A new study published in Nature has revealed that two per cent of the world’s amphibians are already experiencing temperatures beyond their tolerance limits raising alarms about the impact of global warming on these highly vulnerable species.
Researchers studied 5,203 amphibian species and found that 104 are already exposed to overheating in shaded terrestrial conditions. The study warns that if global temperatures rise by 4°C, as many as 7.5 per cent (391 species) could be pushed beyond their physiological limits, significantly increasing the risk of extinction.
Amphibians are ectothermic meaning they regulate body heat using external sources. As over 40 per cent of amphibian species are already under threat rising thermal extremes could accelerate their decline. Scientists analyzed their ability to withstand extreme heat in various habitats, including terrestrial, aquatic and arboreal environments.
The study assumed that amphibians have access to 85 per cent shade and sufficient water to prevent desiccation. However, it warns that habitat destruction, urbanization, and shrinking shaded areas could exacerbate their vulnerability.
The Tipping Point: 2°C or 4°C?
Patrice Pottier, a postdoctoral researcher at the University of New South Wales and lead author of the study noted that species in the Southern Hemisphere’s tropical regions face the highest overheating risks, while non-tropical species in the Northern Hemisphere are also significantly impacted.
Beyond 2°C warming, the effects escalate disproportionately. If temperatures rise by 4°C, shaded terrestrial species could experience overheating on nearly 23 per cent of the year’s warmest days, while arboreal species could face overheating events on 76 days annually.
Although many amphibians can regulate their body temperatures using water bodies, ongoing deforestation and droughts threaten these crucial cooling refuges. Without them, species will be at greater risk of overheating, leading to potential local extinctions.
Amphibians play a crucial role in ecosystems and their decline could disrupt food chains reduce genetic diversity, and harm overall biodiversity. Even before reaching their heat tolerance thresholds, prolonged exposure to high temperatures can disrupt their reproductive cycles, activity levels and survival rates.
As climate change accelerates, protecting amphibian habitats will be critical to preventing widespread losses. The study highlights the urgent need for conservation strategies to safeguard these vulnerable species from a rapidly warming world.