CEB has been used for centuries in Britain. Arid is obviously not a factor. It's also been used for multi-story buildings. I'm not sure how dense housing reduces pollution though. Some of the least polluting housing in the world is rural, e.g. the Amish.
edit: I should have said "earthen" construction has been used in Britain. Cob rather than CEB.
edit: I should have said "earthen" construction has been used in Britain. Cob rather than CEB.