The trouble is that it only really works for new construction, older buildings are not engineered to handle the extra weight on the roof.

I can't seem to edit my post so here's the summary:

Modeling shows green roofs can cool cities and save energy::Extensive greenery coverage on building rooftops could significantly reduce temperatures at the city scale and decrease energy costs, according to a new study.

It’s a cross-post from lemmy.world. Hope I’m doing it right.

I'd like to know how one is supposed to cross post properly too. This links to .world website where you can't comment and you can't click directly on the article url. Afaik you have to use the search function to find the federated post on your local instance (https://slrpnk.net/post/6853635) and then click cross post there. Which just creates a new post with a link to the original article and a link in the summary to "https://lemmy.world/post/12143683" (isntead of your local instance). I think lemmy is still missing functionality in that area so you can cross post stuff better "after the fact".

Green roofs are mandatory in my city since years and there's nothing wrong with it. But it's slowing down solar expansion to some degree and also, extensive green roofs are usually preferred to the intensive type that's shown in the picture.