Quantifying the direct influence of climate change on the rate of spread of wildfires in the Iberian Peninsula

Due to its strong connection with meteorological conditions and vegetation structure, fire activity is affected by anthropogenic climate change. As a direct effect, climate regulates fuel moisture, so warmer and drier conditions are linked to higher fuel flammability, increasing fire risk. We use data from ERA5 and different CMIP6 models to build a database of fuel moisture (for both live and dead fuels) under real conditions (factual) and modified conditions without the influence of global warming (counterfactual). We then calculate the rate of spread of some observed wildfires in the Iberian Peninsula from 2001 to 2021, from both factual and counterfactual data. We find that climate change influence is already noticeable and significant. We also identify the areas most vulnerable to the impacts of climate change and the time of the year when these impacts are strongest.