The article says “ And with such a big new sea in a hot desert, a lot of its water would evaporate. This is good, because it would increase the amount of water being pumped in—generating more electricity—and it would increase the local moisture, which could increase local rainfall.”
Adding a ton of water to the atmosphere is going to cause rain. This may be mostly good but in a hot environment it could week be absolutely incredible downpours.
Adding a ton of water to the atmosphere is going to cause more warming. Water vapour is Earth's most abundant greenhouse gas. It's responsible for about half of Earth's greenhouse effect.
It is vital to consider proportion: 2/3 of the Earth is ocean. These new seas would be absolutely tiny by comparison. The extra water vapour added to the atmosphere would be a rounding error. Unfortunately the same applies to the amount of sea level rise they offset: it too would be a rounding error, a fraction of a percent.
Note, NOT melts; just when it breaks up and floats away, still frozen.
That one ice sheet, currently cracking, is over half resting on rock that is way below sea level. Some is 2000m under sea level. It doesn't need to melt, it just needs to break off and float away. That would cause a 3.5-5m *depending on ow much floated) increase in mean sea level, worldwide, in approximately 12 days.
That is over 1000x time the reduction caused by flooding the Qattara depression.
Or 0.1% -- or as I said, a fraction of a per cent.
Before someone reading this thinks that drying up the planet would cool it down: water in the air acts as a greenhouse gas, but also cools the surface when it evaporates and helps reflect solar radiation when it forms clouds (major factor of our planet's albedo).
Also we are not comparing more water area vs less water area. Water will take more area in any case as sea levels rise. This way it just happens in a bit more controlled way.
Adding water to the atmosphere does not cause more warming due to greenhouse effect at least not on this scale. Water vapor concentration is regulated by condensation, adding more water simply means more rain.
What is actually causing more warming is the increase of temperature, that changes the equilibrium vapor pressure point.
It's always astonishing to me how pretty much every climatologist will tell you "clounds are the joker". It totally makes sense, but that doesn't make it in any way less fascinating and is kind of funny.
Downpours would have to be monsoon level before this caused problems. A new lake causing monsoon level rain? I doubt it but I've been surprised before.
The article says “ And with such a big new sea in a hot desert, a lot of its water would evaporate. This is good, because it would increase the amount of water being pumped in—generating more electricity—and it would increase the local moisture, which could increase local rainfall.”
Adding a ton of water to the atmosphere is going to cause rain. This may be mostly good but in a hot environment it could week be absolutely incredible downpours.