The biggest threat to the insurance industry isn't regulators or terrorism, it's climate change. To reduce their risk, the world's largest insurance companies are using supercomputers to figure out just how costly severe weather prompted by climate change will be.

The Willis Research Network will use one of the world's most powerful supercomputers -- the NEC Earth Simulator in Yokohama, Japan "to help insurers understand the frequency and severity of natural catastrophes in the face of climate change," according to the Insurance Journal. The supercomputer will use the latest climate change models to study the anticipated cost of events such as "El Niño-Southern Oscillation (ENSO), and of climate extremes, such as cyclones, typhoons and hurricanes."

The chairman of Lloyd's of London's called climate change the most important issue for the insurance industry, according to the Globe and Mail.

Around the globe insurance payouts for catastrophic events have increased by 2000 percent during the past 30 years. Insurers are in turn buying more insurance to limit their risk (known as reinsurance), and that cost is skyrocketing too. Insurers will pass the cost on to policy holders, so if your business or homeowners insurance premiums start to rise, climate change will be part of the reason.