Tuesday, November 19, 2013

New paper finds Arctic temperatures peaked before 1950, stable to declining since

A new paper published in Climate of the Past reconstructs temperatures over the past 1100 years from Eastern Arctic ice cores and shows the highest Eastern Arctic temperatures of the 20th century occurred in the 1920's-1940's, followed by a cooling or a warming 'pause' over the remainder of the 20th century. 

Fig. 5a below shows a double peak in proxy temperatures in the 1920's and 1940's followed by cooling to the ice age scare of the 1970's, and temperatures in 2000 below those of the peaks in the 1920's-1940's. Four compilations of meteorological data of the Eastern Arctic in Fig 5b show good agreement to the proxy data.

Figure 6 from the paper shows proxy temperatures began a sharp rise in the late 1700's up the peak in the 1920's, but a declining trend from the 1920's to the end of the record in 2000. 

This is the opposite pattern to what would be expected if man-made greenhouse gases were the cause, as even alarmists claim the increase in greenhouse gases has only had a significant effect since 1950. Instead, this new paper demonstrates Eastern Arctic temperatures peaked in the early 20th century, followed by a declining trend to the end of the record in 2000.


Proxy temperature reconstruction from the paper in graph A, followed by other meteorological data and compilations of the Eastern Arctic.

Clim. Past, 9, 2379-2389, 2013
www.clim-past.net/9/2379/2013/
doi:10.5194/cp-9-2379-2013



T. Opel, D. Fritzsche, and H. Meyer
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Research Unit Potsdam, Telegrafenberg A43, 14473 Potsdam, Germany
Abstract. Understanding recent Arctic climate change requires detailed information on past changes, in particular on a regional scale. The extension of the depth–age relation of the Akademii Nauk (AN) ice core from Severnaya Zemlya (SZ) to the last 1100 yr provides new perspectives on past climate fluctuations in the Barents and Kara seas region. Here, we present the easternmost high-resolution ice-core climate proxy records (δ18O and sodium) from the Arctic. Multi-annual AN δ18O data as near-surface air-temperature proxies reveal major temperature changes over the last millennium, including the absolute minimum around 1800 and the unprecedented warming to a double-peak maximum in the early 20th century. The long-term cooling trend in δ18O is related to a decline in summer insolation but also to the growth of the AN ice cap as indicated by decreasing sodium concentrations. Neither a pronounced Medieval Climate Anomaly nor a Little Ice Age are detectable in the AN δ18O record. In contrast, there is evidence of several abrupt warming and cooling events, such as in the 15th and 16th centuries, partly accompanied by corresponding changes in sodium concentrations. These abrupt changes are assumed to be related to sea-ice cover variability in the Barents and Kara seas region, which might be caused by shifts in atmospheric circulation patterns. Our results indicate a significant impact of internal [natural] climate variability on Arctic climate change in the last millennium.

Related:

New paper finds warming has also 'paused' in the Arctic; debunks warmist study that claimed to get rid of the 'pause'

4 comments:

  1. Ref. on IPCC claims most of the warming since 1950 is anthropogenic

    http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-understanding-and.html

    ReplyDelete
  2. http://wattsupwiththat.com/2013/11/19/an-uh-oh-for-cowtan-way-arctic-temperatures-peaked-before-1950-declining-since/#comment-1479346

    Warmists tend to like avoiding the fact that Arctic sea ice also ‘reacts’ with water temperature, wind / currents. You’d think it’s like Bali up there. :-)

    Here are a few more examples from the 1920s to 1940s showing how the time travelling co2 villain had caused such man made havoc on our steady Arctic temps.

    Abstract
    The Early Twentieth-Century Warming in the Arctic—A Possible Mechanism

    The huge warming of the Arctic that started in the early 1920s and lasted for almost two decades is one of the most spectacular climate events of the twentieth century. During the peak period 1930–40, the annually averaged temperature anomaly for the area 60°–90°N amounted to some 1.7°C…..
    dx.doi.org/10.1175/1520-0442(2004)017%3C4045:TETWIT%3E2.0.CO;2

    Abstract
    The regime shift of the 1920s and 1930s in the North Atlantic

    During the 1920s and 1930s, there was a dramatic warming of the northern North Atlantic Ocean. Warmer-than-normal sea temperatures, reduced sea ice conditions and enhanced Atlantic inflow in northern regions continued through to the 1950s and 1960s, with the timing of the decline to colder temperatures varying with location. Ecosystem changes associated with the warm period included a general northward movement of fish……
    dx.doi.org/10.1016/j.pocean.2006.02.011

