October 06, 2016

Greenie study comes to some awkward conclusions

Some amusing stuff here.  Ozone depletion is doing something new and nasty?  What about the 1989 Montreal Protocol and the ozone hole?  Hasn't the ozone hole mostly healed up by now?  Instead of depleting, shouldn't the ozone be increasing?  Is this report undermining the ozone hole story? It would appear that it is.

And in one way, that's reasonable.  The ozone hole waxes and wanes as it always has and its greatest extent was in fact in September last year.  So the Montreal convention of which Greenies are so proud has in fact achieved exactly nothing. But by the same token ANY systematic change in the ozone levels is a fiction, including ozone depletion.  So the claims below are  rubbish.

I could go on but I like a sentence from the Abstract too much to quarrel further with it:  "climate model simulations that include anthropogenic forcing are not compatible with the observed trends"

Translating that into plain English:  "The global warming theory is wrong.  It does not predict reality".  How's that for today?

Journal abstract follows the summary below


Rising greenhouse gases and ozone depletion over the Antarctic are increasingly pushing rain-bearing storm fronts away from Australia's west and south, according to a new international study.

The research, which involved the Australian National University and 16 other institutions from around the world, has just been published in the Nature Climate Change journal.

It found Southern Ocean westerly winds and associated storms were shifting south, down towards Antarctica, and robbing southern parts of Australia of rain.

ANU Associate Professor Nerilie Abram, the lead Australian researcher, said this had contributed to a decline of more than 20 per cent in winter rainfall in southwestern Australia since the 1970s.

"That band of rainfall that comes in those westerly winds is shifting further south, so closer towards Antarctica," Dr Abram, from the ANU's Research School of Earth Sciences and ARC Centre of Excellence for Climate System Science, said.

The study attributed this shift directly to human-induced climate change, primarily from rising greenhouse gases and ozone depletion.

Dr Abram said the loss of rain combined with "2016 being on track to smash the hottest-year record was ominous for communities and the environment".

"Antarctica and the Southern Ocean are remote but this region influences Australia's heatwaves, affects whether our crops get the winter rainfall they need and determines how quickly our ocean levels rise," she said.

The international research team examined how recent Antarctic climate trends compared to past climate fluctuations using natural archives such as ice cores drilled into the Antarctic ice sheet.

They found the bigger picture of the region's climate trends remained unclear because of Antarctica and the Southern ocean's "extreme fluctuations in climate year to year".

Dr Abram explained the climate measurements were not yet long enough "for the signal of anthropogenic climate change to be clearly separated from this large natural variability".

Lead author Dr Julie Jones, from the University of Sheffield in the United Kingdom, said there was still an enormous amount to learn about the Antarctic climate.

"At face value, many of the climate trends in Antarctica seem counter-intuitive for a warming world," Dr Jones said.

"Scientists have good theories for why, but these ideas are still difficult to prove with the short records we are working with."

SOURCE

Assessing recent trends in high-latitude Southern Hemisphere surface climate

Julie M. Jones et al.

Abstract

Understanding the causes of recent climatic trends and variability in the high-latitude Southern Hemisphere is hampered by a short instrumental record. Here, we analyse recent atmosphere, surface ocean and sea-ice observations in this region and assess their trends in the context of palaeoclimate records and climate model simulations. Over the 36-year satellite era, significant linear trends in annual mean sea-ice extent, surface temperature and sea-level pressure are superimposed on large interannual to decadal variability. Most observed trends, however, are not unusual when compared with Antarctic palaeoclimate records of the past two centuries. With the exception of the positive trend in the Southern Annular Mode, climate model simulations that include anthropogenic forcing are not compatible with the observed trends. This suggests that natural variability overwhelms the forced response in the observations, but the models may not fully represent this natural variability or may overestimate the magnitude of the forced response.

Nature Climate Change 6, 917–926 (2016) doi:10.1038/nclimate3103




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