Terra-forming is the science of transforming a planet to support human life.
Are there ways to terraform Mars — that is, make it habitable for humans? Some scientists think so. They have big plans, but they also face some big obstacles.
Here is a rather nifty short video which gives a general idea as to what steps need to be taken in order for Mars to support human life:
The video makes it looks an easy task but trust when I say it will be far from easy to achieve this. But the fact remains that it is possible.
Raising the atmospheric pressure and surface temperature alone could be achieved in just a few decades. So who knows, maybe in a few centuries time your great great great grandchildren might just be martians living on mars.
If you want to read an in-depth article about how to terraform Mars using current technology I suggest you check out this article : http://www.science20.com/robert_inventor/blog/to_terraform_mars_with_present_technology_far_into_realms_of_magical_thinking_opinion_piece-128009