Green Mars - Kim Stanley Robinson [106]
As always, the posters were a deliciously mixed bag. They were posters rather than talks for a variety of reasons— often the work of graduate students at the university in Sabishii, or concerned with topics peripheral to the conference— but anything might be there, and it was always very interesting to browse. And at this conference there had been no strong attempt to organize the posters into hallways by subject matter, so that “Distribution of Rhizocarpon geographicum in the East Charitum Montes,” detailing the high-altitude fortunes of a crustose lichen that could live up to four thousand years, was facing “Origins of Graupel Snow in Saline Particulates Found in Cirrus, Altostratus and Altocumulus Clouds in Cyclonic Vortexes in North Tharsis,” a meteorological study of some importance.
Sax was interested in everything, but the posters that held him the longest were those that described aspects of the terraforming that he had initiated, or once had a hand in. One of these, “Estimate of the Cumulative Heat Released by the Underhill Windmills,” stopped him in his tracks. He read it through twice, feeling a slight dampening of spirits as he did.
The mean temperature of the Martian surface before their arrival had been around 220°K, and one of the universally agreed-upon goals of terraforming was to raise that mean temperature to something above the freezing point of water, which was 273°K. Raising the average surface temperature of an entire planet by more than 53°K was a very intimidating challenge, requiring, Sax had figured, the application over time of no less than 3.5 X 106 joules to every square centimeter of the Martian surface. Sax in his own modeling had always aimed to reach a mean of about 274°K, figuring that with this as the average, the planet would be warm enough for much of the year to create an active hydrosphere, and thus a biosphere. Many people advocated even more warming than that, but Sax did not see the need.
In any case, all methods for adding heat to the system were judged by how much they had raised the global mean temperature; and this poster examining the effect of Sax’s little windmill heaters estimated that over seven decades they had added no more than 0.05°K. And he could find nothing wrong with the various assumptions and calculations in the model outlined in the poster. Of course heating was not the only reason he had distributed the windmills; he had also wanted to provide warmth and shelter for an early engineered cryptoendolith he had wanted to test on the surface. But all those organisms had in fact died immediately upon exposure, or shortly thereafter. So on the whole the project could not be said to be one of his better efforts.
He moved on. “Application of Process-Level Chemical Data in Hydrochemical Modeling: Dao Vallis Watershed, Hellas.” “Increasing CO2 Tolerance in Bees.” “Epilimnetic Scavenging of Compton Fallout Radionuclides in the Marineris Glacial Lakes.” “Clearing Fines from Piste Reaction Rails.” “Global Warming As a Result of Released Halocarbons.”
This last one stopped him again. The poster was the work of the atmospheric chemist S. Simmon and some of his students, and reading it made Sax feel considerably better. When Sax had been made head of the terraforming project in 2042, he had immediately initiated the construction of factories to produce and release into the atmosphere a special greenhouse gas mix, composed mostly of carbon tetrafluoride, hexafluoroethane, and sulphur hexafluoride, along with some methane and nitrous oxide. The poster referred to this mix as the “Russell Cocktail,” which was what his Echus Overlook team had called it in the old days. The halocarbons in the cocktail were powerful greenhouse gases, and the best thing about them was that they absorbed outgoing planetary