For years, the main threats to tropical forests were seen as drought, heat, rising carbon dioxide, and raging wildfires. But new research reveals that a quieter, often-overlooked culprit may be doing more damage than previously imagined thunderstorms. According to a study published in Ecology Letters on July 1, 2025, these short-lived but intense convective storms could be behind a significant portion of tree deaths across the Amazon.
The study found that convective storms may account for up to 50% of the observed rise in biomass mortality in tropical forests. In some scenarios, the impact could be as low as 12%, or as high as a staggering 118%, depending on various assumptions and data interpretations. The sheer scale of this finding has stunned ecologists, as these storms which span just tens to hundreds of square kilometres had long been considered minor events in comparison to prolonged droughts or fires.
Convective storms are known for their intense winds, towering clouds, and dangerous lightning strikes. Unlike massive cyclones or hurricanes, these storms are localised and short-term, but their power lies in concentrated destruction. Wind and lightning both common features of these storms are now recognized as major drivers of pantropical tree mortality.
Drawing from Amazonian forest inventory data, researchers observed that over half of all tree deaths were due to breakage or uprooting, likely a result of high wind events. The research also revealed the lethal power of lightning. A single strike can damage up to 24 trees and kill about five, even without igniting a fire. With an estimated 35–67 million lightning strikes hitting tropical forests each year, the cumulative toll reaches into the billions.
The study’s lead author, Evan Gora of the Cary Institute of Ecosystem Studies, and his team argue that storms have long been neglected in climate and forest carbon models. Their analysis shows that storms are already responsible for 30–60% of biomass loss across tropical forests a figure comparable to the impact of heat and drought, both of which are more widely studied and discussed.
Perhaps more worrying is the trend these storms are following. Over the past five decades, storm activity in tropical regions has increased by 5–25% per decade, and this is expected to accelerate with global warming. If the frequency and intensity of these convective storms continue to rise, tree mortality will increase accordingly weakening one of the world’s most critical carbon sinks.
The findings have far-reaching implications. As forests lose more trees to storms, their ability to absorb carbon dioxide diminishes, undermining one of the key natural buffers against climate change. Yet, thunderstorm-related forest damage continues to receive little attention in international climate policies and conservation strategies.
The researchers warn that without incorporating storm activity into carbon budget models and forest conservation plans, efforts to combat deforestation and climate change could fall short. In the battle to protect tropical forests, understanding the true causes of tree death is essential — and thunderstorms, once ignored, are now commanding attention