People judge risk poorly. We worry too much about minor hazards and are nonchalant about more serious ones. We’re especially inept at judging chronic long-term risks like climate change.  

Insurance is a major part of how we deal with risk. Can it lead us to more viable ways to address climate issues? The picture is mixed.

When we manage risk by buying insurance, we endure the slow, small pain of insurance premiums in exchange for the promise of significant compensation should something ugly happen. The insurers profit from our lack of knowledge about risk. Buying insurance goes against the grain, but paying our premiums gives us a little more security against fires, earthquakes, business interruption, and the numerous other events against which we can protect ourselves by buying an insurance product.

Insurers review their policies annually and change their terms if they see a change in the probabilities. When no major losses occur, the industry pats itself on the back for judging their risks correctly for that year. They’re happy and profitable. If the risk landscape changes, they absorb the payouts and adjust the terms accordingly.  

The optimistic point of view is that insurance can play a major role in guiding businesses and individuals toward more climate-friendly decisions. In theory, insurers study the real probabilities of known hazards, figure out a viable premium that gives themselves a profit and the policyholders the agreed-upon level of protection against the risk. When climate change raises the risks of flooding, business interruption, and other insurance hazards, the premiums go up, which can lead their policyholders to change their behavior. Financing for a new factory can be prohibitive or even impossible to get if insurers won’t cover it.  

In practice, though, this theory is faulty for several reasons. Climate change poses special challenges to insurers, not merely because they are on the hook for many weather risks such as hurricanes.  

First, to single out one kind of insurance, many factors combine in extreme weather events. A hurricane has many causes, and global warming might only be two percent part of the overall risk. If that part grows from two percent to five percent, it seems negligible, but in fact it’s quite significant. As one insurance executive said, “Even a minor increase in a risk like that can mean billions of dollars in additional losses to insurers.” If the winds are a few miles per hour stronger, and the storm takes a path through a heavily insured area, insurers can be overwhelmed.

The same is true for other climate impacts. There have always been floods, extreme weather, and times when the water cycle intensifies. But if climate change is turning up the dial, these familiar events may break out of their boundaries and become more frequent, more intense, or change in unexpected ways.  

Second, insurers are people too, and the cognitive blind spots that afflict individuals also affect the risk business. In practice, the insurance industry’s grip on certain probabilities often relies on seat-of-the-pants methods that are subjective, and whose over-optimistic assumptions are sometimes rudely corrected by ugly surprises, especially when risks are constantly changing, as they are with climate change.

Like all of us, insurers want certainty, even when they know that certainty cannot be attained. At a 2007 conference about hurricane science for an insurance audience, the world’s top climatologists discussed various topics in modeling and hurricanes. The head of underwriting at a major North American insurer snorted at the hedged, qualified way the scientists state their conclusions. The underwriter then complained, “Why don’t the scientists give us numbers we can use! These probabilities are too nebulous for us to write business with them!”  His impatience is widely shared, but the answer is no.

Third, insurance functions well when the risks of various hazards are truly independent of each other and truly random. One trouble with climate change is that climate instability tends to make floods, windstorms, and other extreme weather more interrelated.

One force binding all these factors together more tightly is land use, which in the U.S. is often part of a highly entrenched political juggernaut promoting the worst possible policies, such as building heavily in flood plains, or on beaches very prone to hurricane damage.

Consider Florida, where the laws, business practices and general culture are geared to developing every square inch of land near water -- oceans, certainly, but also lakes, streams, wetlands. Even in the absence of climate change, this is an obviously dangerous policy. It’s also very popular. John Coomber, former CEO of Swiss Re, once grumbled that every American wants to live on the most vulnerable beaches they can find in Florida.

Governments occasionally try to buck the pro-development tide, but the political pressure against the anti-development forces is swift and merciless. Certainly no politician can withstand it. Rather than resisting, many property and casualty insurers have pulled away from vulnerable coastal property in Florida.

In response, Florida created its own public insurance pool. Result? Development continues, and the state fund is actuarially unsound -- a major storm hitting a developed area would bankrupt the fund in short order. A few more storms would bankrupt the state of Florida, which would then call on the federal government -- as the stand-in for taxpayers in all other states -- to bail them out.

These three factors mean that the insurance industry is weaker than it appears in matters of changing social and economic policies. The only way to change these entrenched policies would be for other social forces to align with the insurance point of view. That will require energetic political leadership and vigorous regulation. The market alone cannot save us.


Brian Thomas left Swiss Re in 2006 and became a sustainability consultant with a focus on communications. He has developed green-themed projects for clients including Merill Lynch Global Markets and Investment Banking, Cofra Holding, Good Energies, Zurich Financial, Edelman, the City of Chicago, the City of New York, and others. He is currently a member of the New York City Panel on Climate Change, EnviroComm, and the Association of Green Technology Auditors, to name a few. Thomas started his blog, Carbon Based, in 2007, after requests from contributors to the Intergovernmental Panel on Climate Change (IPCC). He is the author of Climate Change Adaptation in 2010 and currently resides in West Cornwall, CT, where he is an activist member of the Conservation Commission. For more information, please visit, and his blog,