Per unit of GDP also should not reassure anyone since GDP is constantly growing even faster than CO2-pruduction-per-unit-of-GDP is dropping (according to the data you linked). Additionally, regional improvements in these metrics (prominently showcased for the US and EU) are driven by the fact that manufacturing has been relocated from the first world to developing countries - not because manufacturing is becoming significantly cleaner. In fact, the higher sulfuric acid levels in the Pacific are a direct consequence unfiltered coal burning in China - so we've actually made things worse by moving manufacturing to countries with poor environmental standards.
Net total CO2 emissions are all that matter. Moreover, even ZERO growth of CO2 is insufficient to stop increasing temperatures since CO2 accumulates.
The alternative to aggressive absolute level CO2 caps (something many countries openly refuse to agree to) some are quietly pursuing planning for failure. Planning for human migrations, sea level changes, and local precipitation changes, are things those with means are doing. ...and the more people with wealth and/or power begin to plan for failure, the fewer will work on preventing catastrophe. What emerges is an unfortunate game-theory dilemma without a solution where parties actually produce more CO2 in order to prepare for higher CO2-driven global temperatures, and the regional challenges they bring.