Emails between Shell communication officials were made public as part of a congressional investigation into the fossil fuel industry and climate change.
The hope is to eliminate a source of litter on the streets and microplastics in the water. But some point to studies that show people just buy more plastic bags.
Plastic traded between countries has the carbon footprint of a mid-sized European country. By 2050, it will account for 15% of the world's greenhouse gases.