By Judith D. Schwartz
We often think of water as a “noun”, as something bounded by place. After researching and writing a book on water, however, I’ve come to regard water as a “verb”. Water is always in motion. It expands in volume or retrenches; it retains or releases energy. It changes state, moving from gas to liquid to solid and back again, in an ongoing dialogue with land and sun.
This is not just to fuss over language. Rather, I believe that understanding how water “works”—how it moves across the landscape and through the atmosphere—is essential to truly address our many water challenges. This is so whether we’re contending with scarcity, in the case of drought, or too much water, as in floods. And because the workings of water intersect with factors like climate, biodiversity and food security, we can better grapple with other significant global problems by zeroing in on water processes.
Let’s take a quick look at three ways that water moves:
Infiltration In a functioning landscape, rain is held in the ground and supports plant and microbial life or slowly filters into groundwater stores. Our water “infrastructure” here is soil, and the richer the better: every one percent increase in soil organic matter (mostly carbon) represents an additional 20,000 gallons of water per acre held in the ground. This means it’s a lot harder to make a flood, and the longer the ground stays moist between rains.
What we perceive as a “lack of water” problem is often an “inability to keep water in the ground” problem—itself a symptom of carbon-depleted soil. As Precious Phiri, a land management consultant based in Zimbabwe and Africa Coordinator for Regeneration International, says, “there are places where you will be in a drought no matter how much rain you get.” Simple approaches to building soil carbon, such as managed animal impact, can make a tremendous difference in food security. Jody Butterfield, co-founder of the Africa Centre for Holistic Management in Zimbabwe, says increased water infiltration in animal-treated fields can mean the ability to grow food for seven months rather than merely two—the difference between being self-sufficient and relying on food aid.
Transpiration I interviewed Antonio Nobre of Brazil, author of a report called “The Future Climate of Amazonia”, a formidable document and testament to the power of trees and their role in climate regulation. The Amazon Rainforest has about 4 billion trees, he writes. Together, these trees act like geysers and spout a river of vapor into the air—an aerial river through which flows twenty billion tons of water a day—that exceeds the Amazon River itself.
This flying river is the result of transpiration, the upward movement of water through plants. You can think of it as the plant “sweating”: the stomata on the leaves (or if grass, blades) open to retain or release moisture to cool the plant itself and the nearby vicinity. What’s important is that this is a cooling mechanism: transforming solar energy into latent heat—suspended in vapor—as opposed to sensible heat, or heat you can feel, like a hot sidewalk. Consider a tree, say a good-sized tree in full leaf, whose crown spans some five meters. On a sunny day, when it’s basking in light, our tree will transpire more than 100 liters (26 gallons) of water. This dissipates solar energy: according to Czech plant physiologist Jan Pokorny, the transpiration activity of one tree on one sunny day represents three times the cooling capacity of an air conditioning system in a 5-star hotel room. We can make use of such botanical labor to promote area cooling.
(Download The Future Climate of Amazonia Report)
Condensation On my travels I visited Katherine and Markus Ottmers, who live in the dry area of far West Texas and obtain their household water from condensation. As Markus, explains, “This is because there’s heat on the roof, and breezes coming through. The roof cools off, and then the warm air flows create the condensation.” And so, unlike neighbors who worry about wells going dry, they’re able to keep water in the tank despite cloudless skies. In fact, one winter day in 2012, four months after the last rain, the water tank overflowed.
Condensation is the process of water in its gaseous form turning to liquid, the meteorological mirror of transpiration. There is always water in the atmosphere, even in the desert and even in a drought. The condensation part happens when warm and cold collide. While many ancient cultures had a tradition of collecting dew for drinking or cultivating plants, condensation scarcely comes up in conversations about water. Some say we’ve overlooked a vital water source. Peter Andrews, an Australian farmer and author, emphasizes dew’s significance to what he calls the “daily water cycle.” He calls dew “the most important water on the landscape, and …the purest.”
Just like the water in the desert, the solutions are there—in plain sight. Just think of what we can do as we explore new ways to work with water.
(Read: The New Water Alchemists)
Judith D. Schwartz is a journalist whose work focuses on ecological restoration as a hub for multiple environmental, economic, and social challenges—and for solutions. She is the author of Cows Save the Planet and Other Improbable Ways of Restoring Soil to Heal the Earth (Chelsea Green Publishing, 2013) and Water In Plain Sight: Hope for a Thirsty World (St. Martin’s Press, 2016). A graduate of Brown University and the Columbia University Graduate School of Journalism, she lives in Southern Vermont. Follow her work at http://judithdschwartz.com/