Date of Publication: 26 October 2023

One-Line Summary: Bigger Cities Could Mean Fewer Thunderstorms.

Who did it: Researchers at the University of Delaware and the University of Wyoming.

What did they study: They made a guess at rates of population growth and urbanization* in the US over the next 100 years, then predicted temperature and rainfall patterns from it, using an established weather prediction model.

What they found:  They were surprised to find that, in some cases, the layout of a city can reduce its exposure to climate extremes. For example, they found as the size of a city increased, the people living in it were less exposed to heavy rainfall events.

Why does this matter: The number of people living in cities, compared to those living in rural areas, has increased sharply in recent decades. This trend is expected to continue, and so population increase will lead to bigger cities than ever before. 100 years from now, it is likely that most people on the planet will experience climate from within a city.

What next: If we know how the layout of a city affects how often it experiences extreme climate events*, we can design the cities of the future to make them more livable under climate change. 

Our take: The study predicts the climate of the distant future using a weather prediction model that works well today, but it doesn’t tell us how the growth of cities lowers the amount of rainfall.  The authors make a guess as to how big buildings might disturb wind patterns, but more explanations would make the study stronger. 

*The basics: Urbanization is the process of rural or wild land being converted into city.  Examples of extreme climate events include blizzards, heat waves, thunderstorms and drought.

Who to talk to: Melissa S. Bukovsky, Haub School of Environment and Natural Resources, University of Wyoming. e-mail: melissa.bukovsky@uwyo.edu 

The paper: Gao, J. and Bukovsky, M.S., 2023. Urban land patterns can moderate population exposures to climate extremes over the 21st century. Nature Communications, 14(1), p.6536.

Journal page: https://www.nature.com/articles/s41467-023-36527-8

Keywords: urban development, cities, population increase, thunderstorms, rainfall, weather prediction, extreme climate events, land use change, climate change