TERRAFORMING Engineering Planetary Environments Martyn J. Fogg Chapter 6 The Terraforming of Mars Now the new gases of the planetoid Burst into flame with Mars’s native air; A firestorm rages round the globe, as blue As hydrogen balloons set on a flare; The funguses, which briefly ruled this world, Burn to a fertile ash; a great cloud forms; Last, out of skies as black as Noah’s flood Falls the first rain that Mars has ever known. Frederick Turner 6.1 Problems with a Popular Paradigm It is true to say that the runaway greenhouse model of Martian terraforming, dating as it does back to the early seventies, represents a sort of “standard paradigm” — a framework in which the most influential and cooperative studies of the problem have been conducted. Alternative approaches exist, but these are almost exclusively the work of isolated researchers. The standard paradigm therefore is also the most popular one, receiving the largest share of publicity and media attention. This enthusiasm is perhaps not too surprising as the model promises much — a habitable planet in a period as short as a century — for the cost of a planetary engineering effort involving mass and energy fluxes of which present day civilization is more than capable. The notion that it might be possible to transform the Martian climate by merely tweaking the planet’s environmental parameters, so that free solar energy runs away with the process, not only greatly reduces the amount of planetary engineering that might be involved but also helps to head off any criticism concerning, man’s interference with nature. Returning Mars to a state that was once natural to it, however long ago, will obviously be easier to sell than a wholesale anthropocentric restructuring of the planet into an image of something it never was [1]. In its most optimistic guise therefore, the Runway Greenhouse model offers a vision of a near-miraculous Martian genesis, triggered by a modest and benign human intervention, untainted with that flavour of the homocentric technical fix that Lovelock finds so distasteful [2]. One can therefore be a planetary engineer whilst simultaneously keeping one’s “green” credentials intact. One can argue for ecopoiesis as being a creative act for life as a whole, rather than for man in particular. Such an awesome concept is naturally attractive to popular science writers. However, since the job of such people is to entertain as well as inform, scenarios presented to the public therefore often portray Mars being fully terraformed within a century, i.e. made habitable for higher organisms as well as bacteria [3,4]. Such timescales are unsupported by calculation, or based on unlikely assumptions and are most definitely not predicted by the work that is being reported. However what such coverage demonstrates is that, although the