Designing Earth-like Atmospheres

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Recommends TheDyingOfLight · 2019-08 · Worldbuilding Stack Exchange · on “What gases could be present in a viable atmosphere for humans?”

Firstly it sounds like you want to do bottom-up worldbuilding, meaning you want to get the basic science straight first. I would recommend worldbuilding YouTuber Artifexian [LINK] , as he has a series where he starts with constructing the solar system and has currently reached climate mapping. He breaks down the science to a very digestible minimum. For your question, I recommend watching his videos on atmospheres [this video] , alien atmospheres [LINK] and sky and plant-color [LINK] . Pressure Pressure may vary significantly on "earthlike" planets. Mars has only about 0.006 atm, Earth has 1 atm, Titan has 1.5 atm and Venus 96 atm. Mars and Venus both experienced cataclysmic events in their pasts

Recommends user75058 · 2020-04 · Worldbuilding Stack Exchange · on “Calculating average sea-level air pressure”

I think an acceptable answer might be that it doesn't matter too much. Artifexian, in his video "Designing Earth-like Atmospheres," gave this spreadsheet [this video] to help with calculating an Earth-like atmosphere. Given the figures you provided, you could fill out the entire spreadsheet. But here's the important bit: in the video, there aren't specific instructions to calculate pressure. You just enter the value you want, and it spits out scale height and density. So basically, what AlexP said.

Recommends El Nitromante · 2021-03 · Worldbuilding Stack Exchange · on “Conditions for intelligent and diverse life at high altitudes”

I'm making a planet which hosts three distinct layers of floating islands, each higher than the last one. The islands should be reasonably thick, ranging from a couple hundred metres to three or four kilometres in average, depending on the size of the island and its relief. The layers need some separation between them of course. Taking all of this into account, it's notable the planet is going to need a lot of vertical space, furthermore, inhabitable vertical space, as the islands should house all kinds of lifeforms. I've been playing around with Artifexian's "Earth-like atmospheres" spreadsheet of this [this video] video of his and tuned the planet so, with a similar composition to that of Earth

Cites TheDyingOfLight · 2019-08 · Worldbuilding Stack Exchange · on “Is this atmospheric composition breathable on a planet with 50% more surface pressure?”

As for the breathability of the atmosphere. I encountered this list in a video by worldbuilding YouTuber Artifexian [this video] and have added to it since. I did check several values and found them to be correct. Going down the list it became increasingly difficult to verify the values, so take everything without a link with a grain of salt. N2 < 3 atm [LINK] 1.25 atm, o.k CO2 < 0.02 atm [LINK] 0.015, o.k CO < 0.0001 atm [LINK] not found CH4 < 0.05 atm (not toxic, but explodes at this point [LINK] ) 0.00045 atm, o.k SO2 < 0.000005 atm not found O3 < 0.0000001 atm [LINK] i.e. 0.1ppm 0.000165 atm, exceeded by 3 orders of magnitude O2 < 0,16 – 0,5 atm ( 0.3 - 0.35 atm wildfire limit [LINK] ) For th

Cites TehKaoZ · 2021-08 · Worldbuilding Stack Exchange · on “What atmospheric conditions would be needed produce intense heat, weather and wind that could fry a human in less than 5 minutes at sea-level?”

first time poster here. The premise: I’m trying to design a planet in where sea-level / lowlands are an uninhabitable wasteland with temperatures that would fry a human in less than 5 minutes. In my mind, I’m imagining this area would look like an ash ridden area with intense winds and severe weather. This would be in contrast to highland areas (mountains, plateaus, and so on) which would have a more temperate climate. Research: I am not a science guy, so a lot of the atmospheric stuff takes me a bit to grasp. I found a video [this video] that kind of outlines a possibility by upping the atmospheric composition to feature 1% Co2, but I’m not sure if this would produce the exact conditions I’m loo

Cites Thoth · 2023-02 · Worldbuilding Stack Exchange · on “What color should my planet's skies be?”

Assuming the skies are clear of suspended particles, what color should they be at mid-day if viewed with human eyes? The planet is larger and twice as massive as Earth, with a nearly identical atmosphere composition but a far higher surface pressure. This implies a thicker atmosphere with more scattering, which could produce light, warm-toned skies rather than blue ones. I watched some [this video] videos [LINK] by Artifexian on the subject, and used the spreadsheets and sources he had provided to determine what color they should be. However, I wasn't able to come to a solid conclusion based on some gaps and conflicting info: The two [LINK] calculators [LINK] generally point towards a light, warm