Heat pump solution to pollution I have invented a process that converts an air conditioner into a heat pump. How many metric tons of carbon equivalent could be eliminated from entering the atmosphere annually if 
1.every air conditioner in the temperate zones that is not a heat pump from the factory were upgraded to a heat pump (my dream)
2    Fossil fuel was only burned when ambient is below freezing


*electricity for heat pumping is generated by environmentally friendly means

 A: You need to collect some data to answer this question.  Heat pumps can provide more heat to a building than the electricity they use.  Whether yours does is something that needs to be measured.  Real world efficiencies are often different from lab efficiencies.  The radiator coils can get dusty and be installed in places with poor air flow, for example.  You need to assess the population of air conditioners out there, how much heating is needed where they are (some places that have AC never get cold enough to need heat), and how much of that your heat pump can provide.  For point 2 the cutover point to using fuel for heating will depend on the amount of heat your pump can provide compared to what it takes to keep a building warm.  That may be 0C, but it could be something else.  I would suggest you look at the maximum heat you can provide as a function of outside temperature, then when it is cold enough you can compute how much fuel you displace.
I would suggest that point 3 be deleted and you focus on how much you would save given the current mix of electricity generation and building heating.  You are not proposing to do anything that can change that except to reduce the usage.  It may well be a good idea, but that is for another day.
