Contrasting fate of western Third Pole's water resources under 21st century climate change

Seasonal melting of glaciers and snow from the western Third Pole (TP) plays important role in sustaining water supplies downstream. However, the future water availability of the region, and even today’s runoff regime, are both hotly debated and inadequately quantified. Here, we characterize the contemporary flow regimes and systematically assess the future evolution of total water availability, seasonal shifts, and dry and wet discharge extremes in four most meltwater-dominated basins in the western TP, by using a process-based, well-established glacier-hydrology model, well-constrained historical reference climate data, and the ensemble of 22 global climate models with an advanced statistical downscaling and bias correction technique. We show that these basins face sharply diverging water futures under 21st century climate change. In RCP scenarios 4.5 and 8.5, increased precipitation and glacier runoff in the Upper Indus and Yarkant basins more than compensate for decreased winter snow accumulation, boosting annual and summer water availability through the end of the century. In contrast, the Amu and Syr Darya basins will become more reliant on rainfall runoff as glacier ice and seasonal snow decline. Syr Darya summer river-flows, already low, will fall by 16–30% by end-of-century, and striking increases in peak flood discharge (by >60%), drought duration (by >1 month) and drought intensity (by factor 4.6) will compound the considerable water-sharing challenges on this major transboundary river

Impacts of recent climate change on the hydrology in the source region of the Yellow River basin

AbstractStudy regionThe source region of the Yellow River (SRYE) in the northeastern Tibetan Plateau.Study focusThe spatial-temporal changes of hydrological and meteorological variables and their linkages over the SRYE were investigated for 1961–2013. Meanwhile, we quantified the impacts of precipitation and evapotranspiration on hydrological changes through climate elasticity by applying a land surface hydrological model. Furthermore, the impacts of warming climate on the seasonal snow cover and spring flow over the SRYE were examined.New hydrological insights for the regionDecreased precipitation and lightly increased evapotranspiration both contributed to reduced runoff in the 1990s, with the decreased precipitation playing a more important role (70%) than the increased evapotranspiration (30%). In the 2000s, precipitation contributed 3% to the runoff reduction, while the increased evapotranspiration accounted for 97%. Along with rapid warming, evapotranspiration is playing an increasingly important role in affecting runoff changes in the SRYE. During 2001–2012, snow cover in May decreased over the region. Spring peak flow mainly caused by snowmelt occurred earlier for about 15days at the Jimai hydrological station due to an earlier snow melt associated with the climate warming in the past 3 decades

Characterization of the enhanced infectivity and antibody evasion of Omicron BA.2.75.

Recently emerged SARS-CoV-2 Omicron subvariant, BA.2.75, displayed a growth advantage over circulating BA.2.38, BA.2.76, and BA.5 in India. However, the underlying mechanisms for enhanced infectivity, especially compared with BA.5, remain unclear. Here, we show that BA.2.75 exhibits substantially higher affinity for host receptor angiotensin-converting enzyme 2 (ACE2) than BA.5 and other variants. Structural analyses of BA.2.75 spike shows its decreased thermostability and increased frequency of the receptor binding domain (RBD) in the "up" conformation under acidic conditions, suggesting enhanced low-pH-endosomal cell entry. Relative to BA.4/BA.5, BA.2.75 exhibits reduced evasion of humoral immunity from BA.1/BA.2 breakthrough-infection convalescent plasma but greater evasion of Delta breakthrough-infection convalescent plasma. BA.5 breakthrough-infection plasma also exhibits weaker neutralization against BA.2.75 than BA.5, mainly due to BA.2.75's distinct neutralizing antibody (NAb) escape pattern. Antibody therapeutics Evusheld and Bebtelovimab remain effective against BA.2.75. These results suggest BA.2.75 may prevail after BA.4/BA.5, and its increased receptor-binding capability could support further immune-evasive mutations