Branched glycerol dialkyl glycerol tetraethers and paleoenvironmental reconstruction in Zoigê peat sediments during the last 150 years

A significant increase in mean annual air temperature (MAAT) of approximately 5°C and a rise in pH by 0.8 units have been observed in the Zoigê grassland, located on the eastern margin of the Qinghai-Tibetan Plateau, since the 1980s. This finding was derived from analyzing branched glycerol dialkyl glycerol tetraethers (GDGTs) in peat sediments, which allowed for paleoenvironmental reconstruction over the last 150 years using the cyclization of branched tetraethers (CBT) and methylation of branched tetraethers (MBT) indices. The study identified three distinct stages of variation: a period of stable pH and slow MAAT decrease from 1851 to 1927, followed by rapid decreases in both parameters between 1927 and 1979, and the recent warming trend since the 1980s. These reconstructed temperatures align with tree-ring data from nearby Jiuzhaigou Valley, reinforcing confidence in GDGT-based proxies for continental paleoclimate reconstruction.

Zhou, H., Hu, J., Ming, L., Peng, P., & Zhang, G. (2011). Branched glycerol dialkyl glycerol tetraethers and paleoenvironmental reconstruction in Zoigê peat sediments during the last 150 years. Chinese Science Bulletin, 56(23), 2456–2463. https://doi.org/10.1007/s11434-011-4594-9