The Boston City Council unanimously passed an ordinance on Wednesday that would ban thin plastic shopping bags and create a 5-cent fee on paper bags and thicker bags. The purpose of the ordinance, which was co-sponsored by At-Large City Councilor Michelle Wu and District 6 City Councilor Matt O'Malley, is to reduce litter on the streets, avoid plastic bags ending up in our waterways, trees and harming the environment. Using fewer plastic bags would also reduce greenhouse gas emissions and solid waste, while promoting the use of recyclable bags. A spokesperson for the mayor told Jamaica Plain News that the mayor is "reviewing the proposal." If the mayor approves the ordinance, it would go in effect one year after he signed it into law.