Importance of Framing for Extreme Event Attribution: the Role of Spatial and Temporal Scales
Abstract
Event attribution, which determines how anthropogenic climate change has affected the likelihood of certain types of extreme events, is of broad interest to industries, governments, and the public. Attribution results can be highly dependent on the definition of the event and the characteristics assessed, which are part of framing the attribution question. Despite a widely-acknowledged sensitivity to framing, little work has been done to document the impacts on attribution and the resulting implications. Here, we use a perfect model approach and large ensembles of coupled climate-model simulations to demonstrate how event attribution depends on the spatial and temporal scales used to define the event. In general, stronger attribution is found for events defined over longer time scales and larger spatial scales due to enhanced signal-to-noise ratios. With strong warming trends, most regions see large changes in the likelihood of temperature extremes at all scales, even at low levels of global mean temperature increase. The importance of the event scale for the attribution of temperature extremes decreases with further warming. For precipitation extremes, spatial scale plays a strong role. The occurrence of extreme precipitation can often be attributed for events defined over larger spatial scales, but attribution is more difficult over smaller scales, particularly at the current level of warming. Care must be taken to understand the scales used in event attribution, in order to properly understand the results.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGC21C1258W
- Keywords:
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- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 1694 Instruments and techniques;
- GLOBAL CHANGE;
- 1803 Anthropogenic effects;
- HYDROLOGY;
- 4313 Extreme events;
- NATURAL HAZARDS