You need to account for indirect emissions. Because all the factories are in China means that China emits more, but those iPads are not being sold and used in China.
When you import goods, you import their emissions. It's just super hard to measure (and we like to blame it all on China).
The solution there is to create tariffs based on emissions so that the costs of the emissions get accounted when people import goods.
I don't understand the word "tarries", somehow even after looking it up :-). (Not my first language, sorry)
I meant that in practice it's very difficult to track, because it involves a lot of actors in a lot of countries.