A new study claims that in the next 80 years, the global land area exposed to coastal flooding as a result of climate change is set to increase by roughly 50 percent, threatening tens of millions of people, and up to 20 percent of global GPD. The authors call for immediate action to mitigate climate change, along with the construction of greater coastal defenses to protect both people and the economy.
"A warming climate is driving sea level rise because water expands as it warms, and glaciers are melting," comments lead author Ebru Kirezci, a PhD candidate at the University of Melbourne. "Climate change is also increasing the frequency of extreme seas which will further increase the risk of flooding."
For the new study, an international team of scientists collected extensive models and measured datasets on coastal regions across the globe, including storm surge events and other aggravating factors.
They then used the data to create projections of maximum sea level rise by the year 2100, and utilized topographic data to highlight regions that will be adversely affected by extreme coastal and sea level flooding by the year 2100. Armed with this data, the researchers then estimated the number of people and the amount of assets that are at risk from flooding on a global scale.
Their analysis revealed that, should greenhouse gas emissions continue to rise as they are, the amount of coastal land at risk from extreme flood events would rise by 48 percent, or 250,000 sq km (96,526 sq m) globally.
This would see the number of people put at risk from floods rise from 128 – 171 million to 176 – 287 million people by the year 2100. Furthermore, assets and infrastructure placed in harm's way are estimated to be worth US$14.2 trillion, which equates to roughly 20 percent of global GDP (gross domestic product).
The regions that would be worst hit by the sea rise and flooding include North America, north-west Europe, parts of Australia, New Zealand, China, India, south-east Asia and south-east Africa.
The study authors note that their work does not factor in existing flood defenses.
"This is critical research from a policy point of view because it provides politicians with a credible estimate of the risks and costs we are facing, and a basis or taking action," says Prof. Ian Young, a University of Melbourne infrastructure engineering researcher and co-author of the report. "This data should act as a wake-up call to inform policy at global and local government levels so that more flood defenses can be built to safeguard coastal life and infrastructure."
The paper has been published in the journal Scientific Reports.
Source: University of East Anglia
