Within Kim Stanley Robinson
's Mars Trilogy
one of the primary conflicts is between those who wish to minimize human impact on Mars and those who wish to terraform
the plannet. As with any polarizing issue
, the colonists are split into two political camps - the 'Reds', who wish to preserve the Red Planet
as it is, and the 'Greens', who wish to convert mars into a (relatively) lush, life-sustaining planet. It is not without irony that the anti-environmentalist (or more properly, anti-conservationist) movement is refered to as 'Green
To understand the source of the conflict, its important to understand who would be a part of the first colonizing missions to Mars. The first colonies would consist of engineers, biologists/hydroponicists, planetary geologists (or more properly, areologists) probably including scientists looking for signs of life, and certain support staff, for supplying medical and other services.
The areologists would most likely fall into two categories. Research areologists would be most interested in learning about the geologic history, processes, and structure of Mars. Economic geologists would be tasked with finding ore deposits and water sources required to sustain the colony itself. There would of course be some overlap of these tasks, but some scientists would surely be inclined to favor one goal over the other.
Presumeably, given Mars' significantly different mass and somewhat different chemical makeup, even fairly fundamental geological processes that are now taken for granted on Earth would be entirely different on Mars. Plate tectonics, for example requires a strong, rigid lithosphere over a weak, plastic aesthenosphere. Did Mars ever have a well-developed aesthenosphere? If not, how has that effected its surface geology?
There would be enough areology to occupy all Earth's geologists, full-time, for their entire careers. And for a good portion of that time, surface mapping would be the order of the day. Drastic changes to the climate of Mars, due to terraforming, would lead to significant alterations of the surface. This would, in turn, erase much of the areologic record. Every drop of man-made rain on the surface of Mars would erase a tiny bit of evidence of Mars' areoligic history. Water and life destroy rocks and alter soil, and these rocks and soils would be the primary sources of any history of Mars.
Economic areologists, concerned primarily with metal ores and economically valuable rocks and minerals, would not have an inherent interest in this question beyond functional concerns. In this case their stance on terraforming would be based on three concerns. Would terraforming eliminate clues to underground deposits, or are such deposits going to be found using geophysical methods which would be less impacted by surface changes? Would terraforming, through increased erosion, remove overburden and reveal more economic resources? And would terraforming make extraction of minerals easier by reducing the stress to men and machines by increasing the temperature and reducing the need for bulky environmental suits.
Outside of these groups, this question would be more of an emotional question. Edward Abbey/John Muir style "Mars for Mars' sake" sentiments would probably exist among a minority of Mars Colonists who love Mars as a rugged wilderness. For such people, the smallest patch of terrestrial moss producing atmospheric oxygen would destroy a piece of Mars' unique character. While this might be a minority, they would likely be a very vocal minority, and very motivated.
Ultimately, unless there is strong government, individual communities are likely to perform at least small terraforming projects, even in the absense of a unified Martian terraforming plan. Humans are unlikely to live anywhere for long without causing significant changes to the environment. As these changes compile, this will ultimately render the Red/Green divide moot. However, during this process, it will be at least as divisive as the earthbound environmental debate has been.