China: 183,000 million tons C02
US: 234,000 million tons C02
That's a 1.28x more for the US. Since industrialization in the US started well before 1971 (you can infer this from the graph), this is significant underestimate.
Obviously, the other important estimate is per capita emissions, which would be even lower for China than the 1.28x estimate above.
The rule of 70 is useful; divide 70 by growth rate in percent tobget doubling time in years.
US carbon emissions have been roughly flat, and falling most years since 2005, likely from natgas substitution for coal in electricity generation, though total petroleum use has also fallen:
Too: total energy in the US as of the 1970s was doubling roughly every 20 years (3.5% annual growth), meaning that "all prior history" doesn't matter to much -- half of all emissions had occurred 1950-1970 (very roughly, from memory). Similarly, as coal use was rampling up in the 1860s, contemporary writers noted that a fraction of known reserves would satisfy US energy needs for a million years ... at then-current levels of consumption. What happened, of course, is that low-cost energy spurred growth and coal use exploded. Current reserves as estimated by BP's annual statistical review are closer to 300 years, a reduction in time of over 3,000-fold.
Henry Erni (1865): https://archive.org/details/coaloilpetroleum00erni/page/14
China's emissions were projected to rise 5% in 2018, by one source, a doubling in 15 years.
There's much more to the picture, including equity, offshoring pollution, and history. bBut a simple integration over past use alone is very incomplete.