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Why are CFCs no longer produced?
Because CFCs contribute to ozone depletion in the upper atmosphere, the manufacture of such compounds has been phased out under the Montreal Protocol, and they are being replaced with other products such as hydrofluorocarbons (HFCs) including R-410A and R-134a.
How have CFC emissions been reduced?
The 1987 protocol called for a 50% reduction of CFC emissions by 2000. Scientific advances prompted amendments to the protocol in 1990 and 1992, the most recent of which required signatories to cease production of the main CFCs by 1995. (Exceptions were allowed for limited essential uses, including medical sprays.)
Why are CFC levels in the atmosphere decreasing over the last couple decades?
The atmospheric concentration of trichlorofluoromethane (CFC-11) has been in decline since the production of ozone-depleting substances was phased out under the Montreal Protocol1,2. The decline in global emissions suggests a substantial decrease in unreported CFC-11 production.
How does CFC affect us?
CFCs contribute to the loss of the protective ozone layer, which blocks ultraviolet rays from the sun. This exposes more people to UV radiation, which can cause skin cancer. Additionally, increased contact with ultraviolet rays can cause cataracts, macular degeneration and other eye damage.
Why is CFC depletion of the ozone layer a theory and not a scientific law?
when is ozone formed? why is CFC depletion of the ozone layer a theory and not a law? because CFC’s do not occur naturally, therefore don’t have a relationship with nature. what kind of observation is the breakdown of CFC’s?
Are CFCs increasing or decreasing?
Atmospheric measurements CFC-11 and CFC-12 reported in 1993 showed that their growth rates were decreasing as result of both voluntary and mandated reductions in emissions 9. Many CFCs and selected chlorinated solvents have either leveled off (Figure 1) or decreased in concentration by 1994 9,10.
What is the rate of growth of CFC-11?
The rate of growth has now started to decrease due to the decreased emissions. For example, CFC-11 was growing at about 9–11 ppt/year around 1980; this fell to ∼7 ppt/year in 1990, 3 ppt/year by 1993 ( WMO, 1995 ), and, more recently, to slightly negative values ( Montzka et al., 1996; Cunnold et al., 1997; Derwent et al., 1998 ). FIGURE 12.13.
What is the future impact of CFCs on the environment?
The relatively smaller but significant warming impact from releases of the most abundantly produced CFCs (CFC11 and CFC12) will continue to persist for many further decades into the future. CFCs were phased out via the Montreal Protocol due to their part in ozone depletion .
Why is CFC making its way back into the atmosphere?
The researchers have concluded that the only reason CFC is again making its way in the atmosphere is that someone is making the stuff again. This is a serious problem since whoever is doing so, is violating the international law and is causing the delay in the recovery of the ozone layer by decades.