text: When looking at the historical data, I found that in any year the gross amount of CO2 emissions and the increase in the level of atmospheric CO2 are very closely correlated (to the extent that there's no need to even bother with a proper straight line fit). This stands to reason - human emissions of greenhouse gases have long since far surpassed the ability of the world's sinks to swallow them. After simplifying the relation between emissions and CO2 levels as a basic linear formula, I applied it to the two emissions scenarios detailed above and came up with this graph. Note - to account for Eurasian industrialization and no World War Two between 1917 and 1950, the CO2 level in 1950 is set at 317ppm, corresponding to the real 1960 level, instead of the real 1950 level of 311ppm.