Climate change is expected to trigger the widespread migration of venomous snake species to new regions and countries ill-prepared for their arrival, a new study revealed.

The researchers project that Nepal, Niger, Namibia, China, and Myanmar will experience the greatest influx of venomous snakes from neighboring nations as temperatures rise.

Low-income countries in South and Southeast Asia, as well as parts of Africa, will face heightened vulnerability to snakebites due to the increased presence of venomous snakes, as outlined in the findings published in Lancet Planetary Health.

The study further utilized modeling techniques to assess the potential geographical distribution of 209 venomous snake species that pose medical threats to humans, aiming to identify regions where these species may thrive under climatic conditions projected for the year 2070.

Winners and losers among venomous snake species

Although most venomous snake species are expected to see their habitats shrink due to the loss of tropical and subtropical ecosystems, the study revealed that certain species, such as the West African gaboon viper, may experience an expansion of their habitats by up to 250%.

The ranges of the European asp and the horned viper are also predicted to more than double by the year 2070. However, other species, like the variable bush viper in Africa and the hog-nosed pit viper in the Americas, are projected to lose over 70% of their habitat range.

“As more land is converted for agriculture and livestock rearing, it destroys and fragments the natural habitats that snakes rely on,” said study authors Pablo Ariel Martinez at the Federal University of Sergipe in Brazil and Talita F Amado at the German Centre for Integrative Biodiversity Research in Leipzig, Germany.

“However, some generalist snake species, especially those of medical concern, can adapt to agricultural landscapes and even thrive in certain crop fields or livestock areas that provide food sources like rodents,” the study authors stressed.

“Our research shows that when venomous snakes start showing up in new places, it’s a wake-up call for us to start thinking about how we can keep ourselves and our environment safe,” they added.

According to the World Health Organization (WHO), an estimated 1.8 to 2.7 million individuals suffer venomous snakebites annually, resulting in up to 138,000 fatalities and at least 400,000 cases of amputation or permanent disability. In 2017, the WHO classified snakebite envenomation as a neglected tropical disease of utmost concern.
 
“We are now finally getting a better handle on how snakes will change their distributions with climate change but there is also a major concern that they will bite more people if warm temperatures, severe wet weather events, and flooding that displaces snakes and people get more frequent,” said Anna Pintor, a research scientist with the WHO’s neglected tropical diseases group.

“We urgently need to understand better how exactly this will affect where people get bitten, and how many people get bitten so that we can prepare,” Pintor added.