We simulated the desert planet of Arrakis to see if humans could survive there

Great article! It finishes with this:

"The authors modified a well-used climate model for exoplanet research and applied it to the planet in Dune. The work was carried out in their spare time and is intended as an appropriate outreach piece to demonstrate how climate scientists use mathematical models to better understand our world and exoplanets. It will feed into future academic outputs on desert worlds and exoplanets."

Climate science hacking ;-)

Where would the oxygen would come from?