Repercussion Section: Clouds That Make Clouds

by Sandra Steingraber, SEHN senior scientist and writer in residence

In this column we consider the various unintended consequences of technology that contribute to public health or environmental harms. 

This month, we are considering clouds. Both kinds. The metaphorical ones where our data are stored and fluffy ones up in the actual sky of our actual planet. 

It turns out they are connected. 

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Tom Fisk, CC free-to-use, View Here

But first, a quick meditation on corn sweat. 

In rural Illinois where I grew up, the corn growing in the fields collectively sends 48 million gallons of water each midsummer day into the atmosphere. It all begins in late July when each stalk of field corn simultaneously hits puberty and goes through some wild changes, all of which require lots of water. 

First, there is silking stage, whereby each potential kernel (female ovule) sends out a hair-like tube that grows an astounding 1.5 inches a day, elongated by the turgor pressure of the moisture that is being drawn up by the roots and pushed into the ears. Propelled by water, the silks emerge from the husk leaves and just keep growing until they capture a pollen grain and send it down the shoot to the would-be kernel. 

Or die trying. 

The pollen itself is shaken loose from the male tassels at the top of the stalk. Thus, the tasseling stage, by necessity, also happens in high summer at more or less the same time as the silking stage. It’s a dance of the corn gametes. And, like silking, tasseling is a water-intensive process. A little breeze also helps.

If all goes well and corn sex happens—and, again, all the identical fields of corn are, more or less, doing this at the same time—thereby follows the milking stage where the kernels swell up with a white fluid full of starches and sugars. Milking is also a super water-intensive phase of development. 

By September, everything starts drying out and the need for water plummets. Which is as it should be. But during those intensely sexual weeks during the hottest days of the calendar year—and assuming adequate rainfall—the corn crop sends so much water out of the stomata of its leaves as evapotranspiration that the local humidity rises and turns the air into a swamp, with each acre of corn turning 3,000-4,000 gallons of water into humidity every day. 

That’s the power of corn sweat. (Soybeans also do this; they peak a few weeks later.) 

By adding prodigious amounts of water vapor to the air, corn makes the summer heat in the rural Midwest more miserable, more oppressive, and, in the face of ever-more-frequent heat domes and heat waves, more dangerous for us. The higher the humidity, the more difficult it is for us to cool down. With so much corn sweat in the air, there is no room for our sweat, and evaporative cooling is no longer available to us.

Of course, trees, shrubs, and prairie grasses also all rely on evapotranspiration to photosynthesize, grow, and reproduce. But before the Illinois landscape was plowed up for endless monocultural fields of corn and beans—back when the fields supported diverse ecosystems—not every plant species within view hit puberty at the same moment. There were early bloomers and late bloomers, so their evapotranspiration needs were staggered. Corn sweat capable of surging the regional humidity is a phenomenon of industrial agriculture. 

You could make the claim that high summer humidity in the Midwest is an unintended consequence of the ethanol industry and sort of be right. 

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As we describe elsewhere in this month’s newsletter, data centers, like corn, are water intensive. And they also sweat prodigiously. That’s a direct result of their need for lots and lots of electricity to carry out the computations of AI and cryptocurrency mining, along with all that streaming and cloud storage of data that has de-materialized newspapers, photographs, books, documents, movies, musical albums. 

But for all the artificiality of the intelligence and the virtualness of the currency, the law of thermodynamics, still holds. Which means that nearly all electrical energy that is delivered to the racks of servers inside of the data centers will be converted into heat energy. The higher the current, the higher the heat. Which needs to be whisked away for the servers to keep operating. 

BalticServers, Creative Commons Attribution-Share Alike 3.0 Unported, View Here

For many data centers, the oldest trick in the physics book is deployed to do it: evaporative cooling using vast amounts of piped-in water from a local water utility drawn up from an aquifer, or even drawn directly from a lake. Some of that water undergoes a phase change from liquid to vapor, which then is released into the atmosphere. Or the liquid water full of heat is carried off and discharged somewhere, like Seneca Lake in New York State, presenting a different set of problems. (See Yvonne Taylor’s essay in this newsletter.)

If the water used to cool a data center is pumped out of an aquifer, as is often the case, then some of it is lost to the local watershed as this former groundwater turns into water vapor, rises into the atmosphere, and is carried away by prevailing winds, often to rain down on all the ships at sea and contribute to sea level rise. 

This is how IT clouds beget actual clouds, as is explored more technically in our new fact sheet, included in this month’s newsletter, “Data Centers and the Water Crisis.” It’s a phase change that represents consumptive water use, as this water is no longer available to recharge the local aquifer. 

With data center electricity consumption rising by 30 percent per year, water consumption necessarily rises in tandem with it—but in ways that no one is systemically monitoring.  

Rachel Carson said of clouds in a script she wrote in 1956 for the television program Omnibus, “Clouds are as old as the earth itself—as much part of our world as land or sea. They are the writing of the wind on the sky. They are the cosmic symbols of a process without which life itself could not exist on earth.”

But, in an age of unfettered groundwater pumping from aquifers that will not be recharged on a human timescale and now represent the leading contributor to sea level rise, the fact that some clouds represent the condensing sweat of data centers is not a life-giving message in the sky.