There was this line from the article:
> I see your point, because at 43 percent a lightning strike will cause the entire atmosphere to ignite since it is so high in flammable oxygen.
Is that accurate, and if so where did the 43% number come from?
> I see your point, because at 43 percent a lightning strike will cause the entire atmosphere to ignite since it is so high in flammable oxygen.
Is that accurate, and if so where did the 43% number come from?
If the oxygen concentration was high enough many things on the surface would burn (green plants, metal, etc.), but the air itself wouldn't. Things would probably rust like crazy too.
No matter how much oxygen, the atmosphere would not ignite without fuel.
Forest fires would get epic though.
This trivia about Nitrogen used to be my favorite when I was studying chemistry in the school. Like there’s lot of nitrogen in the atmosphere and oxygen but they don’t “burn” because (almost all?) nitrogen oxidation is endothermic!
<side>must resist the username checks out comment</aside>
"Belcher’s team’s work indicates that while there is not a firm upper limit to the fire window, 30 percent is a practical limit. Burn prevalence increases only slightly between 23 and 30 percent oxygen, and fuel moisture plays an important role too. It would only be possible to have periods with atmospheric oxygen concentrations approaching 30 percent (and preserve terrestrial vegetation) if Earth were much wetter than today." [1]
[1]https://www.earthmagazine.org/article/flammable-planet-fire-...