There might be some advantage to electric motor placements on the airframe or, more useful, the increased reliability of having a battery pack available for climb and to continue flight somewhat when the I.C. engine quits. Having said that, no one deserves a halo for exporting their pollution to the power plant and battery factory etc. etc. Also, the general ignorance about CO2 in our worlds life cycle is appalling. Plants breathe it and ultimately feed us. The early earth had much higher CO2 concentrations and the plant life thrived massively, leaving oil, gas, and coal deposits in the underground past. The current levels of CO2 are merely subsistence living for the remaining plant life. They ate it all up.