One of the book's central themes is the desire to return to a lost England, an Edwardian idyll of country lanes, deep pools and small farming communities. Orwell shows that this England is no longer - when the main character returns to the town of his youth, it has been obliterated by factories and rows of horrible houses and it is teeming with strangers. In one scene in the closing chapters of the book, Orwell seems to poke fun at people such as the Woodcraft Folk, who think that they are living in harmony with the land...but it is too late for all that. Even they have had to drain a deep fishpool to use as a rubbish dump. The assertion is that try as we might, we are now living in a universal rubbish tip from which there is no escape.
For Orwell, the 1930s green obsession was a nostalgia epidemic, which took hold when it was too late to go back.