Drier Soil = Hotter Air

Written by
Sustainable Village
Published on
August 2, 2022 at 11:07:44 AM PDT August 2, 2022 at 11:07:44 AM PDTnd, August 2, 2022 at 11:07:44 AM PDT

Drier Soil = Hotter Air

Better Irrigation = Less Heat Waves

(Drier soil creates hotter ambient air temperatures.)

The more moisture we keep in dry soil, the more environmental benefits.

Since the Industrial Revolution, the world's climate has increased about 2 degrees and countries all over the world now frequently report record-breaking high temperatures and more frequent heat waves that last longer. In the UK, Dr. Eunice Lo attributed 2000 deaths per year to these higher temperatures. According to the World Health Organization, between 1998 and 2017, 166,000 people around the world died because of heat waves, 6.2 million were devastated by wildfires, and 1.5 billion by droughts. More studies estimate 12,000 heat-related deaths in the USA each year with that going to as high as 110,000 by the end of the century with hospitalization costs per person of over $11,000. Crop failures, large scale evacuations, heat strokes, melting roads, buckling rail lines, and huge economic losses add to this list of disasters.


While large scale solutions like ending our dependence on fossil fuels, preventing greenhouse gas emissions, and everyone becoming vegetarians may have the most ability to stop and decrease heat waves; they rely on major financial resources, self-serving corporations, a too-easily duped public, and conflicted political decisions. A large number of individuals working together however, can increase our planet's soil moisture and in this way help solve the problem.

A study by Martin Hirschi from the Institute for Atmospheric and Climate Science in Switzerland showed strong correlation between soil moisture and temperature extremes. A study by Carlos Lozano Fondón, University of Parma, Italy confirms how less soil moisture leads to more severe and frequent hot temperatures. When the soil dries out more, it gets hotter, more moisture evaporates, and the momentum toward desertification increases. On the other hand, when the soil stays more moist, it stays cooler and less water evaporates which makes it less hot; the momentum goes in the positive direction.

This explains why photovoltaic solar arrays become on average 10% more efficient in Agrivoltaic Systems. The more moisture we can all help to keep in dry soil, the more environmental benefits we can help increase.

What can we do? - Collect rainwater, install more efficient irrigation systems, reuse greywater, and replace unnecessary grass lawns with functional gardens. Click the buttons below to learn more!

"Water levels in the soil are essential because moist air prevents the atmosphere heating up as quickly as dry air. Water has a high specific heat capacity, meaning it takes more energy to heat it than it takes to heat dry air. Once the moisture has gone from the soil however, the temperature will rise considerably."

-See Article: The Relationship Between Heat and Soil Moisture Studied - Climate Action