A big fire burning what? How much ice is in the ice caps? will that be enough water? How do you keep the atmosphere there, given that mars has no magnetic field and less gravity keeping it in? How do things live on the surface without a magnetic field protecting them from radiation?

I have of course read/seen many pie in the sky plans for how to make mars habitable, but they are not concrete plans with even napkin math backing them up.

https://astrobiology.nasa.gov/news/how-to-give-mars-an-atmos... A NASA proposal that seemed rather cool to generate an artificial magnetosphere umbrella. It doesn't require any superscience to do, just willingness to build a really enormous generator. Which might be worth doing if the result is a 2nd Earth?

The not having a magnetic field is a smaller problem then people think. The rate of reduction in the atmosphere is not very large.

If you manged to create the atmosphere the radiation on the surface would already be reduced. The extra distance to the sun plus the atmosphere more then makes up for the missing magnetism.

Also, medicine is advancing, if this is actually still the major issue in 30 years is questionable.

But overall I agree, we are not there yet with plans but if we can build a research station there and have constant flights and constantly people living there, space technology will continue to improve and eventually we might reach that level.

The atmosphere bleeds off in million year time scales. Humans can pump it up in hundred year time scales. Things growing in water will get less radiation and hopefully some radiation resistant crops will be bred.

My understanding is that Mars' gravity is much too weak to maintain an atmosphere -- any gas that's produced will literally escape into space. There's also the problem of radiation due to Mars' lack of a strong magnetic field.

You could mitigate these problems by having humans live permanently underground. But that's not exactly terraforming. How can we overcome these significant hurdles to permanent human colonization of Mars?

It took Mars about a billion years to lose its atmosphere.

Wouldn't it be faster to crash a few of comet/icy moon/etc into the atmosphere? Then a decade later put big nuclear powered magnets in orbit to generate a magenetosphere so the new atmosphere won't evaporate after a hundred million years?