Ocean climb will force millions of people to move away from coastal areas, even if the annual increase in global temperature remains below 1.5 ° C, reveals a new study. This change is uncontrollable and it will happen “within the life of our young people.”
The climb of sea level will become uncontrollable with only 1.5 ° C of global warming and will lead to a “catastrophic migration to the interior“The authors of a new study warn.
According to the study, on Tuesday in the magazine Communications Earth and EnvironmentThis scenario may unfold even if the average heating level of the last decade of 1.2 ° C continues in the future.
The loss of ice of the gigantic layers of ice from Granelândia and Antarctica quadrupled since the 1990s Due to the climate crisis and is now the main engine of rising sea level.
O international objective to maintain the increase in global temperature below 1.5 ° C is already almost out of reach.
But the new study found that even if fossil fuel emissions were quickly reduced, The sea level would be up 1 cm per year until the end of the century, faster than speed which nations could construct coastal defenses.
The world is on its way to a global warming from 2.5 ° C to 2.9 ° Cwhich almost certainly would exceed the turning points for the collapse Ice layers of Granelândia and Western Antarctic, note o.
According to the study, the melting of these layers of ice would lead to a “Really terrible” 12 meter sea levels.
Today, about 230 million people live less than 1 meter Above the current sea level, and a thousand million live less than 10 meters above sea level.
Even only 20 cm climb from sea level to 2050 would lead to global damage by flooding of at least 910 billion euros per year for the 136 largest coastal cities in the world and huge impacts and in people’s subsistence means.
However, scientists emphasized that Each degree fraction global warming avoided by climate action It is still importantbecause it delayed the rising of sea level and Gives more time to preparereducing human suffering.
The rising of sea level is the Long -term impact of the climate crisisand research in recent years has shown that it is occurring much faster than previously estimated.
O limit of 1.5 ° C was seen as a way to avoid The worst consequences of global warming, but the new investigation shows that this is not the case for rising sea level.
According to the study authors, the “safe” temperature limit for ice layers is difficult to estimate, but it is probably located at 1 ° C or less.
“I think sometimes, There is a misconception that 1.5 ° C It will mean that all our problems will disappear, ”he says Chris Stokesresearcher at the University of Durham, in the United Kingdom, and the main author of the study, quoted by.
“It must be, undoubtedly, our goal, but will not, by no means, delay or prevent the rising of sea level due to the melting of polar defaults, ”adds the investigator.
“We are starting to see Some of the worst scenarios to unfold almost ahead of us. With the current heating of 1.2 ° C, the rising sea level is accelerating the fees that, if they continue, would become almost uncontrollable before the end of this century, what is within the life time of our young people“Says Chris Stokes.
An climb of the sea level Less 1-2 meters is now inevitablesay the authors of the study.
In Portugalthe 1 meter climb of sea level would especially affect the Setúbal region, one of the most risk zones, the district of Faroin particular the region of Ria Formosathe riverside areas of the Tagus estuaryin flat ground and with urbanization by the water, and all Aveiro regionin particular
Na City of Lisbonthe most affected areas of the Terreiro do Paçothe downtown of the city, the Cais do Sodré and Alcântara.
Second Carlos AntunesSpecialist in Geespacial Engineering at the Lisbon Faculty of Sciences, and author of one of sea level climbing scenarios in Portugal, in our country the middle level of the sea rose 23 cm since the beginning of the last century. In 2050, it will have climbed 44 cmsays the investigator to.
“One secure It is one that allows some level of adaptation, instead of catastrophic migration to the interior and forced migration, and the secure limit is approximately 1 cm per year of sea levels, ”he says Jonathan Bamberresearcher at the University of Bristol in the United Kingdom, and co -author of the study.
“If it comes to it, then it becomes extremely challenging For any kind of adaptation, and let’s see massive terrestrial migration on scales that we have never witnessed in modern civilization, ”he adds.
“The continuous Loss of Ice Layers It represents an existential threat to the world’s coastal populations, ”conclude the study authors, who combined data from hot periods up to 3 million years ago, and observations of ice fusion and rising sea level in recent decades.
Andrea Duttonresearcher at the University of Wisconsin-Madison and co-author of the study, emphasizes that evidence recovered from past periods past suggests that they suggest that Several meters of rising sea level – or more – can be expected when the average global temperature reaches 1.5 ° C or more.
At the end of the last glacial ageabout 15,000 years ago, the sea level was climb the current rate at 10 timesdriven by self-referee feedback that may have been triggered by only a small increase in temperature.
The last time the levels of CO₂ in the atmosphere were as high as today, there about 3 million years, The sea level climb was 10 to 20 meters higher.
Even if humanity can bring the planet back to its pre-industrial temperature by removing CO₂ from the atmosphere, it will still take hundreds to thousands of years For the ice layers to recover, the investigators say.
This means that Land lost to rising sea level will remain lost for a long time, Maybe until the earth comes in the next glacial.
