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      Potty-trained cattle could help reduce pollution

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      You can lead a cow to a water closet, but can you make it pee there? It turns out that yes, you can.

      Researchers in Germany successfully trained cows to use a small, fenced-in area with artificial turf flooring as a bathroom stall. This could allow farms to easily capture and treat cow urine, which often pollutes air, soil and water, researchers report online September 13 in Current Biology. Components of that urine, such as nitrogen and phosphorus, could also be used to make fertilizer (SN: 4/6/21).

      The average cow can pee tens of liters per day, and there are some 1 billion cattle worldwide. In barns, cow pee typically mixes with poop on the floor to create a slurry that emits the air pollutant ammonia (SN: 1/4/19). Out in pastures, cow pee can leach into nearby waterways and release the potent greenhouse gas nitrous oxide (SN: 6/9/14).

      “I’m always of the mind, how can we get animals to help us in their management?” says Lindsay Matthews, a self-described cow psychologist who studies animal behavior at the University of Auckland in New Zealand. Matthews and colleagues set out to potty train 16 calves, which had the free time to learn a new skill. “They’re not so involved with milking and other systems,” he says. “They’re basically just hanging out, eating a bit of food, socializing and resting.”

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      Matthews was optimistic about the cows’ potty-training prospects. “I was convinced that we could do it,” he says. Cows “are much, much smarter than people give them credit for.” Each calf got 45 minutes of what the team calls “MooLoo training” per day. At first, the researchers enclosed the calves inside the makeshift bathroom stall and fed the animals a treat every time they peed.

      Once the calves made the connection between using the bathroom stall and receiving a treat, the team positioned the calves in a hallway leading to the stall. Whenever animals visited the little cows’ room, they got a treat; whenever calves peed in the hallway, the team spritzed them with water. “We had 11 of the 16 calves [potty trained] within about 10 days,” Matthews says. The remaining cows “are probably trainable too,” he adds. “It’s just that we didn’t have enough time.”

      [embedded content]
      Researchers successfully trained 11 calves, such as this one, to urinate in a bathroom stall. Once the cow relieved itself, a window in the stall opened, dispensing a molasses mixture as a treat. Toilet training cows on a large scale and collecting their urine to make fertilizer could cut down on agricultural pollution, the team says.

      Lindsay Whistance, a livestock researcher at the Organic Research Centre in Cirencester, England, is “not surprised by the results.” With proper training and motivation, “I fully expected cattle to be able to learn this task,” says Whistance, who was not involved in the study. The practicality of potty training cows on a large scale, she says, is another matter.

      For MooLoo training to become a widespread practice, “it has to be automated,” Matthews says. “We want to develop automated training systems, automated reward systems.” Those systems are still far from reality, but Matthews and colleagues hope they could have big impacts. If 80 percent of cow pee were collected in latrines, for instance, that could cut associated ammonia emissions in half, previous research suggests.

      “It’s those ammonia emissions that are key to the real environmental benefit, as well as potential for reducing water contamination,” says Jason Hill, a biosystems engineer at the University of Minnesota in St. Paul not involved in the work. “Ammonia from cattle is a major contributor to reduced human health,” he says (SN: 1/16/09). So potty training cattle could help create cleaner air — as well as a cleaner, more comfortable living space for cows themselves. More

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      How AI can help forecast how much Arctic sea ice will shrink

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      In the next week or so, the sea ice floating atop the Arctic Ocean will shrink to its smallest size this year, as summer-warmed waters eat away at the ice’s submerged edges.

      Record lows for sea ice levels will probably not be broken this year, scientists say. In 2020, the ice covered 3.74 million square kilometers of the Arctic at its lowest point, coming nail-bitingly close to an all-time record low. Currently, sea ice is present in just under 5 million square kilometers of Arctic waters, putting it on track to become the 10th-lowest extent of sea ice in the area since satellite record keeping began in 1979. It’s an unexpected finish considering that in early summer, sea ice hit a record low for that time of year.

      The surprise comes in part because the best current statistical- and physics-based forecasting tools can closely predict sea ice extent only a few weeks in advance, but the accuracy of long-range forecasts falters. Now, a new tool that uses artificial intelligence to create sea ice forecasts promises to boost their accuracy — and can do the analysis relatively quickly, researchers report August 26 in Nature Communications.

