I had a dream last night about something that I quite often dream about: the colonization of Mars. I love dreams like this because they always enable me to imagine things that I never would have imagined otherwise.
In this particular dream, Mars had been colonized and built upon to the following extent: There were good roads leading to a wide variety of businesses that existed in support of the primary economy of Mars, which I imagine to be extraction. In other words, it's most likely to me that life on Mars would revolve around mining, and to a lesser extent construction, and that all other businesses would serve to support those industries. There were shops and convenience stores, but they were sparsely stocked. There were bars and restaurants, mostly serving unappealing food like sandwiches, and also serving plenty of alcohol with which the Martian workers could "while away their time."
Interestingly, albeit unrealistically, buildings and cars on my Dream Mars were mostly open-air. Everyone had their doors open and their windows rolled down. Business establishments would generate their own oxygen, somehow, for patrons to breathe. People had grown accustomed to the difficulty of breathing the CO2 atmosphere of Mars as they made their way from Point A to Point B. My "host," the person in my dream who was showing me around the place, could generate oxygen in his car, too, but simply preferred the feel of the open air, just as all the other residents of Mars did. So, a good portion of my visit to Dream Mars was spent kind of suffocating as we traveled from place to place. It was frustrating for me, but my host assured me that I'd get used to it eventually.
Obviously, such a thing would be impossible on real Mars. You'd only be able to last about as long as you could hold your breath. You'd need to find an enclosed building with breathable air as soon as possible, or else port your air with you in a space suit. But my dream wasn't a dream about what would happen if we plopped a bunch of present-day humans on present-day Mars using present-day technology. Instead, it was about the future.
* * *
A while back, I also thought of a similar sort of story. In it, human beings colonize Mars and exist there for hundreds of years before two major factions have an irreconcilable conflict, and the losing faction is banished from the colony. Ill equipped to survive the Martian landscape with whatever technology they could carry with them, and regularly exposed to the high solar radiation of the surface of Mars, this losing faction eventually, over time, evolves the ability to withstand high levels of radiation without suffering biological damage, and also the ability to breathe Martian air - or at least whatever middle-step the atmosphere of a partially colonized Mars might be like.
The rest of this story revolved around the discovery of this very profound human evolution and its implications for the two Martian "factions." Would they separate permanently? Would they intermarry and cooperate? What would happen?
I'll have to actually write the book some day to find out.
* * *
The key feature of all of these dreams and ideas I have about Mars is that building up and maintaining a "bubble world" on the surface of the planet, where humans must always be encased in glass with a steady supply of oxygen pumped around, has always struck me as a terrible way of life, one that is only feasible in the very short run. In my mind, Mars is only inhabitable if it can be terraformed. A generations-long project would have to ensue, during which humans would have to discover a way for Mars to maintain a thicker atmosphere, and for that atmosphere to be made of nitrogen, oxygen, argon, and carbon dioxide, just as Earth's atmosphere is. In order to achieve that, humans would have to discover a way to convert the existing Martian atmosphere to something that it currently isn't. Humans would have to figure out a way to protect that atmosphere from the kind of solar radiation that would destroy it - and that means either manufacturing an electromagnetic field around the planet (since Mars isn't capable of generating its own), or somehow constructing a thick ozone layer, under which an even thicker breathable atmosphere would reside.
All of this, and we haven't even tackled the question of potable water yet. Bear in mind that these materials cannot simply be piped-in from Earth or elsewhere in sufficient quantities to maintain and grow a permanent human population. Conflicts of water rights are the kind of thing that we Earth-dwellers have started wars over. Can you imagine how much conflict there would be between the inhabitants of an environmentally fragile Earth and inhabitants of a terraformed Mars whose existence depends entirely on Earth's willingness to ship its limited water and air resources across the expanse of outer space?
There are plot holes that a clever science-fiction writer can resolve, at least long enough to tell an exciting science-fiction story. However, to the best of human knowledge, there is no way to actually do this on Mars. If Mars will one day be habitable, we don't currently have the technology to do it; perhaps we don't even have the scientific knowledge to do it.
* * *
The primary reason we know we can't colonize Mars at any point in the foreseeable future is because there are vast, dead regions of Earth that human beings have killed and can't bring back to life. A couple of examples include the desertification of the Middle East and large patches of the ocean floor. If we can't build a farm on a plot of land that was farmed as recently as a couple of generations ago - if we can't keep part of a coral reef alive even though it isn't even dead yet - why in the world would we suppose that we can travel to Mars and render its barren soil fertile? (Keep in mind that the primary difference between barren and fertile soil is the presence of existing biological matter. Martian soil doesn't have any biological matter in it. How's it going to get there? Here's one way, but it requires clay from Earth.)
For the entirety of human existence, life has involved extracting resources from out environment and using them. Full stop. Every animal does this, but only human beings make the kind of technology that changes the environment in potentially catastrophic ways. We're the only animal that produces our own fire, for example, and fire can burn a forest down. We're the only animal that has ever managed to scrape the bottom of the ocean floor clean of all life. These are catastrophic changes.
Don't get me wrong, I'm not a luddite. Humankind's ability to produce technology has created a world that our primitive ancestors would certainly have considered to be the work of sorcery. We have become gods in all but one respect: we've figured out how to produce civilization when given wilderness; we have yet to figure out how to produce wilderness when given civilization. It's a tough problem to solve.
If we don't solve it, though, we can kiss our dreams of inhabiting Mars goodbye. Even supposing that Mars proves to be uninhabitable and we go searching for other worlds to colonize, we'll never even reach those worlds until we've figured out how to produce enough nature aboard a spaceship to provide ourselves with food, medicine, water, and technology along the way.
Nor is "environmentalism" the solution to the problem. Covering the surface of the earth with solar panels and windmills is no better for the land upon which they reside than is clear-cutting an acreage of forest. There is no way to reuse or recycle medical waste, and if we intend to heal the sick with medical technology, then we intend to perpetuate medical waste, too. There is only so much leeway we can get from "vertical hydroponic gardens" and other such green fantasies.
No, the problem here is that we human beings simply don't know how to terraform. We don't know anything about it. We know a bit about gardening, and a bit about landfills, and a bit about leaving virgin landscapes untouched. But we know nothing about creating and maintaining a viable ecosystem capable of supporting human life forever.
How truly odd that a species of ape that specializes in manipulating the environment around it in order to survive knows so little about manipulating the environment in order to survive.