Thank you sir

Generally as atmospheric temperature increases it increase ground level ozone, because warmer temperature and solar radiations are required for photochemical ozone formation. In addition to solar radiation and temperature ozone formation requires its precursors (e.g., NOx and hydrocarbon). 

Therefore, CO2 indirectly has a positive effect on ground level ozone formation by increasing atmospheric temperature. Scientists believe that due global warming caused by CO2 and other GHGs ground level ozone might increase, especially in colder areas like UK, Canada and Europe. 

But I personally believe that global warming might cause ozone reduction in some hot countries, where temperature gets as high as 50oC or above. This is due to the fact that ozone formation increase as temperature increase, but reaching a certain level the relationship turns negative. See my paper for more details: 

Munir, S., Habeebullah, T.M., Seroji, A.R., Ropkins, K., 2015. Modelling ozone-temperature slope under atypical high temperature in an arid region of Makkah, Saudi Arabia. Aerosols and Air Quality Research, 15(4): 1281–1290.

You should be able to download the paper freely from my profile or from the journal website. 

Best of luck

thank you sir

You are welcome.

Try to read my paper (given above), it will provide some more insight to the subject.

This issue was first pointed out  for stratospheric ozone in the following paper: KS Groves, SR Mattingly & AF Tuck, 1978, Increased atmospheric carbon dioxide and stratospheric ozone, Nature, 273, 711-715. It was later updated in a pair of papers in Q. J. R. Meteorol. Soc, 1980, 106, 125-140 & 141-157. Several years later there was modelling of the effect in general circulation models by J Austin and others. The biggest effect is the fact that the recombination of oxygen atoms and oxygen molecules to form ozone has a negative temperature coefficient, so the radiative cooling induced in the stratosphere by increased carbon dioxide tends to increase ozone there, so counteracting the destructive effect of chlorine atoms and chlorine monoxide.

That is incorrect. What I said above is true, please check the references.

The ozone destruction extends from the tropopause to the stratopause, and most definitely is via the chain reaction carried by Cl and ClO, with rate determining step k[ClO][O], and operates at all sunlit latitudes. There are many, many references in the literature that attest to this fact. In polar regions inside the winter and spring vortex the chain is different but is still characterised by rate determining step 2k[ClO]**2[M], following reactions releasing chlorine from HCl and chlorine nitrate on polar stratospheric clouds. That is confined to the vortex below 25 km in winter and spring, at both poles but more extensively in the Antarctic.

I suggest you read the latest WMO international assessment to get a true picture. There most definitely has been net loss of stratospheric ozone; while recovery has started, it will not revert to pre-CFC state until well into the next century. Things have moved on from 2D models in 1980; the loss of ozone is seen in observations by balloons, aircraft and satellites and is beyond any reasonable dispute. 

The rising ozone in the 1970s was part of a long term trend that had started in the late 1950s; like everything else in the atmosphere it is variable on all time and space scales. See Nature 244, 545-551 [1973] figures 3,4 &5. You'll forgive me if I say that you are in a tiny minority of scientists who want to deny what the situation is with ozone. I've spent 45 years on this, published many well-cited papers on it, led the 1987 AAOE mission to Antarctica and the 1989 AASE mission to the Arctic. The evidence I gave on those missions to the Senate and Congress, along with Bob Watson, Susan Solomon and a few others made it very clear what the situation was and is. It is indeed beyond dispute to any objective scientist who has examined all the evidence. That doesn't include the likes of S Fred Singer and a tiny handful of others who don't want to believe that CFCs destroy ozone. That against at least 1500 scientists who have actually worked on the subject and really know what they are talking about.

Kenneth gave talks but didn't convince anybody. Kenneths paper on this received zero citations in 20 years. Perhaps just a sediment technician without any knowledge about ozone! 

Kenneth, you are guilty of believing what you want to believe. The facts are against you, it is no use cherry picking bits and pieces of evidence that taken out of context can be used to construct arguments to support a preconceived position. I am not going to waste any more time arguing with you.

