Comments by "Old Scientist" (@OldScientist) on "Arctic to Lose All its Ice Within Next Decade: Study | Vantage with Palki Sharma" video.
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The Arctic minimum summer sea ice trend is zero for the past 17 years. In the past few years it was almost as high as 1995. The probability that this could be due to chance has now dropped to 10% (after Swart et al calculations, 2015). If the hiatus continues until 2027, it will become statistically significant (p<0.05, or less than 5%) and no longer explainable by chance. Using National Snow and Ice Data Centre (NSIDC) information for September minima (million km²):
2007 4.16
2008 4.59
2009 5.12
2010 4.62
2011 4.34
2012 3.39
2013 5.05
2014 5.03
2015 4.43
2016 4.17
2017 4.67
2018 4.66
2019 4.19
2020 3.82
2021 4.77
2022 4.67
2023 4.23
Plot the trend line for this data and it will be flat. ZERO net change in 17 years. The linear trend since 2007 is indistinguishable from zero ( around -0.17% per year ).
In the early 1950s the sea ice concentration anomaly was lower than it is at present. The sea ice anomaly then rose during the 50s, 60s and 70s. This was followed by a decline. This is demonstrated in Arctic and Antarctic Research Institute (AARI) data, which is based on historical sea ice charts from several sources (aircraft, ship, and satellite observations).
The AARI data shows the sea ice concentration anomaly was lower in 1952 (-5%) than 2005 (-3%). The anomaly increased in the 50s, 60s and 70s. In the 80s, 90s and early 2000s it decreased. Since 2007 the trend has been flat.
JAXA (Japanese Aerospace Exploration Agency) satellite data from 2002 to 2024 Arctic Sea Ice Extent (365 day running average) shows no noticeable trend with values close to 10,000,000km² throughout. Their minimum extent for daily values was in 2012. No other year since has come close.
MASIE (Multisensor Analyzed Sea Ice Extent - Northern Hemisphere) shows something similar to JAXA. From 2005 to 2024 Arctic Sea Ice Extent (365 day running average) shows no noticeable trend with values close to 10,000,000km² throughout. Their minimum extent for daily values was in 2012. Again no other year since has come close. It also shows a marked increase in Ice in the Greenland Sea since 2018.
Polyakov et al (2003) show "ice extent (1900-2000) in the Kara, Laptev, East Siberian, and Chukchi Seas provide evidence that long-term ice thickness and extent trends are small and generally not statistically significant". Trend -0.5% per decade (±0.7%).
Vinje (2001) shows a deceleration in the rate of ice loss from 1864 to 2000.
Recent sea ice extent is very high when compared to the last 10,000 years. Also changes in sea ice extent and the speed of those changes were greater in the past (Stein et al, 2017).
HadCRUT4 Arctic (70N - 90N) monthly surface air temperature anomalies record (1920-2021) shows the greatest number and magnitude of positive temperature anomalies occurred between 1930-49. All anomalies in excess of 5°C, including +7°C (referenced to 1961-1990) are from this period. No temperature anomalies from 2000-2019 reach 5°C. It shows no decade warmed faster than the 1930s and the current 'warming' finished in 2005.
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