Climate
The New Colorado River Proposal Buys Valuable Time
An interview with Dave White, a water expert at Arizona State University, about what a breakthrough along the Colorado River really means
An interview with Dave White, a water expert at Arizona State University, about what a breakthrough along the Colorado River really means
An interview with science writer Melissa L. Sevigny about Brave the Wild River: The Untold Story of Two Women Who Mapped the Botany of the Grand Canyon
The Pacific Northwest sizzled beneath its first heat wave of the season. It probably won’t be its last.
Thanks to the Supreme Court, it is a very difficult proposal to talk about.
People without air conditioning fare better during blackouts. Here’s why.
I am, in the summer, the human equivalent of a slightly overcooked noodle.
This is especially true in a coastal city like Washington, D.C., where I live. The heat and humidity seep into my bones and I attain a semi-liquid state in which, despite my enthusiasm for hiking and kayaking and swimming and all those other good summer activities, I find myself craving exactly one thing every time I go outside: Air conditioning.
Air conditioners, for better or worse, have become our default solution for extreme heat. When concrete and steel construction replaced regional architecture around the world, air conditioners — where people could afford them — awkwardly, imperfectly filled the spaces left behind by missing local design and materials that would have otherwise helped cope with the weather. And as the world gets hotter, ACs are growing more and more popular: In India, where I mostly grew up without an AC, sales of ACs have skyrocketed over the past decade from three million units in 2013 to an expected 9.7 million this year.
But there is, of course, a catch. As vernacular architecture disappears, so too does vernacular knowledge; many of us, bowing to our cooling-machine gods, have forgotten how to deal with the heat.
Air conditioning has an odd side effect: It makes us dependent. In a 2021 study from Georgia Tech’s Urban Climate Lab, which modeled indoor heat across Atlanta, Phoenix, and Detroit during heat waves, researchers found that people without air conditioning would fare better during a blackout because they’d be more likely to take other measures to help deal with the heat. These are simple moves, like drinking more water and using curtains to keep their rooms dark and cool, whereas people with air conditioning might put too much faith in their appliances — and be entirely unprepared for those appliances to stop working.
“I think a combined blackout and heat wave is the most deadly climate risk we’re confronting right now,” said Brian Stone Jr., director of the Urban Climate Lab and a Professor in the School of City and Regional Planning at Georgia Tech. “A blackout situation really kind of inverts the traditional risk pyramid. If you don’t have air conditioning in your house, you probably have greater heat resilience. Those of us who have air conditioning whenever we want it are going to be more susceptible.”
Heat waves put extreme stress on power grids, and blackouts are increasingly common as summers get hotter. If more people buy more air conditioners without any work being done to shore up the grid (and, believe me, the grid badly needs shoring up), that extra stress could lead to quicker, more common grid failures. It’s unfortunately easy to imagine just how dangerous a grid failure can be: A major blackout during a heat wave would be the inverse of the Texas blackout during the winter of 2021, when hundreds of Texans died of hypothermia in their own homes.
For someone in a house without an air conditioner, a blackout during a heat wave probably wouldn’t affect the temperature inside much; someone who does have one, however, will inevitably find their house heating up beyond a point they were prepared for. As Rebecca Leber pointed out in Vox, early-season heat waves are dangerous because our bodies aren’t prepared for the heat. The sudden loss of air conditioning for someone used to it is dangerous for the same reason.
Our built environment, like a natural ecosystem, is the sum total of many pieces fitting together, and not all of them fit perfectly. Air conditioners are the perfect example: They aren’t universally good at cooling our buildings down, especially if those buildings weren’t built with air conditioning in mind — they often lack proper insulation, for example, which means cooled air will escape a room quickly. That means air conditioners will have to work harder to cool the air, which both further heats up the air outside and places more stress on the grid. When the built ecosystem fails, its human inhabitants inevitably suffer.
Last week, I wrote about a study out of Portland, Oregon, that measured how hot the units in three public-housing developments got during the summer of 2022. To the surprise of the researchers conducting that study, the units with air conditioners were not much cooler than those that didn’t have them. There were a few reasons for this: first, running an air conditioner is expensive, and residents with air conditioners would often turn the temperature up to save on electricity costs. Second, the buildings weren’t designed for air conditioning, so the apartments couldn’t retain cooled air very well.
Third, and most importantly, the residents who didn’t have air conditioners were both more cognizant of heat dangers and more likely to take other steps to cool their spaces down; they retained, in other words, a sort of vernacular knowledge of how to deal with the heat.
