This saves on extra transport costs and reduces pollution. Still, e-commerce companies need to do more to help customers buy environmentally friendly products.

"E-commerce enterprises could lead customers to environmentally friendly products by marketing methods, such as discount on smart home appliances and advertisements for LED bulbs," said Ma Libo, social responsibility director of JD.com.

But more ideas are needed to reduce waste. JD.com sends out more than 500 million receipts every year or 300 tons of paper. E-receipts would be greener and more popular with customers.

Ma Jun, director of the Institute for Public and Environmental Affairs, said: "As a third party, we will help enterprises promote policies such as e-receipts. We also hope to build a platform where consumers can better understand what their consumption choices actually mean for the environment."