      IceNet, a sea ice forecasting system developed by the British Antarctic Survey, or BAS, is “95 percent accurate in forecasting sea ice two months ahead — higher than the leading physics-based model SEAS5 — while running 2,000 times faster,” says Tom Andersson, a data scientist with BAS’s Artificial Intelligence lab. Whereas SEAS5 takes about six hours on a supercomputer to produce a forecast, IceNet can do the same in less than 10 seconds on a laptop. The system also shows a surprising ability to predict anomalous ice events — unusual highs or lows — up to four months in advance, Andersson and his colleagues found.

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      Tracking sea ice is crucial to keeping tabs on the impacts of climate change. While that’s more of a long game, the advanced notice provided by IceNet could have more immediate benefits, too. For instance, it could give scientists the lead time needed to assess, and plan for, the risks of Arctic fires or wildlife-human conflicts, and it could provide data that Indigenous communities need to make economic and environmental decisions.

      Arctic sea ice extent has steadily declined in all seasons since satellite records began in 1979 (SN: 9/25/19). Scientists have been trying to improve sea ice forecasts for decades, but success has proved elusive. “Forecasting sea ice is really hard because sea ice interacts in complex ways with the atmosphere above and ocean below,” Andersson says.

      [embedded content]
      In 2020, the sea ice in the Arctic shrank to its second lowest extent since satellite monitoring began in 1979. This animation uses those observations to show the change in sea ice coverage from March 5, when the ice was at its maximum, through September 15, when the ice reached its lowest point. The yellow line represents the average minimum extent from 1981 to 2010. Current forecasting tools can accurately predict these changes weeks in advance. A new AI-based tool can predict these changes with nearly 95 percent accuracy several months in advance.

      Existing forecast tools put the laws of physics into computer code to predict how sea ice will change in the future. But partly due to uncertainties in the physical systems governing sea ice, these models struggle to produce accurate long-range forecasts.

      Using a process called deep learning, Andersson and his colleagues loaded observational sea ice data from 1979 to 2011 and climate simulations covering 1850 to 2100 to train IceNet how to predict the state of future sea ice by processing the data from the past.

      To determine the accuracy of its forecasts, the team compared IceNet’s outputs to the observed sea ice extent from 2012 to 2020, and to the forecasts made by SEAS5, the widely cited tool used by the European Centre for Medium-Range Weather Forecasts. IceNet was as much as 2.9 percent more accurate than SEAS5, corresponding to a further 360,000 square kilometers of ocean being correctly labeled as “ice” or “no ice.”

      What’s more, in 2012, a sudden crash in summer sea ice extent heralded a new record low extent in September of that year. In running through past data, IceNet saw the dip coming months in advance. SEAS5 had inklings too but its projections that far out were off by a few hundred thousand square kilometers.

      “This is a significant step forward in sea ice forecasting, boosting our ability to produce accurate forecasts that were typically not thought possible and run them thousands of times faster,” says Andersson. He believes it’s possible that IceNet has better learned the physical processes that determine the evolution of sea ice from the training data while physics-based models still struggle to understand this information.

      “These machine learning techniques have only begun contributing to [forecasting] in the last couple years, and they’ve been doing amazingly well,” says Uma Bhatt, an atmospheric scientist at the University of Alaska Fairbanks Geophysical Institute who was not involved in the new study. She also leads the Sea Ice Prediction Network, a group of multidisciplinary scientists working to improve forecasting.

      Bhatt says that good seasonal ice forecasts are important for assessing the risk of Arctic wildfires, which are tied strongly to the presence of sea ice (SN: 6/23/20). “Knowing where the sea ice is going to be in the spring could potentially help you figure out where you’re likely to have fires — in Siberia, for example, as soon as the sea ice moves away from the shore, the land can warm up very quickly and help set the stage for a bad fire season.”

      Any improvement in sea ice forecasting can also help economic, safety and environmental planning in northern and Indigenous communities. For example, tens of thousands of walruses haul out on land to rest when the sea ice disappears (SN: 10/2/14). Human disturbances can trigger deadly stampedes and lead to high walrus mortality. With seasonal ice forecasts, biologists can anticipate rapid ice loss and manage haul-out sites in advance by limiting human access to those locations.

      Still, limitations remain. At four months of lead time, the system was about 91 percent accurate in predicting the location of September’s ice edge.IceNet, like other forecasting systems, struggles to produce accurate long-range forecasts for late summer due, in part, to what scientists call the “spring predictability barrier.” It’s crucial to know the condition of the sea ice at the start of the spring melting season to be able to forecast end-of-summer conditions.

