Reinsurance does not only spread risk by pooling multiple insurers, but also smears out the impact of catastrophes geographically and temporally: big events in one year, in one part of the world result in more expensive reinsurance all over the globe for a few years forward, as reinsurers collectively stock up on capital again.

So while locally catastrophes can cause other catastrophes, for the most part earthquakes in Thailand does not trigger wildfires in Texas. Nor does a hurricane in Florida one year cause more hurricanes in Florida the next year.