Concentrated rainfall is increasing global aridity, according to new study by an UQAM professor published in Nature

MONTRÉAL, May 13, 2026 /CNW/ - With global warming, rainfall is increasingly falling in short, intense, concentrated bursts separated by longer dry periods, and these changes could have a potentially devastating effect on the planet. These are the conclusions of a new study published in the prestigious scientific journal Nature, co‑authored by Corey Lesk, Professor at the Department of Earth and Atmospheric Sciences at the Université du Québec à Montréal (UQAM), and Justin S. Mankin, Associate Professor of Geography at Dartmouth College in New Hampshire.

Corey Lesk led the study as a Neukom Postdoctoral Fellow at Dartmouth's Climate Modeling and Impacts Group, where professor Mankin is the Principal Investigator. They observed that regardless of the total amount of water received annually, this new rainfall regime alters how precipitation is absorbed by the soil and promotes greater aridity across the Earth's surface.

"Drought is often measured by what is lacking--the total amount of rainfall--but how precipitation falls is just as important," explains Professor Lesk. "Our study shows that this new type of rainfall regime leads to increased evaporation at the land surface, limiting the soil's ability to retain moisture, and thus reducing the amount of water available on land for human populations and ecosystems."

Methodology

By combining satellite-derived terrestrial water storage estimates and multiple
observational precipitation datasets, the authors presented the first observational evidence showing that the concentration of precipitation reduces land water availability across all climates worldwide.

Research findings

The results of this study highlight a previously unknown mechanism through which climate change dries out land, and this new phenomenon could have the potential to endanger global water resources.

Based on a 2 °C global warming projection derived from calculations using a hierarchy of climate models, the authors demonstrate that rainfall concentration will shift the climate to abnormally dry conditions for 27% of the world's population, regardless of total precipitation changes.

"Declining land water availability, including a decrease in the amount of water in lakes and waterways, can affect agricultural productivity, degrade ecosystems, and increase pressure on drinking water supplies, which could have major consequences on human life," adds Professor Lesk. "We will need to rethink the drought monitoring tools we use, as well as climate change adaptation strategies: it is now essential to incorporate not only the amount of precipitation, but also its temporal distribution, into our assessments."

By demonstrating a direct link between intensified rainfall and land drying, and by illustrating the sensitivity of water reserves to the temporal characteristics of precipitation, this study provides new insight into the complex impacts of global warming on our planet and our daily lives.

To read the complete study, click here.

Professor Corey Lesk is available for interviews.

SOURCE Université du Québec à Montréal

Source : Orian Labrèche, Communications Advisor, Press Relations and Special Events Division, Communications Service, Tel.: [phone], poste 20053, [email protected]