Abstract

The response of the atmospheric circulation to climate change is still characterised by large uncertainty and it is not interpretable in a probabilistic sense in multi—model ensemble projections. This affects the confidence in the projections of several impact relevant climate aspects, and it makes it difficult to evaluate the regional implications of different global warming targets. To better characterise and communicate this uncertainty to end-users, I will here present a novel storyline approach where different plausible scenarios of atmospheric circulation change are linked to the response of three remote drivers of climate: the tropical and polar amplification of global warming, and the strength of the stratospheric vortex. By inspecting the CMIP5 models output, different plausible high-impact and low-impact storylines of Mediterranean precipitation and European storminess change will be identified, and contrasted with the impact of the uncertainty in global warming. The potential to use this approach for model selection in the regional downscaling of climate models and to define worst-case scenarios of regional climate change will be discussed.