How much does it cost to save us from a supervolcano?

http://www.sciencealert.com/the-supervolcano-that-caused-one-of-the-biggest-eruptions-in-history-has-started-to-stir

A 12-km wide cauldron that forms a vast supervolcano on the coast of Italy is showing signs of reawakening after almost 500 years of inactivity.

Not only is this site rumoured to be responsible for the extinction of the Neanderthals, it’s got 500,000 people living around it right now, and researchers say it appears to be approaching a critical pressure point that could lead to an eruption.

Since its formation, Campi Flegrei has only had two major eruptions - 35,000 years ago and 12,000 years ago - and a smaller eruption that occurred in 1538.

But when we say "smaller", it’s all relative, because the 1538 eruption lasted for eight days straight, and spewed so much material into the surrounding area, it formed a new mountain, Monte Nuovo.

It’s the whole site that’s a concern though - the eruption that occurred 200,000 years ago is thought to have been so cataclysmic, a 2010 study suggests that it triggered a 'volcanic winter', that ultimately led to the extinction of the Neanderthals.

While the connection of the demise of the Neanderthals remains purely speculative until further evidence can be found, the eruption, which is thought to have spewed almost 1 trillion gallons (3.7 trillion litres) of molten rock onto the surface - along and with just as much sulphur into the atmosphere - is not.

"These areas can give rise to the only eruptions that can have global catastrophic effects comparable to major meteorite impacts," Giuseppe De Natale from Italy’s National Institute for Geophysics and Volcanology, told Reuters back in 2012.

I find it amusing that there is a cost to salvation. Geology has never been easily manipulated by men, and certainly if what you suggest could be a large eruption, then humans can and always have been victims of sudden eruptions which Italy has ample proof.

Imagine if we could harness the energy somehow. We've used similar energy... but nothing on this scale.

https://en.m.wikipedia.org/wiki/Geothermal_energy

A bit closer to home, all Yellowstone National Park is a super volcano.

Is Yellowstone a volcano?
Yes. Within the past two million years, episodic volcanic eruptions have occurred in the Yellowstone area—three of them major.

What is the caldera shown on the park map?
The Yellowstone Caldera was created by a massive volcanic eruption approximately 640,000 years ago. Subsequent lava flows filled in much of the caldera, and it is now measured at 30 x 45 miles. Its rim can best be seen from the Washburn Hot Springs overlook, south of Dunraven Pass. Gibbon Falls, Lewis Falls, Lake Butte, and Flat Mountain Arm of Yellowstone Lake are part of the rim.

When did the Yellowstone volcano last erupt?
An eruption approximately 174,000 years ago created what is now the West Thumb of Yellowstone Lake. The last lava flow was about 70,000 years ago.

Is the volcano still active?
Yes. The park’s many hydrothermal features attest to the heat still beneath this area. Earthquakes—1,000 to 3,000 per year—also reveal activity below ground. The University of Utah Seismograph Station tracks this activity closely.

What is Yellowstone National Park doing to prevent an eruption?
Nothing can be done to prevent an eruption. The temperatures, pressures, physical characteristics of partially molten rock, and immensity of the magma chamber are beyond human ability to impact—much less control.

What is a supervolcano?
Some scientists consider Yellowstone to be a “supervolcano,” which refers to volcano capable of an eruption of more than 240 cubic miles of magma. Two of Yellowstone’s three major eruptions met the criteria.

Will the Yellowstone volcano erupt soon?
Current geologic activity at Yellowstone has remained relatively constant since scientists first started monitoring more than 30 years ago. Another caldera-forming eruption is theoretically possible, but it is very unlikely in the next thousand or even 10,000 years. Scientists have also found no indication of an imminent smaller eruption of lava.