Threat from rising sea levels

Recently, the Intergovernmental Panel on Climate change has released the fifth assessment report on the Impacts, Vulnerability and Adaptation aspects. The report extensively covers the challenges posed to the small island developing states and the unique conditions they face. There are nearly 52 islands as recorded by the United Nations Department for Economic and Social Affairs.

The islands face threats from not only the rising sea levels but also exposure to cyclones and storm surges. Sea levels are projected to increase with a greater degree of certainty with the thermal expansion of oceans and snow and ice melt contributions. It is predicted that while the frequency of cyclones in the future may not increase, the intensities are likely to increase.

Impact are widespread with loss of land due to inundation, degradation of land due to salinization, contamination of surface and ground water sources, and coastal erosion. Rising sea surface temperatures and sea acidification affect corals and fish availability and its diversity, further affecting the economy and disrupting the social structure in many of these countries where fisheries and tourism constitutes a significant share of incomes.

Low lying coastal areas and small islands are to be the most affected, given the limited space in which population and infrastructure are concentrated. Coastal flooding and damage to life and property are likely to be huge. Island communities thus will be greatly affected and will end up paying a huge price for environmental damage. These impacts however are influenced by other factors also, like sea water contamination, pollution loads, subsidence, sedimentation and tectonic activities.

The extent of risk however would vary from one island to the other and will be determinant on many factors apart from the exposure, including geographical location, geomorphological features and socioeconomic conditions that define adaptive capacities of a region. For instance, the risk to the east and west coast of India is likely to vary, and many islands or island countries below a metre face a threat of inundation and loss of land.

In some cases island countries like Tuvalu have no options and face extreme risks of getting inundated no matter how much the adaptive capacity were to vary. The Polynesian archipelago is bound to be inundated dislocating its entire population. The islands are just 10 cm above sea level. Many of their islands have already become uninhabitable. Tuvalu is not alone other small island nations like Kirabati, the Marshall Islands and the Maldives are also in the same league. A new domain of legal experts exploring climate change law has now emerged internationally fighting for the rights of citizens who are likely to be affected.

However, there are many challenges to this as in many cases there is no clarity or consistency in the understanding of issues and with many areas not defined, the whole subject actually has a certain sense of vagueness surrounding it.

Adaptation to climate change may assist in reducing the risks to the islands but may not be able to avert the conditions.

Coastal protection, risk proofing infra-structure, protection of marine biodiversity, promotion of rain water harvesting structures, and storm water drainage systems are some of the options being explored in these countries. The most recent study on costs for coastal protection from sea level rise in Singapore highlighted the costs to US$0.3-5.7 million by 2050 to $0.9-16.8 million by 2100. Given that some of the costs for protection are huge, there is a need for international assistance that can strengthen the response mechanism and help islands to adapt better to the posed risks. Co-benefits of adaptation measures to mitigation could be explored especially in the tourism sector. Public out-reach and awareness on the risks will play a critical role in response to extremes.

Tags: Rising sea level