Antarctic Sea Ice Photo Provided by New Scientist Magazine 

SUMMARY: The sudden and unsustained drop in sea ice extent at a 4-year time scale may indicate that the causal agent of this event is geological and not the atmosphere. Only if this trend is found to be sustained over a longer time span can atmospheric causes be considered. A survey of the extensive geological heat sources in the Antarctic is presented in a related post  [LINK] .

DETAILS BELOW

RELATED POST: ANTARCTIC SEA ICE EXTENT 1979-2018: [LINK]

RELATED POST: GEOLOGY OF ANTARCTICA: [LINK]

[LIST OF POSTS ON THIS SITE]

Figure 1: Jan-May Average Sea Ice Extent 1979-2019 

Figure 2: South Polar Ocean Lower Troposphere Temperature Anomaly 1979-2019

Figure 3: Correlation between sea ice extent and temperature

Figure 4: Regression Table

1. CONTEXT: In July 2019 a climate change alarm was raised that “Antarctic sea ice is declining dramatically and we don’t know why”. This post is a response to this alarm with the relevant data.
2. January-May average sea ice extent for the Antarctic and the corresponding lower troposphere temperature anomalies are displayed in Figure 1 and Figure 2 respectively. Neither series shows a statistically significant trend. However, a steep decline in Jan-May average sea ice extent from 2015 to 2019 is seen in the data This result is consistent with the claims in the media. However, a plot of sea ice extent against temperature in Figure 3 does not indicate a relationship between sea ice extent and temperature.
3. Results of regression analysis appear in Figure 4. A statistically significant relationship is not indicated in the results. We conclude from the above analysis that sea ice extent is not responsive to atmospheric temperature. This result is consistent with prior studies of sea ice reported in related posts on Antarctic sea ice [LINK]  as well as Arctic sea ice extent [LINK] .
4.  The sudden and unsustained drop in sea ice extent at a 4-year time scale may indicate that the causal agent of this event is geological and not the atmosphere. Only if this trend is found to be sustained over a longer time span can atmospheric causes be considered. A survey of the extensive geological heat sources in the Antarctic is presented in a related post  [LINK] .