{"id":192102,"date":"2022-03-17T18:00:25","date_gmt":"2022-03-17T17:00:25","guid":{"rendered":"https:\/\/climatescience.press\/?p=192102"},"modified":"2022-03-17T18:00:27","modified_gmt":"2022-03-17T17:00:27","slug":"new-analysis-of-greenlands-gisp2-temperatures-expose-selection-bias-in-paleo-reconstructions","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=192102","title":{"rendered":"New Analysis of Greenland\u2019s GISP2 Temperatures Expose Selection Bias in Paleo Reconstructions"},"content":{"rendered":"\n

Scientists admit that 3 different Greenland Summit (GISP2) temperature reconstruction \u201cstrategies\u201d produce 3 different paleoclimate temperature results. The reconstructions chosen as the most \u201crobust\u201d are therefore the ones that align best with the authors\u2019 presuppositions.<\/strong><\/h4>\n\n\n\n

In a new study published in Quaternary Science Reviews<\/em> scientists (D\u00f6ring and Luenberger, 2022<\/a><\/strong>) report they reject a reconstruction of Greenland Summit temperatures that shows it has cooled ~4\u00b0C since Roman times (shown below as the red trend line, extended to 2000 C.E.).<\/p>\n\n\n

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\"\"<\/figure>\n<\/div>\n\n\n

Image Source:\u00a0D\u00f6ring and Luenberger, 2022<\/a><\/strong><\/h3>\n\n\n\n

<\/p>\n\n\n\n

They claim this temperature reconstruction showing cooling into the recent century is \u201chighly unrealistic\u201d. It doesn\u2019t support the claims of an alarmingly rapid and unprecedented warming of the modern Arctic. It also doesn\u2019t align with two other GISP2 reconstructions that use different model \u201cstrategies\u201d and thus produce different temperature results.<\/p>\n\n\n\n

Had this reconstruction depicted unusual warming in the last century (to 2000 C.E.), it would likely not have been rejected. This may demonstrate the selection bias inherent in paleoclimate studies. Scientists are not above tendentiously tossing out the data that do not conform to what they believe to be truth<\/em>.<\/p>\n\n\n\n

For example, Neftel et al. (1982)<\/a><\/strong> had published a paper in the journal Nature <\/em>documenting a CO2 rise of about 230 ppm (~190 ppm to 430 ppm) from roughly 12,000 to 10,000 years ago for a Greenland ice core. The CO2 record showed fluctuations of >100 ppm throughout the Holocene. Then, using the very same data from the same ice core a few years later, Neftel et al. (1988)<\/a><\/strong> only displayed the CO2 readings that aligned with the narrative that CO2 only fluctuated between 250 and 280 ppm between 12,000 and 5,000 years ago. The 390, 410, and 430 ppm CO2 measurements still existed, but they were not shown in the more recent publication.<\/p>\n\n\n

\n
\"\"<\/figure>\n<\/div>\n\n\n

Image Source:\u00a0Neftel et al. (1982)<\/a><\/strong>\u00a0and\u00a0Neftel et al. (1988)<\/a><\/strong><\/h3>\n\n\n\n

<\/p>\n\n\n

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\"\"<\/figure>\n<\/div>\n\n\n

<\/p>\n\n\n\n

The ~4\u00b0C Greenland Summit cooling since the Roman Warm Period depicted in the D\u00f6ring and Luenberger reconstruction is consistent with other reconstructions for this region documenting a conspicuous Late Holocene expansion of Greenland\u2019s ice volume and ice area extending into the modern period (Mikkelsen et al., 2018<\/a><\/strong>, Weiser et al., 2021<\/a><\/strong>, Nielsen et al., 2018<\/a><\/strong>). These reconstructions suggest Mid-Holocene temperatures may have been \u201cmore than 5\u00b0C above present\u201d across Greenland.<\/p>\n\n\n\n

Image Source:\u00a0Mikkelsen et al., 2018<\/a><\/strong><\/h3>\n\n\n\n

<\/p>\n\n\n

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\"\"<\/figure>\n<\/div>\n\n\n

