{"id":258137,"date":"2023-05-19T19:13:02","date_gmt":"2023-05-19T17:13:02","guid":{"rendered":"https:\/\/climatescience.press\/?p=258137"},"modified":"2023-05-19T19:13:04","modified_gmt":"2023-05-19T17:13:04","slug":"new-study-the-lowest-tibetan-plateau-glacial-temps-were-still-3c-warmer-than-today","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=258137","title":{"rendered":"New Study: The Lowest Tibetan Plateau Glacial Temps Were Still 3\u00b0C Warmer Than Today"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

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

From NoTricksZone<\/a><\/p>\n\n\n\n

By\u00a0Kenneth Richard<\/a>\u00a0on\u00a0<\/em>18. May 2023<\/p>\n\n\n\n

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

\u201cEven the lowest pollen derived Pleistocene MAT\u00a0[mean annual temperature]\u00a0estimates are still \u223c3.5 to 2.5 \u00b0C warmer than the modern KPB MATs [Kunlun Pass Basin] of \u223c \u22126.1 \u00b0C.\u201d\u00a0 \u2013 Schwarz et al., 2023<\/em><\/strong><\/p>\n\n\n\n

The Kunlun Pass Basin (KPB) in the northeastern Tibetan Plateau is the largest alpine permafrost region on Earth.<\/p>\n\n\n\n

About 4 million years ago, during the Pliocene epoch, this location was permafrost-free. The mean annual temperatures (MAT) were more than 14\u00b0C warmer than they are today (Schwarz et al., 2023<\/a><\/strong>).<\/p>\n\n\n\n

While scientists have sometimes claimed the higher Pliocene CO2 concentrations (~420 ppm) were at least partly responsible for this warmth, it is well established that CO2 concentration changes follow<\/em> temperature changes by centuries to millennia in paleoclimate reconstructions (F<\/a><\/strong>ischer et al., 1999<\/a><\/strong>;Monnin et al., 2001<\/a><\/strong>; Caillon et al., 2003<\/a><\/strong>; Stott et al., 2007<\/a><\/strong>; Kawamura et al., 2007<\/a><\/strong>). Since causes cannot lag effects, this largely precludes CO2 as a driving mechanism for ancient temperature fluctuations.<\/p>\n\n\n\n

To further clarify CO2 concentrations are not a climate driver, pollen records in the KPB indicate that even the lowest glacial temperatures and lowest CO2 concentrations (\u201cbelow 200 ppm\u201d) of the Quaternary ice age (last ~2.5 million years) were still<\/em> \u201c~3.5 to 2.5\u2212\u00b0C warmer\u201d than they are with today\u2019s CO2 (~420 ppm) concentrations (Schwarz et al., 2023<\/a><\/strong>).<\/p>\n\n\n

\n
\"\"<\/figure>\n<\/div>\n\n\n
Image Source: Schwarz et al., 2023<\/a><\/strong><\/h6>\n\n\n\n

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