The above three papers are invalidated by more recent work. Modelling has moved on a great deal since 1980 (which among other things preceded discovery of polar ozone loss by 5 years). The Mani paper is regarded as being based on ozone observations that were not as well as calibrated as others in the database, and in any case is outweighed by by data from other tropical stations. The Rood paper says nothing about the meaning for ozone loss, and in fact what record there is back to 1926 shows past maxima and minima over a larger range than that described there - see 1940 for example. Everyone interested in this should consult WMO Global Ozone Research and Monitoring Report No. 52: SCIENTIFIC ASSESSMENT OF OZONE DEPLETION:2010. In particular there is exhaustive exposition of all observations of both reactive gases that destroy ozone (Chapter 1) and ozone distributions and losses (Chapter 2). Figures 2.4 and 2.7 in particular make it very clear that there are observed ozone losses in midlatitudes and the tropics as well as at the poles, throughout the altitude range of the stratosphere, and are consistent with the vertical ClO profile shown in the figure under Q8, page Q21,in the final section of the Report: Twenty Questions and Answers About the Ozone Layer: 2010 update. What's more, the observational data show that reactive chlorine has been declining in the stratosphere (because of the international phase out of CFCs) while ozone has been increasing since the late 1990s and early 2000s, further evidence that the halocarbons are indeed responsible for the observed ozone losses in midlatitudes as well as at the poles. Finally, three dimensional models using the latest data are a huge improvement on what went on in the 1990s let alone the 1980s, and their calculations are consistent with the observations. One simply cannot pick three obsolete papers and put them against the solid wall of evidence in the above report, which received far more review than the average literature paper.

stratosphere

So CO2 can both indirectly increase and decrease the ozone level depending on the atmospheric level?

Sunil Kumar Srivastava, please look over my papers on this theme:

I. G. Dyominov and A. M. Zadorozhny, Greenhouse gases and future long-term changes in the stratospheric temperature and the ozone layer. – International Journal of Remote Sensing, 2008, Vol. 29, No. 9, p. 2749 – 2774

I. G. Dyominov and A. M. Zadorozhny, Greenhouse gases and recovery of the Earth's ozone layer. – Adv. Space Res., 2005, Vol. 35, No. 8, p. 1369 – 1374

Kenneth,

Can you explain why, if there was no significant net loss,  the satellites did not measure the loss because it was too great?

"Antarctic ozone hole

The discovery of the Antarctic "ozone hole" by British Antarctic Survey scientists Farman, Gardiner and Shanklin (first reported in a paper in Nature in May 1985[92]) came as a shock to the scientific community, because the observed decline in polar ozone was far larger than anyone had anticipated.[34] Satellite measurements showing massive depletion of ozone around the south pole were becoming available at the same time. However, these were initially rejected as unreasonable by data quality control algorithms (they were filtered out as errors since the values were unexpectedly low); the ozone hole was detected only in satellite data when the raw data was reprocessed following evidence of ozone depletion in in situ observations.[58] When the software was rerun without the flags, the ozone hole was seen as far back as 1976.[93]"

https://en.wikipedia.org/wiki/Ozone_depletion#Antarctic_ozone_hole

Alastair, Kenneth: It simply is not true that there has been no ozone loss. Below is a cut and paste from the recent assessment which it makes clear.

Scientific Summary Chapter 2: Update on Global Ozone: Past, Present, and Future

Download the complete chapter 

Past Changes in Total Column Ozone

This chapter deals with the evolution of global ozone outside of the polar regions. The increase of ozone- depleting substance (ODS) concentrations caused the large ozone decline observed from 1980 to the mid- 1990s. Since the late 1990s, concentrations of ODSs have been declining due to the successful implementation of the Montreal Protocol. As reported in the last Assessment, global ozone levels have remained stable since 2000. Ozone columns observed in the last four years have largely remained in the range observed since 2000.

Over the next decades we expect increasing global-mean stratospheric ozone columns, as ODSs decline further. Climate change and emissions of greenhouse gases, especially carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), also affect the evolution of global stratospheric ozone, particularly in the second half of the 21st century, when ODS concentrations are expected to be low.

Compared to 1964–1980 total column ozone, ground-based and space-based observations show that present-day (circa 2008–2013) ozone columns are:

lower by about 2% for the near-global average (60°S–60°N), compared to 2.5% reported in the last Assessment;

lower by about 3.5% in the Northern Hemisphere (35°N–60°N), as reported in the last Assessment;

lower by about 6% in the Southern Hemisphere (35°S–60°S), as reported in the last Assessment. The larger depletion in the Southern Hemisphere is linked to the Antarctic ozone hole; and

almost unchanged in the tropics (20°S–20°N), as in the last Assessment.

