Shopping online is 24 times better for environment than taking a car

Researchers at Heriot-Watt University compared the carbon footprint of a typical trip from a local delivery depot with that of average shopping trips by car and by bus, and found home deliveries involved a much lower level of carbon emissions.

The work, which assumes only one item was bought per trip, focused on the last stage of the retail process when goods are delivered to the home or customers travel to the shops to collect them in person.

The team from the Logistics Research Centre at the university found that a typical van-based home delivery produces 181g of , compared with 1,265g for a bus trip and 4,274g for a trip by car. It means a shopper would have to buy 24 items when going by car or seven items when going by bus to equal the lower level of carbon emissions created by having one item delivered by van.

Professor Alan McKinnon, director of the Logistics Research Centre, and one of the authors of the study, said the findings showed that online shopping for single items could be a great deal "greener" than a conventional trip to the shops.

"Some online retailers were claiming that if you shopped online you were doing something good for the environment – but until now we lacked hard evidence," he said. "The results suggest that is true. What this shows is if you are buying small non-food items it is better for someone to get them delivered than to go to the shops by car or bus."

But Prof McKinnon said there were other factors involved that could make online shopping less environmentally friendly.

"What we are comparing is the best case," he said. "We are assuming that the product is not returned and that the person is at home to received the goods."

He said he hoped the findings would encourage shoppers to think about the environmental impact of their shopping choices.

James Roper, chief executive of the Interactive Media in Retail Group, which represents online retailers, said he was not surprised to find online shopping was more energy efficient.

"I am not surprised because we have been studying this sector for many years," he said. "It is important because we are reading every day about what mankind is doing to the planet, and it is down to all of us to do whatever we can to increase efficiency. To me, this is the only beginning of showing us the work we have got to do."

However, Fiona Moriarty, the director of the Scottish Retail Consortium, said she thought the study sounded like "a very limited piece of research".

"If you are going shopping on the high street you are very unlikely to buy only one item," she said. "We have to look very carefully at what this research is telling us. It doesn't take into account that you might buy more than one item and it doesn't take into account the impact of carbon emissions throughout the distribution process.

"There is also the issue of packaging, which may be substantially more if an item is delivered to your home," she went on.

"Our research tells us that internet retailing is growing, but it still represents a very small part of overall spend. In many cases the two things are complementary. Most of our members would have both a high-street and an online presence.

"It's about consumers making choices that are right for them. Retailers are working very hard to make sure there is a wide range of choice, whether in terms of high-street shopping or online shopping."