      Another limit is “the fact that the weather is so variable,” says Mark Serreze, director of the National Snow and Ice Data Center in Boulder, Colo. Though sea ice seemed primed to set a new annual record low at the start of July, the speed of ice loss ultimately slowed due to cool atmospheric temperatures. “We know that sea ice responds very strongly to summer weather patterns, but we can’t get good weather predictions. Weather predictability is about 10 days in advance.” More

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      50 years ago, chemical pollutants were linked to odd animal behavior

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      Sea life’s chemical senses Science News, September 18, 1971

      For fish and other underwater life, a sensitivity to chemicals plays the same role as the sense of smell does for land animals.… [Researchers] have been studying the subtle ways this delicate fish-communication system can be disrupted by pollutants…. One study examined the effects of kerosene pollution on the behavior of lobsters…. The experiments demonstrate that chemical communication interference takes place at extremely low dilutions.

      Update

      Chemical pollution — from sewage and agricultural runoff to pharmaceutical waste — muddles aquatic animals’ senses with potentially dire effects, decades of research has shown. A chemical used to treat sewage seems to limit some fish species’ abilities to form schools, making the fish vulnerable to predators (SN: 10/27/07, p. 262). Drug-tainted waters can have a variety of effects on fish, including suppressing their appetites (SN: 12/20/08, p. 15). A plastic chemical also appears to confuse senses: Its scent can lure sea turtles into eating plastic debris (SN: 3/28/20, p. 14). More

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      Clouds affected by wildfire smoke may produce less rain

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      When smoke rises from wildfires in the western United States, it pummels clouds with tiny airborne particles. What happens next with these clouds has been largely unstudied. But during the 2018 wildfire season, researchers embarked on a series of seven research flights, including over the Pacific Northwest, to help fill this gap.

      Using airborne instruments to analyze small cumulus clouds affected by the smoke, the scientists found that these clouds contained, on average, five times as many water droplets as unaffected clouds. That in itself was not a huge surprise; it’s known that organic and inorganic particles in smoke can serve as tiny nuclei for forming droplets (SN: 12/15/20). But the sheer abundance of droplets in the affected clouds astounded the team. 

      Counterintuitively, those numerous droplets didn’t make the clouds more likely to produce rain. In fact, the opposite occurred. Because the droplets were about half as big as those found in a typical cloud, they were unlikely to collide and merge with enough other droplets to result in rain. The chances of rain were “virtually zero,” the researchers write in the August Geophysical Research Letters.

      The new research suggests that wildfires could lead to clouds producing less rain in the U.S. West, feeding into drought conditions and potentially increasing future wildfire risk.

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      But the environmental dynamics involved are complex, says Cynthia Twohy. She’s a San Diego–based atmospheric scientist at NorthWest Research Associates, a research organization specializing in geophysical and space sciences headquartered in Redmond, Wash. For instance, Twohy and her colleagues found that “the ratio of light-absorbing to light-scattering particles in the smoke was somewhat lower than measured in many prior studies,” she says.  

      “The take-home message is that while other studies have shown wildfire smoke has an absorbing (warming) influence that can be important for cloud formation and development, these impacts may be less in the western U.S., because the smoke is not as dark,” Twohy says. The impact of the lighter smoke is still an open question. “It’s just another way that smoke-cloud interactions are a wild card in the region.”  

      The team used onboard probes to sample clouds affected by wildfire smoke and compare them to their more pristine counterparts. The probes measured how many cloud droplets were present in the samples, the size range of those droplets and the liquid water content of the clouds.

      A special tube mounted on the exterior of the plane to collect and evaporate cloud droplets was used to “reveal the particles that the droplets were condensed on,” says Robert Yokelson, an atmospheric chemist at the University of Montana in Missoula who was not involved with the research. This process enabled the researchers to confirm what the original smoke particles were made of, a technique that Yokelson calls “neat.”

      The analysis detected the amounts of carbon, oxygen, nitrogen, sulfur and potassium found in residual particles evaporated from cloud droplets. These elements were present in similar amounts to those found in smoke particles sampled from below the clouds, “implying that the cloud droplets also formed on smoke particles,” Twohy says.

      Previous studies conducted in the Amazon have shown that “smoke will make the cloud droplets smaller and more numerous,” thereby reducing rainfall, Yokelson says. But this study provides robust evidence that the phenomenon isn’t isolated to the Amazon. It echoes the results of a much smaller 1974 study of smoke-filled clouds over the western United States, providing a crucial present-day snapshot of the challenges facing the region.

