Zillow deleting home climate risk scores reveals limits of flood, fire data

"When Zillow Group Inc. removed climate risk scores from its home listings last month, following a complaint from the real estate industry, many observers took to the press and social media to warn that disappearing the data doesn't get rid of the risk. In a world assailed by extreme weather, homeowners and purchasers need to know their property's vulnerability to wildfire or flooding."

"Ratings like those Zillow took down which use the latest science, advanced computing and satellite imagery are a big improvement on often outdated federal flood maps and state wildfire maps. But they're far from perfect, a growing body of research shows, with different models often yielding different results. In October, a UK industry group, the Climate Financial Risk Forum, looked at how 13 different climate-risk companies each rated the same 100 properties around the world."

"Bloomberg Green last year compared two flood risk models, one by First Street Technology Inc. the company that generated the scores Zillow used and another by researchers at the University of California at Irvine, and found they matched just 21% of the time. If companies oversimplify their climate-impact projections or worse, get them wrong it could depress the value of some people's assets for no reason and distort market pricing."

Zillow removed climate-risk scores from its home listings after a complaint from the real estate industry, with the sitewide removal taking effect Nov. 14. Modeled risk scores use recent science, advanced computing and satellite imagery and can improve on outdated federal flood and state wildfire maps. Multiple independent evaluations show substantial disagreement among providers, including mislocated properties and widely varying vulnerability ratings. A comparison of two flood models matched only 21% of the time. Climate-risk modeling remains a new discipline without established norms. Incorrect or oversimplified projections can depress asset values and distort property-market pricing.

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