A new scientific assessment has found that human-driven climate change and decades of ecological disruption sharply intensified the deadly floods that swept across South and Southeast Asia in late 2025, leaving hundreds dead and millions struggling to recover.
Researchers from City University of Hong Kong examined the unfolding disaster and concluded that the season’s rainfall-already strong-was made far more destructive by a combination of global warming, rapid urban expansion, and the loss of natural flood barriers. According to the team, these forces created a “compounding effect” that transformed normal monsoon conditions into a sweeping regional crisis.
Thailand endured the heaviest toll, with 182 confirmed deaths and more than 1 million people affected. Weeks of unrelenting floodwaters inundated large swaths of Prachinburi, Nakhon Nayok and Chachoengsao, where entire neighborhoods remained submerged long after the storms passed. National authorities reported damage to over 400 roads and nearly 50 bridges, straining the country’s transportation and logistics networks.
The study highlights three interconnected human influences behind the disaster:
- Global heating: A warmer atmosphere held significantly more moisture, fueling intense, erratic rainfall that exceeded the region’s drainage capacity.
- Urbanization: Sprawling development replaced wetlands and open spaces with concrete, leaving stormwater with nowhere to go except rapidly into streets and communities.
- Ecosystem degradation: Mangrove forests and natural floodplains-once a vital buffer against storm surges-have steadily disappeared, removing critical protection for coastal and low-lying areas.
Beyond Thailand, the floods battered neighboring countries as well. Southern India also recorded deaths, with Tamil Nadu and Kerala seeing widespread inundation and landslides. Vietnam faced extensive displacement as rising waters triggered evacuations and crippled infrastructure.
The economic fallout has been severe. Industrial hubs in Thailand experienced temporary shutdowns, affecting supply chains for electronics and automobiles. Large tracts of farmland across the region remain underwater, raising concerns about food security and long-term livelihoods for rural communities.
While governments have mobilized soldiers, emergency responders, and shelters to support affected residents, the study warns that disaster response alone will not be enough. Scientists argue that countries must urgently invest in long-term resilience-restoring mangroves, protecting floodplains, expanding urban green spaces, and adopting planning policies that respect natural water systems.
Without such systemic change, the researchers caution, Asia could see increasingly lethal floods as climate change accelerates and the region’s population grows.
