News feature
Photo of a shallow, drying pond blocked off by a low fence in a hilly grassland with trees in the background.
News feature
Photo of a shallow, drying pond blocked off by a low fence in a hilly grassland with trees in the background.

Severe Drought, Heat Upended Research This Summer

Researchers scramble to adapt as bouts of severe heat and aridity increasingly become the norm.

black and white image of young man in sunglasses with trees in background
Dan Robitzski

Dan is a Staff Writer and Editor at The Scientist. He writes and edits for the news desk and oversees the “The Literature” and “Modus Operandi” sections of the monthly TS Digest and quarterly print magazine. He has a background in neuroscience and earned his master's in science journalism at New York University.

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ABOVE: An artificial pond in Fort Ord, California, that was used in a study to compare and contrast the mating and feeding behaviors of native versus invasive salamanders in ponds that dry out after varying amounts of time ROBERT COOPER

Severe, record-shattering heat and unusually low rainfall plagued much of the world with intense droughts this summer. In the US, more than 7,000 daily temperature records and 27 all-time temperature records were broken. In Europe, entire lakes vanished and hunger stones, centuries-old water level markings chiseled into riverbeds recording droughts and warning of the attendant famines, resurfaced.

The effects have been far-reaching, including water restrictions, power outages, signs of desertification, and, in Europe, thousands of recorded deaths. Science, too, suffered. Life sciences researchers in parts of the US and Europe tell The Scientist that they had to postpone projects—many of them, ironically, on the effects of drought—or otherwise had work disrupted by aridity and heat, and that they anticipate more problems as the climate crisis worsens in the future.

“There is a lingering thought every day that something is going to happen . . . it’s going to be too hot,” University of Milan geneticist Lucio Conti says. “This kind of thing, in the long run, is going to have an effect” on research.

Thus far, none of the researchers contacted by The Scientist say they’ve had to deal with water restrictions that would have affected their indoor lab experiments, and a few didn’t experience any disruptions to their fieldwork this summer. However, some say restrictions could affect them in the future, and Conti notes that heat and the risk of power outages strained his lab members and instruments. Still, recent heatwaves and drought took a serious toll on fieldwork, scientists say.

These challenges will likely grow and become more frequent in the near future. A World Weather Attribution report published this month shows that, while the heatwave and drought that swept North America, Europe, and China this summer was an extreme event, human-induced climate change has made such events several times more likely. In other words, more are coming.

The case of the missing ponds

Brad Shaffer, an ecologist and evolutionary biologist at the University of California, Los Angeles, describes an experiment that was nearly ruined by the heatwave that hit southern California this summer. He and a postdoc, Robert Cooper, wanted to compare the feeding and mating behaviors of native California tiger salamanders (Ambystoma californiense) with those of the invasive barred tiger salamander (Ambystoma mavortium), which Shaffer says has been outcompeting the native species.

The native species is adapted to and relies on natural ponds—which, historically, have filled up in the winter and dried out in the summer—for its annual excursion to mate and reproduce. But the invasive species, which didn’t adapt to reproducing in local ponds, uses artificial ponds ranchers have dug and filled for their livestock, which tend to be deeper and available year-round.

Shaffer and Cooper designed an array of 18 ponds that were 30 feet wide and of varying depths, expecting that the pools would fill up during the rainy season and retain water for different lengths of time. Once they had filled, the plan was to leave eggs of one or both species at each pond to see how each species fared, recording mating and feeding behavior as well as overall survival to quantify the extent to which subtle differences in how long gradually drying ponds last affect the invasive salamanders versus the native ones.

Bird’s-eye view photo of a yellow and black salamander surrounded by dried twigs, leaves, and dirt
A salamander, likely a hybrid of the native and invasive species, near an experimental pond in Brad Shaffer and Robert Cooper’s experiment

“We have all these detailed models” for how long the ponds will last and how the salamanders will fare, says Shaffer. “Then it doesn’t rain.”

