Drought Threatens Increased Tree Mortality: Earth to Grow Heavier with Warmth
Trees stand as nature’s quiet guardians. They offer shade, call forth the rains, hold the soil firmly in place, and gift us oxygen for breathing. Yet, intensifying droughts are gradually draining the strength of these quiet protectors. A global study warns that droughts in tropical areas will raise tree deaths, significantly affecting the Earth’s temperature and environmental balance.
This research was conducted by Professor Pieter Zuidema from Wageningen University in the Netherlands and Professor Pieter Greenberg from the University of Campinas in Brazil. Collaborators included Professor Mizanur Rahman from Shahjalal University of Science and Technology, Professor Valerie Trouet from the University of Arizona, and Professor Florin Babst, among others. The study titled “Small Effects of Drought on Stem Growth in Tropical Trees” was published in the journal Science on July 31, 2025.
The study analyzed nearly a century of data. From 1930 to the 2020s, researchers examined the growth rings of more than 20,000 trees from 500 sites across 36 countries. They studied the most severe drought years, assessing how much tree growth slowed during those times and how much trees recovered in the next two years. Tree rings function as nature’s silent chronicle, with each ring encapsulating the climatic narrative of its respective year.
In the world’s tropical regions, the study found that tree growth drops by an average of 2.5% during drought years. Most trees regain their previous growth rate the following year. However, in Bangladesh, the situation is far harsher. Professor Mizanur Rahman reported that in drought years, tree growth there can fall by nearly half. In 1999, the severe drought caused chikrashi tree growth in the Rema-Kalenga forest to decline by 55% from the previous year.
The study further revealed that drought could cause an additional 0.1% of trees to die each year. While that figure may seem small, its impact is enormous. Fewer trees reduce carbon absorption, and when trees die and decay, they release more carbon into the atmosphere. This contributes to further warming of the planet and makes the challenges of climate change even more complex.
So far, tropical forests have shown a relatively quick recovery after drought. But if climate change is not halted, the frequency and severity of droughts will increase, gradually eroding this resilience. Professor Mizanur Rahman states, “Nature can heal itself, but if we push it too hard, it will eventually fail to cope.”
Trees are not just green canopies—they are the lungs of our planet. Protecting them means protecting our own future. In this age of drought, climate change, and human-induced pressures, safeguarding trees has become an unavoidable commitment to nature itself.
