That is why I was suggesting the giant planetary shield. Think in the future with better materials and technology we should be able to at low cost basically turn the entire planet into an enclosed climate controlled structure. Artificial light could simulate more earth like lighting or a means to rout the sunlight in such a manor could also work. The structure itself could also shield the planet in place of its poor magnetic field. Although it is mars that basically had no magnetic field and the problem with mars is that any atmosphere we create will be blow off due to solar winds and the low gravity. Ultimately we may need to somehow enclose mars as well in order to prevent the atmosphere from being removed.
I just like to imagine that if we truly are going to start to colonize we need to think of radical approaches to creating earth like conditions for large areas.