In a few decades, when you’re graying your hair and you can get on the bus with your pensioner’s card, perhaps you’ll look at the beach where you played in the summers of your childhood and say to your grandson with a deep air: “When I was a child, all this it was sandy.” He may not pay you the slightest attention; but it will be true If you’re walking right along the edge, soaking your calves in the waves, chances are you’re treading on ground that years ago was more sheltered from the tide.
The sea level is rising. And more will. You won’t have to pull memories to find out. The studies by a priori organizations as solvent as the Intergovernmental Group of Experts on Climate Change (IPCC) say so —and clearly, too. Professor Robert Kopp, author of the chapter that the agency’s sixth report dedicates to the Earth’s oceans, explained it clearly in 2021. Since 1970 the global level has been rising at an accelerated rate. So much so, that the last one has been the century that has left the greatest increase in, at least, a period of 3,000 years.
And the panorama drawn by the latest balance of the IPCC is not more encouraging. “In the next 2,000 years the average sea level will rise between two and three meters if global warming is limited to 1.5 degrees and will reach between two and six meters if it does not exceed two degrees,” the authors detail, warning of that a rise in the oceans is already “inevitable for the next centuries or millennia”.
A coastline with an expiration date
“During the last decade, the global mean sea level has risen at a rate of about four millimeters per year. This increase is mainly due to two factors: the melting of ice in mountain glaciers and at the poles and the expansion of the water in the ocean as it absorbs heat,” Kopp said in an article published in The Conversation. Only between 2013 and 2019, the time that elapsed between the reports of the intergovernmental group, the experts verified signs that show how the loss of the ice sheet is “accelerating”.
According to the calculations handled by Kopp, it is likely that towards the middle of this century we will find that the sea level has risen, on average, between 15 and 30 centimeters.
The worst thing is that this drift can hardly be stopped. “The change to 2050 is largely fixed,” she warns. His calculations are in line with those of other institutions. At the beginning of 2022, NASA and other US government agencies, including NOAA, published a report concluding that in the next 30 years the seas could rise as much as in the last century.
Experts estimate that along the coasts of the United States the sea level will rise between 25 and 30 centimeters. Beyond 2050 the scenario is complex and depends on what we do in the coming years, but Kopp points out that if we don’t change, we keep emissions and allow temperatures to rise between three and four degrees by 2100, the planet will will face a sea level rise of approximately 0.7 meters. In the worst case scenario, with heavy contamination, it even speaks of 2 meters at the end of the century.
In Spain, with 8,000 kilometers of coastline, that would be a considerable problem. The report on climate change presented in 2021 by the Government outlines a scenario in which the flood level in part of the country’s coasts —Atlantic, Cantabrian and Alborán Sea— could grow by 8% by 2040. In the Canary Islands it would increase by 6 % and between 2 and 3% in the rest of the Mediterranean and the Gulf of Cádiz. The study points to the risk of million dollar flood damage in the most exposed coastal cities and how the rise of the seas would also harm the tourism sector.
Valencian coast. Land affected by a water level of 10 meters above the high tide line. Climate Central sets the stage by a combination of several factors: sea level rise itself, tides, and storm surges.
Coast of the area of Barcelona and L´Hospitalet. Land affected by a water level of 5.3 meters above the high tide line. Climate Central sets the stage by a combination of several factors: sea level rise itself, tides, and storm surges.
Part of the Rias Baixas. Land affected by a water level of 10 meters above the high tide line. The projection raises the combination of several factors: the rise in sea level, tides and storm surge.
Gijón and Avilés area. Land affected by a water level of 5.1 meters above the high tide line. The projection raises the combination of several factors: the rise in sea level, tides and storm surge.
Majorcan coast. Land affected by a water level of 10 meters above the high tide line. The projection raises the combination of several factors: the rise in sea level, tides and storm surges.
It is not necessary to imagine how the country would change with the rise of the seas. Climate Central, an organization dedicated to climate change research, has produced online maps where you can see in detail how different scenarios of sea level rise would affect our cities. Some correspond to the calculations of the experts in the medium term; others go further and allow us to see what would happen if the sea level rose exponentially.
The interactive Climate Central tool allows you to see what would happen, for example, with increases of between 0.5 and 30 meters and different circumstances, such as an unbridled rise in pollution, moderate control or even an “extreme reduction” in emissions carbon.
His projections are interesting above all to explore how the rise in the level of the oceans can affect the flood risk and how exposed sensitive areas are, especially if strong swells and factors that aggravate it are added to the increase in water.
Climate Central also contributes forecasts for some locations coastlines. “With uncontrolled contamination, the median forecast for when the rise in sea level reaches 1.5 m in Barcelona is 2190, with a very probable interval of 2130-2200 +”, he details in the case of Barcelona. The forecast is very similar in other points of the national Mediterranean, such as L’Estartit (2190), Valencia (2200), or Palma (2180). The same happens in the Atlantic and Cantabrian.
Climate Central simulations also show urban areas that would be affected by rising sea levels. In the case of Vigo, for example, it reveals that with a rise of only two meters, part of its landfill would already be affected. With a greater rise, of five meters, the impact would even extend to part of the Lagares river bed, which crosses the city.
Land that could be below the level of the annual flood in 2150 in part of the Levantine coast.
Land that could be below the level of annual flooding in 2150 in part of the Catalan coast.
Part of the coast of Mallorca that would be below the annual flood level in 2150.
The impact would also be noticeable in estuaries such as Avilés, San Esteban de Pravia, Foz or Betanzos. Other points where the increase in level would be strongly felt, both due to its proximity to the sea and altitude, is the Ebro Delta, the Llobregat Delta and the mouth of the Guadalquivir.
The archipelagos would also suffer the effect in a marked way. As already stated in the Balearic Sea Report, the western Mediterranean and specifically the Balearic Islands are considered one of the most vulnerable points to the rise in sea level. According to their data, there are scenarios that contemplate increases of between 57 and 75 centimeters at the end of the century, which would imply that the beaches would recede considerably: between seven and 50 metersdepending on the case.
The Climate Central maps also reflect coastal hazards. For example, in the case of Valencia they show a wide strip that would be affected with a water level of 10 meters above the high tide line. It is a high figure, but it would not be related only to a rise in sea level. The study proposes this scenario with the sum of several factors: the variation of the sea, the tides and a storm surge. The maps also show areas that would be under water as time passed, taking expert projections into account.
After all, you may not need to wait for retirement and have grandchildren appreciate how the rising oceans blur the shorelines you knew as a child.
Images: Climate Central
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