July 30, 2026

expert reaction to new analysis by World Weather Attribution (WWA) on whether human-induced climate change made the extreme weather driving the wildfires in Spain and France more likely

Scientists comment on a Word Weather Attribution (WWA) analysis on human-induced climate change, extreme weather and wildfires in Spain and France. 

Prof Tim Palmer, Royal Society Research Professor Emeritus in Climate Physics, University of Oxford, said:

“The proximate cause of the especially dry and hot conditions across Western Europe this summer is the persistent quasi-stationary anticyclonic weather pattern which has amplified the effects of global warming over Europe. A key question for attribution studies (such as WWA’s) is whether these atmospheric circulation patterns are themselves linked to human climate change: we call this the dynamical attribution problem. Insofar as these anticyclonic patterns do appear to be becoming more frequent in recent summers, it would seem that they are linked to climate change, in which case the extreme summer we are experiencing now may become the new normal. However, it is also possible that the increased likelihood of anticyclonic weather is an unforced decadal-timescale chaotic fluctuation in climate. If the latter, then although we can still expect warmer drier summers, they won’t always be as extreme as this year.  In principle, this attribution question can be answered using global climate models. However, the current generation of climate model does a poor job in simulating long-lived anticyclonic circulation anomalies. Hence we simply can’t answer the dynamical attribution problem with confidence. The WWA report does not address this crucially important issue.

“On the other hand, a very recent US National Academies report on extreme event attribution  (https://www.nationalacademies.org/projects/DELS-BASCPR-23-02) did comment on this issue, saying that development of higher-resolution climate models is essential if we are to tackle reliably the dynamical attribution problem, and not be surprised by climate events as they unfold. 

“The coming months will be critical for countries facing massive water shortages. If dry conditions continue into the winter, 2027 could be a truly catastrophic year for many European countries. The seasonal forecasts of El Nino and its global impacts will be anticipated with considerable eagerness.” 

From our friends at SMC Spain:

Dr Gustavo Saiz, a forestry engineer and senior scientist at the National Institute for Agricultural and Food Research and Technology (INIA-CSIC), said:

“According to a new analysis by World Weather Attribution, human-induced climate change has significantly amplified the major wildfires that have just devastated vast regions of central Spain and south-western France. The fires, described as among the worst ever recorded in both countries, have claimed several lives, destroyed thousands of homes and forced the evacuation of more than 300,000 people. The analysis examines historical weather patterns to assess how fire-prone weather conditions have changed over time. To do this, they used a daily fire severity index (DSR), which takes into account heat, dryness and wind conditions, and reflects the difficulty of extinguishing a fire once it has started. The researchers analysed the seven-day period with the highest DSR in the regions where the fires occurred.

“The report states that climate change has led to extreme weather conditions conducive to the occurrence of these fires. Under current climate conditions, such high-intensity fires are expected to occur approximately once every six years in central Spain and once every 20 years in south-western France, demonstrating that climate change is not only intensifying individual fires but is also increasing their synchronisation across all regions, thereby exacerbating the humanitarian and environmental consequences.

“Science is, by its very nature, very cautious when it comes to establishing causality. This scientific caution is particularly evident in the field of climate change science, despite the wealth of evidence of the climate crisis that has accumulated over recent decades. Attribution studies, such as those by the WWA, are not based on opinions or viewpoints, but apply rigorous methodologies and only publish results when the scientific evidence is robust. It is an approach designed not to exaggerate in the slightest: if something cannot be proven with a high degree of certainty, it is simply not claimed. That is why, when such a rigorous and cautious organisation concludes that, under current climate conditions, high-intensity wildfires are expected to occur approximately once every 20 years in south-western France and once every six years in central Spain, or that the conditions that fuelled the wildfires in Spain and Portugal in 2025 are 40 times more likely due to climate change, this is not an exaggeration: it is, if anything, a conservative estimate.

“A report such as this is only published if the evidence is solid. The fact that the most cautious scientists are issuing such a stark warning should not only alarm us, but spur us to act now, by cutting emissions and preparing our ecosystems and societies for the stark reality that is already upon us.”

‘Climate change increases likelihood of compounding drivers of severe wildfire conditions in France and Spain’ by World Weather Attribution was made available at 23:01 UK time Thursday 30 July. 

Declared interests

Prof Tim Palmer: “No interests to declare.”

Dr Gustavo Saiz: He doesn’t declare conflicts of interest.