Amazon.com is trying to take the guilt out of online shipping with its patent for “Environmentally conscious electronic transactions” reports Fast Company.

The patent, granted earlier this week, explains that Amazon hopes to offer both carbon credits and environmentally friendly shipping options. The catch? You have to wait longer–and pay more–for your packages.

An environmentally friendly option might use a smaller shipping company that takes advantage of hybrid or hydrogen-powered vehicles, or that places items onto vehicles with empty space that are already scheduled for a particular route. Another option might be one that always uses low-emission vehicles, but that may make several stops along the way and thus might take more time… a customer can also specify to use environmentally friendly materials, even at additional cost … The customer also can have the ability to select packaging materials that were made in an environmentally friendly facility.

It’s the ultimate solution for green-minded customers who want to justify giving up brick-and-mortar stores for Amazon.

Photo by Amazon.com.