Challenges in assessing the contribution of climate change to observed record-breaking heat waves
Abstract
Record-setting heat waves have large impacts on public health and society due to increased mortality rate, wild fires, property damages and agricultural loss. There is increasing interest in understanding the causes of such extreme events including the role of climate change. We use the example of the link between atmospheric blocking frequency and summertime seasonal temperature extreme to address some challenges in determining the relative contributions of natural variability and climate change on the occurrence and magnitude of extreme climate-related events. We utilize the 62-year record of observational data from 1960 to 2011 and long integrations with the NCARs Community Climate System Model Version 4 (CCSM4). This climate model represents well atmospheric blocking frequency and related weather features over the European/Ural region. Both observations and long climate integrations suggest that seasonal temperature extremes over the Northern European/Ural region are strongly conditioned by blocking. We illustrate that one challenge in climate event attribution is related to the fact that very long records are necessary to sufficiently sample the frequency of occurrence of the principal driver of a record-setting climate event. We further illustrate that there is a strong regional dependence on how the link between blocking frequency and extreme temperature anomalies is modified due to climate change suggesting that event attribution results are often not transferable from one region to another.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMGC51B0971P
- Keywords:
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- 1637 GLOBAL CHANGE Regional climate change;
- 1616 GLOBAL CHANGE Climate variability;
- 1620 GLOBAL CHANGE Climate dynamics;
- 1626 GLOBAL CHANGE Global climate models