[RayChuang88]

It's really scary. Remember, when Mount Tambora massively erupted in 1815, it spewed 15 cubic miles of volcanic and a massive amount of sulfur particles into the atmosphere. The result caused major weather change for 2-3 years afterward, including the famous "Year Without Summer" of 1816.

If the Yellowstone Caldera erupts again, we're talking 15 to 20 times the amount of volcanic ash and sulfur particles erupted at Tambora. That's enough to effectively blot out the Sun for several months, which will plunge Earth into a mini Ice Age, if not a real Ice Age. The resulting destruction to agriculture will devastate the human population.

[Robert A Cook PE]

Yes, the Yellowstone Caldera IS a tremendous volcanic threat.

But it has erupted at the 400,000 - 500,000 year interval. NOT every 50 years, 500 years, 5000 years, nor even 50000 years. The caldera is slowly expanding (rising) as it refills from below, but problems are not threatening even in the next 1000 - 2,000 years.

Far more likely than a Yellowstone even is a mudslide/loose snow-lava flow down the Washington and Oregon volcanoes.

However, the Los Angeles fault network of cracks IS overdue for a 7.5 to 8.0 earthquake, and THAT ENTIRE REGION IS overdue by a few dozen years for a major esarythquake.

AND even worse, the Portland - Seattle subduction zone fault zone IS overdue by about 200 years and IT DOES break regularly at 500 year-600 year intervals. THAT off-shore earthquake "typically" has tsunamis and magnitude 8.0 - 9.5 earthquakes that are tens times the energy released by the "usual" California big earthquakes.

[Ozark Tom]

There has been 80 eruption events since the last big one 640,000 years ago.

https://volcanoes.usgs.gov/volcanoes/yellowstone/yellowstone_sub_page_54.html