These technologies may help more animals and plants survive climate change
As the climate changes, the ripples will reach everywhere. Better data is needed for both plants and animals, and scientists are looking for genes that could allow crops to survive.
This article originally appeared in One Health/One Planet, a single-issue magazine that explores how climate change and other environmental shifts are making us more vulnerable to infectious diseases by land and by sea - and how scientists are working on solutions.
Along the west coast of South Florida and the Keys, Florida Bay is a nursery for young Caribbean spiny lobsters, a favorite local delicacy. Growing up in small shallow basins, they are especially vulnerable to warmer, more saline water. Climate change has brought tidal floods, bleached coral reefs and toxic algal blooms to the state, and since the 1990s, the population of the Caribbean spiny lobster has dropped some 20 percent, diminishing an important food for snapper, grouper, and herons, as well as people. In 1999, marine ecologist Donald Behringer discovered the first known virus among lobsters, Panulirus argus virus—about a quarter of juveniles die from it before they mature.
“When the water is warm PaV1 progresses much more quickly,” says Behringer, who is based at the Emerging Pathogens Institute at the University of Florida in Gainesville.
Caribbean spiny lobsters are only one example of many species that are struggling in the era of climate change, both at sea and on land. As the oceans heat up, absorbing greenhouse gases and growing more acidic, marine diseases are emerging at an accelerated rate. Marine creatures are migrating to new places, and carrying pathogens with them. The latest grim report in the journal Science, states that if global warming continues at the current rate, the extinction of marine species will rival the Permian–Triassic extinction, sometimes called the “Great Dying,” when volcanoes poisoned the air and wiped out as much as 90 percent of all marine life 252 million years ago.
Similarly, on land, climate change has exposed wildlife, trees and crops to new or more virulent pathogens. Warming environments allow fungi, bacteria, viruses and infectious worms to proliferate in new species and locations or become more virulent. One paper modeling records of nearly 1,400 wildlife species projects that parasites will double by 2070 in the far north and in high-altitude places. Right now, we are seeing the effects most clearly on the fringes—along the coasts, up north and high in the mountains—but as the climate continues changing, the ripples will reach everywhere.
Few species are spared
On the Hawaiian Islands, mosquitoes are killing more songbirds. The dusky gray akikiki of Kauai and the chartreuse-yellow kiwikiu of Maui could vanish in two years, under assault from mosquitoes bearing avian malaria, according to a University of Hawaiʻi 2022 report. Previously, the birds could escape infection by roosting high in the cold mountains, where the pests couldn’t thrive, but climate change expanded the range of the mosquito and narrowed theirs.
Likewise, as more midge larvae survive over warm winters and breed better during drier summers, they bite more white-tailed deer, spreading often-fatal epizootic hemorrhagic disease. Especially in northern regions of the globe, climate change brings the threat of midges carrying blue tongue disease, a virus, to sheep and other animals. Tick-borne diseases like encephalitis and Lyme disease may become a greater threat to animals and perhaps humans.
"If you put all your eggs in one basket and then a pest comes a long, then you are more vulnerable to those risks," says Mehroad Ehsani, managing director of the food initiative in Africa for the Rockefeller Foundation. "Research is needed on resilient, climate smart, regenerative agriculture."
In the “thermal mismatch” theory of wildlife disease, cold-adapted species are at greater risk when their habitats warm, and warm-adapted species suffer when their habitats cool. Mammals can adjust their body temperature to adapt to some extent. Amphibians, fish and insects that cannot regulate body temperatures may be at greater risk. Many scientists see amphibians, especially, as canaries in the coalmine, signaling toxicity.
