State of Wildfires 2025-26: WWA Attribution and Future Projection of Focal Events Using FWI95

This dataset supports the State of Wildfires 2025-26 report submitting to Earth System Science Data (Burton et al., under review). The dataset quantifies changes in the likelihood of fire weather extremes (represented by the 95th percentile of the Canadian Fire Weather Index) associated with the focal events by: (a) assessing how their likelihood has changed relative to past (a preindustrial global warming level -1.3°C cooler than the four-year smoothed GSAT of 2025-26); and (b) projecting how this likelihood may evolve under future global warming levels of +1.5°C, +2.0°C and +3.0°C above the recent baseline climate (+1.3°C). The analysis was conducted according to the WWA probabilistic attribution protocol (Philip et al., 2020; Otto et al., 2024). Climate model data was taken from all available CMIP6 and HighResMIP models on the DKRZ and Jasmin climate computing clusters. Reanalysis values were calculated from ERA5 and MERRA2. This upload includes: All time-series calculated The methodology for this calculation The evaluation of each climate model The probabilistic attribution of FWI95 for models and reanalysis. The calculation of confidence intervals on the trend in each focal region. The synthesis of attributed trends between models, and combining models and reanalysis. Plotting functions. References: Philip, S., Kew, S., van Oldenborgh, G.J., Otto, F., Vautard, R., van Der Wiel, K., King, A., Lott, F., Arrighi, J., Singh, R. and van Aalst, M., 2020. A protocol for probabilistic extreme event attribution analyses. Advances in Statistical Climatology, Meteorology and Oceanography, 6(2), pp.177-203. Otto, F.E., Barnes, C., Philip, S., Kew, S., Van Oldenborgh, G.J. and Vautard, R., 2024. Formally combining different lines of evidence in extreme-event attribution. Advances in Statistical Climatology, Meteorology and Oceanography, 10(2), pp.159-171.