20...Super Volcano

A supervolcano erupts at least 1000 cubic kilometres (240 cubic miles) of material, with a volcanic explosive index of at least 8.

The Yellowstone National Park super volcano erupts every 600,000 years and is now due to erupt again. It is powered by a hot spot deep below the Earth's crust. There are at least 43 hot spots on planet Earth, located mainly under the ocean floor. On the surface, there are five in Africa, one in the Canary Islands, S.E. Australia & Iceland and four offshore along the geological fault line from Alaska to southern Mexico.

As far as I know none of these sites on land, are being managed. It would be relatively easy to ensure that the hot spot got no bigger and no hotter simply by building a geothermal power station above them. Maybe tourists at Yellowstone are considered to be more important to the USG than preventing the American dream from becoming a nightmare. Come to think of it, it would turn the entire northern hemisphere into a nightmare if it erupted.

Judging by the inaction, it would appear that only a world technocracy would manage these hot spots effectively. The electricity they produce would be piped to the super conducting global electricity grid. However, such an idea maybe too late. As of September 2022, 700 tremors have been recorded at Lake Taupo, New Zealand since last May. Lake Taupo is a supervolcano which last exploded 1,800 years ago and was the most violent eruption in the last 5,000 years.