Reacción a "Deaths due to wildfires could double in Europe by the end of the century"

The first article focusses on the impact of forest fires on premature deaths and radiative forcing from particulate matter smaller than 2.5 μm. Its strengths lie in its projections for the period 2015–2099, especially the last five years, and its analysis across all countries. To do so, it uses a model trained over a short period, from 2000 to 2014, and the authors then compare two periods. One is called historical, from 2010 to 2014, and the other corresponds to the end of the current century, from 2095 to 2099. The different scenarios presented are notable not only for their projected values ​​but also for their uncertainty intervals.

Although the work is commendable due to the volume of information handled, it also presents certain limitations, such as the considerations assumed for certain variables when calculating the projections. However, two important drawbacks deserve to be highlighted. The first is the short training interval compared to the projection interval. Perhaps the results would have been more robust if the training period had been much further in the past and the results were compared with a current period and then projected into the future. The second drawback is that the past evolution of some atmospheric variables exhibits periods of uneven behavior, making it risky to project their future evolution. In any case, future developments based on current data are questionable both due to the progress of atmospheric behavior and the development of human activity itself.

The second study relates exposure to wildfire smoke with mortality in the United States in the context of climate change. The amount of information handled is considerable, as results are presented not only by state but also in much smaller administrative units, such as counties. From an academic perspective, it addresses the issues of uncertainty in the response of fire emissions to climate change, uncertainty in modeled concentrations, and the common use of an exposure-response function based on total exposures to particles smaller than 2.5 μm. The article uses data from 2001 to 2021 and projects results between 2026 and 2055 under three different climate change scenarios. The goal is to understand the impact of climate change on changes in wildfire smoke and their effects on air quality and population health. A relevant section is dedicated to the implications. The economic implications of this mortality are significant.

Therefore, the research objectives and the work carried out are noteworthy. However, when performing calculations, processing such a large volume of data entails certain simplifications. For example, the authors focus on average values ​​rather than specific estimates, both spatially and temporally, because these specific estimates could be affected by random processes. Furthermore, among other variables, they indicate that they focused on emissions from fires rather than the influence of meteorology on particle concentrations, although they considered future projections of these variables in a sensitivity analysis.

Initially, they group the comparison between observed and predicted values ​​in three regions of North America, plus Canada-Alaska and Mexico, where the comparison for the northeastern United States seems questionable. Their emission projections generally present significant uncertainty, particularly for the western United States.

It is worth highlighting the empirical function provided by particle concentrations versus wind direction, where they present very low concentrations starting at 1,000 km.

Finally, they analyzed the spatial distribution by county of projected fire smoke mortality under climate change, finding the lowest values ​​in the center of the country.