A new global study has found that a combination of man-made sea level rise, storms and tides could bring another 23 million people to coastal floods over the next 30 years, even with relatively ambitious reductions in greenhouse gas emissions.
In the worst case, when emissions continue to rise and no effort is made to adapt to rising sea levels, onshore assets amount to 14.2 tons. ̵1; about 20% of world GDP – could threaten by the end of the century.
Sea level rise caused by global warming, which expands the oceans and melts on land on ice, could mean that currents that are now occurring for 100 years will turn into one year for 10 years by the end of the century. Floods can affect as much as 4% of the world’s population.
A study published in the journal Scientific Reports identified a “hot spot” in regions at risk of heavy flooding.
Particularly at risk are southeastern China, northern Australia, Bangladesh, West Bengal and Gujarat in India. In the United States, North Carolina, Virginia, and Maryland, the United Kingdom, northern France, and northern Germany were considered the largest.
But research also shows how the risk of damage from rising sea levels and rapid surges will continue to rise, even if emissions are kept at levels that would support rising global temperatures well below 2C by the end of this century.
The new study is based on findings published by the United Nations Intergovernmental Panel on Climate Change in 2019, which predicts that emergencies at sea level could be almost annual, by the middle of this century, on many coasts.
Prof. Ian Young, co-author of the study at the University of Melbourne, said: “We usually need to mitigate our greenhouse gases, but that won’t solve the problem.
“Sea level rise has already been recorded – even if we reduce emissions today, sea levels will continue to rise as glaciers continue to melt for hundreds of years.”
According to research, today about 148 million people worldwide are exposed to floods.
If greenhouse gas emissions increase moderately – the equivalent of 1.8C global warming by the end of the century – another 54 million people will be affected. But if we allow the spiral to be produced in the worst case scenario, this number will increase to 77 million.
About 10.2 tons. Coastal assets are subject to flooding of coastal areas in 2100, even if emissions are kept at a moderate level, according to the study.
All figures simulated in the study suggest that no adaptation measures are taken, illustrating the benefits of taking early measures to reduce the impact of floods.
Young said: “When most people think about sea level rise, they think about 3 or 4 mm a year, but when there are floods, it happens when you also have a storm.
“It’s happening today, and we saw it on the coast of New South Wales last week. Rising sea levels increase the scale – and increase the frequency – of these floods.
“The area of flooded land is much larger, and this will have a significant economic impact on infrastructure.
“Even if we mitigate greenhouse gases, it doesn’t have much effect. We have to adapt to this – it will happen, so we will have to look for either difficult engineering solutions, or we are looking at planned retreats and relocations, and it is incredibly difficult, or there are coastal defense systems. “
Ebru Kirecci, a senior fellow at the University of Melbourne, said: “We need to adapt to rising sea levels and climate change.
“Adaptation is the only way out, and we need to adopt some risk reduction strategies, such as sea walls and dams, and develop forecasting and warning systems, or retreat ashore, which means relocating coastal communities to safer places.”
Prof. John Church, a leading sea level expert at the Climate Change Research Center at the University of New South Wales, who was not involved in the study, said the data were valuable.
He said the study had gathered several elements to assess the extreme effects, but work still needed to be done to understand the additional effects of changes in storm severity and waves.
According to him, it is also likely to have significant consequences along the estuaries, and it is important to note that “sea level rise will not stop in 2100 in any scenario.”
He said: “The more emissions, the higher [sea level] rises, with commitments to sea level rise meters over the coming centuries under higher scenarios. Influence until 2100 is an entry into the future. “
Although coastal flooding could affect 20% of world GDP, he said it was a reflection of a society that “loves the coast”.
“We need more thoughtful and forward-looking planning.”