These calculations are necessarily based on very hand-waving maths. They try to focus on only one specific facet of what is absolutely and completely a systems problem. The only level at which it makes sense to talk about emissions is on a large scale like a country or even the whole world. Otherwise, you risk turning the "effort" into one of externalising carbon costs to other people's counters.
But, that's too complicated, so people will go and calculate the emissions produced in the fabrication of a cheeseburger, as if that was a useful thing to know. And then they'll write countless blog posts about it.
I submit to you that there is absolutely no value whatsoever in that calculation, or in the result of it.
Even if the calculation could be relied on, what does it mean? Is there any actionable element to this calculation? Should we do something about it? Should we care?
Counting the grams in a cheeseburger, or in a Google search, is a gimmick used to get people excited about CO2 for no particularly good reason, and with no specific result in mind. It achieves nothing other than to waste our time and provide yet another vague, shapeless concept with which people with an agenda can manipulate others into doing whatever they want.