The whole "over-population" hysteria is a hoax. As is the idea of colonizing the distant and woefully uninhabitable of Mars. Two-Thirds of the Earth's surface is unpopulated and full of protein-rich food and vegetation, Oxygen, H20, precious and non-precious minerals and fuel and thermal energy in amounts which stagger the imagination.
Do the math, count on technical innovations that are sure to come and ask yourselves whether it make sense to, craft by billion dollar craft, over decades, to reach that barren Planet and then try and move billions of people there taking decades and trillions more or, instead, develop the technologies to build massive cities under our Oceans, extract potable water from the other oceans below, along with short-term fossil fuels, extract Oxygen from sea water and survive with the Oceans' other bounties?
Living under our Seas would also protect us from severe climate changes, pole shifts, man-made and Solar/Cosmic radiation. Thermal energy rising from the seafloors could be the new sustainable energy to protect humankind as well as run industries of a scope unimaginable.
To this engineeranon, this solution is so elegantly simple and achievable yet there is NO published science on the possibility. Why is that, I wonder? Instead, we are fed dreams of inter-planetary exploration and colonization which are patently unrealistic in the near and not too distant future. Any thoughts, anons?