Impacts of Climate Change on Biological Diversity: A Sri Lankan Perspective on Vulnerability and Resilience

Abstract

There is now a growing body of evidence that climate change is likely to cause adverse impacts on biodiversity worldwide. Sri Lanka, a tropical island supporting exceptionally high levels of biodiversity and endemism, would be particularly vulnerable, with varying impacts on species and habitats. There is a dearth of information locally on direct impacts of climate change on species. But circumstantial evidence from Sri Lanka and elsewhere suggests that a rise in global temperature is likely to alter life history traits, retard growth, alter rates of development, and cause physiological malfunctioning in both plants and animals leading to range reductions and shifts in distribution. Global warming would also hinder processes such as nutrient cycling which are critical for functioning of many natural ecosystems. Climate change will also bring about numerous other biophysical changes affecting Sri Lanka such as increased frequency of flooding and prolonged drought, which will be especially detrimental to species inhabiting ephemeral aquatic habitats and those in the dry and arid zones where water is limiting. Global warming and sea level rise combined will affect intertidal habitats (e.g. mangroves) and marine ecosystems (e.g. coral reefs) which are important in the context of the island’s biodiversity. The depletion and fragmentation of the country’s natural forest cover coupled with overexploitation has already placed many of the country’s species at the brink of extinction. Climate change would exacerbate the situation. This paper deals with the potential impacts of climate change on components of biodiversity in Sri Lanka, citing local examples. Activities that could build resilience of species and habitats, facilitating adaptation and tolerance, are also discussed.