Comment on Penn Engineers Discover a New Class of Materials That Passively Harvest Water from Air
spankmonkey@lemmy.world 1 week agoI am fairly certain they are referring to the fact that we are already removing water from the fresh water cycle, and this could remove even more. For example, global warming combined with draining the aquafers means less water in the cycle as it was drained into the ocean and isn’t beaing replenished as snow/glaicers.
Yes, the total volume of water on the planet isn’t being changed by that shift, but the amount of freshwater is.
Eheran@lemmy.world 1 week ago
Nobody will remove water from ambient air in relevant amounts. Roughly 0.5 % of air is water vapor, a total of something like 10’000 km³ liquid water. This is replaced (residence time) about once every 10 days, so roughly 1’000 km³ daily.
Say we extract 10 km³ (10’000’000 m³) daily, enough for roughly 10 million people (including all industry, zero recycling of the water etc.). By that time you deal with 1 % of earths atmosphere every day. May I remind everyone how absurdly costly in any conceivable way that would be? You would rather lay a few pipes and purify sea water at a tiny(!) fraction of the cost.
spankmonkey@lemmy.world 1 week ago
They won’t drain the aquifers, nature will replace that much water!
They won’t cut down all the forests, the trees will just regrow!
They don’t have to cycle the entire atmosphere to cause havoc. Pulling the moisture out in local areas that already have lost aquifers and ice in the mountains is the obvious issue. Plus, you don’t know the cost in the long run, it could end up being fairly cheap.
Eheran@lemmy.world 1 week ago
People were able to (and at some places did) cut down every tree WELL before they had power tools and even saws. Just with axes. The comparison is laughable.
No, massive air moving structures can not be cheap. Neither building nor operating them.