Abandoned world with floating Skyscrapers, climate change

[Carol799]

I read this book back in the 1970s. Man and woman are on an abandoned planet which is undergoing climate change. They travel looking for something I can’t remember. At one point they discover skyscrapers that float. Some have crashed but others are still functional. The temperature has risen and the desert is encroaching. I’ve thought of this book off and on for years but cannot identify it. Interested because of the climate change theme. Any ideas?

 

[Danny McG]

This puts me in mind of Ringworld, there were various abandoned buildings floating in the air

 

[hitmouse]

Restaurant at the End of the Universe?

 

[Vince W]

This puts me in mind of The Jewels of Aptor by Samuel Delany.

 

[Pyan]

Certainly reminds me of Ringworld, as Danny suggested

 

[monkeypooper]

Wasnt there vampires or something i vaguely remember living in the floating houses or mansions or in the shadows in ringworld