In Patagonia’s dense forests, some trees tower above the rest. The largest have grown as tall as a 20-story building and are nearly as thick as a small school bus is long, surviving everything nature has thrown at them for thousands of years. But now, the world may have to watch them burn.
In early January, severe wildfires erupted in Argentina’s Patagonia region, tearing through scrubland and forest in Chubut Province. By mid-month, new fires had ignited in southern Chile. As crews struggled to contain the blazes, they spread across northern Patagonia and the Andean foothills of central-southern Chile—killing 23 people, forcing tens of thousands to evacuate, and scorching dense native forests and national parks.
While the situation has somewhat improved, wildfires are still actively burning in both countries. A report published today by World Weather Attribution—a non-profit that quantifies how climate change influences the intensity and likelihood of a given natural disaster—found that excessive heat, months of drought, and fierce winds driven by human activity are fueling this wildfire crisis.
At the same time, these fires are destroying our best lines of defense against climate change: ancient forests. In Argentine Patagonia, the blazes are decimating large swaths of Los Alerces National Park, a UNESCO World Heritage Site famous for its ancient Alerce trees—some of the oldest living trees on Earth.
A climate feedback loop
The park is home to the longest-living population of Alerce trees in the world, according to the UNESCO World Heritage Center. The oldest, largest specimen stands nearly 200 feet (60 meters) tall and is estimated to be 2,600 years old. It could live another thousand years if it survives these fires—the Alerce is the second-longest-living tree species in the world.
Over the course of their very long lives, these trees draw massive amounts of carbon dioxide out of the atmosphere and store it in their biomass—their trunk, branches, roots, and leaves. Research has shown that the largest 1% of trees store roughly half of the above-ground biomass carbon across forest biomes. Keeping carbon out of the atmosphere directly mitigates the greenhouse effect, tempering the rise of global temperatures.
But when these giant trees burn, it’s basically like setting off a carbon bomb. Their stored carbon is released back into the atmosphere, fueling global warming and creating hotter, drier conditions that make wildfires more likely and severe—as seen in the current crisis in Chile and Argentina. More forests burn, and the cycle starts over again.
All forest fires emit carbon dioxide, but the burning of ancient, massive trees releases far more than the burning of younger forests. At the same time, the destruction of expansive old-growth forests—like those in Los Alerces National Park—reduces terrestrial carbon storage capacity.
A devastating blow to conservation efforts
As Los Alerces burns, carbon emissions aren’t the only cause for concern. The World Weather Attribution report states that the destruction of critical habitat is putting vulnerable species at risk, including the South Andean deer, the pudú (the world’s smallest deer species), and the Magellanic woodpecker.
The protection of this forest is also vital for the conservation of the Alerce tree, which is itself a threatened species.
The report concludes that wildfire poses a growing threat to this world heritage site and the flora and fauna it protects. Across both the Chilean and Argentine regions affected by the current wildfire crisis, all climate models project a continued shift toward more severe fire weather conditions alongside declining seasonal rainfall.
“This strong agreement among models gives us high confidence that the changes already observed are driven by climate change,” the report states.
It’s too soon to say how much damage the forests of Los Alerces will sustain from these fires, but if the global temperature continues to rise unabated, humanity may be the force that finally kills the park’s millennia-old giants.
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