Check page 160 and 161 of the manual for the information you want. Generally:
- Any level of non-terran atmosphere, biological hazard, inclement temperature, or background radiation, will mean that your population will suffer morale penalties or casualties. A Single Asset with its required upkeep will protect ALL population in that hex from ANY Atmospheric, Biological, or temperature based environmental hazard. A fair amount of radiation hazard protection is provided too, but in some circumstances this can go beyond the base generic asset protection, and can require the Radiation Treatment Asset, Anti-Radiation infrastructure, or both. Insufficient environmental protection can also cause population migration, and greater ease of military/colonial recruitment from an affected population. Free folk settlements are assumed to be adapted to environmental hazards either from their own infrastructure or genetic modification, but IF they are suffering environmental hazards somehow, they are more likely to migrate to your cities, assuming those cities have adequate environmental protection.
- Non-Terran atmosphere, biological hazards, or inclement temperature, will reduce the output of Open farming assets, depending on the severity of the environmental hazard. In these circumstances you will be required to use either Xeno Farming (If the planet's native life has any nutritional value), domed farming, or Hydroponic food factories (once researched). A late game tech can mitigate some of this hazard for open terran farming but it's not worth it.
- Your soldiers are also affected by Atmospheric/Biological hazard and will suffer morale penalties and attrition as well. This can be mitigated or cancelled entirely by issuing them with Filters (For minor atmospheric/biological hazards), thermosuits (For moderate temperature hazards), both, or Envirosuits for greater protection and also radiation mitigation. This increases the cost of infantry in the early game, however the first infantry armor upgrade includes an envirosuit, and higher levels of troop armor also include environmental protection. Vehicles also provide environmental protection by default.
As far as atmospheric thickness, that mainly affects the Air forces module. Heavier atmosphere will increase the lift generated by aircraft wings, and the force generated by propeller engines, but also the effect of atmospheric drag. Thinner atmospheres have less atmospheric resistance, but will also require more wing area to give the necessary lift for flight, and reduce the efficiency of propellers. The combination of atmospheric thickness and gravitational force will affect how you design your aircraft and how effective they can be. Planets with insufficient atmosphere for propeller-driven or aspirating (oxygen-using, Jets+Turbojets) aircraft engines can only use rocket engines for propulsion.
Atmospheric composition also might mean certain industrial technologies are not available to you. Atmospheres without significant CO2 content cannot use Methane Synthesis plants, and Water Atmospheric recomposition will require a specific combination of certain gasses to be present.
< Message edited by Mina -- 2/27/2021 2:13:10 PM >