Shaffer says that the drought conditions, especially the absence of typical January rains, “wreaked havoc” on the experiment. While Shaffer was in danger of losing out on valuable data, which he says could have helped manage the species, “in nature . . . it has more devastating impacts because this [is] where the real populations are. . . . The salamanders come out to breed in December, they need 100 days of continuously filled pond for their larvae [to grow and survive].” When the ponds don’t last that long, everything dies and the population loses an entire year’s worth of offspring.

See “Tropical Birds Differ in Their Responses to Drought

In the end, Shaffer says, he and Cooper managed to salvage the experiment, but only by modifying its scope and by spending a lot more money to get water trucked to their remote study site. The water sometimes arrived chlorinated, in which case they had to dig extra ponds to let it off-gas before using it to maintain their array.

Many similar stories played out around the world this summer, researchers tell The Scientist, as the organisms or ecosystems they studied were altered by drought or vanished altogether, disrupting both individual experiments and long-term studies gathering years’ or decades’ worth of data.

Data dries up

Disruptions to experiments can stymie efforts to understand long-term ecological trends. Antonio Camacho, a biologist who studies aquatic systems at the University of Valencia in Spain, tells The Scientist that the severe drought in Europe this summer cost him around six months of data for his projects. His work involves modeling how the ecological health of wetlands in and around the Mediterranean corresponds with their greenhouse gas emissions and their ability to store carbon, based on a combination of field studies and extrapolation from decades of satellite imaging data.

Because some of these systems dried up entirely and will take a long time to rebound (if they do at all), Camacho explains, he was unable to properly calibrate his models, delaying their development until he could find new field sites. “There’s no way to manage the data” from the now-dried-out sites he previously relied on, Camacho says. “If you designed a specific experiment or you need some standard conditions, you have problems,” especially because rewetting a field site doesn’t immediately restore it to its former ecological health, he adds. “When drought is producing abnormal experiments, recovery doesn’t bring it easily to the original conditions” for which existing models are calibrated.

We’re going to keep doing what we can do for as long as we can do it.

—Alexandra “Sasha” Wright, California State University, Los Angeles

Conti, the geneticist from the University of Milan, says that he and his team ended up cancelling experiments they’d planned for the summer due to the lack of a rainy season earlier in the year, and because the heat was too intense for the tomatoes they had planned to grow in an outdoor field. “We kept postponing and postponing for the right moment, but the moment really never arrived,” Conti says, adding that this summer’s historic drought has made him “more mindful that all the experiments you are doing are outside of your control.”

When science becomes dangerous

In addition to the direct effects of drought or heat on fieldwork, the increased risk of wildfires in and around study sites or the health risks of prolonged heat exposure have prevented some projects from continuing.

Nathan Kraft, a plant ecologist at University of California, Los Angeles, tells The Scientist that the heat and long-term drought in southern California have him and his colleagues reconsidering the “human field safety” aspect of conducting studies, especially in remote areas. Mary Van Dyke, a PhD candidate in Kraft’s lab, says that she’s now required to carry a fire extinguisher and a shovel while studying plant biodiversity and interspecies dynamics at her field site in southern California, because the land has become so dry that even leaving her car idling over a patch of grass could set a whole field ablaze.

Meanwhile, Sandra Saura Mas, an environmental biologist at the Autonomous University of Barcelona, says that the risk of wildfire is so great at one study site in the shrubland of Cap de Creus Natural Park in Spain that it was closed off even to scientists during a critical time period for her research, because authorities “cannot ensure they can help you if you are there.”

That’s proven challenging, she says, because much of her work requires her to gather data at precise times, such as during the brief window when a plant she’s studying is typically pollinated, which she’s now been forced to miss. In this case, she says, she had hoped to study three endangered plant species in the area: the fern Cosentinia vellaea, the small purple flower Convolvulus siculus, and the spurge olive Cneorum tricoccon.

