ROBIN ROY
The Nepal disaster may have happened weeks ago, but it is time we realise how speed ily we are heading towards a disaster and its apparent cost and impact on human lives. As we look at the statis tics, it is imperative to note that the ocean is rising fast er now than at any point in recorded history. Land, homes and livelihoods face an imminent threat. Rising sea levels threaten not only human lives and land but also human rights, economies, health and cul ture. Saving the climate and environment should, therefore, be a key agen da for governments and concerned agencies across the world. In the next 10 years, world leaders must set targets to tackle rising sea levels and counter this generational crisis. Between 2014 and 2023, global sea levels rose 4.7 mm a year. In 2024, the rise hit a record 5.9 mm.
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By optimistic esti mates, oceans could rise up to 0.55 metres by 2100 and, in the worst-case sce nario, by over a meter. What causes this • About 91% of the planet’s excess heat is ab sorbed by the oceans. As the climate warms due to increased harmful gas emissions, future rises are locked in. • Melting glaciers and ice sheets. • Thermal expansion — warming oceans take up more space. How it will impact hu man lives? Close to 770 million peo ple, roughly one in every 10 humans, live less than five metres above the high-tide line. Freshwater wells and farmland are turning salty, while flooding damages roads, schools, hospitals and sanitation systems. Flooding also leads to waterborne diseases and threatens drinking water supplies, adding to the psy chological stress of lakhs of people affected or living in fear. Coastal economies de pendent on fisheries and tourism are being disrupt ed. Some areas face severe land erosion following flooding and landslides, compounded by immense tree-felling. Some estimates suggest about 1.2 billion people could be displaced world wide by 2050 as they seek safer ground and places to rebuild their livelihoods.
Pay a hefty price Damage to coastal infra structure already exceeds Dollar 1.8 trillion. Small Island developing states lost Dollar 153 billion to climate hazards between 1970 and 2020. In the US, home insurance premi ums in disaster-risk are as jumped 33% between 2020 and 2023. Ports, which handle more than 80% of global trade, are increasingly exposed to flooding, threatening sup ply chains. Chances of going on back gear Some damage has al ready been done and the losses are irreparable. Much now depends on how far harmful emissions can be cut. The vulnerable points A few Pacific nations face relative sea-level rise of more than twice the global average and remain par ticularly vulnerable to in creasingly frequent flooding. Cities such as Dhaka, Mumbai and Kolkata are also at risk, according to a global report.
Adapting the future ASAP Governments and ad ministrations must focus on moving away from cli mate-changing fossil fuels to slow global warming. Early-warning and upgrad ed meteorological systems are needed to alert peo ple. Better data reception and management are also essential as many regions still lack basic monitoring of sea conditions. Develop ing countries need an esti mated Dollar 310-365 bil lion a year for adaptation, while global adaptation finance was pegged at only around Dollar 26 billion in 2023. Facts not fiction Between about 21,000 and 11,700 years ago, Earth warmed about 4°C (7.2°F) and oceans rose, with a slight lag after warming began, about 85 metres, or 280 feet. Sea levels continued ris ing another 45 metres, or about 150 feet, after the warming ended, taking the total rise to 130 metres, or about 430 feet. They reached their modern level about 3,000 years ago. From about 3,000 years ago to around 100 years ago, sea levels naturally rose and declined slightly, with little change in the overall trend. Over the past 100 years, global temperatures have risen about 1°C (1.8°F), with sea levels rising about 160-210 mm, or six to eight inches.
About half of that rise has occurred since 1993. The current rate of sea-level rise is unprece dented over the past sever al millennia. Key data Global sea levels rose at an average 4.7 mm a year from 2014 to 2023, with the increase reaching a re cord 5.9 mm in 2024, driv en by ocean warming and melting glaciers. Historical data compiled by NASA and reported in Communications Earth & Environment show that global mean sea level has risen over 11 cm since 1993. The average annual rise increased from 3.6 mm during 2006-2015 to 4.7 mm during 2014-2023 and around 5.9 mm in 2024. Sea-level rise is not uni form. Regional ocean cur rents, changes in Earth’s gravity caused by melting ice and local land subsid ence mean communities in the Western Pacific and In dian Ocean regions can ex perience rises much higher than the global average.
In some regions, ocean warming is occurring fast er than at any time in the past 4,000 years, and the rate is expected to continue increasing through 2050. The annual rate of sea-level rise was 4.75 mm during 2012-2025, with the 2025 global mean sea level remaining compara ble to the record-high lev els of 2024. This followed a rapid rise of about 5 mm during 2023-2024 ow ing to exceptional ocean warming associated with El Niño. What’s in Global temperatures passing 1.5°C will trig ger longer, harder and more frequent heat waves. Every fraction of a degree of warming brings worse storms, heavier floods and prolonged droughts. Glaciers will shrink fur ther, adding to rising sea levels and threatening coastal com munities. (Robin Roy is a Senior Journalist and former Senior Associate Editor, O Heraldo, Goa)