Early melting ice can foster disease. Climate models predict that the spring thaw will come ever-earlier in the lakes of the French Pyrenees, for instance, which traditionally stayed frozen for up to half the year. The tadpoles of the midwife toad live under the ice, where they are often infected with amphibian chytrid fungus. When a seven-year study tracked the virus in three species of amphibians in Pyrenees’s Lac Arlet, the research team found that, the earlier the spring thaw arrived, the more infection rates rose in common toads— , while remaining high among the midwife toads. But the team made another sad discovery: with early thaws, the common frog, which was thought to be free of the disease in Europe, also became infected with the fungus and died in large numbers.
Changing habitats affect animal behavior. Normally, spiny lobsters rely on chemical cues to avoid predators and sick lobsters. New conditions may be hampering their ability to “social distance”—which may help PaV1 spread, Behringer’s research suggests. Migration brings other risks. In April 2022, an international team led by scientists at Georgetown University announced the first comprehensive overview, published in the journal Nature, of how wild mammals under pressure from a changing climate may mingle with new populations and species—giving viruses a deadly opportunity to jump between hosts. Droughts, for example, will push animals to congregate at the few places where water remains.
Plants face threats also. At the timberline of the cold, windy, snowy mountains of the U.S. west, whitebark pine forests are facing a double threat, from white pine blister rust, a fungal disease, and multiplying pine beetles. “If we do nothing, we will lose the species,” says Robert Keane, a research ecologist for the U.S. Forest Service, based in Missoula, Montana. That would be a huge shift, he explains: “It’s a keystone species. There are over 110 animals that depend on it, many insects, and hundreds of plants.” In the past, beetle larvae would take two years to complete their lifecycle, and many died in frost. “With climate change, we're seeing more and more beetles survive, and sometimes the beetle can complete its lifecycle in one year,” he says.
Quintessential crops are under threat too
As some pathogens move north and new ones develop, they pose novel threats to the crops humans depend upon. This is already happening to wheat, coffee, bananas and maize.
Breeding against wheat stem rust, a fungus long linked to famine, was a key success in the mid-20th century Green Revolution, which brought higher yields around the world. In 2013, wheat stem rust reemerged in Germany after decades of absence. It ravaged both bread and durum wheat in Sicily in 2016 and has spread as far as England and Ireland. Wheat blast disease, caused by a different fungus, appeared in Bangladesh in 2016, and spread to India, the world’s second largest producer of wheat.
Insects, moths, worms, and coffee leaf rust—a fungus now found in all coffee-growing countries—threaten the livelihoods of millions of people who grow coffee, as well as everybody’s cup of joe. More heat, more intense rain, and higher humidity have allowed coffee leaf rust to cycle more rapidly. It has grown exponentially, overcoming the agricultural chemicals that once kept it under control.
To identify new diseases and fine-tune crops for resistance, scientists are increasingly relying on genomic tools.
Tar spot, a fungus native to Latin America that can cut corn production in half, has emerged in highland areas of Central Mexico and parts of the U.S.. Meanwhile, maize lethal necrosis disease has spread to multiple countries in Africa, notes Mehrdad Ehsani, Managing Director for the Food Initiative in Africa of the Rockefeller Foundation. The Cavendish banana, which most people eat today, was bred to be resistant to the fungus Panama 1. Now a new fungus, Panama 4, has emerged on every continent–including areas of Latin America that rely on the Cavendish for their income, reported a recent story in the Guardian. New threats are poised to emerge. Potato growers in the Andes Mountains have been shielded from disease because of colder weather at high altitude, but temperature fluxes and warming weather are expected to make this crop vulnerable to potato blight, found plant pathologist Erica Goss, at the Emerging Pathogens Institute.
Science seeks solutions
To protect food supplies in the era of climate change, scientists are calling for integrated global surveillance systems for crop disease outbreaks. “You can imagine that a new crop variety that is drought-tolerant could be susceptible to a pathogen that previous varieties had some resistance against,” Goss says. “Or a country suffers from a calamitous weather event, has to import seed from another country, and that seed is contaminated with a new pathogen or more virulent strain of an existing pathogen.” Researchers at the John Innes Center in Norwich and Aarhus University in Denmark have established ways to monitor wheat rust, for example.
