Editing IPCC:AR6/WGI/Chapter-1 (section)

=== Attribution of weather and climate events to anthropogenic forcing ===

New methods have emerged since AR5 to attribute the change in likelihood or characteristics of weather or climate events or classes of events to underlying drivers (WGI Sections 10.4.1 and 11.2.2; [[#NA%20SEM--2016|NA SEM, 2016]] ; Stott et al. , 2016; Jézéquel et al. , 2018; Wehner et al. , 2018; Wang et al. , 2021) . Typically, historical changes, simulated under observed forcings, are compared to a counterfactual climate simulated in the absence of anthropogenic forcing. Another approach examines facets of the weather and thermodynamic status of an event through process-based attribution (WGI [https://www.ipcc.ch/report/ar6/wg1/chapter/chapter-11 Chapter 11] and Section 10.4.1; Hauser et al. , 2016; Shepherd et al. , 2018; Grose et al. , 2019) . Events where attributable human influence have been found include hot and cold temperature extremes (including some with widespread impacts), heavy precipitation, and certain types of droughts and tropical cyclones (AR6 WGI Section 11.9; e.g., [[#Vogel--2019|Vogel et al., 2019]] ; [[#Herring--2021|Herring et al., 2021]] ). Event attribution techniques have sometimes been extended to ‘end-to-end’ assessments from climate forcing to the impacts of events on natural or human systems ( [[#Otto--2017|Otto, 2017]] ).

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