I have sat through countless discussions about climate risk over the years. They usually revolve around scenarios, disclosures, transition plans, and increasingly sophisticated models projecting what might happen in 2030, 2040, or 2050. Those conversations are important, but I have come to believe we are overlooking one of the clearest climate indicators available today.
It is not found in a sustainability report.
It is found in an insurance policy.
The insurance industry has a habit of cutting through theory. Insurers do not have the luxury of debating whether a risk is real - they have to price it. Every premium, deductible, and coverage decision reflects observed losses, actuarial data, and the simple requirement that claims cannot consistently exceed income. When insurers raise premiums dramatically, reduce coverage, or leave a market altogether, they are not making a political statement. They are responding to economics.
That is why I think insurance withdrawal deserves far more attention than it receives. Long before a company's climate scenario identifies increasing physical risk, insurers have often already adjusted their pricing. In some regions, homeowners are discovering they can no longer obtain affordable insurance. Businesses face higher operating costs. Lenders begin asking different questions. Property values become harder to defend. The financial consequences start long before the language in annual reports catches up.
The second observation is that insurance does not just reflect climate risk - it transmits it. Once insurance becomes expensive or unavailable, the effects ripple through the wider economy. Mortgages become more difficult to secure. Municipal finances come under pressure. Investment decisions change. Supply chains adapt. What begins as an underwriting decision quickly becomes an economic signal that reaches far beyond the insurance sector itself.
Finally, I wonder whether investors are paying enough attention. We spend enormous effort analysing corporate climate disclosures, yet one of the most dynamic market-based indicators already exists. If insurers are withdrawing from a geography, should that not become an immediate flag for investors, lenders, and boards? Markets have always been good at aggregating information. Insurance markets may simply be telling us something before everyone else is prepared to admit it.
I am not suggesting insurers are infallible. They can misprice risk like any other market participant. But they have one characteristic that climate debates often lack: they must continuously put capital behind their judgement.
Perhaps that is why I increasingly see insurance withdrawal as more than an industry issue. It is an early warning system. And when a market decides it can no longer insure an asset or a region on viable terms, the conversation about climate risk has already moved beyond theory and into cash flow.