivity during heat-drought events, but often their impact is amplified by compounding ecosystem disturbances, such as wildfires or insect outbreaks.  Through their impact on ecosystem functioning and structure, compound climate extremes and ecosystem disturbances modulate land-atmosphere exchanges of water, energy, and greenhouse-gases, which in turn influence atmospheric properties from local to global scales, thus feeding-back to climate change.  Recent observations indicate that such feedbacks are, however, non-negligible and might result in a much weaker role of the biosphere in climate change mitigation, especially under high emission scenarios.

Currently, ecosystem disturbances are not appropriately represented in most Earth System Models, which implies that extreme-event induced climate-biosphere feedbacks are likely overlooked in future climate simulations. Here, we will examine observation-based evidence for extreme-event induced climate-biosphere feedbacks through CO₂ and land-atmosphere water and energy exchanges at different scales. We will then showcase recent developments in simulating some of these feedbacks in a global land-surface model and discuss the resulting implications for climate change adaptation and mitigation.