Blue Mars(112)

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So given all this, the executive council was meeting for long hours every day to discuss legislation and other government programs. It was so time-consuming that Nadia almost forgot there was a conference she had initiated going on at the same time in Sabishii. On good nights, however, she spent a last hour or two on-screen with friends in Sabishii, and it looked like things were going fairly well there too. Many of Mars’s environmental scientists were on hand, and they were in agreement that massively increasing greenhouse-gas emissions would ease the effects of the mirror loss. Of course CO2 was the easiest greenhouse gas to emit, but even without using it— as they were still trying to reduce it in the atmosphere to breathable levels— the consensus was that the more complex and powerful gases could be created and released in the quantities needed. And at first they did not think this would be a problem, politically; the constitution legislated an atmosphere no thicker than 350 millibars at the six-kilometer contour, but said nothing about what gases could be used to create this pressure. If the halocarbons and other greenhouse gases in the Russell cocktail were pumped out until they formed one hundred parts per million of the atmosphere, rather than the twenty-seven parts per million that were currently up there, then heat retention would rise by several degrees K, they calculated, and an ice age would be forestalled, or at least greatly shortened. So the plan called for production and release of tons of carbon tetrafluoride, hexafluoroethane, sulfur hexafluoride, methane, nitrous oxide, and trace elements of other chemicals which helped to decrease the rate at which UV radiation destroyed these halocarbons.

Completing the melting of the North Sea ice was the other obvious abatement strategy most often mentioned at the conference. Until it was all liquid, the albedo of the ice was bouncing a lot of energy back into space, and a truly lively water cycle was somewhat capped off. If they could get a liquid ocean, or, given how far north it was, a summer-liquid ocean, then any ice age would be done for, and terraformation essentially complete: they would have robust currents, waves, evaporation, clouds, precipitation, melting, streams, rivers, deltas— the full hydrological cycle. This was a primary goal, and so there was a variety of methods being proposed to speed the melting of the ice: feeding nuclear-power-plant exhaust heat into the ocean, scattering black algae on the ice, deploying microwave and ultrasound transmitters as heaters, even sailing big icebreakers through the shallow pack to aid the breakup.

Of course the increased greenhouse gases would help here as well; the ocean’s surface ice would melt on its own, after all, as soon as the air stayed regularly above 273 K. But as the conference proceeded, more and more problems with the greenhouse-gas plan were being pointed out. It entailed another huge industrial effort, almost the equal of the metanat monster projects, like the nitrogen shipments from Titan, or the soletta itself. And it was not a onetime thing; the gases were constantly destroyed by UV radiation in the upper atmosphere, so they had to overproduce to reach the desired levels, and then continue producing for as long as they wanted the gases up there. Thus mining the raw materials, and constructing the factories to turn those materials into the desired gases, were enormous projects, and necessarily a largely robotic effort, with self-guided and replicating miners, self-building and regulating factories, upper-atmosphere sampler drones— an entire machine enterprise.

The technical challenge of this was not the issue; as Nadia pointed out to her friends at the conference, Martian technology had been highly robotic from the very beginning. In this case, thousands of small robotic cars would wander Mars on their own, looking for good deposits of carbon, sulfur, or fluorite, migrating from source to source like the old Arab mining caravans on the Great Escarpment; then when new feedstocks were found in high concentrations, the robots could settle down and construct little processing plants out of clay, iron, magnesium, and trace metals, providing the parts that could not be constructed on-site, and then assembling the whole. Fleets of automated diggers and carts would be manufactured to haul the processed material in to centralized factories, where the material would be gassified and released from tall mobile stacks. It wasn’t that different from the earlier mining for atmospheric gases; just a larger effort.

But the most obvious deposits had already been mined, as people were now pointing out. And surface mining couldn’t be done the way it used to be; there were plants growing almost everywhere now, and in many places a kind of desert pavement was developing on the surface, as a result of hydration, bacterial action, and chemical reactions in the clays. This crust helped greatly to cut down on dust storms, which were still a constant problem; so ripping it up to get to underlying deposits of feedstock materials was no longer acceptable, either ecologically or politically. Red members of the legislature were calling for a ban on just this kind of robotic surface mining, and for good reasons, even in terraforming terms.