The inverse of a 33% reduction is not a 33% increase. It is a 50% increase. In other words, humanity has added half of the preindustrial CO2 level on top of the

The inverse of a 33% reduction is not a 33% increase. It is a 50% increase. In other words, humanity has added half of the preindustrial CO2 level on top of the preindustrial CO2 level. What you probably meant is that 33% of the CO2 in the atmosphere is "man-made".