      Wildfires in the western United States have been breaking records in recent years — increasing in number and size due to climate change — a trend that scientists think will get worse as the globe continues to warm (SN: 12/21/20). As a result, Twohy says, it’s increasingly important that researchers continue to monitor these fires’ influence on the atmosphere. More

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      Climate change made Europe’s flash floods in July more likely

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      Climate change has increased the likelihood of heavy downpours in Western Europe such as the July rains that led to devastating flash floods, researchers affiliated with the World Weather Attribution network report August 23. Such extreme rains are 1.2 to 9 times more likely to happen — and those downpours are 3 to 19 percent heavier — as a result of human-caused climate change, the team found.

      The World Weather Attribution conducts quick analyses of extreme events to assess the contribution of climate change (SN: 7/7/21). The new study focused on two regions where record-setting rains fell July 12–15 and triggered floods that killed more than 200 people.

      In a single day, an average 93 millimeters of rain fell near Germany’s Ahr and Erft rivers; in just two days, 106 millimeters of rain fell in Belgium’s Meuse River region. With many river measurement stations destroyed, the researchers focused on assessing the contribution of climate change to the intense rainfall using climate simulations comparing conditions with and without human-caused climate change.

      That intense rainfall might occur once every 400 years under current climate conditions, but those odds are likely to increase as the world continues to warm, said coauthor Maarten van Aalst on August 23 at a news conference on the report. It’s “still a rare event, but a rare event we should prepare for,” said van Aalst, a climate and disaster risk researcher at the University of Twente in the Netherlands and the director of the Red Cross Red Crescent Climate Centre.

      That finding is consistent with data cited in the Intergovernmental Panel on Climate Change’s sixth assessment report, which notes that as global temperatures continue to rise, western and central Europe will see more intense rainfall events (SN: 8/9/21). More

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      Windbreaks, surprisingly, could help wind farms boost power output

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      Windbreaks may sound like a counterintuitive idea for boosting the performance of a wind turbine. But physicists report that low walls that block wind could actually help wind farms produce more power.

      Scientists already knew that the output of a single wind turbine could be improved with a windbreak. While windbreaks slow wind speed close to the ground, above the height of the windbreak, wind speeds actually increase as air rushes over the top. But for large wind farms, there’s a drawback. A windbreak’s wake slows the flow of air as it travels farther through the rows of turbines. That could suggest that windbreaks would be a wash for wind farms with many turbines.

      But by striking a balance between these competing effects, windbreaks placed in front of each turbine can increase power output, new computer simulations suggest. It comes down to the windbreaks’ dimensions. Squat, wide barriers are the way to go, according to a simulated wind farm with six rows of turbines. To optimize performance, windbreaks should be a tenth the height of the turbine and at least five times the width of the blades, physicists report July 30 in Physical Review Fluids. Such an arrangement could increase the total power by about 10 percent, the researchers found. That’s the equivalent of adding an additional turbine, on average, for every 10 in a wind farm.

      In the simulations, the wind always came from the same direction, suggesting the technique might be useful in locations where wind tends to blow one way, such as coastal regions. Future studies could investigate how this technique might apply in places where wind direction varies.

      In a computer simulation of a wind farm with 24 turbines, scientists found that windbreaks (red) improved the overall power output. Wakes created by the windbreaks appear in dark blue, and wakes of the turbines are light blue.L. Liu and R.J.A.M. Stevens/Physical Review Fluids 2021, Visualizations by Srinidhi N. Gadde More

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      The new UN climate change report shows there’s no time for denial or delay

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      The science is unequivocal: Humans are dramatically overhauling Earth’s climate. The effects of climate change are now found everywhere around the globe and are intensifying rapidly, states a sweeping new analysis released August 9 by the United Nations’ Intergovernmental Panel on Climate Change, or IPCC. And the window to reverse some of these effects is closing.

      “There is no room for doubt any longer” about humans’ responsibility for current climate change, says Kim Cobb, a climate scientist at Georgia Tech in Atlanta and an author on the first chapter of the report. “And now we can say quite definitely that a whole class of extreme [events]” is linked to human-caused climate change.

