It would have been interesting to also estimate how much CO2 would be reduced if instead of a glass roof they used a normal properly insulated roof. Buildings

It would have been interesting to also estimate how much CO2 would be reduced if instead of a glass roof they used a normal properly insulated roof. Buildings like this in Paris are often so tightly packed together that windows in walls barely provide any light. Replacing the roof with a more standard one would necessitate giving up any daylight and having lights on all the time.