text: F-gases are ozone-friendly, enable energy efficiency, and are relatively safe for use by the public due to their low levels of toxicity and flammability. However, most F-gases have a high global warming potential (GWP), and some are nearly inert to removal by chemical processes.  If released, HFCs stay in the atmosphere for decades and both PFCs and SF can stay in the atmosphere for millennia.   
  The total atmospheric concentration of F-gases, CFCs, and HCFCs has grown rapidly since the mid-twentieth century; a time which marks the start of their production and use at industrial scale.   As a group in year 2019, these unnatural man-made gases are responsible for about one-tenth of the direct radiative forcing from all long-lived anthropogenic greenhouse gases.   
  F-gases are used in a number of applications intended for climate change mitigation, that can generate further positive feedback for atmospheric heating.  For example, refrigeration and air conditioning systems are increasingly utilized by humans within a warming environment.   Likewise,  expansions of electrical infrastructure, as driven by the alternatives to fossil fuels, has led to rising demand for SF.  If recent trends of aggressive (5% and greater CAGR) annual growth for such types of F-gas production were to continue into the future without complimentary reductions in GWP and/or atmospheric leakage, their warming influence could soon rival those of CO and CH which are trending at less than about 2% annual growth.