>> Well, I'd want to check what they're doing with it first, and how environmentally friendly it is...<<

Yeah, I was concerned about the environmental impact, but unless it's awful they probably come out ahead.

>> but imagine a few billion tons of this film, turned into glitter, and blasted up into the troposphere, cooling the earth. Although hopefully not too much.. I've seen Snowpiercer, that's not a future I'd fancy.<<

I absolutely do not trust humans with geoengineering. They don't understand enough about how the planet works, and they don't give a flying fuck about it.

>> Failing that, a big sheet of it for the ice-caps.<<

That's a thought.

>> IIRC there are crystals that are very good at turning LWIR into SWIR, I don't know exactly how easy they are to make, but they are made of pretty common stuff. But they have this neat trick of whatever way the light enters them, that's the direction it's bounced back, kinda like a radar corner. You could make a powder or paint of that, and just apply it where you need cooling. <<

Very useful. We could use that to coat buildings, roofs, sunshades -- if it's durable or can be incorporated into things, pavement too.