Let's remember that the greatest efficiency comes in not shipping so much stuff. We ship a lot of junk. Buying less stuff would lower emissions with no costs. On the contrary, we'd improve our lives.
What is considered junk exactly? I mostly buy groceries and toiletries.
Groceries and toiletries are rarely shipped by sea. I'd define junk as something disposable that isn't consumed. Really anything by harbor freight that breaks easily.
> Groceries and toiletries are rarely shipped by sea.