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Deserts and sandylands that are located in the semi-arid and arid regions in the middle latitudes of the Northern Hemisphere are usually regarded as environmentally sensitive change belts which respond to global climatic change. In northern China, activation or immobilization of sand dunes is mainly influenced by humid and dry variation and is related to stronger or weaker Asian monsoons. In this paper, the history of Holocene millennial-scale climatic and environmental change is reconstructed by the systematic analysis of the geochemical element contents and parameters, along with the OSL and C chronologies, from the different lithologies of the palaeosol-aeolian sand sequence in the south-eastern Mu Us Desert, northern China. Our results indicate that the region was dominated by a dry climate with intensive aeolian activity before 7.2 ka BP, and there was an optimal humid climate and fixed desert in 7.2-4.6 ka. Afterwards, the dune fields became mobile again as the effective humidity declined. Additionally, six dry events were discovered with times of ~7.2, 7.0-6.8, 6.6-5.7, 4.6-4.1, 3.7-3.5, and 3.3-2.5 ka, which were not only coincident with the intervals of millennial-scale weaker Asian summer monsoons, but also accordant with the cold events evidenced in the ice cores and deep-sea deposits of the high latitudes in the Northern Hemisphere. In general, the Holocene climatic and environmental changes had the characteristics of the 'monsoonal mode' and 'abrupt millennial-scale oscillation' in the Mu Us Desert. [ABSTRACT FROM AUTHOR]

The article highlights the difficulties connected with getting secure fixed-points for sea-level curve construction and emphasises the care that should be taken with data interpretation. As such, it is a welcome contribution to this important topic. On the other hand, the paper has, in my opinion, several weaknesses. It not only disregards a large body of reliable and highly relevant information on sea-level changes available from investigations carried out using a variety of methodologies, but also makes assumptions that seem to be based, to varying degrees, on misconceptions and misunderstandings. Many of these misunderstandings might have been avoided had the discussions, that are referred to in the Acknowledgements, actually taken place. I wish to take this opportunity to set the record straight by stating that no such discussions took place. [ABSTRACT FROM AUTHOR]