Desert Planet

Desert Planets are otherwise ordinary silicate terrestrial planets who are almost completely devoid of surface water (other than perhaps a small amount at the planet’s poles). These desert planets, however, in order to be considered habitable, need a minimum of 1% humidity to wash off atmospheric carbon dioxide.

Interestingly, desert planets may have larger habitable zones than other terrestrial planets. This is because a decreased amount of water would allow the planet to absorb more heat, thereby increasing the outer habitable zone limit, but would also reduce the planet’s heat retention and allowing it to remain habitable closer to the star without experiencing runaway greenhouse effects. This is not affected by subsurface water, and thus a desert planet with large enough reserves of water could be considered habitable.

Worldbuilding in Practice
"Electra is a habitable desert planet in the Agamemnon system, colonised by the Federation of Gaia. Its mass and radius are very similar to Earth and this factor, combined with its pleasant weather and mild seasons, making it a popular colony. Although unsuitable for agriculture and relying on nearby Orestes for water supply, the planet boasts a booming industrial colony, Noella, where minerals from the system are refined and processed for use across the galaxy."