      Climate change is already affecting every region on Earth in multiple ways, from drought and fire conditions in the U.S. West to heat waves in Europe and flooding in Asia, the report notes  (SN: 7/7/21). Each of the past four decades has been the warmest on record since preindustrial times (SN: 5/26/21).

      The study also looks at several different scenarios of greenhouse gas warming, including perhaps the most hopeful scenarios in which by 2050 the world achieves “net zero” carbon emissions, where emitted gases are balanced by carbon removal from the atmosphere.

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      If the world gets down to net-zero emissions, the decades afterward hold “hints of light,” says Baylor Fox-Kemper, an oceanographer at Brown University in Providence, R.I., and the coordinating lead author of the new report’s chapter on oceans and Earth’s icy regions. “Temperatures come back down a little — not all the way back to preindustrial times, but there’s a little recovery.”

      But other changes are irreversible on near-future timescales — that is, the next century or more, Fox-Kemper says. Even in those mid-century net-zero emissions scenarios, “it’s still pretty bad,” he says. Sea levels, for example, will continue to rise until about the year 2300, driven in part by the juggernaut of Greenland’s melting ice sheet (SN: 9/30/20). “We may have already crossed [the] threshold beyond which Greenland’s melting could be stopped,” he says. Still, swift and deep emissions reductions would significantly slow how much sea levels will rise by the end of the century, the report finds.

      The new analysis is the sixth in a series of massive assessment reports undertaken by the IPCC since 1990. In each report, hundreds of scientists from around the world analyze the findings of thousands of studies to form a consensus picture of how Earth’s climate is changing and what role people play in those changes.

      “The key message [of this report] is still the same as was first published in 1990 … human-induced emissions of greenhouse gases pose a threat for humans’ well-being and the biosphere,” said Petteri Taalas, Secretary-General of the World Meteorological Organization, at an event announcing the report’s release August 9.

      But researchers understand climate change far better now than they did in 1990, when the first assessment report was released. In the last three decades, new findings have poured in from tens of thousands more observing stations, from a wealth of satellite instruments, and from dramatically improved climate simulations (SN: 1/7/20).

      The IPCC’s fifth assessment report, released in several parts during 2013 and 2014, was itself a game changer. It was the first to state that greenhouse gas emissions from human activities are driving climate change — a conclusion that set the stage for 195 nations to agree in Paris in 2015 to curb those emissions (SN: 4/13/14; SN: 12/12/15).

      The Paris Agreement set a target of limiting the global average temperature to 2 degrees Celsius above preindustrial times. But many island nations and others most threatened by climate change feared that this target wasn’t stringent enough. So in an unprecedented step, the U.N. commissioned a report by the IPCC to compare how a future Earth might look if warming were limited to just 1.5 degrees Celsius instead.

      The Dixie Fire, the largest individual wildfire in California’s history, started on July 13, 2021 and left the town of Greenville, including its library (shown) in ruins. The IPCC’s sixth assessment report finds that humans are unequivocally responsible for the planet’s rising temperatures since the late 1800s, and links these changes to extreme weather including wildfires, drought, heat waves, extreme precipitation and properties of tropical cyclones. Trevor Bexon/Getty Images

      That special report, released in 2018, revealed in fine detail how just half a degree of extra warming by 2100 could matter, from the increased likelihood of heat waves to higher sea levels (SN: 12/17/18). The one-two punch of those concrete findings and scorching temperatures in 2019 grabbed the attention of public and policy makers alike.

      Scientists were surprised by how hard the 1.5 degree report landed. “Even for me,” says Ko Barrett, vice chair of the IPCC and a senior advisor for climate at the U.S. National Oceanic and Atmospheric Administration, “a person who has dedicated my entire professional career to addressing climate change, the report caused me to rethink my personal contribution to the climate problem. Climate change was not some distant temperature target to be hit in the ethereal future. It was close; it was now.”

      IPCC scientists hope the new report, with its powerful emphasis on the regional and local effects of climate change — fully a third of the report is devoted to outlining those — will have a similar impact. And its timing is significant. Beginning October 31, heads of state from around the world are scheduled to meet in Glasgow, Scotland, to discuss updated — and hopefully increasingly ambitious — plans to reduce emissions to meet the targets of the 2015 Paris Agreement. 

      With previous reports, “the world listened, but it didn’t hear. Or the world listened, but it didn’t act strongly enough,” said Inger Andersen, executive director of the U.N. Environment Programme, at the Aug. 9 event for the report’s release. “We certainly urge them … to listen to the facts on the table now.” More