How engineers are reinventing coastal protection

The article "How engineers are reinventing coastal protection" highlights the urgent need to rethink flood defense strategies in the face of increasing coastal risks driven by climate change. With nearly a billion people in low-lying cities vulnerable to coastal hazards by 2100, and global coastal defense costs projected to rise from tens of billions annually to potentially hundreds of billions by 2050, engineers are tasked with developing more resilient and adaptive solutions. Traditional approaches based on hard infrastructure, such as concrete seawalls, are being reconsidered due to their high costs, maintenance demands, and catastrophic failure risks if overtopped. A key focus of the article is the comparison between "gray" (hard) infrastructure and "green" (nature-based) solutions. Gray infrastructure like seawalls and rock breakwaters typically have high capital costs ($5,600–18,500 per foot for seawalls), long design lives (50–100+ years), but pose risks of sudden catastrophic failure. In contrast, green infrastructure such as veget