Dive Brief:

• Florida Attorney General James Uthmeier filed a lawsuit against First Street Technology, a physical climate risk modeling company, last month over climate risk scores it issues for Florida homebuyers on real estate platforms like Zillow, RedFin and Realtor.com.
• Uthmeier alleged that First Street is violating the Florida Deceptive and Unfair Trade Practices Act, alleging the scores are misleading and based on “faulty risk factors,” according to the complaint Uthmeier filed in state court on Oct. 23. The AG said the scores caused Florida homes to take longer to sell and sell for less due to the scores.
• In his complaint, Uthmeier accused the company of “climate chicanery” and “marketing fear to advance a climate activism agenda” to gain profits. “First Street assigns numbers for flood, heat and other risks and presents them as accurate and scientific, but they’re not,” the state AG said in a separate video announcing the lawsuit posted on X, formerly known as Twitter.

Dive Insight:

The lawsuit targets First Street’s climate risk product, “Risk Factor” — which assesses the flood risk, fire risk, air quality risk and heat risk to a property, according to the complaint. The lawsuit alleges that offering its risk factor product on homebuying sites like Zillow, Redfin and Realtor.com “generates consumer exposure and market adoption that First Street then leverages to sell other paid products, namely property-specific climate risk reports.”

Uthmeier’s complaint notes that First Street’s flood risk data deviates from that provided by the Federal Emergency Management Agency’s floodplain maps. First Street has explained that its flood risk scores are different from FEMA’s because the agency projects flood risk at the community level, while First Street says its flood risk calculation looks at the property level and “accounts for changing climate conditions, and considers the risk of flooding due to high-intensity rainfall,” according to the complaint.

“Those inflated scores have real consequences. Homes take longer to sell; they sell for less. Insurance costs rise, and when homeowners try to correct obvious errors, First Street refuses,” Uthmeier said in the post on X. “Their models are speculative, based on undisclosed choices, and frequently contradict official data. They claim transparency and peer review, yet underlying details are hidden behind a paywall, and independent analysis shows major discrepancies.”

Uthmeier’s lawsuit alleges that First Street’s claims that its risk factors are peer-reviewed are “deceptive and misleading.” Additionally, the suit notes that Zillow and Redfin have separately found that “climate risk scores, such as First Street’s Flood Factor, can negatively impact the sale of homes that are deemed risky by First Street.” 

The suit pointed to Zillow’s findings that note that such homes are more likely to sell for less than the original price and take longer to sell than homes deemed to have a low flood risk. Zillow stopped displaying First Street’s climate risk scores directly on its website’s listings and switched to external links in late 2025.

First Street was acquired by financial analytics and indexing firm MSCI this year, in a $120 million-deal that was announced in June and closed in August. MSCI declined to comment for this story.

Uthmeier is seeking a jury trial, and the lawsuit seeks to enjoin First Street from making a number of claims, including that its risk factors are “peer reviewed,” “transparent” and “accurate” and represent accurate predictions. The lawsuit also seeks $10,000 for each violation of Florida’s deceptive and unfair trade practices law and $15,000 for each violation involving a senior citizen.