Climate Central Temperature Attribution System Methods

The Climate Central Temperature Attribution System (CC-TAS) version 2.0 utilizes ERA5 reanalysis data and CMIP6 models to estimate the influence of climate change on temperature events. It employs a skew-normal distribution to fit temperature data and uses the 'occurrence ratio' (OR) as its primary attribution metric. To ensure conservative results, the system averages estimates from median-scaling, quantile-scaling, and model-based methods, converting them into a categorical Climate Shift Index (CSI). A screening procedure is also implemented to mask regions where GFS forecast errors might confound attribution estimates.

• The system has transitioned from Climate Forecast System (CFS) climatologies to the fifth generation ECMWF reanalysis for the global climate and weather (ERA5), which increases horizontal resolution fourfold and removes model discontinuities that could cause spurious historical trends.
• CC-TAS version 2.0 replaces quantile-based empirical methods for assigning temperature likelihoods with a method that fits a skew-normal distribution to observations or models.
• The model-based attribution method utilizes 24 paired forced and pre-industrial CMIP6 models, which are bias-adjusted using the 1991–2020 ERA5 climatology.
• The Climate Shift Index (CSI) is a categorical scale derived from a 'climate factor' (CF), which is the average of median-scaling, quantile-scaling, and model-average estimates. To maintain conservatism, the CF is set to 0 if the three methods disagree on the sign, and the CSI is capped at a maximum value of 5.

APA

Pershing, A., Gilford, D. M., & Giguere, J. (2023). Climate Central Temperature Attribution System Methods. Climate Central. https://assets.ctfassets.net/cxgxgstp8r5d/1Lp10KKgzy8jEp5nbPdovf/68abc3f8c1c7a8bbcfa9655f6db58eb5/methods-doc-v2.pdf

Chicago

Pershing, Andrew, Daniel M. Gilford, and Joseph Giguere. Climate Central Temperature Attribution System Methods. Climate Central, 2023. https://assets.ctfassets.net/cxgxgstp8r5d/1Lp10KKgzy8jEp5nbPdovf/68abc3f8c1c7a8bbcfa9655f6db58eb5/methods-doc-v2.pdf.

Wikipedia

{{cite report |last1=Pershing |first1=Andrew |last2=Gilford |first2=Daniel M. |last3=Giguere |first3=Joseph |title=Climate Central Temperature Attribution System Methods |publisher=Climate Central |date=March 2023 |url=https://assets.ctfassets.net/cxgxgstp8r5d/1Lp10KKgzy8jEp5nbPdovf/68abc3f8c1c7a8bbcfa9655f6db58eb5/methods-doc-v2.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{pershing2023climate, author = {Pershing, Andrew and Gilford, Daniel M. and Giguere, Joseph}, title = {{Climate Central Temperature Attribution System Methods}}, institution = {Climate Central}, year = {2023}, month = mar, url = {https://assets.ctfassets.net/cxgxgstp8r5d/1Lp10KKgzy8jEp5nbPdovf/68abc3f8c1c7a8bbcfa9655f6db58eb5/methods-doc-v2.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }