A while back I was playing an online game and the guy I was with started talking about colonizing Mars. He thought the Earth was done, with all the pollution, climate change and social discord, and that humanity had to start over on another planet just to survive. He thought independent, go-it-alone entrepreneur types would be the salvation of mankind. In other words, he had drunk the Elon Musk Koolaid.
He was wrong on every level.
First, the facts. Even in the worst possible climate scenario we've got, Earth is far more hospitable than the moon, freestanding space colonies, Mars or Venus.
Venus is right out because it's suffering from a runaway greenhouse effect: the atmosphere is mostly carbon dioxide with a dash of sulfuric acid. The surface temperature is hot enough to melt lead. The air pressure is 90 atmospheres, equivalent to being half a mile below the ocean. You might be able to live in the clouds of Venus (making a floating habitat would be relatively easy because of the dense atmosphere), but then access to raw materials would be difficult.
The moon has no atmosphere and no magnetic field, which means it is constantly bombarded by cosmic radiation and high-energy particles from solar flares. Radiation exposure is 200 times what it is on Earth. The temperature varies from 280 degrees below zero to 260 degrees Fahrenheit. Apollo astronauts traveling to the moon were only gone about a week, so they suffered only minimal damage. But long-term residents would have to either build electrostatic shields (which need a lot of power), or live underground (which is problematic because lunar soil also emits radiation, like some building materials on earth). Water would be a problem, though there might be some under the surface at the poles. And of course you have to make your own air. It's not clear what the implications of lower gravity would be on human health and childhood growth.
Freestanding space colonies, like the O'Neill cylinders, are a neat idea, but they are fixed size and can't be totally self-sufficient. They require constant maintenance, import of raw materials and ongoing trade with Earth and other colonies for supplies and exchange of genetic material.
Mars has a thin atmosphere of carbon dioxide (.006 of Earth's atmospheric pressure) and no magnetic field, making it only slightly better than the moon in terms of radiation exposure. The average temperature is -81. However, it can get up to 70 degrees at noon in the summer, but it gets to -200 at the poles.
There was probably water on the Martian surface billions of years ago, and there might be some left below the surface over much of the planet, and there's water ice at the poles. In the winters about a quarter of the atmosphere freezes out at the poles, forming a crust of dry ice that sublimates in the spring.
Clearly Mars is the most Earth-like planet and the best candidate for human habitation. But people would probably still have to live underground, surrounding themselves with radiation shields of one sort or another. Surface excursions would have to be severely limited to reduce radiation exposure to prevent an epidemic of cancer and rampant genetic mutations. Food production would always be a struggle with the lower solar radiation (less than half of what Earth gets).
But the biggest challenge wouldn't be the harsh environment: it would be the people. The kind of people who are attracted to such a barren frontier -- the fiercely independent, go-it-alone, rule-breaking entrepreneur types -- are the worst kind of people to make a home on Mars.
On Mars everyone has to follow all the rules, all the time. In a place where punching a hole in the wall will kill everyone in the room, there's no place for anger or pettiness. One or two people could sabotage a Martian settlement's food, water or air supply, killing everyone.
On Mars there would be no room for rebels and malcontents. Every marriage and birth would have to be approved by the government because resources would have to be so tightly controlled. Because a Martian colony would be a completely closed system, every aspect of your life would be dictated: how much power you use, where you live, how much space you get, what you eat, what you drink, what you excrete, even what you breathe. It would be like living on a nuclear submarine your whole life.
There would essentially be no freedom. Mars would not be a libertarian utopia: it would be a communist dictatorship. The survival of the group would override every other consideration.
The thing is, even if Earth suffers the ultimate disaster scenario -- worst-case climate
change, massive sea level rise, global thermonuclear war -- Earth
will still be more hospitable than Mars. People survived Hiroshima and Nagasaki and Chernobyl. People survived multiple ice ages. That's because no matter how bad it got on Earth, there has been air, water and food in the form of plants and animals, even in places as desolate as Antarctica.
None of that is true for Mars.
There's no shortage of failed attempts at colonization here on Earth. The Vikings made two settlements in Greenland, but abandoned both. The Vikings' North American colony in Vinland failed. The first Roanoke colony, led by Sir Walter Raleigh in 1585,
failed and everyone returned to England. The second Roanoke colony just
disappeared, leaving the enigmatic word "Croatoan" carved on a fence
post. And on and on.
Given the number of robotic missions to Mars that have failed (two-thirds), it's clear that crewed expeditions to Mars will result in numerous failures and numerous deaths, just as our attempts to reach the north and south poles did. We lost 14 astronauts in the Challenger and Columbia shuttle disasters, and three astronauts in the Apollo 1 launch pad fire. People will die in our attempts to reach Mars.
That's not to say we shouldn't go to Mars, we most definitely should. The risk of death is just the reality of exploration of any new territory. Just look at how many people die climbing Mount Everest. But for the foreseeable future Mars will be like an Antarctic research post. Not a place to raise a family.
Maybe, someday, thousands of years in the future, we could terraform Mars, creating a biosphere, and humans could survive on the surface
without artificial aids. But not in time for us to write off planet
Earth. A self-sustaining Martian colony is basically impossible for centuries: the level of technology required for basic survival mandates the huge industrial base of the Earth.
It basically comes down this: there is zero room for error on Mars. People and technology are simply not reliable enough for Mars to be the sole repository for mankind. And even if we do manage to terraform Mars, the solar wind would eventually blow the atmosphere away, like it did billions of years ago.
So the upshot is: there is no Planet B. There is only Earth.
Last year an Australian group published a study
that said civilization will collapse by 2050 if we don't stop mucking
with the climate. That's just 30 years from now. It was immediately pooh-poohed by conservatives. But
as we've seen, last year Australia was burning out of control, and this year the West Coast is burning out of control and
the Gulf Coast is getting hammered by hurricanes once or twice a month. Miami is sinking into the sea.
This is not sustainable. And it's only getting worse.
Obviously we should stop screwing up the climate right now. Because if we don't, there's going to be a huge exodus from the South to the North and from the coasts to inland areas, as oceans rise and swallow cities like New Orleans and Miami and New York, and entire states and countries are destroyed by fires and droughts and hurricane after hurricane. If we don't stop fouling our nest, competition for breathable air, arable land and potable water will result in endless wars, which will eventually go nuclear.
Yeah, some small part of humanity will survive the cataclysm, like we survived the ice ages. But that means the industrial base will be destroyed, rendering all our cars and guns and air conditioners and furnaces useless, and the seven or eight billion people who depend on that industrial base are going to die, including most of the United States.
Who will survive? Ironically, those people who are used to living in squalid conditions, who eke out a subsistence living in those "shithole" countries Donald Trump loves to hate.
In other words, the meek shall inherit the earth.