The simple answer to plastic bag pollution has already been invented. It's called 'paper bags'.
People per km2 UK: 268 Switzerland: 203 Poland: 123 USA: 33 Norway: 16; but almost everyone lives within 50km of the coast, the mountains and the high plateau are even more sparsely populated.
Source: https://en.wikipedia.org/wiki/List_of_countries_and_territor...