Returning packages to online retailers takes a serious toll on the environment, the Los Angeles Times reports.

In December alone, more than 1 million packages will be returned to retailers each day. Between initial shipping, return shipping and disposal, these returns will emit up to 15 million tons of carbon this year.

Not only is the shipping process of these detrimental, but the packaging process also contributes to the environmental burden, with more than 1 billion trees’ worth of cardboard shipped out each year.

Although some products can be resold upon return, many items – like underwear and swimsuits, packaged foods, and cosmetics – must be disposed of. Packages like these will contribute 5 billion pounds of waste to landfills in 2019 and early 2020.

According to the LA Times, Americans have begun sending back more of their purchases each year, with 10% of purchases sent back in 2018. That 10% is valued at approximately $369 billion, an increase of 8% from 2016.

In some places, like Sweden, returns are as high as 60% on certain types of products.

The full article from the LA Times can be found here.