Ground- and space-based observations indicate that near-global (60°S–60°N) column ozone has increased by around 1% ± 1.7% (2 sigma) between 2000 and 2013. However, there is substantial disagreement among the data sets about the magnitude and statistical significance of this increase. Two out of three independent data sets show increases at the upper end; one recently updated data set shows an increase at the lower end. The CCMVal-2 multi-model mean predicts a 1% increase between 2000 and 2013 for the near-global (60°S–60°N) column ozone.

Total column ozone (dominated by lower stratospheric ozone) displays large, dynamically forced year-to-year variability in the middle and high latitudes, exemplified by unusually high ozone in 2010 and low ozone in 2011 in the Northern Hemisphere, and low ozone in 2006 in the Southern Hemisphere. The recent decline (15% since 1997) in concentrations of ODSs, as described by Equivalent Effective Stratospheric Chlorine (EESC), is expected to have had only a small impact on total ozone recovery (approximately 3 Dobson units (DU), or 1%, since 2000). Separation of the small recent ODS-related ozone increase from the large natural variability (up to 15 DU or 5% change from one year to the next) can currently not be made with a high level of confidence.

Past Changes in Ozone Profiles

Additional and improved data sets have strengthened our ability to assess ozone profile changes over the last 10 to 15 years. Data from the upper stratosphere now confirm the significance of ozone increases that were already suggested in the last Assessment. Large ozone variability in the lower stratosphere complicates the identification of long-term ozone changes in this region. Chemistry-climate model (CCM) simulations that include realistic time variations of greenhouse gas (GHG) and ODS concentrations capture changes in the ozone profile that agree quite well with those observed. These CCM simulations provide a means of attributing changes in ozone to different processes.

Measurements show a statistically significant increase in upper stratospheric ozone (35–45 km altitude) in middle latitudes and the tropics since around 2000. Following a large observed decline of 5–8% per decade through the 1980s and middle 1990s, ozone has increased by 2.5–5% per decade over the 2000 to 2013 period.

About half of the upper stratospheric ozone increase after 2000 can be attributed to the decline of ODS since the late 1990s.Increasing CO2 concentrations have led to a cooling of the upper stratosphere. CCM simulations reveal that, between the 1980s and the present this has contributed to an increase in ozone concentrations. Before the middle 1990s, this ozone increase was substantially smaller than the ozone decrease caused by ODS increases. From 2000 to 2013, the ozone increase arising from the decline in ODS concentrations is of comparable magnitude to that caused by upper stratospheric cooling.

As reported in the last Assessment (WMO, 2011), CCMs consistently show a long-term decline of ozone in the lowermost tropical stratosphere by up to 20% between 1960 and 2060. This modeled ozone decline is caused by an increase in the strength of upwelling in the tropical lower stratosphere. This increased upwelling is associated with a strengthening Brewer-Dobson circulation caused by GHG-induced climate change.

In-situ and space-based observations reveal that ozone concentrations in the lowermost tropical stratosphere have declined by as much as 10% between 1984 and 2005. There are several additional data sets available since 2002. Continued ozone decreases are not detected in the presence of large natural variability during 2002–2013. This observed behavior is consistent with that computed in CCMs, which also show periods of strong interannual and decadal variability.

Adrian,

I am not saying there was no loss. I am saying the loss was so great that the satellites measurements did not record it thinking it was a false reading.  

But from long experience, as Henrik will agree, Ken the Denier, will always come back with a provocative reply. I suspect he gets a fee from a think tank for each post and response he creates.

It is a waste of time giving him a considered reply as you did, or posting a killer argument as I did. It only gets him yet one more fee!

Alastair, I think you are right, rational argument is just met with slippery denials, as above. The assertion that ClO is isolated from the ozone layer is just complete rubbish. trying to pin dishonest deniers down with facts is like trying to spear tomato pips with the blunt end of a baseball bat. It's unfortunate that  Researchgate is open to this kind of abuse.

CO2 influence on stratospheric ozone is complicated. Cooling of stratosphere by CO2 decrease the intensity of the ozone catalitical destruction cycles and leads to ozone increase. However, tropospheric warming caused by CO2 intensify meridional circulation leading to substantial ozone depletion in the tropical lower stratosphere and ozone increase over mid-latitudes. See Zubov et al., 2013, Atmos. Chem. Phys., 13, 4697–4706, 2013, doi:10.5194/acp-13-4697-2013. This paper is free to read.

There is no evidence. Only denial.

Really it's fun...by burning human energy also add some amount of heat to the atmosphere like our computers....