Comment by hathchip

This is very dubious. Unless paper bags are produced using timber from first-growth forests, growing and then cutting down the trees that were used to make them took carbon out of the atmosphere. When the paper bag decays or is burnt, they become roughly carbon neutral. But things that take carbon out of the atmosphere for a while as part of a cycle are generally good - by the time one particular paper bag has returned its carbon to the atmosphere, others have been made, and so there is some greenhouse gas reduction long term.