Huge offshore wind farms can protect vulnerable coastal cities against devastating cyclones like Katrina and Sandy by tempering winds and ocean surges before they reach land, a study says.

Had such installations existed at the time, Hurricane Katrina, which ravaged New Orleans in 2005, and Sandy, which smashed the coastlines of New York and New Jersey in 2012, would have been reduced to strong but not devastating winds, it said. “The little turbines can fight back the beast,” said…