By Suchismita Pattanaik
In a true sense, all continents in the world are Islands. However, big and developed nations being part of a large continent are reasonably safe during climatic hazards and natural calamities. Conventionally, small land areas surrounded by seas and oceans are referred to as islands that occupy only 5.3% of the global terrestrial area. Nevertheless, they have wide biodiversity hosting around 19% of bird species, 17% of rodents, 17% of flowering plants, and 27% of human languages. The endemism of the Islands is far more than continents. Out of 35 biodiversity hotspots in the world, ten are based on islands. The climate changes not only threaten the existence of these islands but also the diversity on islands is threatened. Many of them started disappearing either in whole or in parts in the last century. A recent study of 4500 islands in ten biodiversity hotspots found that with a 1 to 6 meter rise in sea level, 6 to 19 percent of these islands might be completely inundated, endangering the extinction of over 300 endemic species. The principal cause is rising sea levels as a result of climate change. Climate change and its impacts on the ecosystem are going to be severe in the forthcoming days. The oceans are getting warmer and the corresponding increase in the volume of water leads to sea-level rise. The other phenomena that are adding to the sea level rise are the rapid melting of ice sheets and glaciers over the past century. According to the Intergovernmental Panel on Climate Change, some islands and coastal districts will be drowned in due course due to the predicted rise in sea level induced by rising CO2 levels in the atmosphere (IPCC). There is sufficient evidence that the global sea level has risen gradually in the latter half of the twentieth century, owing mostly to human activity. Prior to the 19th century, the sea level has not altered considerably for 2 to 3 thousand years, according to the IPCC assessment. In comparison, the worldwide average sea level rose at a rate of roughly 1.7 millimeters per year over the twentieth century. The IPCC’s First through Fourth Assessment Reports estimated potential sea-level rises of 31-110 cm, 13-94 cm, 9-88 cm, and 18-59 cm, respectively, by 2100. Different climate models and scenarios for greenhouse gas (GHG) emissions were used to compute these expected rises. According to tidal gauges, the worldwide sea level has risen by around 7 inches. Satellite data show that this number has increased about twice as rapidly in the last 20 years as it has in the previous century, growing at a pace of 3mm/year. So, during the next century, how much will the sea level rise? It’s a difficult question to accurately answer. Although we have worldwide sea-level rise data, they vary based on offshore oceanographic conditions and whether the land is rising or sinking owing to tectonic activity. For example, the land is rising near San Diego, California, due to tectonic plate movement, thus negating sea level rise. Nevertheless, a large offshore earthquake might produce quick subsidence of the landmass, resulting in an immediate rise in sea level. Climate change and sea-level rise observations and predictions show that the sea level will continue to rise significantly in the future. However, there exist uncertainties, Comments 27 which make precise forecasts impossible. The further we proceed in time, the more are the uncertainties. The impact of the sea-level rise shall have a disastrous consequence on certain coastal and low-land areas of the world. Many west coast communities already experienced coastal erosion, flooding, inundation, and loss of wetlands due to elevated sea level. Millions of people living in the low-lying areas are going to be the “climate change refugees” as their residences would be under the sea. Near about 13-94 million people residing in coastal areas are going to be homeless and landless by the end of the 21st century due to a possible 40 cm sea-level rise. Most parts of South- and Southeast Asia could be submerged under seawater. The major land area of Bangladesh, along with the major cities of India such as Mumbai, Kolkata and Chennai, is likely to be submerged. The atoll islands are subjected to increasing environmental stressors, and the coral reef being the most sensitive species, may not withstand these adverse environmental conditions. Global climate change is pushing for greater floods, coastal erosion, and salinity intrusion, which is weakening the resilience and viability of tiny island ecosystems, causing migration and reducing the ability of islands to maintain human habitations. Islands like Kiribati, Tuvalu, the Marshall Islands, and the Maldives may eventually be completely submerged. The Maldives is inviting tourists with the marketing slogan, “ come to Maldives before we disappear”. The inundation of such highly populated areas worldwide would cause a massive displacement of people (climate refugees) from low-lying areas. Climate change displacements have already happened but have not grabbed the necessary attention of the common people. According to the World Vision International study, the islanders have given up their hope and consented to be among the world’s first “climate change refugees” after a fight against the ocean for more than twenty years (building sea walls and planting mangroves). The islanders are victims of something that they are neither responsible for nor have committed. These islands belong to them and their future generations. They are not enjoying the privileged status of industrialized countries whereas they are taking the toll. The islands are experiencing and suffering from the brunt of these greenhouse gases. The climate change that is caused by us is taking away the sovereignty of the people. It may happen that the words ‘island’ and the ‘islanders’ shall migrate from the Oxford dictionary and take refuge in the storybooks of our grandchildren. The future policy, developmental goal, and research should be concentrated on better understanding and predicting the rise in sealevel and impacts of climatic shifts at both the organismal and ecosystem levels on islands. More so, islands should be considered as the priority areas for integrated conservation efforts because they have 14 times greater density of critically endangered terrestrial species and six times greater density of critically endangered languages than continental areas. Invasive species and habitat loss are the most significant threats to island terrestrial species diversity. Further, the outcome of the research should be rapidly integrated into the planning and prioritizations to combat the adverse effects of climate change. The assessment also focused on the island’s species that are most likely to be at risk from future climate change and the options for preventing their extinction. Proven management actions can reduce the threats, benefiting both local peoples and species diversity on islands. The nations should collectively and cumulatively involve in coastal management and policymaking with an objective for future robust coastal-management planning. There should be binding agreements and mainstreaming of policies incorporating both national and international agencies for the islanders to save their lives, livelihood, their lands, their rights and their sovereignty.