Sea level rise caused by climate change ‘will destroy island nations’
From many effects that climate change on our planet, rising sea levels are probably the most alarming for some nations ― because it means they could no longer exist.
Much of the Indian Ocean archipelago Maldivesfor example, is a few meters above sea level and is therefore expected to disappear under the waves during this century.
“The biggest impact of climate change will be sea level rise,” said Norwegian climate change researcher Dr Nasser Karami. “It will destroy island countries in the Pacific Ocean, Indian Ocean or other places.”
Larger and wealthier nations may not face an existential crisis, but they are far from immune to the effects of rising sea levels.
UN figures show that around 40% of the world’s population live within 100 kilometers of a coast, so a significant number of people could see their lives turned upside down.
Major coastal cities such as New York can face significant challenges, Dr. Karami said. Simulations by advocacy group Union of Concerned Scientists indicate that much of the US East Coast could experience dozens of floods a year as early as 2035, even without accounting for storm surges.
Sea levels will rise faster today than in past decades
With warmer temperatures causing seas to expand and melting glaciers and ice caps, the world’s seas have risen by an average of more than 20 centimeters since the end of the 19th century.
A February report by the US National Oceanic and Atmospheric Administration and other US government agencies projects that by 2050 seas will rise another 10 to 12 inches (25 to 30 centimeters) – more than they only did so in the previous century.
Mid-Century Moderate flooding, which disrupts and damages infrastructureis likely to occur 10 times more often than currently.
In addition to the effects on coastal communities, there will be consequences for agricultural areas and underground aquifers, which could be contaminated by salt. Wildlife will suffer when natural environments are flooded.
Sea level rise is accompanied by an increase in the frequency of typhoons, hurricanes and other extreme events, causing storm surges that can devastate coastal communities.
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Richard Crowther, marine sector manager at WSP Middle East, an engineering consultancy that advises on coastal developments, said more extreme weather events were already being seen in the The Gulf of Oman and the Indian Ocean.
WSP modeling carried out with Sohar International Port Company of Oman and Deltares, another consultancy firm, suggests that recent cyclones like Gonu (in 2007) and Kyarr (in 2019) were worse than expected once per century.
“So this indicates that estimated return periods for predicted weather events have been overestimated, with larger events apparently occurring more frequently,” Crowther said.
The problems will intensify, because even under low emission scenarios, sea levels will continue to rise.
The US National Oceanic and Atmospheric Administration’s 2022 Sea Level Rise Technical Report found that at least a two-foot (0.61 meter) rise is likely along the US coast of 2100 due to rejected emissions so far.
“Failure to reduce emissions could lead to an additional rise of 1.5 to 5 feet, for a total of 3.5 to 7 feet by the end of this century,” the report’s summary states.
A 2021 report by the Intergovernmental Panel on Climate Change warned that global mean sea level could rise by two meters if greenhouse gas emissions continued at a high pace.
“This presents a hook-22 for the GCC region, as many coastal developments are currently being designed using appropriate conservative considerations, which predict sea level rise of approximately one meter over the next 100 years,” Mr. Crowther said.
The vulnerability of infrastructure and populations to sea level rise varies greatly, said Fawzi Dibis, sustainability and climate change manager at WSP Middle East. This is due to differences in geography, altitude and business models.
“The World Bank stresses that low-lying coastal areas in Tunisia, Qatar, Libya, the United Arab Emirates, Kuwait and in particular Egypt are at risk,” he said.
Areas that will be affected by a 1m sea level rise, according to Climate Central modeling:
The Nile Deltafor example, will face increasing rates of erosion; flooding of wetlands and other low areas; increased flooding; faster coastline retreat, including erosion of sand dunes and coastal sand belt; breaking of coastal barriers; and damage to coastal inlets.
“This would impact the livelihoods of huge population centers in Egypt and pose a threat to food security, as most agricultural production takes place in the Nile Delta,” Dibis said. He added that creating sand dunes and levees and preserving existing wetlands could reduce the risks.
As growing numbers of people and assets could be at risk, Mr Crowther said it was “crucial to ensure that the formation levels of urban developments on coastal areas are high”.
He said investing in a project early to ensure it is able to cope with the stresses of climate change could reduce risk and cost and “guarantee fewer stranded assets”.
Some projects take into account the potential for significant sea level rises, and the protection of developments can be discreet and have the potential to be strengthened over time.
Mr Crowther cited as an example WSP’s work on the Sea Life Institute, which is part of a development called Amaala on the northwest coast of Saudi Arabia.
“We designed bulkheads for a single seawall around the perimeter, which is deliberately designed to take into account sea level rise and waves by mitigating side-to-side water exchange, while limiting visual impact,” he said. .
“By designing this unique feature with an evolutionary approach, the height of the acrylic bulkhead can be changed as sea levels rise over time to both preserve the visual impact of the structure and extend the life life of the global asset.”
Coral bleaching and higher salinity
Sea level rise is far from the only effect of climate change on seas and oceans. Coral Reef Bleachingin which heat stress causes the coral to expel algae essential to its functioning, is another consequence, as is damage to fish numbers from high temperatures.
When it comes to temperature increases, the Persian Gulf is probably one of the most affected seas in the world. The Intergovernmental Panel on Climate Change predicts a 4.26°C increase in surface temperature between 2010 and 2039.
“Algal blooms and dead zones are likely to develop as temperature increases lead to increased stratification of oxygenated water and concentration of pollutants, negatively impacting coastal tourism,” said Mr Dibis.
“Additionally, increased evaporation has been linked to increased seawater salinity, which can disrupt marine ecosystems. This could evolve into the potential loss of mangroves and other species.”
Higher salinity could also affect desalination plants, power plants and other infrastructure, which operators will need to consider.
“Integrating systematic risk management frameworks, adaptation and resilience strategies, and an accelerated path to decarbonization is critical,” Dibis said.
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Updated: November 04, 2022, 6:00 p.m.