Image Source:\u00a0Weiser et al., 2021<\/a><\/strong><\/h3>\n\n\n\n

<\/p>\n\n\n

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\"\"<\/figure>\n<\/div>\n\n\n

Image Source:\u00a0Nielsen et al., 2018<\/a><\/strong><\/h3>\n\n\n\n

<\/p>\n\n\n\n

Other temperature reconstructions indicate modern Greenland temperatures are 6-8\u00b0C colder than they were during the Early and Middle Holocene (Allan et al., 2021<\/a><\/strong>), and there were as-warm or warmer temperatures during the 1600s to 1800s (Krawczyk et al., 2021<\/a><\/strong>) in southwest Greenland, with a \u201cslightly decreasing trend\u201d in recent decades.<\/p>\n\n\n\n

Thus, a progressive cooling for the last 2,000 years continuing into the 21st century may be no less \u201crealistic\u201d than other Greenland temperature reconstructions that depict less modern era cooling.<\/p>\n\n\n

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\"\"<\/figure>\n<\/div>\n\n\n

Image Source:\u00a0Allan et al., 2021<\/a><\/strong><\/h3>\n\n\n\n

<\/p>\n\n\n

\n
\"\"<\/figure>\n<\/div>\n\n\n

Image Source:\u00a0Krawczyk et al., 2021<\/a><\/strong><\/h3>\n\n\n\n

<\/p>\n\n\n\n

via NoTricksZone<\/mark><\/em><\/strong><\/p>\n\n\n\n

https:\/\/ift.tt\/36WZXut<\/a><\/p>\n\n\n\n

March 17, 2022<\/p>\n","protected":false},"excerpt":{"rendered":"

Scientists admit that 3 different Greenland Summit (GISP2) temperature reconstruction \u201cstrategies\u201d produce 3 different paleoclimate temperature results. The reconstructions chosen as the most \u201crobust\u201d are therefore the ones that align best with the authors\u2019 presuppositions. In a new study published in Quaternary Science Reviews scientists (D\u00f6ring and Luenberger, 2022) report they reject a reconstruction of Greenland Summit […]<\/p>\n","protected":false},"author":121246920,"featured_media":192112,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_crdt_document":"","advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[1],"tags":[],"class_list":{"0":"post-192102","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","6":"hentry","7":"category-uncategorized","9":"fallback-thumbnail"},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2022\/03\/00Holocene-Cooling-SW-Greenland-6-8C-warmer-10-5-ka-Allan-2021.jpg?fit=1628%2C868&ssl=1","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paxLW1-NYq","jetpack-related-posts":[{"id":345601,"url":"https:\/\/climatescience.press\/?p=345601","url_meta":{"origin":192102,"position":0},"title":"\u00a0Not About CO2\u2026Greenland Still Much Colder Today Than Much Of The Past 10,000 Years","author":"uwe.roland.gross","date":"06\/10\/2024","format":false,"excerpt":"Norwegian climate blog site\u00a0avdekt.no here reports\u00a0how the GISP2 ice core data from Greenland shows the current temperature is well below the Holocene average.\u00a0","rel":"","context":"In \"GISP2 ice core data\"","block_context":{"text":"GISP2 ice core data","link":"https:\/\/climatescience.press\/?tag=gisp2-ice-core-data"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/10\/0Screenshot-2024-10-06-103524.png?fit=1200%2C618&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/10\/0Screenshot-2024-10-06-103524.png?fit=1200%2C618&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/10\/0Screenshot-2024-10-06-103524.png?fit=1200%2C618&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/10\/0Screenshot-2024-10-06-103524.png?fit=1200%2C618&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/10\/0Screenshot-2024-10-06-103524.png?fit=1200%2C618&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":257156,"url":"https:\/\/climatescience.press\/?p=257156","url_meta":{"origin":192102,"position":1},"title":"1875 was coldest in 10,000 years, Warming A Good\u00a0Thing","author":"uwe.roland.gross","date":"12\/05\/2023","format":false,"excerpt":"And then around 1875 we have right here the lowest point in the last 10,000 years. 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