http://www.huffingtonpost.com/2013/12/18/yellowstone-volcano-magma_n_4467243.html?1387388047&icid=maing-grid7%7Chtmlws-main-bb%7Cdl10%7Csec1_lnk3%26pLid%3D421345 When -- not "if," but when -- this beast erupts, it would trash the American and Canadian Midwest, cause crop-failures due to freezing cold across the world, destroy the world's economy, and cause an enormous mass extinction event globally. And there's little, if anything, we can do about it, other than moving to Mars.