In the spring of 2011, heavy rains swelled the Mississippi River to record levels, flooding trailer parks and driving up gas prices as refineries and fuel terminals along the waterway were shut down. While surveying the debris, Heather McTeer Toney, then mayor of Greenville, Mississippi, found a key partner in the international conglomerate Mars, Inc., which makes M&Ms and pet food. Mars operates an 80-acre rice farm in Greenville—the largest factory in the world. The company sent senior officials and shared with Toney its internal risk assessment, which helped it plan the city’s police and fire response, design street upgrades, identify weaknesses in sewage and levee systems, and work with the Army Corps of Engineers. “Today, we would call it a climate risk,” Toney told the Associated Press. Prospect, but at the time it was “just infrastructure protection.” More from Lee Harris. Local officials, civil engineers and homeowners describe a growing need for information about exposure to extreme weather risks. Demand has exploded over the past five years. But not all cities have anchor businesses as willing to share as Mars, and many would rather not rely on private industry for public planning. Meanwhile, financial markets and private companies are in an “arms race” for climate intelligence. Some firms have announced plans to decarbonize, while others have pledged to double down on fossil fuels. Regulators, struggling to keep up, have demanded more disclosure. Private climate risk modelers have cashed in on this gold rush. Their guidance falls into two groups: physical risk, or significant asset exposure to hazards, or transition risk, which includes the consequences of policy changes, the impact on the financial system and reputation. Financial institutions have acquired these modelers, leading to rapid consolidation in the nascent industry. BlackRock, the world’s largest asset manager, runs a platform called Aladdin, which it calls the “central nervous system” of the investment industry. It recently acquired a climate modeler to launch Aladdin Climate, a company that tracks exposure to environmental risks. Rating agencies like Moody’s and S&P have joined in, acquiring their own climate ratings firms.