From the Steig et al. is still dead department:
The rapid warming of the Antarctic Peninsula, which occurred from the early-1950s to the late 1990s, has paused. Stabilisation of the ozone hole along with natural climate variability were significant in bringing about the change. Together these influences have now caused the peninsula to enter a temporary cooling phase. Temperatures remain higher than measured during the middle of the 20th Century and glacial retreat is still taking place. However, scientists predict that if greenhouse gas concentrations continue to rise at the current rate, temperatures will increase across the Antarctic Peninsula by several degrees Centigrade by the end of this century.
Reporting this week in the journal Nature researchers from British Antarctic Survey (BAS) describe how the stabilisation of the ozone hole and changing wind patterns has driven a regional cooling phase that is temporarily masking the warming influence of greenhouse gases.
Lead author, Professor John Turner of British Antarctic Survey says: “The Antarctic Peninsula is one of the most challenging places on Earth on which to identify the causes of decade-to-decade temperature changes. The Antarctic Peninsula climate system shows large natural variations, which can overwhelm the signals of human-induced global warming. In recent years, there has been an international research effort to explain what’s happening in the region and to understand the implications for the Antarctic environment and future sea-level rise.
“Our study highlights the complexity and difficulty of attributing effect to cause. The ozone hole, sea-ice and westerly winds have been significant in influencing regional climate change in recent years. Even in a generally warming world, over the next couple of decades, temperatures in this region may go up or down, but our models predict that in the longer term greenhouse gases will lead to an increase in temperatures by the end of the 21st Century.”
A wide range of climate data was analysed for this study, including atmospheric circulation fields, sea-ice records, ocean surface temperatures and meteorological observations from six Antarctic Peninsula research stations with near-continuous records extending back to the 1950s.
During the Twentieth Century, Antarctic Peninsula temperatures increased by up to 0.5? C per decade, helping to trigger the dramatic collapse of ice shelves and causing many glaciers to retreat. Whilst there was a decrease in sea ice extent around the Antarctic Peninsula towards the end of the last century it has been increasing in recent years, particularly in the north-east of the region. The cold easterly winds observed in the 21st Century have had a greater impact on the region because the sea ice has prevented ocean heat from entering the atmosphere.
To set their observations in a longer-term context, the research team looked at a 2,000 year climate reconstruction using the chemical signals in ice cores. As previously reported, analysis suggests that peninsula warming over the whole twentieth century was unusual, but not unprecedented in the context of the past 2,000 years. The reconstruction shows a warming starting in the 1920s, which is consistent with the warming trends recorded by the meteorological stations. The ice core records also reveal periods of warming and cooling over the last several centuries that were comparable to those observed in the post-1950s instrumental record. This highlights the large natural variability of temperatures in this region of Antarctica that has influenced more recent climate changes.
Dr Robert Mulvaney, is a leading ice core researcher at British Antarctic Survey. He says:
“Meteorological observations from the Antarctic Peninsula research stations only cover the last 60 years or so. If we are to get a better idea of the long-term trend we need to look back in time. The ice core record helps us see how the climate evolves over the longer term. We can also look at the levels of carbon dioxide and other chemicals that were in the atmosphere and compare them with observations from today.”
In the last month, the levels of the greenhouse gas carbon dioxide (CO2) in the atmosphere above Antarctica rose past the 400 parts per million milestone, contrasting with the pre-industrial level of 280 parts per million recorded in Antarctic ice cores. Climate model simulations predict that if greenhouse gas concentrations continue to increase at currently projected rates their warming effect will dominate over natural variability (and the cooling effect associated with recovering ozone levels) and there will be a warming of several degrees across the region by the end of this century.
###
The paper:
Absence of 21st century warming on Antarctic Peninsula consistent with natural variability by John Turner, Hua Lu, Ian White, John C. King, Tony Phillips, J. Scott Hosking, Thomas J. Bracegirdle, Gareth J. Marshall, Robert Mulvaney and Pranab Deb is published this week in Nature
Abstract:
Since the 1950s, research stations on the Antarctic Peninsula have recorded some of the largest increases in near-surface air temperature in the Southern Hemisphere1. This warming has contributed to the regional retreat of glaciers2, disintegration of floating ice shelves3 and a ‘greening’ through the expansion in range of various flora4. Several interlinked processes have been suggested as contributing to the warming, including stratospheric ozone depletion5, local sea-ice loss6, an increase in westerly winds5, 7, and changes in the strength and location of low–high-latitude atmospheric teleconnections8, 9. Here we use a stacked temperature record to show an absence of regional warming since the late 1990s. The annual mean temperature has decreased at a statistically significant rate, with the most rapid cooling during the Austral summer. Temperatures have decreased as a consequence of a greater frequency of cold, east-to-southeasterly winds, resulting from more cyclonic conditions in the northern Weddell Sea associated with a strengthening mid-latitude jet. These circulation changes have also increased the advection of sea ice towards the east coast of the peninsula, amplifying their effects. Our findings cover only 1% of the Antarctic continent and emphasize that decadal temperature changes in this region are not primarily associated with the drivers of global temperature change but, rather, reflect the extreme natural internal variability of the regional atmospheric circulation.
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The Holocene began in Antarctica; it could end there too.
I qoute: “Reporting this week in the journal Nature researchers from British Antarctic Survey (BAS) describe how the stabilisation of the ozone hole and changing wind patterns has driven a regional cooling phase that is temporarily masking the warming influence of greenhouse gases.”
