Re:NASA’s Double Asteroid Redirection Test Is a Smashing Suc...
by XorNot on Saturday January 14, 2023 @07:36PM
(#34385567)
It's not that it happens at 500 million years, it's that it starts happening - i.e. it's not that the ocean's boil, it's that the rate of evaporation increases, which exposes more rock, which increases weathering etc.
It's a pile of problems related to a common cause (increase solar radiance) that steadily is on a single definite trend.
Put it another way: at 288 Kelvin the partial pressure of water vapor is ~1.7 kPa. At 294K it's ~2.5 kPa. That's a 47% increase (naively). And that line trends upwards only.
Re:NASA’s Double Asteroid Redirection Test Is a Smashing Suc...
by Retric on Saturday January 14, 2023 @07:42PM
(#34385596)
What matters is what happens to the water in the atmosphere not the oceans surface. Evaporation requires energy, it cools the surface of the oceans and needs to be driven by sunlight heating that surface, rain is the reverse it heats clouds which then radiate that energy to space.
To boil the oceans you would need the upper atmosphere to retain that moisture or you just get more weather not net evaporation. 1 inch of rainfall represents a shocking amount of energy flow.
In general it would take a very large change in the suns output to make a noticeable difference on earth. There are critical secondary effects and feedback loops etc, but black body radiation is T^4 so you take the square root of the square root of the increase in output. A 5% increase in output should be something like a 1.2% increase in temperature kelvin.