The Sahara lacks a CO2 atmosphere, it also lacks substantial quantities of subsurface ice. Besides which, about 4 million people live in the Sahara today, desp

The Sahara lacks a CO2 atmosphere, it also lacks substantial quantities of subsurface ice. Besides which, about 4 million people live in the Sahara today, despite many of the surrounding countries being some of the poorest and least developed on Earth. The point of living on Mars is not to find the most convenient place possible to live. That would not be Mars, nor would it be the Sahara, nor would it even be Copenhagen, Dubai, or the Netherlands (where 10 million people live on land that used to be under the sea). But people live in those places even so because it turns out there are compelling reasons to live there. Just as, I believe, there are compelling reasons to live on Mars (much more so than in living in the Sahara). Edit: most people living in the developed world today are swaddled in the embrace of a vast web of advanced technology and industry. The hammer used to build the home down the street was mined and forged an ocean away. The phone you use every day contains components developed and manufactured across a handful of continents. The food you eat could come from next door or across the world. But that web of technology and industry is familiar to us, whereas one involving living on Mars is alien and implausible to our sensibilities. But over the course of decades and centuries as technology advances, as industry develops, as the unusual becomes more commonplace, maybe people will start to view life on Mars in a similar fashion. Maybe it won't seem so impractical when the bounty of martian agriculture feeds substantial populations, when martian industry is a multi-billion dollar or multi-trillion dollar business, when cities full of people exist on Mars, and so on.