Precipitation whiplash, including abrupt shifts between wet and dry extremes, can cause large adverse impacts on human and natural systems. Here we quantify observed and projected changes in characteristics of sub-seasonal precipitation whiplash and investigate the role of individual anthropogenic influences on these changes. Results show that the occurrence frequency of global precipitation whiplash is projected to be 2.56 ± 0.16 times higher than in 1979–2019 by the end of the 21^stCentury, with increasingly rapid and intense transitions between two extremes. The most dramatic increases of whiplash show in the polar and monsoon regions. Changes in precipitation whiplash show a much higher percentage change than precipitation totals. In historical simulations, anthropogenic greenhouse gas (GHG) and aerosol emissions have increased and decreased precipitation whiplash occurrences, respectively. By 2079, anthropogenic GHGs are projected to increase 55 ± 4% of the occurrences risk of precipitation whiplash, which is driven by shifts in circulation patterns conducive to precipitation extremes.

Understanding the impacts of climate change and human activities on hydrological processes, especially the baseflow, is vital for sustainable water resource management. We analyzed the global changes in baseflow and baseflow index (BFI) for 2,374 global streamflow stations from 1970 to 2016 to examine their associations with precipitation, temperature, terrestrial water storage (TWS), normalized difference vegetation index (NDVI) representing the vegetation regimes, potential evapotranspiration (PET), and a humidity index (HI)‐precipitation/PET. Results showed that changes in both baseflow and BFI are significantly region dependent in continents, due to spatial differences of changes in climate and vegetation that determines the baseflow generation. Seasonal baseflow changed slightly, while seasonal BFI varied greatly, partly due to the shift from snowfall to rainfall and warming effects on glacial retreat and the timing of snowmelt. The multibasin baseflow elasticity analyses show that baseflow (BFI) was highly sensitive to changes in NDVI, precipitation, and temperature (temperature and PET). The multivariate regression analyses show that globally, changes in precipitation and TWS contributed to the majority (64.8% and 20.2%) of changes in baseflow, while changes in HI, PET, and precipitation contributed to the majority (30.3%, 28.9%, and 27.5%) of changes in BFI. The spatially varying interaction between climate, vegetation, and baseflow implies that regional adaptation of water resources utilization to climate change should consider the regional shifts in vegetation. This study quantified the elasticity and relative contribution of changes in geographic factors to changes in baseflow and BFI around the world and could inform practices for sustainable water management.

To detect significant interannual and interdecadal oscillations and their teleconnections to large‐scale climate anomalies such as El Niño–Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and North Atlantic Oscillation (NAO), monthly and seasonal maximum daily precipitation (MMDP and SMDP) from 131 stations across Canada were analyzed by using variants of wavelet analysis. Interannual (1–8 years) oscillations were found to be more significant than interdecadal (8–30 years) oscillations for all selected stations, and the oscillations are both spatial and time‐dependent. Similarly, the significant wavelet coherence and the phase difference between leading principal components of monthly precipitation extremes and climate indices were highly variable in time and in periodicity, and a single climate index explains less than 40% of the total variability. Partial wavelet coherence analysis shows that both ENSO and PDO modulated the interannual variability and PDO modulated the interdecadal variability, of MMDP over Canada. NAO is correlated with the western MMDP at interdecadal scale and the eastern MMDP at interannual scale. The composite analysis shows that precipitation extremes at about three fourths of the stations have been significantly influenced by ENSO and PDO patterns, while about one half of the stations by the NAO patterns. The magnitude of SMDP in extreme El Niño years, and extreme PDO event of positive phase, was mostly lower (higher) over the Canadian Prairies in summer and winter (spring and autumn) than in extreme La Niña years. Overall, the degree of influence of large‐scale climate patterns on Canadian precipitation extremes varies by season and by region.