An unexpected and persistent increase in global emissions of ozone-depleting CFC-11

  title={An unexpected and persistent increase in global emissions of ozone-depleting CFC-11},
  author={Stephen A. Montzka and Geoff S. Dutton and Pengfei Yu and Eric A. Ray and Robert W. Portmann and John Daniel and Lambert J. M. Kuijpers and Bradley D. Hall and Debra J. Mondeel and Carolina Siso and J. David Nance and Matthew L. Rigby and Alistair J. Manning and Lei Hu and Fred L. Moore and Benjamin R. Miller and James W. Elkins},
The Montreal Protocol was designed to protect the stratospheric ozone layer by enabling reductions in the abundance of ozone-depleting substances such as chlorofluorocarbons (CFCs) in the atmosphere1–3. The reduction in the atmospheric concentration of trichlorofluoromethane (CFC-11) has made the second-largest contribution to the decline in the total atmospheric concentration of ozone-depleting chlorine since the 1990s1. However, CFC-11 still contributes one-quarter of all chlorine reaching… 
Renewed and emerging concerns over the production and emission of ozone-depleting substances
Stratospheric ozone depletion, first observed in the 1980s, has been caused by the increased production and use of substances such as chlorofluorocarbons (CFCs), halons and other chlorine-containing
A decline in global CFC-11 emissions during 2018-2019.
The decline in global emissions suggests a substantial decrease in unreported CFC-11 production, which would delay the recovery of the stratospheric ozone layer and any associated future ozone depletion is likely to be limited.
Increase in CFC-11 emissions from eastern China based on atmospheric observations
Emissions from eastern China account for approximately 40 to 60 per cent of the global rise in emissions of trichlorofluoromethane (CFC-11), which may be a result of new production and use, which is inconsistent with the Montreal Protocol agreement to phase out global chlor ofluorocarbon production by 2010.
The Impact of Continuing CFC‐11 Emissions on Stratospheric Ozone
Trichlorofluoromethane (CFC‐11, CFCl3) is a major anthropogenic ozone‐depleting substance and greenhouse gas, and its production and consumption are controlled under the Montreal Protocol. However,
Challenges for the recovery of the ozone layer
The recovery of stratospheric ozone from past depletion is underway owing to the 1987 Montreal Protocol and its subsequent amendments, which have been effective in phasing out the production and
Modelling the potential impacts of the recent, unexpected increase in CFC-11 emissions on total column ozone recovery
Abstract. The temporal evolution of the abundance of long-lived, anthropogenic chlorofluorocarbons in the atmosphere is a major factor in determining the timing of total column ozone (TCO) recovery.
Possible implications of enhanced chlorofluorocarbon-11 concentrations on ozone
Abstract. This numerical model study is motivated by the observed global deviation from assumed emissions of chlorofluorocarbon-11 (CFC-11, CFCl3 ) in recent years. Montzka et al. (2018) discussed a
On the effects of the ocean on atmospheric CFC-11 lifetimes and emissions
It is shown that, as anthropogenic production ceases, ocean fluxes become more important, suggesting a need for further studies with high-resolution global models linking atmospheric chemistry and ocean processes, and the need to understand processes that could affect the CFC-11 lifetime.
Australian chlorofluorocarbon (CFC) emissions: 1960–2017
Environmental contextChlorofluorocarbons (CFCs) are potent greenhouse and stratospheric ozone depleting trace gases. Their atmospheric concentrations are in decline, thanks to global production and
Report on the International Symposium on the Unexpected Increase in Emissions of Ozone-Depleting CFC-11
Recent findings of an unexpected emission increase of chlorofluorocarbon-11 (trichlorofluoromethane, CFC-11, CCl3F) [Montzka et al., 2018]1 has raised important issues within the atmospheric sciences


The increasing threat to stratospheric ozone from dichloromethane
Use of atmospheric model simulations shows that although currently modest, the impact of dichloromethane on ozone has increased markedly in recent years and if these increases continue into the future, the return of Antarctic ozone to pre-1980 levels could be substantially delayed.
Re-evaluation of the lifetimes of the major CFCs and CH 3 CCl 3 using atmospheric trends
Abstract. Since the Montreal Protocol on Substances that Deplete the Ozone Layer and its amendments came into effect, growth rates of the major ozone depleting substances (ODS), particularly CFC-11,
A growing threat to the ozone layer from short-lived anthropogenic chlorocarbons
Abstract. Large and effective reductions in emissions of long-lived ozone-depleting substance (ODS) are being achieved through the Montreal Protocol, the effectiveness of which can be seen in the
Considerable contribution of the Montreal Protocol to declining greenhouse gas emissions from the United States
Ozone depleting substances (ODSs) controlled by the Montreal Protocol are potent greenhouse gases (GHGs), as are their substitutes, the hydrofluorocarbons (HFCs). Here we provide for the first time a
Interannual fluctuations in the seasonal cycle of nitrous oxide and chlorofluorocarbons due to the Brewer‐Dobson circulation
The tropospheric seasonal cycles of N2O, CFC‐11 (CCl3F), and CFC‐12 (CCl2F2) are influenced by atmospheric dynamics. The interannually varying summertime minima in mole fractions of these trace gases
Decline in the Tropospheric Abundance of Halogen from Halocarbons: Implications for Stratospheric Ozone Depletion
The results suggest that the amount of reactive chlorine and bromine will reach a maximum in the stratosphere between 1997 and 1999 and will decline thereafter if limits outlined in the adjusted and amended Montreal Protocol on Substances That Deplete the Ozone Layer are not exceeded in future years.
Constraining the carbon tetrachloride (CCl4) budget using its global trend and inter‐hemispheric gradient
Carbon tetrachloride (CCl4) is a major anthropogenic ozone‐depleting substance and greenhouse gas and has been regulated under the Montreal Protocol. However, the near‐zero 2007–2012 emissions
Evaluation of emissions and transport of CFCs using surface observations and their seasonal cycles and the GEOS CCM simulation with emissions‐based forcing
[1] Levels of ozone depleting substances (ODSs) in our atmosphere are determined by production, emission, and loss processes. However, atmospheric models are forced by the specified mixing ratios of
A history of chemically and radiatively important gases in air deduced from ALE/GAGE/AGAGE
We describe in detail the instrumentation and calibrations used in the Atmospheric Lifetime Experiment (ALE), the Global Atmospheric Gases Experiment (GAGE), and the Advanced Global Atmospheric Gases