Premium increase insurance

Marginal Revolution and the Wall Street Journal both pass on a great quote from Warren Buffett:

It’s understandable that the sponsor of the proxy proposal believes Berkshire is especially threatened by climate change because we are a huge insurer, covering all sorts of risks. The sponsor may worry that property losses will skyrocket because of weather changes. And such worries might, in fact, be warranted if we wrote ten- or twenty-year policies at fixed prices. But insurance policies are customarily written for one year and repriced annually to reflect changing exposures. Increased possibilities of loss translate promptly into increased premiums. . . .

Up to now, climate change has not produced more frequent nor more costly hurricanes nor other weather-related events covered by insurance. As a consequence, U.S. super-cat rates have fallen steadily in recent years, which is why we have backed away from that business. If super-cats become costlier and more frequent, the likely—though far from certain—effect on Berkshire’s insurance business would be to make it larger and more profitable.

As a citizen, you may understandably find climate change keeping you up nights. As a homeowner in a low-lying area, you may wish to consider moving. But when you are thinking only as a shareholder of a major insurer, climate change should not be on your list of worries.

The puzzle to me is, why doesn't Berkshire Hathaway write ten- or twenty-year policies at fixed prices? Or, better, why does it not offer a second contract, that ensures you against the event that your regular insurance will be repriced every six months? If people are worried about it, and nobody else is doing it, it would seem they could charge a huge premium.

You may say BH doesn't want the risk, but in a previous letter Buffett explained that BH was selling 99 year put options. And being hugely diversified is precisely what allows a company like this to take some risk.

If it doesn't want to hold the risk it could sell it. Surely there are lots of investors who are  skeptics of climate change -- not warming, but the claim that warming will give rise to more extreme weather and higher insurance payouts; people who cheered at that quote in the WSG -- and would be happy to put their money where their mouths are in the reinsurance market.  

(These thoughts are obviously related to health insurance,  premium increase insurance and long-term guaranteed renewable contracts that solve the preexisting conditions problem.)