“The residents who don’t have air conditioners go to great lengths to keep their homes cool,” said Dana Hellman, a program manager at CAPA Strategies, the climate consultancy that ran the Portland study for the city. “For example, they made DIY insulation for their windows or kept all their lights off or their curtains closed all day long. It’s burdensome, but it might be leveling the field a little bit.”
Which isn’t to say that air conditioners should be abandoned wholesale. If indoor temperatures rise too much, everyone is at risk of heat stroke. Many cities, including Portland, operate cooling centers for residents to go to during extreme heat events. But none of those cities mandate that those centers have some sort of backup power option, and even if they did there aren’t nearly enough centers to serve every resident.
As with climate change more broadly, there are obvious equity issues here: The people who are most likely to use cooling centers are the people who are most likely vulnerable in other ways, as well. More well-off residents can afford to pay for an air conditioner, its associated costs, and possibly also a backup generator to help them ride out a heat wave in the comfort of their own homes; many cooling centers are understaffed and under-resourced, which raises safety concerns for residents who then have to choose whether to stay home or potentially put themselves at risk for the sake of finding relief from the heat.
So what should we do as the world continues to heat up?
We can start with the long, hard task of adapting the grid to keep us safe during heat waves, a fix that Stone points out is decades overdue. “Back in the 90s, the idea was that we’d be successful in reducing global emissions and wouldn’t need to adapt [to global warming],” Stone said. “If we had acknowledged to ourselves that it was going to be a 20 to 50 year project just to start adapting, we might have been more attuned to the fact that the electrical grid is a life support system for us when it is too hot outside to be healthy. But that’s been a slow realization.”
In Portland, the housing authority has a program to provide public housing residents with free air conditioners. But there are other forms of adaptation, too: Stone and his colleagues found that cool roofs, which reflect more sunlight than traditional roofs, can lower ambient temperatures by 1 to 1.5 degrees Celsius. Urban tree cover, which throws potentially life-saving shade onto houses and roads alike, can also go a long way towards cooling things down.
Most important, however, is actually going to be changing the way we interact with heat. Education — getting people to take heat waves as seriously as, say, a hurricane or wildfire — is just as important as modifying our built environment. Perhaps we'll all, as Morgan Meaker wrote in Wired last year, take a leaf out of the Spanish playbook and adopt the siesta (an idea that I personally endorse), or learn to live in the dark caves of our curtain-darkened apartments in the peak of summer.
I may even start turning up my AC to let my body acclimatize to its natural state of noodle. Whatever the solution, heat must re-enter our vernacular: not just as something we mechanically force out of our homes, but as something we figure out how to live with.
Inside California’s audacious plan to stash more than a trillion gallons of water underground
The world is slowly but surely running out of groundwater. A resource that for centuries has seemed unending is being lapped up faster than nature can replenish it.
“Globally speaking, there’s a groundwater crisis,” said Michael Kiparsky, director of the Wheeler Water Institute at UC Berkeley’s Center for Law, Energy, and the Environment. “We have treated groundwater as a free and limitless source of water in effect, even as we have learned that it’s not that.”
Aquifers are the porous, sponge-like bodies of rock underground that store groundwater; they can be tapped by wells and discharge naturally at springs or wetlands. Especially in places that have already been hard-hit by climate change, many aquifers have become so depleted that humans need to step in; the Arabian Aquifer in Saudi Arabia and the Murzuk-Djado Basin in North Africa, per a 2015 study, are particularly stressed and have little hope of recharging. In the U.S., aquifers are depleting fast from the Pacific Northwest to the Gulf, but drought-stricken California is the poster-child of both water stress and efforts to undo the damage.
In March, the state approved plans to actively replenish its groundwater after months of being inundated by unexpected levels of rainfall. While this move is not brand-new — the state’s Water Resources Control Board has been structuring water restrictions to encourage enhanced aquifer recharge since 2015 in the brief windows when California has water to spare — the scale of this year’s effort is unprecedented.
But just how will all that flood water get back underground? California’s approach, which promotes flooding certain fields and letting the water seep down slowly through soil and rocks to the aquifers below, represents just one potential technique. There are others, from injecting water straight into wells to developing pits and basins designed specifically for infiltration. It’s a plumbing challenge on an unprecedented scale.
The act of putting water back into aquifers has a number of unglamorous names — enhanced aquifer recharge, water banking, artificial groundwater recharge, and aquifer storage and recovery, among others — with some nuanced differences between them. But they all mean roughly the same thing: increasing the amount of water that infiltrates into the ground and ultimately into aquifers.
