With climate change, sunny day flooding incur losses too

No one is hurt, no roofs are torn off, and the neighborhood isn't evacuated as it might be in a hurricane.

But these less spectacular events also incur economic costs, in the form of fewer tourists or residents coming to shop or eat at one of the historic City Dock's 16 businesses.

Researchers at Stanford University are using a novel method to estimate the cost, published Friday in the journal Science Advances, in hopes of raising awareness of the more mundane, everyday consequences of a warming climate.

"So often we think of climate change and sea level rise as these huge ideas happening at a global scale, but high-tide flooding is one way to experience these changes in your daily life," said Miyuki Hino, a Stanford graduate student and co-author of the study.

The researchers have methodically gathered photos and satellite images of the parking area to document the number of high tide flooding days: 63 in 2017, against an average of four a year in the 1960s.

They then estimated the corresponding decline in the number of visitors, using parking receipts as documentation.

Their conclusion: 3,000 fewer visits in 2017, signifying a loss of between $86,000 and $172,000 in revenues.

That is only a two percent decline in annual visits. But if sea levels were to rise seven centimeters, or three inches, the decline could double, by the researchers' estimate.

At 30 centimeters, or 12 inches -- a conceivable sea level rise by mid-century -- the researchers calculate there would be a 24 percent drop in visits, with a resulting loss of hundreds of thousands of dollars in revenues.