Science vs. Fiction
Make no mistake about it, though, planetary engineering is rocket science. It is also philosophy and mathematics and industrial might. Most of all, terraforming Mars will require dedication beyond any given to any task in human history.
Unfortunately, that brings us to another thing planetary engineering is: political science. That it currently garners so little monetary support is indicative of the problem. As I mentioned earlier, planetary engineers offer time estimates for terraforming Mars ranging from 300 years to almost 900, assuming today's technologies and a consistent effort throughout. More recent papers seem to support the smaller estimates and significant advances in the state of the art will, presumably, lower the estimates still more. Historically, however, only a very few governments and a few more religions have even survived long enough to complete the work of terraforming a planet. It is, in fact, hard to conceive of this project succeeding unless it becomes a worldwide effort.
That nine-hundred year clock can't even be started, though, until public support puts the project on the agenda. If my judgment of current public enthusiasm for space programs is correct, such public support won't happen soon, and consistent effort over long periods of time also seems very unlikely. While the scientists who have looked at the idea agree that it is possible, most realists, including many enthusiastic supporters, have little expectation that terraforming Mars will even begin in the first half of the twenty-first century. We will, perhaps, have outposts there by then, but even that depends on a great many unknown variables.
Our moral obligation, as the only species having the ability to do it, may be to preserve the Lifeforce, but there's no way in hell humans will go down the path I've just outlined unless their own survival is a possible outcome. We're not that kind of beast. Fortunately, it is conceivable that we might make it to Mars, too.