As the world tries to price the cost of climate change, Japan's second-largest nonlife insurer, MS&AD, foresees the potential rise in claim payments in 2050 from current levels to be anywhere between 5% and 50%.

Sompo Holdings, the No. 3 nonlife insurer, also plans to announce a similar estimate in August but with plenty of caveats, its officials say.

Others, including industry leader Tokio Marine & Nichido Fire Insurance, are wary of even producing estimates, citing a lack of data.