Forest fires and pest outbreaks could double in Europe before the end of this century

This study defines a future scenario of environmental change in which European society—both in the Mediterranean area and in regions historically less affected—will coexist with even more frequent and intense fires and pest outbreaks as a result of climate change, among other factors. This will lead to even greater social, economic, and environmental costs. The continued degradation of Europe’s forested systems projected by the modeling confirms previous findings.

The analysis provides a foundation for more decisively advancing climate change adaptation policies and preventive action against multi-hazard disasters through landscape planning and environmental conservation measures aimed at restoring degraded ecosystem services. At the same time, it highlights the need for policies to be adapted at both European and national levels in order to address the specific characteristics of different biomass types and ecosystems, adopting a differentiated strategy for the European Union.

The structure and composition of forests have changed as a result of the evolution of these systems, forest exploitation, climate change, and past events, and they will continue to do so in an even more dynamic way. Understanding the direction of these changes requires periodically repeating this type of analysis in order to identify trends and project future scenarios, enabling public policies to be regularly adjusted to the new context.

The study offers one of the most robust approaches to date for anticipating how major forest disturbances in Europe (fires, bark beetles and wind) will change. Its main strength is methodological, as it combines a continental analysis with 100 m simulations and integrates vegetation feedback and the interaction between disturbance agents, which is highly innovative.

The results are compelling, showing how disturbances increase under all climate scenarios. The study predicts a particularly large impact in the Mediterranean region, which is key for Spain, projecting an increase in severely disturbed areas of between 52% and 89% by the end of the century, depending on the climate scenario. In this region, the dominant disturbance is fire, and the projected pattern is in line with previously demonstrated evidence, such as that warming increases the meteorological fire hazard, weakens the night-time barrier to fire, that fire seasons are becoming longer and that, as a consequence of the above, among other factors, the most extreme fire events appear to be increasing in recent times, as seen in 2025. Even so, the area of forest burned in Europe has not shown an upward trend in recent decades.

As in any large-scale study, the data and models are not ideal, but rather those available, which in this case are used to generate the best possible evidence about future dynamics. In this regard, the authors acknowledge some limitations, including assumptions in their simulations such as no changes in forest management. In addition, they focus only on high-severity disturbances. Added to this are other uncertainties related to the use of thresholds or the modelling process. Scrub is not explicitly addressed despite its role in fire, and species composition comes from remote sensing, maps and distribution models, not from field inventories, which would be more accurate.

All in all, the message is difficult to ignore: without mitigation, Europe, and especially the Mediterranean, is heading towards more disturbed areas and relative losses of mature forests, with increasing impacts as temperatures rise. The practical implication is twofold: it indicates that the cause (emissions) must be addressed and management must be reoriented towards forest resilience.

In recent decades, hundreds of scientific papers have been published analysing how anthropogenic climate change and other factors linked to global change are altering or may alter the composition, structure and functioning of forests. Although the effects found vary depending on the region, the spatial or temporal scale of analysis, or the type of system studied, the underlying message is consistent: we are heading towards a more variable and uncertain future. In this context, disturbance regimes, i.e. the frequency, intensity and duration of phenomena such as fires or forest pests, are set to play a central role in the transformation of European forests.

This article addresses this issue with unusual ambition and scope. Its authors attempt to anticipate how some of the main disturbances affecting European forests—forest fires, pests and windstorms—might evolve throughout the 21st century. Their results point to significant, albeit uneven, increases in the forest area subject to more severe disturbances under three different climate scenarios (RCP 2.6, 4.5 and 8.5). According to their predictions, between 50 and 70 per cent of areas with Mediterranean, boreal and temperate forests will be subject to more severe disturbances. Mediterranean regions appear to be the most affected, but the results show that temperate and boreal areas will not be spared from these changes either. In fact, the increase in the area affected by intense disturbances is reproduced, to varying degrees, in the three scenarios considered. Furthermore, the results show that forest fires are the most significant disturbance among those studied in the future of European forests. While it is prudent to interpret these projections with caution, the consistency and magnitude of the trends they find make it difficult to dismiss them.

From a personal perspective, I consider the results related to the demography of European forests to be particularly relevant. The study suggests that rising temperatures and disturbances could lead to a continent with younger forests on average. This is no minor issue: the maturity of a forest is closely linked to many of the benefits that society derives from it. Mature forests, for example, harbour higher levels of biomass and therefore carbon, but also greater structural complexity and support high levels of biodiversity. According to the results of this article, temperature increases of around +3 °C would lead to an increase of ~18% in the proportion of young forests in the Mediterranean region and ~5% across Europe. If these projections are confirmed, we would not only be facing a change in the frequency of fires or pests, but also a profound transformation in the structure and functioning of European forest ecosystems, and by extension of the landscapes of which they form part, with far-reaching ecological and social implications.

The recent study led by Marc Grünig and Rupert Seidl (Technical University of Munich), with the participation of Spanish entities (CREAF, Centre for Forest Science and Technology of Catalonia, University of Girona), indicates that, under high emission scenarios, forest disturbances in Europe – especially fires and pests – could increase significantly throughout the century. It should be noted that the projections are based on a recent period (2001-2020) that has already been severely affected, which underscores the seriousness of the findings. However, as with all modelling studies, it should be remembered that these are projections based on climate scenarios, not exact predictions.

The fact that this study is published in Science and uses IPCC climate scenarios indicates that the work has undergone rigorous review and is based on sound scientific frameworks. Even so, the results depend on the model's assumptions, for example, that forest management will remain largely unchanged. The authors have probably taken multiple factors into account (climate, forest structure, pest dynamics), but there are always uncertainties associated with the actual ecological response, socio-economic developments and possible adaptation measures that could modify the predicted trajectories.

This work is consistent with extensive previous evidence pointing to an increased risk of fires and insect pest outbreaks in a warmer and drier climate, especially in the Mediterranean region. Its implications are significant: an increase in disturbances can reduce the capacity of forests to act as carbon sinks, affect biodiversity and generate economic impacts. At the same time, the study reinforces an important message for journalists and policymakers: the magnitude of the impact depends largely on future emissions and forest management, which means that there is still room for action to limit the risks.