Better data is essential, for both plants and animals. Historically, models of climate change predicted effects on plant pathogens based on mean temperatures, and scientists tracked plant responses to constant temperatures, explains Goss. “There is a need for more realistic tests of the effects of changing temperatures, particularly changes in daily high and low temperatures on pathogens,” she says.
To identify new diseases and fine-tune crops for resistance, scientists are increasingly relying on genomic tools. Goss suggests factoring the impact of climate change into those tools. Genomic efforts to select soft red winter wheat that is resistant to Fusarium head blight (FHB), a fungus that plagues farmers in the Southeastern U.S., have had early success. But temperature changes introduce a new factor.
A fundamental solution would be to bring back diversification in farming, says Ehsani. Thousands of plant species are edible, yet we rely on a handful. Wild relatives of domesticated crops are a store of possibly useful genes that may confer resistance to disease. The same is true for livestock. “If you put all your eggs in one basket and then a pest comes along, then you are more vulnerable to those risks. Research is needed on resilient, climate smart, regenerative agriculture,” Ehsani says.
Jonathan Sleeman, director of the U.S. Geological Survey National Wildlife Health Center, has called for data on wildlife health to be systematically collected and integrated with climate and other variables because more comprehensive data will result in better preventive action. “We have focused on detecting diseases,” he says, but a more holistic strategy would apply human public health concepts to assuring animal wellbeing. (For example, one study asked experts to draw a diagram of relationships of all the factors affecting the health of a particular group of caribou.) We must not take the health of plants and animals for granted, because their vulnerability inevitably affects us too, Sleeman says. “We need to improve the resilience of wildlife populations so they can withstand the impact of climate change.”
The Friday Five: A new blood test to detect Alzheimer's
A new blood test has been developed to detect Alzheimer's. Other promising studies covered in this week's Friday Five include: vets with PTSD can take their psychologist anywhere with a new device, intermittent fasting could improve circadian rhythms, a new year's resolution for living longer, and a discovery in 3-D printing eye tissue.
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
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Here are the promising studies covered in this week's Friday Five:
- A blood test to detect Alzheimer's
- War vets can take their psychologist wherever they go
- Does intermittent fasting affect circadian rhythms?
- A new year's resolution for living longer
- 3-D printed eyes?
Staying well in the 21st century is like playing a game of chess
The control of infectious diseases was considered to be one of the “10 Great Public Health Achievements.” What we didn’t take into account was the very concept of evolution: as we built better protections, our enemies eventually boosted their attacking prowess, so soon enough we found ourselves on the defensive once again.
This article originally appeared in One Health/One Planet, a single-issue magazine that explores how climate change and other environmental shifts are increasing vulnerabilities to infectious diseases by land and by sea. The magazine probes how scientists are making progress with leaders in other fields toward solutions that embrace diverse perspectives and the interconnectedness of all lifeforms and the planet.
On July 30, 1999, the Centers for Disease Control and Prevention published a report comparing data on the control of infectious disease from the beginning of the 20th century to the end. The data showed that deaths from infectious diseases declined markedly. In the early 1900s, pneumonia, tuberculosis and diarrheal diseases were the three leading killers, accounting for one-third of total deaths in the U.S.—with 40 percent being children under five.
Mass vaccinations, the discovery of antibiotics and overall sanitation and hygiene measures eventually eradicated smallpox, beat down polio, cured cholera, nearly rid the world of tuberculosis and extended the U.S. life expectancy by 25 years. By 1997, there was a shift in population health in the U.S. such that cancer, diabetes and heart disease were now the leading causes of death.
The control of infectious diseases is considered to be one of the “10 Great Public Health Achievements.” Yet on the brink of the 21st century, new trouble was already brewing. Hospitals were seeing periodic cases of antibiotic-resistant infections. Novel viruses, or those that previously didn’t afflict humans, began to emerge, causing outbreaks of West Nile, SARS, MERS or swine flu.In the years that followed, tuberculosis made a comeback, at least in certain parts of the world. What we didn’t take into account was the very concept of evolution: as we built better protections, our enemies eventually boosted their attacking prowess, so soon enough we found ourselves on the defensive once again.