This can have the overall effect of smoothing the high peaks and deep valleys of water supply in places dealing with extreme weather fluctuations. The idea is to capture the extra water that floods during periods of intense rainfall, and bank it for use during droughts. (While aquifers can also be recharged using any old freshwater, water rights are so complicated in the West that floodwater often represents “the only surface water that’s not spoken for,” Thomas Harter, a groundwater hydrology professor at U.C. Davis, told local television outlet KCRA.)
Recharge has the potential added benefit of protecting groundwater from saltwater intrusion. As water is pumped from a coastal aquifer, water from the ocean can seep in to fill the empty space, potentially poisoning the well for future use for agriculture or drinking water. It’s a risk that will only get bigger as the climate warms and sea levels rise.
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According to the Environmental Protection Agency, aquifer recharge is most often used in places where groundwater demand is high and increasing even as supply remains limited. These tend to be places with lots of people and lots of farms; the San Joaquin Valley, which is the focus of California’s current plan, checks all of those boxes. Aquifers are the source of nearly 40% of water used by farms and cities in California, per the Public Policy Institute of California, and more in dry years. And, until 2023, most recent years have been dry.
In response to this year’s sudden reversal of California’s water fortunes, the state’s Water Board — which regulates water rights — allowed local contractors of the U.S. Bureau of Reclamation to move up to 600,000 acre-feet of water, or well over a trillion gallons, to places that normally would be off-limits this time of year. Those contractors, who are largely farmers and other major landowners, have until July 30 to take advantage.
“California is essentially the pilot project for how we want to do this in the future,” said Erik Ekdahl, deputy director for the Water Board’s water rights division. It won’t be until the end of the year that the state will know exactly how much water was successfully banked, but Ekdahl said anecdotally that some contractors have already taken steps to put the spare water underground.
This comes as California’s enormous snowpack begins to melt: a potential boon for the aquifers that could also mean problematic and dangerous floods for the communities downstream of the runoff.
How does enhanced aquifer recharge actually happen? It’s not as if the vast underground stretches of rock and sediment have faucets or even obvious holes leading to their watery depths. People aiming to reverse the centuries-long trend of drawing up water without actively replacing it have a range of artificial recharge options, which either speed along the natural seepage process or direct water straight to the aquifer below.
In the former cases, one option is to allow water to flood fields left fallow, a process known as “surface spreading,” as is beginning to happen in the San Joaquin Valley.
Heatmap Illustration/Getty Images
Water can also be directed to dedicated recharge basins and canals. In both cases, excess water is absorbed by fast-draining soil, which encourages it to pass below ground. Aside from the technical challenge of redirecting water from typical flood patterns, these approaches tend to be low-tech.
Heatmap Illustration/Getty Images
But in cases of aquifer depletion where those approaches are impractical — such as when the aquifer is under impermeable rock — injection wells represent a direct connection to the groundwater. These are either deep pits that drain into sedimentary layers above an underground drinking water source (like a traditional well functioning in reverse), or else webs of tubes and casing that blast water straight into the source.
Heatmap Illustration/Getty Images
Cities are also experimenting with aquifer recharge on a smaller scale. For urban stormwater, the EPA promotes certain “green infrastructure” approaches that mold the built environment to mimic natural hydrology. For instance, shallow channels lined with vegetation, known as bioswales, redirect stormwater while encouraging it to seep through the ground. Permeable pavement — in use in several Northeastern states — works much the same way. Meanwhile, rain gardens designed to prevent flooding have the added benefit of replenishing groundwater.
Determining when and where to use different approaches to aquifer recharge, though, can be unclear. We are still a long way from widespread or coordinated adoption of these techniques, but researchers are working on weighing their costs and benefits.
Supported by a $2 million EPA grant, Kiparsky is part of a U.C. Berkeley team looking at how to make California-esque recharge work on a national scale. , including by developing a cost-benefit tool for water managers. Some of the geochemical and physical considerations are relatively simple to measure: Is the soil in question porous? Are there gravel-filled “paleo valleys” that could allow water to rapidly seep to the aquifers below, as one 2022 study found?
More complicated, potentially immeasurable, but no less important are the legal and regulatory considerations around water rights. It is, as Kiparsky put it, one of the quintessential modern examples of the tragedy of the commons. Whether the government will be able to entice individuals to use their own little corner of Earth to fill an aquifer for the benefit of the many is an open question.
But Kiparsky is fairly optimistic that recharge will take hold in years where there is water to spare, as the West recognizes that future drought must be prepared for, especially when it’s raining.
“Is recharge going to become a bigger part of water management? I would say absolutely,” he said. “I’m not usually in the game of making predictions, but I would predict the answer is yes. When we can figure out how to do it.”
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