It certainly doesn't imply that this is the main cause, it suggests that it's an important cause (say, > 10%) that has to be acknowledged in a 10k word article.

It certainly doesn't imply that this is the main cause, it suggests that it's an important cause (say, > 10%) that has to be acknowledged in a 10k word article. I also think dwelling on a "culture of littering" is much vaguer and less likely to make falsifiable predictions.