At the same time, new, previously unknown or extremely rare disorders began to rise, such as autoimmune or genetic conditions. Two decades later, scientists began thinking about health differently—not as a static achievement guaranteed to last, but as something dynamic and constantly changing—and sometimes, for the worse.
What emerged since then is a different paradigm that makes our interactions with the microbial world more like a biological chess match, says Victoria McGovern, a biochemist and program officer for the Burroughs Wellcome Fund’s Infectious Disease and Population Sciences Program. In this chess game, humans may make a clever strategic move, which could involve creating a new vaccine or a potent antibiotic, but that advantage is fleeting. At some point, the organisms we are up against could respond with a move of their own—such as developing resistance to medication or genetic mutations that attack our bodies. Simply eradicating the “opponent,” or the pathogenic microbes, as efficiently as possible isn’t enough to keep humans healthy long-term.
Instead, scientists should focus on studying the complexity of interactions between humans and their pathogens. “We need to better understand the lifestyles of things that afflict us,” McGovern says. “The solutions are going to be in understanding various parts of their biology so we can influence how they behave around our systems.”
Genetics and cell biology, combined with imaging techniques that allow one to see tissues and individual cells in actions, will enable scientists to define and quantify what it means to be healthy at the molecular level.
What is being proposed will require a pivot to basic biology and other disciplines that have suffered from lack of research funding in recent years. Yet, according to McGovern, the research teams of funded proposals are answering bigger questions. “We look for people exploring questions about hosts and pathogens, and what happens when they touch, but we’re also looking for people with big ideas,” she says. For example, if one specific infection causes a chain of pathological events in the body, can other infections cause them too? And if we find a way to break that chain for one pathogen, can we play the same trick on another? “We really want to see people thinking of not just one experiment but about big implications of their work,” McGovern says.
Jonah Cool, a cell biologist, geneticist and science officer at the Chan Zuckerberg Initiative, says that it’s necessary to define what constitutes a healthy organism and how it overcomes infections or environmental assaults, such as pollution from forest fires or toxins from industrial smokestacks. An organism that catches a disease isn’t necessarily an unhealthy one, as long as it fights it off successfully—an ability that arises from the complex interplay of its genes, the immune system, age, stress levels and other factors. Modern science allows many of these factors to be measured, recorded and compared. “We need a data-driven, deep-phenotyping approach to defining healthy biological systems and their responses to insults—which can be infectious disease or environmental exposures—and their ability to navigate their way through that space,” Cool says.
Genetics and cell biology, combined with imaging techniques that allow one to see tissues and individual cells in actions, will enable scientists to define and quantify what it means to be healthy at the molecular level. “As a geneticist and cell biologist, I believe in all these molecular underpinnings and how they arise in phenotypic differences in cells, genes, proteins—and how their combinations form complex cellular states,” Cool says.
Julie Graves, a physician, public health consultant, former adjunct professor of management, policy and community health at the University of Texas Health Science Center in Houston, stresses the necessity of nutritious diets. According to the Rockefeller Food Initiative, “poor diet is the leading risk factor for disease, disability and premature death in the majority of countries around the world.” Adequate nutrition is critical for maintaining human health and life. Yet, Western diets are often low in essential nutrients, high in calories and heavy on processed foods. Overconsumption of these foods has contributed to high rates of obesity and chronic disease in the U.S. In fact, more than half of American adults have at least one chronic disease, and 27 percent have more than one—which increases vulnerability to COVID-19 infections, according to the 2018 National Health Interview Survey.
