Seawalls to protect US against rising oceans could cost $416bn by 2040

Seawalls could cost as much as the initial investment in the interstate highway system, with Florida facing $76bn, report finds

Defending against rising seas could cost US communities $416bn in the next 20 years, according to a new report.

Spending on seawalls alone could total almost as much as the initial investment in the interstate highway system, the authors said. And the billions involved will represent just a fraction of adaptation efforts governments in coastal states will have to fund if they do not want to simply retreat.