It's difficult to pinpoint a single inventor of the concept of "net zero," as it emerged from scientific research.
The concept of net zero wasn't invented by a single individual. Rather, it evolved from scientific research in the late 2000s that studied the interaction between the atmosphere, oceans, and the carbon cycle concerning CO2 emissions. This research indicated that global warming would only cease when CO2 emissions reached net zero. This understanding became fundamental to the goals outlined in the Paris Agreement. Therefore, net zero is best understood as a concept developed through scientific inquiry rather than a singular invention.
In short, net zero emerged from research into climate science rather than from a single person's invention.