Climate Change Fuels Surge In Snakebites In Sri Lanka

Shakila Ifham

September 14, 2024

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In the heart of tropical and subtropical regions, a silent and deadly threat slithers under the
radar, growing more menacing with each passing year. As the planet heats up and weather
patterns become increasingly erratic, venomous snakes are emerging as an unexpected yet
lethal consequence of climate change. This story delves into the alarming rise in snakebite
incidents and how the shifting climate is exacerbating the danger posed by these stealthy
predators.

A recent study conducted by an expert team, including Gerardo Martín, Joseph James Erinjery,
Dileepa Ediriweera, Eyal Goldstein, and other international researchers, provides critical
insights into how these global changes will impact human-snake interactions in the coming
decades.
Socioeconomic Pathway (SSP) scenario analysis framework, WorldClim data, regional climate
models(RCM) and population density data was employed by the team to study the envenoming
patterns up to 2050.
One of the study’s key findings is that climate change, particularly rising temperatures, will
significantly affect snake physiology, as snakes are ectotherms (relying on external heat
sources). Additionally, land cover changes, primarily driven by human population growth,
directly alter snake habitats. This interaction between climate, land use, and human
populations is central to understanding future snakebite risks.
Sri Lanka, with its diverse landscape and significant human-snake interaction, is particularly
vulnerable. In the central highlands, where temperatures are expected to rise, venomous
snakes are likely to migrate to higher altitudes to track favorable conditions. This shift is
predicted to increase snakebite risk in these areas, which traditionally experience fewer
incidents.
The study focused on seven medically significant snake species found in Sri Lanka, including the
Russell’s viper (Daboia russelii), the Sri Lankan krait (Bungarus ceylonicus), and the common

cobra (Naja naja). Predictions show that changes in climate and habitat could lead to increased
snake abundance in certain regions, posing a greater threat to local populations.
The team of scientist also stated that, “We projected the snake abundance models using the
average climate of each year and the two preceding. To feed the snakebite envenoming model
with predictions of snake abundance, human population density, and land cover, we upscaled
the 1 km 2 predictions to 25 km 2 by aggregating snake point intensity and population density;
land cover predictions were upscaled by majority vote, assigning the class to the upscaled area
depending on which class covered the largest area in the 1 km 2 area.”

To obtain annual pixel-wise human population values, the bias-corrected population with piece
wise Hermite polynomials for every year between the intervals 2010–2020–2030–2040–2050
was used.

However, human population growth may counterbalance some of the climate-driven increases
in snakebite risk. As more people settle and develop land, human-snake competition intensifies,
which might decrease snakebite incidence in populated areas. This interaction highlights the
complex relationship between environmental change and human activity.
The findings suggest that as Sri Lanka’s landscape changes, biodiversity loss could further alter
snake abundance patterns, with certain species adapting and others potentially declining. The
study underscores the importance of balancing land development with the preservation of
natural habitats, as the repercussions extend beyond wildlife conservation to public health.
The country must prepare for the dual challenges of managing climate change and safeguarding
against the increased threat of snakebites. This research highlights the need for integrated
conservation and public health strategies, ensuring that as Sri Lanka’s population grows and its
landscapes shift, both human and ecological well-being are prioritized.