A BIMSTEC problem: Weathering climate threats in South Asia

South Asia is confronting a new class of security threats—those driven by climate change.

- Tarun Agarwal & Pooja Arora

In the BIMSTEC countries (Bangladesh, Bhutan, India, Myanmar, Nepal, Sri Lanka, and Thailand), rising seas, erratic weather patterns, and ecological degradation are no longer merely environmental concerns; they have become accelerators of instability. Major urban centres like Dhaka, Kolkata, Yangon, and Bangkok are among the most at-risk globally.

Among the most urgent knock-on effects of climate stress is the growing wave of human migration—first internal, then potentially international. As large swathes of land become uninhabitable due to salinization, floods, and drought, people are increasingly moving in search of stability, water, and opportunity. According to the World Bank, South Asia could see around 40 million internal climate migrants by 2050 in the absence of concerted action. These urban influxes can become flashpoints for tension, particularly in contexts already marked by inequality, ethnic divides, or resource scarcity. As climate shocks intensify, there's also the possibility that migration will spill across national borders—particularly from Bangladesh into India's northeastern states, where terrain is higher and perceived safety is greater. Assam has long been a site of agitation over alleged Bangladeshi immigration; climate migration could exacerbate these tensions, fuelling 'insider vs. outsider' narratives and ethnic polarization.