Why? Per capita seems a lot fairer to me.
Whilst per capita might seem "fairer" the real denominator we should be adhering to is absolute totals, the environment doesn't care about per-capita totals afterall.
In that regard, China is the biggest offender, whilst the likes of Europe are going extremely clean.
However the flip side is... China has the most green energy and is investing the most while still having an insatiable appetite for coal.
There are many things that need to be considered take Australia a lot of graphs have us high because they factor in the exports of products like gas and coal not at the point of use but the country of origin so all the greenhouse emissions from Australian exported fuels are added to Australia's total ,now there is a 20 billion dollar project to deliver solar energy from the Northern Territory in Australia to Singapore via undersea cable on the table this would cut into Singapore's reliance on gas it would be interesting if this would count toward Australia or Singapore , Australia's argument is the demand is from India and without it we would not be exporting the coal so they should have it counted since they control the rate of consumption,my take is both the supplier and consumer should be counted the world is a finite space shared by us all.
one more thought when it comes to renewables taking the Singapore project as an example. if it happens only the amount of reduction should count if it is all used up in increased demand then it should be seen as neutral.
The thing that worries me is loopholes and semantics that tend to crop up in these global problem, i remember reading about proposed carbon credit scheme years ago where a manufacturer could buy credits to offset their carbon, and this was seen to help drive down carbon but it had loopholes like Volkswagen could offset its porsche division without making any changes to its porsches because the system gave an average carbon number for the industry rather than brands and Volkswagen could use credits from existing cars that came in under that average to offset the carbon used by its sports cars rather than needing to reduce carbon reduction to gain those credits.