# Screwy Carbon Tax Calculations (unless they’re at source)

Trying to figure out carbon footprints for manufactured products is absurd. Let’s take an extremely simple example. It must be easy to work out how much carbon it would take to produce and sell something as simple as a woodscrew, right?

Take a look at my attempt below and tell me if I’ve put anything in which is wrong (not if I’ve missed anything – I know I have). My aim here is to show how impossibly complex a full analysis would be, not even to try attempt a full analysis. I also want to show that an incomplete analysis doesn’t even give you a rough lower bound – it could even be too high if you don’t take everything into account (although it’s not likely to be).

Each item is a clear contributor of CO2 caused by the manufacture and/or sale of the screw. A complete analysis would have to calculate the fraction of the total lifetime CO2 contribution of each item which contributes to the screw manufacture and sale.
**??**>> indicates a complexity rat-hole which would need to be expanded out creating further minblowingly complex analysis.

```* Dig iron ore out of the ground
* The digger manufacture including every nut and bolt **??**>>
* The digger fuel used
* Digging out the digger fuel from the ground
* Oil rig - manufacture, installation, running **??**>>
* Transporting fuel to the digger **??**>>
* The driver's work - how much less carbon would he/she use if not
working? **??**>>
* Transport of iron ore to the smelting works **??**>>
* Smelt the iron
* Collect and add pig iron and carbon (to make steel) **??**>>
* Coal used for smelting **??**>>
* Machines used to do the smelting. **??**>>
* Smelting works employees, the cars they use to get to work
etc... **??**>>
* Mould and shape the screw
* Machines used **??**>>
* Employee energy and transport **??**>>
* How much steel is wasted and/or reheated
* Chrome plating the screw - or however they make them
look shiny **??**>>
* Package the screw **??**>>
* Transport to shop **??**>>
* Shop running costs **??**>>