All we have to know is how breakout works, and why breakout and expansion to the space frontier -- thus into mass and energy: mass and energy transformed to life -- [is] energy, thus [is] money, to know it is an imperative.
Michio Kaku wrote of mankind's increase in numbers one-million-fold over the last two million years and how that wasn't the problem. The problem is similar to the child in the womb in the ninth month of its life and its future in the womb versus birth out into a new frontier. It has space age limbs, space age organs, space age energies, and space age needs and wants, without having any real space (thus real time), without having any real space age! It cannot remain without birth, a plant cannot remain without seeding, and so on. The increase in numbers one-million-fold from two million years ago means nothing. Mankind's increases since then in energies, infrastructure, complexity and reaches, two-million-fold average per every man, woman, and child living now (one-million-fold of that two-million-fold coming in the last 78 years) means it all.
Rome's closed systemic implosion once it reached its limits of European, Asian, and African expansion (limits to growth) in the ancient world; Communism's closed systemic implosion behind the "Iron Curtain," and a child's implosion in the womb after a due time of starting birthing out, is nothing to what is coming for mankind on Earth if it can't, or won't, break out in expansion to the masses, the energies, the space, and the time, of the High Frontier of the Solar System.
Stephen Hawking saw the physic and warned about it, Will Durant, the chronicler of Civilization and the lessons of history, saw it in a different context, among many others in many different fields who've seen, realized, and warned that mankind is in danger right here on Earth if cannot or will not breakout in expansion to that space frontier. Michio Kaku didn't put it exactly so, but the meaning of what he did tell us was that what we do face is a growing entropy, a growing degradation and deformation, in the closed bubble of [a distance shrunken] Earth. We can do nothing about the inexorable increase in entropy over all mankind's world here on Earth without breakout and expansion now; due to our space age increases in energies, infrastructure, complexity and reaches, two-million-fold average per every man, woman, and child now living. It will be suicide not to break out. Not only mankind's suicide, but because of what mankind is, possibly all life on Earth's suicide. Worse may be, if a pyramidical life on Earth produced us at its apex for exactly the reason of being life's carrier, life's Ark so to speak, in life's breakout from Earth to that outland Hight Frontier as a natural measure against life's inevitable mass extinction in one single mudhole . , , on one single rock . . . in one single world. If we can't or won't do it, if there is time, we could then be made extinct, or our civilization made extinct, and be replaced with another species, or species of civilization, less caring of Earth by itself and more single-mindedly ruthless enough to do the job of breakout. And how it might go about doing extinction (so to be replaced) might not be very caring or very pretty.