BUT I DON’T WANT TO: Forget About Terraforming Mars. Here’s Why.

“The rate of loss of gas today is very low — slow enough that it would take billions of years to remove the equivalent amount of gas that is in the atmosphere,” principal investigator Bruce Jakosky said in an email. There is some CO2 left in the polar ice and in carbon-bearing materials, he added, but not nearly enough to warm the temperature significantly if it somehow was put back in the atmosphere.

“There isn’t a source of CO2 that could replenish the atmosphere — even outgassing of CO2 from volcanoes has got to be incredibly slow today,” Jakosky added. “If we wanted to put enough CO2 into the atmosphere to raise temperatures significantly, it would take something like 10 million kilometer-sized comets (if they were all made entirely of CO2). This is just not feasible.”

That is… inconvenient.