To many answers that are somewhat superfluous to choose from for an answer on the topic of when the world will collapse. The world could be compared to a souffle’ that is on the brink of collapse, yet it might be more like a lemon meringue pie with the frilly stuff actually somewhat solid or foamy in the better cases, and that could be compared to the inner Earth with various levels of hot stone running toward magma and deep within a nickel iron core of chewy nougat for science fiction league extra-terrestrial mole-mining engines from deep space. One might prefer something more serious than the house of cards kind of thing though.
There is apparently 3x the water in the oceans located 400 miles down in the Earth’s transition zone. Not much danger of the plates floating over convection currents to deflate like an air mattress floating on the ocean though. So one can move on from that.Scientists discover an ocean 400 miles beneath our feet that could fill our oceans three times over – ExtremeTechAfter decades of theorizing and searching, scientists are reporting that they’ve finally found a massive reservoir of water in the Earth’s mantle — a reservoir so vast that could fill the Earth’s oceans three times over. As always, the more we understand about how the Earth formed, and how its multitude of interior layers continue to function, the more accurately we can predict the future. Weather, sea levels, climate change — these are all closely linked to the tectonic activity that endlessly churns away beneath our feet.https://www.extremetech.com/extreme/184564-scientists-discover-an-ocean-400-miles-beneath-our-feet-that-could-fill-our-oceans-three-times-over
If the world is entangled massless particles in the Higgs field that have a relative third dimension because they slow to sub-light speed in the viscous cosmologically constant gooeyness of it- it might be compared to hand sanitizer gel I suppose, then the world and Universe could collapse from three dimensions to two any second now. One can be certain or precise about that obviously; time is just an apparent quality of the three dimensional mass moving or jostling about in the Higgs field, thus for massless particles not trapped into being mass time may not exist. That brings up all kinds of questions plainly concerning what the Higgs field is in-itself and why does it have time at all.
If time does not exist for zero-dimension points believed to be the foundation of matter when it is energy before it expands or something into one-dimension strings, how can they ever exist for a moment. If time does not exist for zero-dimension points of energy that is something to consider as it pertains to the ‘whenness’ of the collapse of the Universe and the place called the firmament or stardusty-clumped planet Y’Earth.
It might be better to consider the planetary economy and the voracious consumption of natural resources going on by the 8 billion people living in-the-word and of it- a collapse of the resource base and global economy could happen by the turn of the century or sooner through various kinds of military conflict or viral wmds. Optimistically though the planet might return to some new general Christian ethics and try to repair the damage its caused to the Environment, to the poor and others living on Earth. Perhaps that is unlikely yet it isn’t impossible.
With very good sense and intelligence that allows better political ideas and social coordination the people of the world might just squeak through hard times ahead in the next two centuries with new means of food production in zero gravity food-growing bubbles with potatoes the size of Manhattan or Rhode Island being grown like vast centrist fungal planets in forests underground, dehydrated and sent to Earth if special delivery packages that won’t burn up in the atmosphere. Anything is possible really. Otherwise James Lovelock and Jacques Cousteau each said humanity had about 200 or 300 years to go before the collapse of the bubble of human civilization.