Jingszo !

Our models suggest that periods of habitability on Mars have been the exception, rather than the rule, and that Mars generally self-regulates as a desert planet.

When it comes to keeping a planet balmy and mild, it isn't enough just to start out that way—there need to be mechanisms for stability over time that can respond to changes on and around the planet.

Scientists think that Earth does this through a finely balanced system that moves carbon from sky to rock and back again. Carbon dioxide in the atmosphere warms the planet, but warmer temperatures also speed up reactions that lock up carbon dioxide into rock, which eventually counteracts the temperature rise. Eventually, carbon leaks back out into the atmosphere via volcanic eruptions. Over millions of years, this cycle appears to have kept Earth relatively stable and hospitable for life.

On Mars, the researchers suggested, a similar cycle could also take place—but a self-limiting one.

Paper:

Carbonate formation and fluctuating habitability on Mars

https://www.nature.com/articles/s41586-025-09161-1