One year ago, Scotland started charging five pence for plastic grocery bags. In the following year, 650 million fewer bags have been used, an 80% reduction. Before the ban on free carrier bags, as they’re called over there, Scotland was the U.K.’s worst offender.

As a conscientious shopper, you might bristle when you see somebody double-bag a cold beverage or bag a single item that has its own handle anyway. Compulsory bag charges might not be popular with these people, but they’re certainly effective. “It’s now becoming second nature to shoppers to reuse their carrier bags and hopefully to think more about our impact on the environment,” Scotland’s Environment Secretary Richard Lochhead told the Guardian.

According to the Scottish government, 650 million bags weighs in at 4,400 tons of plastic, which is equivalent to saving 2,800 tons of CO2, even when accounting for the reusable bags that have taken the place of the disposables.

England banned free carrier bags earlier this month. Ireland banned them in 2013, leading to a 71% drop in the first year, and Wales banned them in 2011, also giving a 71% drop.

So far in the U.K., the effects has been similar, with a 90% drop in bag use reported by the Asda supermarket chain.

Not everyone is happy about the charge. Faced with a five penny charge for bags, some shoppers are skipping it in favor of stealing shopping carts, which only need a £1 coin to release.