Inventory of CO2 available for terraforming Mars

There is not enough CO2 or any other such gas on Mars to make an atmosphere better than 5% of Earth's, even if you razed the surface kilometers down and boiled the ice caps and installed an artificial magnetosphere. https://doi.org/10.1038/s41550-018-0529-6 20 millibars is essentially the long-term limit without piping in gas from other planets or comets. There's plenty of science and exploration to be done on Mars, and efforts towards getting people there are admirable, but let's keep it red. Non-scientists (like Elon) should at least consider not ignoring the data we've spent billions of dollars collecting and confirming over the past 50 years.

The excellent Casey Handmer covers some of the new facts that have come to light since this paper was written. > Last week, a Nature paper (https://www.nature.com/articles/s41550-018-0529-6) was published by Jakosky and Edwards arguing that, based on data from more recent orbiters, the total near-surface reserves of CO2 are much too low to built up the atmosphere enough for terraforming. What a bummer! http://caseyexaustralia.blogspot.com/2018/08/atmospheres-and... He describes some of the back-and-forth dispute, but ultimately comes down pretty pessamistic on Mars terraforming.

Seems a somewhat odd project, at least for the stated purpose, given that there's now evidence that there is not even enough CO2 on Mars to easily create a breathable atmosphere: https://www.nature.com/articles/s41550-018-0529-6

And yet again, there isn't a single link to the paper anywhere in the article. A pop-up autoplaying video doesn't replace good journalism. https://www.nature.com/articles/s41550-018-0529-6