As global warming continues to reshape the Earth's climate, both the occurrence and mechanisms of extreme precipitation events, such as rain and snow, are undergoing profound transformation. These changes in frequency and intensity directly affect agricultural security, ecosystem stability, and infrastructure resilience.

A research team led by Prof. CHEN Yaning from the Xinjiang Institute of Ecology and Geography (XIEG) of the Chinese Academy of Sciences (CAS) has recently revealed how different types of precipitation (liquid and solid) respond to global warming. Their work was published in Advances in Climate Change Research.

Using ERA5-Land reanalysis data from 1950 to 2022, the researchers conducted a comprehensive analysis of long-term trends, temperature sensitivity, and the driving mechanisms of extreme rainfall and extreme snowfall across the Northern Hemisphere.

They found that over the past seven decades, extreme rainfall has intensified at a rate of 0.269 mm per year, nearly nine times faster than the rate of increase in extreme snowfall, which is 0.029 mm per year.

The study also highlights the opposite responses of rainfall and snowfall to warming. Extreme rainfall strengthens significantly with rising temperature, showing a sensitivity of +2.27 mm/K.

In contrast, extreme snowfall weakens, with a sensitivity of –1.63 mm/K, especially across the mid-latitudes (30°–60°N). These results clearly demonstrate that liquid precipitation responds far more strongly to warming than solid precipitation.

Spatially, regions with increasing extreme rainfall now account for 22% of the Northern Hemisphere, whereas those with significant snowfall intensification cover only 4.7%, mainly confined to high-latitude (>70°N) and high-altitude areas.

Ongoing extreme precipitation is transforming global hydrological patterns. Each year, the share of extreme rainfall within all precipitation is climbing by a notable 0.038%, while the contribution of extreme snowfall is also on the rise, albeit at a slower pace of 0.017% annually. These trends suggest a future water cycle dominated by more intense and abrupt events, which would dramatically increase flood dangers in mid-latitude areas and contribute to fragile and unstable snowpacks in colder regions.

"Extreme precipitation is a critical factor for risk management," said LI Yupeng, first author of the study. "Mid-latitude regions should prioritize managing flood risks driven by intensified rainfall, while high-latitude and alpine regions must address hazard risks related to snow."

This study provides a crucial scientific foundation for understanding extreme precipitation behavior globally and enables the development of tailored climate adaptation and disaster prevention strategies.