The risk to people and property due to acts of nature.
Example:
Building a village in close proximity to a volcano that has been dormant for 300 years. There is some evidence that the volcano is not permanently dormant.
Downside Scenario:
The volcano erupts suddenly and powerfully, demolishing the village and contaminating the air over a large body of land.
Upside Scenario:
The vocano remains dormant and becomes a focal point of nature walks and scientific research, both of which enrich the local community.