July 5, 2022
NEW DELHI – Climate change has stamped its signature on the world’s oceans and atmosphere. A primary contributor to climate change is global warming, which modulates the wind and wave field patterns, sea surface temperature, and sea level pressure anomalies. These changes may result in oceanic warming and hasten the melting of ice caps, ice sheets, and glaciers, leading to accelerated sea level rise (SLR) globally and regionally. Rising sea levels pose a potential threat to the habitat of coastal and offshore communities by intensifying the impacts of coastal hazards such as floods, storm surges, tsunamis, high tides, extreme waves, and erosion in the low-lying areas.
The Paris Agreement of 2015 (UNFCCC 2015) proposed to restrict the increases in global warming to well below 2.0°C above the preindustrial level, preferably to 1.5°C. The amount by which sea levels rise as a result of ice sheet melting might be nearly halved if global warming is kept to 1.5°C. However, a recent report from the Intergovernmental Panel on Climate Change (IPCC) portrays a rather gloomy picture of the challenges we confront due to SLR. On a global scale, the sea level is continuously rising and “accelerating” at the rate of 3.6 mm per year. The IPCC’s sixth assessment report (AR6, 2022) also notes that human imprints have enhanced greenhouse gas emissions, contributing to fast-rising sea levels.
Over the course of the twenty first century, the risk along the coastlines ill increase by at least one order of magnitude. These hazards are primarily focused in and around coastal towns and settlements. They will intensify beyond 2050, and will continue to worsen well through 2100, even if global warming ceases. By 2100, historically catastrophic and extreme sea-level rises will happen every year, endangering the lives of millions of people who live near the coast. In the coming decades, increased exposure to SLR will be caused mainly by rapid urbanization and population expansion in lowlying coastal zones. In Africa, 108–116 million people will be exposed to SLR by 2030 (compared to 54 million in 2000), and the number will rise to 190–245 million by 2060.
According to the IPCC’s AR6, by 2050, a billion people living in low-lying cities and towns will be at risk from climate hazards. If the global mean sea level rises by 0.15 m relative to current levels, the population in coastal towns and communities at risk of a catastrophic coastal flood will grow by about 20 per cent. By the end of the twenty first century, coastal flood damage in Europe is expected to spike least ten fold with existing adaptation and mitigation measures. As curated by IPCC, it is anticipated that as many as 510 million people and as much as US$12,739 billion in assets will be exposed by 2100 in several coastal regions across the globe. Overall, the damage is projected to reach far beyond coastal towns and cities.
Severe damage to ports is likely to endanger global supply chains and maritime trade, with broad geopolitical and economic repercussions. If nations enhance their collective mitigation targets and move towards adaptation, there is some optimism amid these concerns. Hoe sung Lee, the head of the IPCC, urged the fostering of resilience as a part of adaptation efforts. He observed, “If we reduce emissions sharply, the consequences for people and their livelihoods will still be challenging, but potentially more manageable for …. the most vulnerable.” The only solution is to adapt, plan and build infrastructure that is climate resilient.