Megafires: the Cause and Effect of Climate Change

By José Luis Gallego, environmental communicator (@ecogallego)

Acting as an effective firebreak is one of the most important and least recognized functions of vineyards in nature.


In the Mediterranean, where winegrowing often takes place in forested settings, vineyards can block the spread of wildfires, thus providing a vital service for the survival of woodland areas and protecting the landscape. 



Viñedos, propiedad de la Familia Torres, rodeados de bosques

Vineyards, Familia Torres property, surrounded by forests



Climate change, however, is creating a set of circumstances – here and in other Mediterranean climate areas – where significant increases in average temperature and desertification are giving rise to a new generation of wildfires that are capable of overwhelming any and all firebreaks.


For years, experts in wildfire management have insisted that the climate crisis is leading to a new kind of forest fire. This new generation is much more virulent and burns with greater intensity, which makes it far more devastating. These are known as megafires: extreme disasters capable of burning through half a million hectares in a matter of days, completely destroying villages and towns and putting thousands of people at risk.


We have seen these blazes devastate entire regions in Australia, California, Portugal, and Chile. In the past five years, they have charred millions of hectares of forested land and burned thousands of homes and buildings from Patagonia to Siberia, where several fires are actively burning as I write these lines.  And worst of all: they have claimed many lives.



Un helicóptero realizando tareas de exterminación de un incendio en un entorno montañoso

An helicopter performing fire extermination tasks in a mountainous environment



The main cause of these megafires (as they have come to be called) is climate change, specifically rising temperatures and water stress which are having a serious impact on forests across the planet, making the Earth's surface increasingly vulnerable to fire.


The dangers of megafires go beyond the immense tragedy of lost lives and the destruction of entire towns, beyond the environmental disaster, the enormous loss of biodiversity, and the scarred landscape they leave behind. Scientists studying the evolution of megafires also point to the serious consequences of the smoke they generate. 


First off, forest fires release vast quantities of CO2, but are generally considered carbon neutral events, because the CO2 in question had previously been absorbed and sequestered by the trees. These fires, however, also create immense columns of smoke that exacerbate the negative effects of the climate crisis within the affected region. 


A while back, the scientific journal Geophysical Research Letters published a NASA report that showed how the smoke released by forest fires reduced rainfall in the fire-ravaged areas. As a result, the fire gains intensity and spreads with more destructive force due to the dry vegetation. 


According to the researchers, when the smoke reaches the atmosphere, it penetrates the clouds and suppresses the natural processes that generate rain. Proving this phenomenon has led scientists to categorize megafires as both a cause and an effect of climate change, which amplifies the consequences of this natural disaster. 


One of the starkest examples of this cause/effect relationship is the severe drought in Indonesia, which began after enormous wildfires consumed more than 1.5 million hectares of jungle last year.


After the fires, scientists conducted studies of alterations in weather patterns and concluded that high concentrations of smoke had led to the formation of so-called “sterile clouds” that directly impede rainfall and are the main cause of the severe drought that has affected the country since.


The severity of the situation is forcing Indonesian authorities to turn to artificial rain in a place that has traditionally been one of rainiest in all of Southeast Asia.


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