New studies show that the problem is increasing twice as fast as previously thought
The growing problem of sea level rise can end up provoking that one in ten people on the planet has to leave their homeaccording to two recent scientific studies, one from the World Meteorological Organization and another published in the journal Earth’s Future from the American Geophysical Union (AGU). This conclusion considerably worsens the forecasts that were made up to now.
The AGU study concludes that the increase in flooding now detected will occur in the section of the first two meters of sea level rise. That means water will cover more than twice the land than old models of sea level rise predicted.
This worsening of predictions is due to high-resolution measurements of Earth’s elevation provided by NASA’s ICESat-2 lidar satellite. Previous assessments used to rely on radar data, which is less accurate.
“Radar is unable to fully penetrate vegetation and therefore overestimates surface elevation”, interpreting that as solid ground, said Ronald Vernimmen, a researcher who led the study. “Many coastal areas are lower than scientists believed,” he added.
Overestimating the elevation of the land means that coastal communities have less time than anticipated to prepare for sea level rise, and that the greatest impacts of sea rise will occur sooner than previously thought.
After the measurements, Vernimmen and Aljosja Hooijer, co-author of the study, discovered that coastal areas are much lower than old radar data suggested. Analyzes of the new model revealed that uA two-meter rise in sea level would cover up to 2.4 times more land area than previous models had shown radar based. This threatens the homes of 900 million people, and some 400 million of them 80 years from now.
Entire cities under the sea
For example, a 2 meter rise in sea level could bring most of Bangkok, Thailand, and its 10 million people below sea level. Whereas previous data suggested that Bangkok would still be largely above mean sea level with that same amount of sea level rise.
In total, with a two meter rise in sea level, Vernimmen and Hooijer calculate that 240 million people more will live below mean sea level. After 3 and 4 meters of sea level rise, that number increases by 140 million and 116 million, respectively.
Not all cities that fall below sea level in the future will necessarily be submerged, because levees and pumping stations can protect some areas from rising seas. Amsterdam and New Orleans are clearer examples of this situation.
However, these protective measures can be expensive and take decades to implement. If vulnerable communities want to minimize the damage, they must act before the sea rises those first meters, according to Vernimmen.
Meanwhile, the Secretary General of the United Nations, António Guterres, in the first debate of the Security Council expressed that the rise in sea level has “unthinkable” risks for billions of people around the world.
“The impact of rising sea levels is already creating new sources of instability and conflict,” said Guterres, who opened the meeting days ago. He called for action on the causes and prevention within the framework of human rights and current regulations.
“Mass exodus”
After noting that the costs of some countries have already seen the average rate of sea level rise triple, warned that, in the coming decades, low-lying communities – and entire countries – could disappear forever. “We would witness a massive exodus of entire populations”, he warned. He stressed that there would be increasing competition for fresh water, land and other resources.
“Global mean sea level has risen faster since 1900 than in any other century in the last 3,000 years. The global ocean has warmed faster in the last century than at any time in the last 11,000 years,” Guterres said.
“Meanwhile, the World Meteorological Organization (WMO) tells us that even if global warming is miraculously limited to 1.5 degrees, there will still be significant sea level rise”, said the head of the United Nations.
The rate of sea level rise has doubled since 1993. It has risen by almost 10 millimeters since January 2020 to reach a new record in 2022. Just the last two and a half years account for 10% of global sea level rise since which began satellite measurements almost 30 years ago.
1 in 10 people threatened
Guterres warned the Security Council that, in any scenario of rising temperatures, countries like Bangladesh, China, India and the Netherlands they will be in danger. Megacities on all continents will suffer dire consequences. He pointed to Lagos (Nigeria), Bangkok (Thailand), Bombay (Indian) and Shanghai (China), London, United Kingdom), Buenos Aires (Argentina) and NY (USA).
The danger is especially acute for some 900 million people who live in low-lying coastal areas.. That is, one in ten inhabitants of the planet.
Csaba Kőrösi, current President of the General Assembly, also addressed the Council, recalling that climate change is “the greatest challenge of our generation”. He mentioned the projections: Between 250 and 400 million people will probably need new housing in new locations in less than 80 years.
He also warned of the devastating consequences for the “breadbaskets” of the world, especially the fertile deltas of the Needhe Mekong and other rivers. “What is needed now, as always, is the political will to act,” he said.
………
Contact of the Environment section: [email protected]