Critical IntelOur Destiny in the Stars: The Reality Behind TerraformingCritical Intel - RSS 2.0
Worldhouses: Life In the Bubble
You may have noticed that throughout the thought experiment above, humans weren't living in the open air on Mars, but in habitation modules and "dome communities." While these would be necessary for full-planet terraforming, another school of thought holds that rather than terraforming a whole planet, humanity should form colonies in closed ecological systems. Most likely these would look like enormous greenhouses or geodesic domes, with various climates inside.
There have been a few closed ecological systems built already, but none has achieved self-sufficiency. The most ambitious experiment was Biosphere 2, an odd project that replicated biomes including rainforest, mangrove wetlands, savannah, fog desert, agricultural systems, human quarters and even an 850 square meter ocean with coral reefs. The project, however, was a litany of hard lessons - population explosions from ants and vines, lower than expected oxygen production and even a schism within the human inhabitants. The experiment was such a disaster it inspired a Pauly Shore movie.
Biosphere 2's failure notwithstanding, closed environments known as paraterraforming or worldhouses have a lot to recommend them. Because they're smaller than full-planet conversions, the return on investment is more immediate, and artificially manipulating their environment will likely be easier. Their modular design means settlers can build outward from the initial habitation, and they allow colonization on small bodies like asteroids that can't retain an atmosphere.
There are drawbacks too, of course. A worldhouse would need its own closed water system, continuous maintenance, and be more susceptible to catastrophic failure due to meteor strikes or warfare. But those issues aside, it's likely any future space colonization will have these worldhouses as their hub.
The Economic Problem
Terraforming's biggest hurdle is financial. An expert panel recently estimated that a manned Mars program would cost between $80 and $100 billion over twenty years, culminating in a single manned mission. While that's not unfeasible (the F-35 fighter program alone may end up costing over a trillion dollars) it would only put one crew on Mars. The cost for building a long-term habitation would be much higher, not to mention the infrastructure necessary for terraforming. NASA estimates, for example, that each chlorofluorocarbon-producing factory in their scenario would have energy needs equal to a dedicated nuclear power plant, and those aren't cheap to build on Earth - much less on Mars. While it's true that there will be new industries and technologies by that time, we're still talking about vast quantities of capital investment. Terraforming Mars would likely take an international effort, even a global one.
And that in itself runs into geopolitical issues. Since the days of Magellan, competition - not common interest - has spurred our need to explore. Our most productive period in manned space exploration was during the Cold War, when our main objective was to beat the Soviets. As tensions thawed and scientific inquiry became the focus, the U.S. public and politicians quickly lost interest in space travel. Terraforming planets will only happen after we've made a major shift in our politics - to conquer Mars, we will first have to conquer our own divisions.
Of course, we're talking about great lengths of time here. Who knows what geopolitics and economics may look like a few centuries in the future? In three hundred years, capitalism may no longer be the world's predominant economic system. The nations we know today may be as distant as Austro-Hungary or the Ottoman Empire are to us today. Technologies and industries we can only speculate about may unlock new avenues of capital and lower costs. We could be mining oxygen with microbes and have perfected the process for manufacturing concrete out of moon rock.
But even if we could terraform, there's always the question of whether we should.