This is utter rubbish. First, the warming influence of the greenhouse gases like carbon dioxide is non-existent. A child can see this by comparing the global CO2 curve with the global temperature chart. The carbon dioxide graph is smooth and shows no sign of having created the numerous ups and downs the global temperature since 1850 it is credited with having created. Furthermore, stabilization of the ozone hole does not cause any warming. As long as there is ozone in the stratosphere it stops solar shortwave ultra-violet from reaching the ground by simply absorbing it. But create an ozone hole by pushing it aside and the short-wave solar ultraviolet goes straight down to the ground. There it warms the ground and creates havoc among living things by causing skin cancer and cellular damage to vulnerable wildlife. And by the way, what is this about the ozone hole stabilizing? Did they not get the Montreal Protocol passed by promising that if we give up Freon the ozone hole will go away?
Typo correction: “… cause any warming.” should be: “… cause any cooling.” sorry.
Arno Arrak (@ArnoArrak) July 21, 2016 at 3:49 pm
This is utter rubbish. First, the warming influence of the greenhouse gases like carbon dioxide is non-existent. A child can see this by comparing the global CO2 curve with the global temperature chart. The carbon dioxide graph is smooth and shows no sign of having created the numerous ups and downs the global temperature since 1850 it is credited with having created.
Where do you get this nonsense from? As Hansen said in his Congressional testimony:
“the signal [greenhouse effect] is at best just beginning to emerge”
“There are certainly other climate change factors involved in addition to the greenhouse effect.”
Furthermore, stabilization of the ozone hole does not cause any warming. As long as there is ozone in the stratosphere it stops solar shortwave ultra-violet from reaching the ground by simply absorbing it. But create an ozone hole
by pushing it asidereacting it with Cl atoms and the short-wave solar ultraviolet goes straight down to the ground. There it warms the ground and creates havoc among living things by causing skin cancer and cellular damage to vulnerable wildlife. And by the way, what is this about the ozone hole stabilizing? Did they not get the Montreal Protocol passed by promising that if we give up Freon the ozone hole will go away?They also said that the lifetime of the most important O3 depleting CFCs was ~100 years so that it would take a long time for the ozone hole to go away. The CFCs are starting to decrease:
http://cdiac.ornl.gov/oceans/images/nhemispherecfcs5.png
Arno Arrack is completely right here about Ozone just being pushed aside.
As the Antarctic winter goes longer and longer, the south polar vortex just gets stronger and stronger and the Ozone is merely MOVED OUT to the 40S-60S latitudes.
When the Ozone Hole shows up in September and October, the 40S-60S latitude Ozone levels sky-rocket to the highest levels measured anywhere in the stratosphere.
After the September/October end of winter period is over, the Ozone filters back in from the 40S-60S latitude and the Ozone Hole dissappears and the 40S-60S latitude Ozone go back to normal Earth levels.
The Hole is just a big scam.
If it wasn’t a scam and the scientists had any kind of integrity, we would hear research about the big Hole at the Pole and the massive RECORD levels at 40S-60S. Nope, you don’t hear that anywhere except when I try to point it here.
Ozone Hole in Spetember 2000 with record levels at 40S-60S.
http://science.nasa.gov/media/medialibrary/2000/10/02/ast02oct_1_resources/et000927.gif
But in March, no Hole and no Excess at 40S-60S.
http://exp-studies.tor.ec.gc.ca/tmp/16164308820to20160321.gif
Bill Illis July 23, 2016 at 4:24 pm
Arno Arrack is completely right here about Ozone just being pushed aside.
No he’s not!
As the Antarctic winter goes longer and longer, the south polar vortex just gets stronger and stronger and the Ozone is merely MOVED OUT to the 40S-60S latitudes.
As the Antarctic winter progresses the south polar vortex gets stronger, isolating the polar stratosphere and allowing it to get colder. The O3 that is already there is trapped but since there is no sunlight it doesn’t dissociate so the concentration stays constant. Outside the polar vortex the Brewer-Dobson circulation continues to bring ozone from the tropics but it’s unable to cross the polar night jet so it accumulates there.
http://www.ccpo.odu.edu/~lizsmith/SEES/ozone/class/Chap_6/6_Js/6-03.jpg
The polar stratosphere gets so cold that polar stratospheric clouds form at about -78ºC, the heterogeneous reactions on the ice particles produces Cl2 which in the absence of UV light just accumulates between ~14 and 22 km. Once sun rises over the pole the Cl2 is photolysed by the UV into Cl and the clouds are dispersed as the temperature rises. The Cl reacts with the O3 forming ClO and the O3 concentration drops to ~0 at that altitude and ClO concentration peaks at about 18-20km (each Cl atom accounts for ~1000 O3 molecules). As the temperature warms up O3 starts to form again and the vortex weakens allowing the O3 from outside to re-enter the polar stratosphere.
Here is the status over the S pole now:
http://www.esrl.noaa.gov/gmd/webdata/ozwv/ozsondes/spo/iadv/SPO_2016-07-07.21.png
By the middle of September you’ll see the O3 peak start to drop (blue curve).
By the middle of October the O3 will be zero between 15 and 20km.
By the end of December the peak will be back and the temperature will be much higher.
One more piece of evidence that Earth’s real thermostat is the ozone layer. The glut of CFC release during the latter years of the 20th century is over, and now things are returning to normal. Surprise, surprise.