{"id":288557,"date":"2023-11-25T15:31:10","date_gmt":"2023-11-25T14:31:10","guid":{"rendered":"https:\/\/climatescience.press\/?p=288557"},"modified":"2023-11-25T15:31:12","modified_gmt":"2023-11-25T14:31:12","slug":"new-study-modern-sea-ice-extent-is-nearly-the-highest-in-9000-years-across-the-arctic","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=288557","title":{"rendered":"New Study: Modern Sea Ice Extent Is Nearly The Highest In 9000 Years Across the Arctic"},"content":{"rendered":"\n
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From NoTricksZone<\/a><\/p>\n\n\n\n

By\u00a0Kenneth Richard<\/a>\u00a0on\u00a0<\/em>20. November 2023<\/p>\n\n\n\n

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Millennial-scale Arctic sea ice reconstructions do not corroborate alarmist claims of unprecedented sea ice losses in modern times.\u00a0<\/strong><\/h4>\n\n\n\n

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Using sea ice biomarker proxy (IP25<\/sub>), scientists (Kolling et al., 2023<\/strong><\/a>) have determined that the sea ice extent in the Labrador Sea was nearly absent throughout the year (close to 0.0 \u03bcg\/gTOC) for much of the last 9,000 years. The sea ice was lowest (~0.1 \u03bcg\/gTOC) 9,300 to 8,900 years ago, and low (~0.4 \u03bcg\/gTOC) from 7,500 to 4,000 years ago.<\/p>\n\n\n\n

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Image Source:\u00a0Kolling et al., 2023<\/strong><\/a><\/figcaption><\/figure>\n\n\n\n

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The lack of a trend in sea ice loss across the Labrador Sea is consistent with observations that show the region has not warmed in the last 70 years (Yashayaev and Loder, 2017<\/a><\/strong>).<\/p>\n\n\n\n

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Image Source:\u00a0Yashayaev and Loder, 2017<\/a><\/strong><\/figcaption><\/figure>\n\n\n\n

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Other scientists (Wu et al., 2020<\/a><\/strong>) determined that from about 14,000 to 8,000 years ago, when CO2 lingered near 250 ppm, the Beaufort Sea (Arctic) was \u201cnearly ice free throughout the year\u201d (<0.2 PIP25<\/sub>) and ~4\u00b0C warmer than today in winter.<\/p>\n\n\n\n

With modern (1988-2007) CO2 at ~400 ppm, this region is 70-100% ice-covered (>0.8 PIP25<\/sub>) for 10 to 11 months per year.<\/p>\n\n\n\n

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Image Source:\u00a0Wu et al., 2020<\/a><\/strong><\/figcaption><\/figure>\n\n\n\n

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Svalbard sea ice has expanded to its highest extent of the Holocene (11,700 years ago to present) during the last 500 to 700 years (Allaart et al., 2020<\/a><\/strong>).<\/p>\n\n\n\n

The Holocene\u2019s sea ice maximum just developed during modern times, as the authors note there has been an \u201cincrease in IP25\u00a0<\/sub>concentrations after c. 0.7\u00b10.2 cal. ka BP, with a maximum in the modern sediments.\u201d<\/p>\n\n\n\n

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Image Source:\u00a0Allaart et al., 2020<\/a><\/strong><\/figcaption><\/figure>\n\n\n\n

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A study site northeast of Svalbard, scientists (Brice et al., 2020<\/a><\/strong>) find today\u2019s sea surface temperatures of \u201c<0\u00b0C\u201d are at least 4\u00b0C colder than they were just a few thousand years ago, when the Arctic was sea ice free for all but \u201ca couple of months\u201d every year.<\/p>\n\n\n\n

Today\u2019s sea ice monthly duration (~11 months per year) and summer sea surface temperatures (zero degrees Celsius) are among the highest and lowest (respectively) of the Holocene.<\/p>\n\n\n\n

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Image Source:\u00a0Brice et al., 2020<\/a><\/strong><\/figcaption><\/figure>\n\n\n\n

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