Snakes On The Move: Climate Change To Push India's Deadly 'Big Four' To North, Northeast

A new scientific study published in PLOS Neglected Tropical Diseases warns that climate change could change where India's most dangerous snakes live,  pushing the so-called 'Big Four' species toward the northern and northeastern states over the next five decades. The shift could create new snakebite hotspots in areas that so far have seen few deadly snake encounters.

India already bears the heaviest burden of snakebite deaths in the world. Annual fatalities in the country are estimated between 46,000 and 60,000, far higher than in any other nation. The World Health Organization and recent studies have repeatedly flagged snakebite as a major but neglected public-health problem in India.

The fatal 'Big Four' Indian snakes

The 'Big Four', namely the Spectacled Cobra (Naja naja), Common Krait (Bungarus caeruleus), Russell's Viper (Daboia russelii), and Saw-scaled Viper (Echis carinatus), cause most fatal envenoming in India. The study says these four snake species account for the vast majority of dangerous bites and therefore drive most snakebite deaths nationwide. 

Researchers used species distribution models, climate scenarios and district-level socioeconomic and health data to map current habitats and predict future changes. They combined these outputs into a snakebite risk index to show which districts and states may face higher or lower risk under different climate pathways. The analysis highlights both losses and gains in suitable habitat for the Big Four, depending on the species and region.

Today, many of the highest-risk areas are in southern and eastern states. States such as Andhra Pradesh, Uttar Pradesh, Kerala, West Bengal, Odisha and Maharashtra currently register high numbers of snakebite deaths and remain areas of serious concern. Meanwhile, Karnataka presently shows extensive highly suitable habitat for several species - especially the saw-scaled viper.

But the study's models show a marked northward and northeastward shift in future suitability for the Big Four. Regions that now have little or no suitable habitat, including parts of Manipur, Meghalaya, Nagaland and Arunachal Pradesh, could see large increases in habitat suitability. For some northeastern states the projected rise in suitable habitat exceeds 100%, researchers say, raising the prospect of new and expanding risk zones for snakebite.

This geographical shift matters because the projected expansion overlaps with farming areas and growing towns. That means more people, including those who work in fields or live near forest edges, may face greater chances of encountering venomous snakes. The paper warns that such changes could complicate medical management and prevention of snakebite across both rural and urban settings.

Awareness and healthcare upgrades a MUST!

Public-health experts say the findings point to clear action areas. Health systems must broaden antivenom availability, train doctors in correct treatment and strengthen rural emergency care. Community awareness programmes, safer agricultural practices, better protective clothing for field workers, and faster transport for bite victims are also needed. International and national coordination will be important to match antivenom stocks with changing local risks.

The study's authors call for targeted planning at state and district levels. They argue that mapping likely future hotspots can help authorities pre-position antivenom, upgrade primary health centres, and run prevention campaigns where risk is growing. Without such steps, areas newly exposed to venomous snakes could face higher death and disability rates.

In short, climate change may redraw the map of snakebite risk in India. That makes it urgent to treat snakebite not only as a rural, local problem but as a dynamic, climate-sensitive public-health challenge. Policymakers, health officials and scientists need to work together now so the country can save lives as habitats and risks shift in the coming decades.

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