Yes, a lot of thought has been given to how to make Mars warm enough to support Earth type life:
http://en.wikipedia.org/wiki/Terraforming_of_Mars
And yes, a lot of it has to do with dumping as many greenhouse gases into Mar's atmosphere as can be done. Some plans even call for simply firing rockets filled with CFCs to crash into Mars, literally and deliberately polluting it with pollutants that were banned on Earth because they were destroying the ozone layer.