Experts have raised concerns that high winds linked to the El Niño phenomenon could lead to significant tree mortality among species already stressed by an extended period of extreme heat and drought.
This summer, Europe has experienced a series of unprecedented heatwaves attributed to the climate crisis, severely impacting the English countryside where lush greenery has turned brown. Many trees are exhibiting signs of “early autumn,” shedding leaves prematurely as a response to the excessive heat.
Kevin Martin, who oversees tree collections at Kew Gardens, explained that due to these harsh conditions, trees have struggled to grow normally, resulting in increased brittleness and reduced flexibility.
“If we encounter the severe winds anticipated this year as a result of El Niño, we could witness significant consequences for the trees,” he stated.
The UK’s Met Office has indicated that the El Niño event, which is currently developing in the Pacific, is expected to be the most potent in over a century, leading to forecasts of heightened rainfall and storms affecting the UK this autumn. El Niño, a natural climate occurrence, is exacerbated by global warming.
Martin expressed concern that such extreme weather could cause root death, where the transition from dry conditions to heavy rainfall destabilizes the soil structure.
“We may begin to see some trees fail at their root plates. I have serious concerns about this autumn,” he remarked.
This year’s severe weather has been so drastic that Martin believes some tree species could vanish from certain landscapes entirely. “We might see the loss of species such as silver birch, common beech, and oak from areas where they have long been prevalent,” he noted.
The heat has disproportionately impacted the oldest trees, with warnings that England’s ancient oaks are suffering due to the hot and dry climate.
Martin pointed out that the spring heatwave of 2026, which saw temperatures soar to 35°C, established a record for the hottest May ever. “This entire growing season has been under immense stress, and I don’t think we’ve faced environmental impacts of this magnitude before,” he remarked.
Simon Richmond, a technical officer at the Arboricultural Association, acknowledged that trees are remarkably resilient and can adapt to occasional extreme weather events. However, he cautioned that the real threat lies in the likelihood of these patterns becoming more persistent due to climate change.
Following the heatwave of 2022, Kew Gardens lost over 400 trees due to heat and drought conditions. Martin anticipates that the repercussions of the 2026 heatwave could be even more severe.
“From my observations at Kew, I expect to see a significant increase in tree mortality compared to 2022 because many trees that survived last year may not endure this year’s conditions,” he stated. Nonetheless, he emphasized that the full extent of this year’s extreme weather effects may not be fully understood for another two to three years.
Marcus Lindner, a principal scientist at the European Forest Institute, warned that multiple years of extreme weather could push certain tree species beyond their limits, with nearly all tree types facing risks from the evolving climate.
“Typically, drought-resistant species can handle a certain degree of drought stress, but continuous and repeated drought can eventually overwhelm even these trees,” he cautioned.
