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Through the Earth's ∼ 4.54 billion year history, icehouse climates have been relatively short-lived but have exerted a significant impact on the evolution of the habitable environment. These icehouse episodes, such as those that occurred in the Cryogenian, mid-Ediacaran, Late Ordovician, and Late Paleozoic, developed through the complex interaction of Earth System processes; however, there is still ongoing debate regarding the causes, processes, and consequences of these glaciations. To improve our understanding of the past history of icehouse climates and the responses of the Earth System, we present this new special issue entitled The Earth System during Icehouse Climate Modes: Contributions from Glacial Records in China. This special issue includes eighteen papers that focus on four major icehouse events: the Cryogenian Snowball Earth glaciations (Sturtian and Marinoan global glaciations), the Ediacaran glaciation, the Ordovician glaciation, and the late Paleozoic Ice Age. This collection of papers provide novel insights into glacial processes, marine environments, and chemical weathering through key intervals of Earth History. We anticipate that this special issue will attract wide interest across the geosciences field. [ABSTRACT FROM AUTHOR]

In recent years, studies have found that drought can occur rapidly under anomalous atmospheric circulation patterns and underlying surface conditions. This type of drought is defined as "flash drought". It is more sensitive to global warming compared to traditional drought and may become a common drought phenomenon in the future and require intensive research. But the characteristics and development mechanism of flash drought in northern China has been studied much less than in southern China, and thus deserve further study. Based on the daily station data and GLDAS grid data from 1978 to 2020, this paper identified the flash drought in northern China, analyzed its evolution of temporal-spatial characteristics and explored the meteorological driving factors of flash drought. The main results are as follows: (1)The frequency of flash drought in the year is the highest in WNW (West of Northwest), followed by ENW (East of Northwest), NC (North China) and NE (Northeast China), while the frequency in the plant growing season is the highest in the south of NE and the south of NC, and low in the other regions. (2)The hotspot areas of flash drought showed an obvious eastward trend from WNW to ENW in northern China from the 1980s to 2010s. (3) There is a good relationship between soil moisture and precipitation in WNW and ENW, while the soil moisture is affected by both temperature and precipitation in NC and NE. (4) Flash drought could occur all through the year in WNW and NC, while it mainly occurred in the summer half-year and summer in EWN and NE. The main high occurrence period of flash drought in each region is in late spring and early summer, while a second high occurrence period appears from early September to late October in WNW. (5) From the perspective of the driving of water vapor changes, the flash drought in WNW and ENW is mainly driven by water vapor advection, while that in NC and NE is mainly driven by wind field divergence. • The hotspot areas of flash drought showed an obvious eastward movement from WNW to ENW in northern China. • The main high occurrence period is around early May to early July in northern China, with a second one in WNW. • Flash drought in WNW and ENW (NC and NE) is mainly driven by water vapor advection (wind field divergence). [ABSTRACT FROM AUTHOR]

The end-Permian mass extinction (EPME) severely impacted global biodiversity. Extinction selectivity of biotas behaved differently in various environmental settings, and biotic variations before, during, and after the EPME on the shallow platform remain unclear. This paper describes a new microbialite near the Permian-Triassic (P-Tr) boundary (PTB) from the Xiejiacao section, South China. The PTB microbialite comprises thrombolite and dendrolite fabrics and yields abundant columnar cyanobacteria and various microspheroids. Abundant metazoan fossils, including conodonts, foraminifers, ostracods, gastropods, ammonoids, brachiopods, and ophiuroids, are reported from the uppermost Permian bioclastic limestone, PTB microbialite (PTBM), and lowest Triassic strata in Xiejiacao. Stratigraphic occurrences of these taxa display a two-fold decline pattern of the end-Permian mass extinction, calibrating to the base and top of the PTB microbialite and corresponding to the first extinction phase (EP1) and second extinction phase (EP2) of the EPME, respectively. This two-fold extinction pattern is also reinforced by fossil fragment components of various clades through the P-Tr transition in Xiejiacao. Updated dataset of metazoan fossil records from 25 PTBM sections in South China is also compiled, and it shows the two-fold declines in biodiversity. The dominance role of foraminifers in the latest Permian faunas switched to ostracods in the PTB microbialite after EP1, and then to bivalves after EP2. Proportions of infaunal, stationary, and omnivore forms declined continuously across the EP1 and EP2, while pelagic, fast-moving, suspension-feeding, and predatory taxa underwent stepwise increases across these two extinctions. Proportions of epifaunal, slow-moving, and deposit-feeding taxa increased after EP1 but decreased after EP2. This might be associated with the extinction of brachiopods and, the immigration, and the proliferation of mollusks (bivalves, gastropods, and ammonoids). The metazoan fossil dataset of all PTBM sections across South China refutes the taphonomic window hypothesis and the refuge scenario, instead, supports that the post-extinction unique palaeoceanographic conditions in microbial ecosystems may have been beneficial to diversification of the PTBM faunas. The dataset of the stratigraphic distributions of all PTBM taxa in all palaeoenvironmental settings across South China shows that the drastic decline in biodiversity of the PTBM faunas during the cessation of microbialite was not due to facies control on fossil preservation, but closely related to the biotic extinction in EP2 of the EPME. • New PTB microbialite comprises thrombolite and dendrolite fabrics • Species ranges display a two-fold decline pattern, coinciding with two phases of the EPME • Proportions of infaunal, stationary, omnivore forms decline across the EP1 and EP2 • Proportions of pelagic, fast-moving, suspension-feeding and predatory taxa increase after the EPME [ABSTRACT FROM AUTHOR]