Projected Changes in Seasonal Precipitation Extremes Over the United States in CMIP6 Simulations
Our study quantifies the impact of global warming on precipitation extremes over the United States (US) using newly developed Earth system models (i.e., CMIP6). Overall, the study findings identify a robust projected increase in the intensity of winter precipitation across models, with less agreement in summer. Winter heavy precipitation and summer consecutive dry days are projected to amplify in the future, especially over the northern US.
Extreme precipitation events can have large impacts on the society and economy, and its projections especially at subregional scales are vital to informing climate change adaptation and policy planning. Our study quantifies the projected changes in seasonal extreme precipitation over the US and its subregions and highlights the seasons and subregions where the projected changes are robust and where they do not, which is critical for future planning against natural disasters such as floods and droughts.
Quantifying how climate change may impact precipitation extremes is a priority for informing adaptation and policy planning. In this study, Coupled Model Intercomparison Project phase 6 global climate models are analyzed to identify robust signals of projected changes in summer and winter precipitation extremes over the United States (US). Under a projected fossil-fuel-based economic (i.e. high greenhouse gas emissions) scenario, our results show consistent changes in the seasonal patterns for many precipitation extremes by the end of the 21st century. We find a robust projected increase in the intensity of winter precipitation across models, with less agreement during the summer. Similarly, a robust projected amplification of heavy precipitation over the northern US is evident in winter, while intermodel spread is prevalent in summer projections. Specifically, the heavy and very heavy winter precipitation days (R10mm and R20mm) exhibit larger increases compared to other aspects of precipitation. Additionally, changes in dry extremes (e.g. consecutive dry days) are found to differ significantly across various subregions and seasons. Overall, our results suggest that the US may suffer more natural disasters such as floods and droughts in the future.