According to the Swiss Re Institute1, the main factor in the overall loss number is the continued growth of secondary perils
Their preliminary estimates are:
Source: 1. https://www.swissre.com/media/news-releases/nr-20201215-sigma-full-year-2020-preliminary-natcat-loss-estimates.html
Losses were driven by a record number of severe convective storms (thunderstorms with tornadoes, floods and hail) and wildfires in the U.S.1
These and other secondary peril events around the world accounted for 70% of the $76b insured losses from natural catastrophes
The insurance industry covered 45% of global economic losses in 2020, above the ten-year-average of 37%
Source : 1. https://www.swissre.com/media/news-releases/nr-20201215-sigma-full-year-2020-preliminary-natcat-loss-estimates.html