Estimating GHG emissions per money unit spent through sectoral climate footprints

If you want to know how much you're emitting, a good way to go is to look for the money you spend. Very little of our lifestyle causes emissions and does NOT cost anything. And the other way round, in today's fossil fuel based economy, almost every penny you spend will create some emissions.

So here is a way to use that for making your personal emissions estimations: simply take the amount of money you spent and multiply it with the factor from the sector below. Then adjust for the carbon intensity of your country's economy, by multiplying with the percentage from the second row from the right of your country from the table below (if it's 100% of the UK, you don't do anything, if it's 87 then you must multiply by 0.87, if it's 144 then you must multiply by 1.44).

This will not help to tell the difference between two products within the same sector which cost the same. But it is a very helpful first approximation of the likely emissions associated with a product. The method is called input-output analysis.

(Source: How bad are bananas? by Mike Berners-Lee)