■As San Francisco’s mayor in 2007, Gavin Newsom signed the nation’s first plastic bag ban.

■Study found the amount of plastic shopping bags trashed per person grew from 8 pounds in 2004 to 11 pounds in 2021.

■Twelve states, including California, already have some type of statewide plastic bag ban.

SACRAMENTO — California would ban all plastic shopping bags in 2026 under a new bill announced Thursday in the state Legislature.

California already bans thin plastic shopping bags at grocery stores and other shops, but shoppers at checkout can purchase bags made with a thicker plastic that purportedly makes them reusable and recyclable.

Democratic state Sen. Catherine Blakespear said people are not reusing or recycling those bags. She points to a state study that found the amount of plastic shopping bags trashed per person grew from 8 pounds per year in 2004 to 11 pounds per year in 2021.

“It shows that the plastic bag ban that we passed in this state in 2014 did not reduce the overall use of plastic. It actually resulted in a substantial increase in plastic,” Blakespear, a Democrat from Encinitas, said Thursday. “We are literally choking our planet with plastic waste.”

Twelve states, including California, already have some type of statewide plastic bag ban in place, according to the environmental advocacy group Environment America Research & Policy Center. Hundreds of cities across 28 states also have their own plastic bag bans in place.

The California Legislature passed its statewide ban on plastic bags in 2014. The law was later affirmed by voters in a 2016 referendum.

If the Legislature passes this bill, it would be up to Democratic Gov. Gavin Newsom to decide whether to sign it into law. As San Francisco’s mayor in 2007, Newsom signed the nation’s first plastic bag ban.