>It takes more than four times as much energy to manufacture a paper bag as it does to manufacture a plastic bag. [...] The majority of paper bags are made by heating wood chips under pressure at high temperatures in a chemical solution. The use of these toxic chemicals contributes to both air pollution, such as acid rain, and water pollution. These chemicals can pollute waterways; the toxicity of the chemicals is long-term and settles into the sediments, working its way through the food chain. Further toxicity is generated as both plastic and paper bags degrade. Paper bags generate 70% more air and 50 times more water pollutants than plastic bags.
http://www.niassembly.gov.uk/globalassets/documents/raise/pu...
Paper bags have to be reused 3 times in order to be as environmentally friendly as a single-use plastic bag; if you reuse your plastic bags as trash can liners, that number increases to 7 reuses.
https://assets.publishing.service.gov.uk/government/uploads/...