Reacción a "Study assesses benefits of prescribed forest fires for air pollution"

Smoke from wildfires is a silent killer which, globally, is estimated to cause the premature death of 330,000 people. As a result of the fires in Canada in 2023, and the movement of air masses, it has been estimated that 22,000 people in Europe died prematurely. This is largely due to fine particulate matter (PM2.5), that is, tiny particles of soot, resins and tars that are so fine that the lungs are unable to filter them out and they enter the bloodstream. Those most affected are people with pre-existing conditions, such as asthmatics, or those most vulnerable due to their age, such as newborns or the elderly.

One of the most effective techniques for managing fuel and minimising the likelihood of mega-fires is controlled burning. We are talking about traditional burning, as practised by shepherds, but refined by science and transformed into an engineering project to maximise efficiency and minimise risks. It is a very effective way of reducing fuel load but, despite its effectiveness, these burns have been criticised because they also generate smoke. This study demonstrates how the smoke produced by prescribed burns is far less than that produced by wildfires. This is because, when a fire encounters a treated area, its intensity decreases, which provides an opportunity for firefighting teams and also results in less smoke being emitted. Prescribed burning is a very low-cost and highly effective technique. Therefore, the smoke emissions from prescribed burning mean that fires subsequently emit much less, so the overall balance is positive.

In fact, the study did not look at prescribed burns, but at low-intensity fires. This is relevant because there is currently a move towards managing, or ‘herding’, fires: when they occur under low-intensity conditions, we can safely allow the fire to burn, or direct it where we want, as this is a way of managing the fuel. In other words, we should shift the paradigm and, instead of extinguishing all fires as quickly as possible, we should manage some fires. In this way, we can manage the fuel and, given the low emissions from these fires, reduce pollution.

It is to be hoped that other fuel management techniques, such as grazing, forest management or agriculture, also offer these benefits in terms of air quality, as they are also effective in reducing fire intensity.