It is frequently argued

It is frequently argued that the refrigerants used in heat pumps today are safe and that their impact on the environment during the equipment life cycle is negligible. That may be true and significant as well, but the fact remains that a much better job can be done. There is significant scope for improved performance and initial cost reduction. Both will lead to a better environment and decreased energy consumption.
Worldwide, approximately 100 million heat pumps are now installed. Their total annual thermal output is around 1,300 TWh. This represents an annual equivalent CO2 emission reduction of 0.13 Gt (0.6%), against the backdrop of an annual global emission of CO2 of more than 22 Gt. However, the current reduction potential of heat pumps is 6% of global CO2 emission, and improved technology could increase this to 16% in future