Found it at last!

The book with a talking dog called Bob and the hole in the ozone layer was almost certainly "Hole in the Head", by Nicholas Fisk! Now after all that exhaustive internet research, I just need to find a copy...

I may have been posting quite a lot about old books just lately, but I DO have several other fascinating things going on, it's just that I don't want to write about them until they happen, so I can only really think to blog about the books. I've just re-read Annerton Pit by Peter Dickinson, and it's even better than I remembered!