Shopping has become a cloak-and-dagger affair. Conspicuous consumption does not look good during a recession, which explains why so many of us are embracing e-commerce. Online shopping on these shores is projected to grow from sales of ￡ 8.9bn to around ￡ 21.3bn by the end of 2011.
    Often people proclaim they've embraced e-commerce because it's "green"  This is understandable. If many shopping bags in a recession look bad, bricks and mortar retail—huge out-of-town shopping centers, retail emporia that insist on leaving their doors open even in winter and grocery stores full of the most inefficient freezers—look terrible during an ecological emergency.
    Should we buy the idea that e-commerce is any better? Several studies have tried to answer this with cold, hard data. A 2000 study on Webvan, a now defunct(已废止的) US online grocer, concluded that a wider adoption of e-commerce would not give us environmental gains, while a 2002 study of US book retailing found no greater energy savings selling online. But the study that all e-tailors are talking about is a new one from Carnegie Mellon University, which has found that shopping online via Buy. corn's e-commerce model for electronic products uses 35 per cent less energy consumption and CO₂ emissions than a traditional bricks-and-mortar model.
    This is largely because it avoids the usual retail distribution model and, of course, the impact of consumers driving to a store (the average person drives 14 miles in total, to purchase three items). And, from the shopper's perspective, online buying often allows you to avoid the ephemera of retail, like the 100m coat hangers that end up in landfill each year, or elongated till receipts. (Seek out shoehoxx, co. uk which allows you to organize all your receipts online, ultimately doing away with them. )
    But both models are flawed, because online or on the high street, retailers are dependent on a hydrocarbon(碳氢化合物)-fuelled delivery system. Trucks deliver 4.8m tons of freight each day in the UK, which works out at about 80kg per person. To make matters worse, after a truck drops off the goods it often returns empty to the depot. A 2002 study of 20,000 haulage trips found that only 2.4% of return journey legs found suitable backloads. This journey represents a large part of the impact of what we buy.  There will be a growth of e-commerce in the next few years because ______.