I was looking at some time series data in particular SH ozone and the AAO(SAM)
I noticed a clear and abrupt change around 1998 and onwards.
OZONE TIME SERIES
http://www.cpc.ncep.noaa.gov/products/CDB/Extratropics/figs5.shtml
AAO Time series
I thought l might check Google to see if researchers had documented a climate shift and the answer was yes.
There have been major climate shifts noted in 1925,1945,1975,1998
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The Shifts Hypothesis – an alternative view of global climate change
source
The Shifts Hypothesis – an alternative view of global climate change
Guest post by Pavel Belolipetsky
( BTW..when was searching for information on google for ‘climate shift’, l noted l got next to NOTHING..,It appears google have removed the term and given full priority to the term ‘climate change’.
I think l might change my search engine)
……..
CRIKEY !#&@ ...... IT'S THE WEATHER CYCLES 
Deser et. al (2004) considered shifts in 1925, 1946 and 1976 years.
Interesting Crikey. Ozone impact – but what perturbs the ozone balance? I have no ldea myself.
Thanks for your ongoing interest Petros.
Of course the AGW sites will say the hydroflurocarbon ban has restored levels of ozone but l suspect there is a longer term driver/s