https://indianexpress.com/article/explained/explained-climate/sea-levels-rising-9591199/

Key Points on Rising Sea Levels and Global Response

• Sea levels are rising faster now than at any point in the last 3,000 years, with the pace accelerating, particularly since the start of the 20th century. This poses a serious threat, especially to low-lying islands and coastal cities.
• Since 1880, global sea levels have risen more than 20 cm (8 inches), with the World Meteorological Organization reporting record heights in 2023.
• The rise is uneven due to ocean dynamics and the Earth’s gravity field. Some areas in the Southwestern Pacific have seen sea levels rise nearly twice the global rate since 1993.
• Global warming is the primary driver, caused by emissions like carbon dioxide and methane from the burning of fossil fuels. This leads to ocean heating, with the seas absorbing 90% of atmospheric warming in the past 50 years.
• The oceans heat up, leading to thermal expansion. Additionally, the melting of ice sheets and glaciers contributes significantly to rising sea levels, with 150 billion tons of ice lost annually from Antarctica and 270 billion tons from Greenland.
• The risk of climate tipping points is concerning. An increase beyond 1.5 degrees Celsius could trigger the irreversible collapse of the Greenland and West Antarctic ice sheets, leading to catastrophic sea level rise.
• By 2100, global sea levels could rise further by 38 to 56 cm, depending on how well global emissions are controlled. Some scenarios predict a rise of up to 2 meters by the end of the century.
• Every 2.5 cm of sea level rise leads to 2.5 meters of lost beachfront, with high tides and storm surges becoming more dangerous. For each centimeter of sea level rise, an estimated 6 million people are exposed to coastal flooding.

 

Impacts on Vulnerable Regions

• Small island nations like Fiji, Maldives, and Tuvalu face existential threats, even with moderate sea level rise.
• 40% of the global population lives near coastlines, with 900 million residing in low-elevation zones. Many areas are already experiencing coastal erosion, saltwater intrusion, and destructive flooding.
• Particularly vulnerable regions include river deltas, like those in Bangladesh, India, and China, as well as megacities such as Mumbai, Cairo, Los Angeles, London, and Lagos.

 

Response and Adaptation Measures

• The key to preventing catastrophic sea level rise is rapid emission reductions. However, some rise is inevitable, even if emissions stop now, due to the time lag between global warming and its impact on ocean temperatures and ice melting.
• Adaptation measures are essential. Countries are building sea walls, storm surge barriers, and enhancing drainage systems and flood-resistant infrastructure.
• Nature-based solutions are being employed, such as regenerating mangrove forests in regions like Cameroon, which help protect coastal areas from erosion and storms.
• Simple yet effective solutions include driving wooden stakes into beaches to combat erosion, as seen in Senegal.
• Long-term resilience involves both infrastructure development and natural ecosystem restoration, while international cooperation and funding for vulnerable regions remain crucial.

These key actions and insights are critical in managing the threat of rising seas and protecting coastal communities globally.