According to the Lloyd’s “City Risk Index” which was created in collaboration with Cambridge University, those risks have an estimated annual impact of $320 billion of global gross domestic product (GDP) for some 279 cities. They are a much bigger economic threat than hurricanes, floods, earthquakes and volcanoes.
The index has measured the impact of 22 threats (both man-made and natural) and showed that 279 major cities across the world (with a combined GDP of $35.4 trillion) risk losing on average $546.5 billion in economic output annually. That comprises $320.1 billion to man-made risks and $226.4 billion to natural catastrophes.
source: https://www.rt.com/business/429386-man-made-risks-cost/