Many of the researchers who spoke with The Scientist say they have job security at their respective institutions and years or decades of work under their belts. But disruptions to or cancellations of planned studies could leave younger scientists—especially graduate students or postdocs—in precarious positions as they work to build a publication record. Several researchers say they suspect this could become a bigger risk in the next few years, if these issues recur.

See “Repeated El Niño Events Could Spark Big Ecological Shifts

Conti says that he heard “horror stories” from colleagues whose experiments were ruined. It’s not unusual in ecological field research that occasionally “fields are just lost,” he says. “But I think this year was particularly challenging.” Normally, he says, scientists hedge their bets: “You put all your eggs in different baskets just to avoid this kind of thing. This year[’s drought] was across the whole continent. . . . If you’re a postdoc or a PhD student and you rely on multiple-year measurements . . . you essentially lost one year, which is a lot considering that typical contracts are two [to] three years.”

How scientists adapt to a changing world

For junior scientists who’ve had their fieldwork disrupted or ruined by drought, heat, or otherwise extreme conditions—especially those who have planned to conduct field studies on a rapidly changing or slow-recovering ecosystem—Camacho recommends planning lab experiments that can yield the same kind of findings as backup so that researchers can publish, graduate, and progress in their careers.

But even senior scientists have had to adapt in order to salvage their research, or pivot to new projects. Much as Shaffer sent truckloads of water to his experimental lakes, other scientists say they’ve had to artificially enrich their study sites, making up for lost rainy seasons or otherwise unusual aridity.

Kraft and Van Dyke, for example, have had to water their field study sites—while there was enough rain for the plants they study to germinate, there wasn’t enough to keep them alive. The duo says that they have to start planning experiments months prior to planting seeds, and that weather or heat-related disruptions result in a “huge” financial cost. If droughts continue and worsen, they say, they may have to start using other plant species, move to a new field site, or both. “I do think, long-term, if we have to think about adding not just one rainstorm’s worth but two, three, four—we would have to think about working at a different place,” says Kraft.

Alexandra “Sasha” Wright, a plant ecologist at California State University, Los Angeles, says she also has water usage on her mind with regard to her own experiments, which involve creating fog in outdoor chambers in order to measure the effects of humidity levels on soil and local flora. “We’re experimental ecologists, so we’re very creative,” she says. “Working within the constraints is something I’ve spent my career doing. It would never be worth just throwing your hands in the air and saying ‘I guess we’ll turn it off for the year.’”

Photo of an outdoor plot of land. Grasses are shown growing inside cylindrical, open-top chambers that generate humidity, which are being provided with water by a large, white pipe. A parking lot and university building can be seen behind the plot’s fence.
An experimental setup at California State University, Los Angeles, that uses outdoor fog chambers to measure the effects of various humidity levels on California native perennial grasses

Her work is particularly valuable nowadays, she adds, as it measures how plants cope with extreme heat events. Therefore, she says, “we’re going to keep doing what we can do for as long as we can do it.”

Several scientists echoed the sentiment that creative thinking and adapting to changing conditions is part of the job when doing fieldwork. Barcelona’s Saura Mas, for instance, gathered what data she could on the three endangered plants she wanted to study during the weeks before and after peak wildfire risk, when she was allowed to access the relevant part of the nature park.

“The thing that worries me is that these species cannot adapt like me,” she says. “Maybe I go again and they will not be there.” With the risk of fields catching fire and rivers drying up, the species she studies “have to make their life cycle in a shorter piece of time. We’ll see how long they can wait.”

In spite of the hazards associated with extreme drought and heat, Conti says that their very existence, and the fact that they’ve led to such dire effects on scientific research, “made us more confident or more aware that we are working on something that could be useful.” He adds that one potential silver lining could be that funders become more aware of the imminent threat of climate change and the value of research designed to make sense of it.

“It should serve as a cautionary tale that we need this kind of research,” he says.