The introduction of a 5p charge on plastic carrier bags to cut down their use has proved so successful that it could pave the way for other measures to reduce waste, say researchers from Cardiff University.

In 2014, 8.5 billion single-use plastic bags were used by customers in British supermarkets. After the introduction of the 5p English plastic bag charge in October 2015, plastic bag use fell by almost 80%. Importantly, says Professor Wouter Poortinga, the 5p charge also made people think more about the environment and become more supportive of other environmental policies.

The study shows plastic bag charges actually increased in popularity after they were introduced. In England, a majority (52%) already supported the charge before it was introduced, but support increased to 60% one month after. A similar effect had occurred earlier in Wales when it introduced charging in 2011.

"One reason why people became more positive was that it is easy for them to adapt to the charge," Professor Poortinga points out. "Shoppers quickly found new routines, such as keeping bags in the car.

He says: "Our research found that the charge was effective at breaking old habits – it acted as a 'habit disruptor' and made people stop and think about waste."

Support for the plastic bag charge has 'spilled over' into increased support for other charges to reduce waste, say researchers. Support for a hypothetical additional 5p charge on each plastic water bottle purchased increased from 34% to 40% six months after the plastic bag charge was introduced. Similar increases in support were found in Wales (from 44% to 50%) and in Scotland (from 25% to 34%). Similarly, support for a hypothetical 5p charge on products with excess packaging also increased.

"Plastic waste and littering in general are major issues," says Professor Poortinga. "Now may therefore be the right time to trial other policies, such as a deposit return scheme for drinks cans and bottles or a charge on disposable coffee cups."

The study reveals, however, that about one in 10 people still persistently buy single-use plastic bags. "Additional research is needed to find out how a more sustainable use of shopping bags can be encouraged in this group – including perhaps the phasing out of all single use plastic bags by retailers."