    Abstract
    Early 20th century Arctic warming in upper-air data
    Between around 1915 and 1945, Arctic surface air temperatures increased by about 1.8°C. Understanding this rapid warming, its possible feedbacks and underlying causes, is vital in order to better asses the current and future climate changes in the Arctic.
    http://meetings.copernicus.org/www.cosis.net/abstracts/EGU2007/04015/EGU2007-J-04015.pdf

    Monthly Weather Review October 10, 1922.
    “The Arctic seems to be warming up. Reports from fishermen, seal hunters, and explores who sail the seas about Spitsbergen and the eastern Arctic, all point to a radical change in climatic conditions, and hitherto unheard-of high temperatures in that part of the earth’s surface….

    In August, 1922, the Norwegian Department of Commerce sent an expedition to Spitsbergen and Bear Island under Dr. Adolf Hoel, lecturer on geology at the University of Christiania. The oceanographic observations (reported that) Ice conditions were exceptional. In fact, so little ice has never before been noted. The expedition all but established a record, sailing as far north as 81o 29′ in ice-free water. This is the farthest north ever reached with modern oceanographic apparatus…..”
    docs.lib.noaa.gov/rescue/mwr/050/mwr-050-11-0589a.pdf

    Examiner (Launceston, Tas. – 25 April 1939
    …It has been noted that year by year, for the past two decades, the fringe of the Polar icepack has been creeping northward in the Barents Sea. As compared with the year 1900, the total ice surface of this body of water has decreased by twenty per cent. Various expeditions have discovered that warmth-loving species of fish have migrated in great shoals to waters farther north than they had ever been seen before….
    http://tinyurl.com/aak64qf

    IPCC – AR4
    Average arctic temperatures increased at almost twice the global average rate in the past 100 years. Arctic temperatures have high decadal variability, and a warm period was also observed from 1925 to 1945.
    http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-direct-observations.html

    It’s unprecedented and worse than we thought!

    ReplyDelete
  3. http://wattsupwiththat.com/2013/11/19/new-paper-arctic-temperatures-peaked-before-1950-declining-since/

    ReplyDelete
  4. http://link.springer.com/article/10.1023%2FB%3ACLIM.0000018509.74228.03
    The Greenland coastal temperatures have followed the early 20th century global warming trend. Since 1940, however, the Greenland coastal stations data have undergone predominantly a cooling trend. At the summit of the Greenland ice sheet the summer average temperature has decreased at the rate of 2.2 °C per decade since the beginning of the measurements in 1987. This suggests that the Greenland ice sheet and coastal regions are not following the current global warming trend. A considerable and rapid warming over all of coastal Greenland occurred in the 1920s when the average annual surface air temperature rose between 2 and 4 °C in less than ten years (at some stations the increase in winter temperature was as high as 6 °C). This rapid warming, at a time when the change in anthropogenic production of greenhouse gases was well below the current level, suggests a high natural variability in the regional climate.
    -----------------------------------------
    http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/Hanna.pdf
    Analysis of new data for eight stations in coastal southern Greenland, 1958–2001, shows a significant cooling (trend-line change −1.29°C for the 44 years), as do sea-surface temperatures in the adjacent part of the Labrador Sea, in contrast to global warming (+0.53°C over the same period).
    -----------------------------------------
    http://www.joelschwartz.com/pdfs/Chylek.pdf
    [1] We provide an analysis of Greenland temperature records to compare the current (1995–2005) warming period with the previous (1920–1930) Greenland warming. We find that the current Greenland warming is not unprecedented in recent Greenland history. Temperature increases in the two warming periods are of a similar magnitude, however, the rate of warming in 1920–1930 was about 50% higher than that in 1995–2005.
    ------------------------------------------
    http://www.biogeosciences.net/9/5391/2012/bg-9-5391-2012.pdf
    Sea surface temperature (Arctic Ocean) between ∼ AD 1885–1935 are warmer by up to 3◦C with respect to the average modern temperature at the coring site. For the period ∼ AD 1887–1945, reconstructed sea ice cover values are on average 8.3 months per year which is 1.1 months per year lower than the modern [2012] values [9.4 months of sea ice cover per year]. Moreover, reconstructions of sea-surface parameters for the time-period covered by the core show SSTs and SSSs above modern values during positive phases of the PDO: AD 1886–1912; AD 1925–1946 and AD 1979–1996.

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