"Nuke the Red Planet?" (Sticknmuv, space.com)

The argument of terraforming versus ecopoiesis continues in Sticknmuv's posting at space.com (click on the title to link to the original posting). Fortunately, I wrote my dissertation on "...The Application of Desert Reclaimation Techniques To Ecopoiesis On Mars," so have studied the subject in depth. 'Ecopoiesis' is a 'softer' term for terraforming, meaning the 'making of a home,' without the invasive, transformative connotations of terraforming. Ecopoiesis supports the notion of protected, enclosed habitats, e.g. underground and/or dome-covered compounds, protected from the existing conditions of Mars, so that the presence of settlements would have a minimal impact on Mars itself. "Nuking Mars," in addition to having a negligible and short term effect on global surface temperatures (most of the thermal energy released is as a radiant flash, very little would be absorbed by the crust, and would cool rapidly) would result in massive clouds of lethally irradiated dust being kicked up into the atmosphere, probably covering Mars in a radioactive dust storm that would filter out the already scant sunlight, plunging temperatures at the surface even lower, and presenting any would-be future inhabitants with a less than desirable top-soil to grow their Martian crops in, should said radioactive dust storm ever settle. Furthermore, any interest in visiting Mars would most likely be scientific, with teams of geologists (soon to be areologists) eager to study rock formations in the Martian landscape. Not much to study if you blew it up.... And, as pointed out, there might actually be something living there already! Even if there isn't, why deny future generations the pleasure of trying to find the elusive "Loch Mars Monster?" The "loss of atmosphere," some people seem concerned with is a combined function of Mars' low gravity and incident sunlight, which very gradually depletes the water vapour in the atmosphere of hydrogen atoms; incoming photons 'knock' the atoms at the upper limits of Mars' atmosphere out in to space. The rest of the atmosphere is quite safe. The only other 'atmospheric loss' is through chemical weathering of the regolith, but this is not a loss to space, only to the ground; life cycles or processing could potentially release such gases back into the atmosphere again. One unaccounted for benefit of impacting the surface of Mars, be it with nukes, icy or metallic asteroids, is outgassing; a hard enough strike against the crust would vapourise gas-forming elements from the weathered regolith and breach to the Martian mantle, releasing further atmospheric elements in a similar way to vulcanism here on Earth. Since Mars no longer has vulcanism, die-hard terraformers might wish to consider a program of impact outgassing to replenish atmospheric elements and raise overall air pressure (and therefore surface temperature). Rather than randomly peppering the surface with redirected asteroids or comets, which would represent a considerable hazard to anyone on the surface, an exhaustively studied and remote site of little further geological interest could be selected as a repetitive outgassing target, and an orbital railgun could be used to accurately impact this target with metallic projectiles formed from mined asteroids or materials acquired from surface mining operations (William Gibson gave me this idea in one of his cyberpunk novels - "Mona Lisa Overdrive," I think...?). The Martian atmosphere is thin - around 6 millibars, depending on the season, but comprised mostly of carbon dioxide, so that there is roughly the same amount of CO2 in Mars' and Earth's atmospheres. Oxygen is not a greenhouse gas, so converting the available CO2 to oxygen via photosynthesis would result in further cooling at the surface of Mars. Adding atmospheric elements, e.g. nitrogen, water vapour (also a greenhouse gas) or oxygen not sourced from the existing CO2, and thereby raising the atmospheric pressure, would lead to an increase in the greenhouse effect of the existing CO2, which becomes more effective at higher pressures, leading to an increase in surface temperatures. Nitrogen makes up about 70% of Earth's atmosphere - instead of nuking Mars, if you were really committed to terraforming to the extent that humans could walk around on the Martian surface without any protection from the environmental conditions, you'd need to think of a way to pump Mars' atmosphere full of the missing nitrogen. Maybe there's enough nitrogen fixed in the soil there already to do the job....