Further, the contamination of our food supply with various agricultural and industrial toxins—petrochemicals, pesticides, PFAS and others—has implications for morbidity, mortality, and overall quality of life. “These chemicals are insidiously in everything, including our bodies,” Graves says—and they are interfering with our normal biological functions. “We need to stop how we manufacture food,” she adds, and rid our sustenance of these contaminants.
According to the Humane Society of the United States, factory farms result in nearly 40 percent of emissions of methane. Concentrated animal feeding operations or CAFOs may serve as breeding grounds for pandemics, scientists warn, so humans should research better ways to raise and treat livestock. Diego Rose, a professor of food and nutrition policy at Tulane University School of Public Health & Tropical Medicine, and his colleagues found that “20 percent of Americans’ diets account for about 45 percent of the environmental impacts [that come from food].” A subsequent study explored the impacts of specific foods and found that substituting beef for chicken lowers an individual’s carbon footprint by nearly 50 percent, with water usage decreased by 30 percent. Notably, however, eating too much red meat has been associated with a variety of illnesses.
In some communities, the option to swap food types is limited or impossible. For example, “many populations live in relative food deserts where there’s not a local grocery store that has any fresh produce,” says Louis Muglia, the president and CEO of Burroughs Wellcome. Individuals in these communities suffer from an insufficient intake of beneficial macronutrients, and they’re “probably being exposed to phenols and other toxins that are in the packaging.” An equitable, sustainable and nutritious food supply will be vital to humanity’s wellbeing in the era of climate change, unpredictable weather and spillover events.
A recent report by See Change Institute and the Climate Mental Health Network showed that people who are experiencing socioeconomic inequalities, including many people of color, contribute the least to climate change, yet they are impacted the most. For example, people in low-income communities are disproportionately exposed to vehicle emissions, Muglia says. Through its Climate Change and Human Health Seed Grants program, Burroughs Wellcome funds research that aims to understand how various factors related to climate change and environmental chemicals contribute to premature births, associated with health vulnerabilities over the course of a person’s life—and map such hot spots.
“It’s very complex, the combinations of socio-economic environment, race, ethnicity and environmental exposure, whether that’s heat or toxic chemicals,” Muglia explains. “Disentangling those things really requires a very sophisticated, multidisciplinary team. That’s what we’ve put together to describe where these hotspots are and see how they correlate with different toxin exposure levels.”
In addition to mapping the risks, researchers are developing novel therapeutics that will be crucial to our armor arsenal, but we will have to be smarter at designing and using them. We will need more potent, better-working monoclonal antibodies. Instead of directly attacking a pathogen, we may have to learn to stimulate the immune system—training it to fight the disease-causing microbes on its own. And rather than indiscriminately killing all bacteria with broad-scope drugs, we would need more targeted medications. “Instead of wiping out the entire gut flora, we will need to come up with ways that kill harmful bacteria but not healthy ones,” Graves says. Training our immune systems to recognize and react to pathogens by way of vaccination will keep us ahead of our biological opponents, too. “Continued development of vaccines against infectious diseases is critical,” says Graves.
With all of the unpredictable events that lie ahead, it is difficult to foresee what achievements in public health will be reported at the end of the 21st century. Yet, technological advances, better modeling and pursuing bigger questions in science, along with education and working closely with communities will help overcome the challenges. The Chan Zuckerberg Initiative displays an optimistic message on its website: “Is it possible to cure, prevent, or manage all diseases by the end of this century? We think so.” Cool shares the view of his employer—and believes that science can get us there. Just give it some time and a chance. “It’s a big, bold statement,” he says, “but the end of the century is a long way away.”Lina Zeldovich has written about science, medicine and technology for Popular Science, Smithsonian, National Geographic, Scientific American, Reader’s Digest, the New York Times and other major national and international publications. A Columbia J-School alumna, she has won several awards for her stories, including the ASJA Crisis Coverage Award for Covid reporting, and has been a contributing editor at Nautilus Magazine. In 2021, Zeldovich released her first book, The Other Dark Matter, published by the University of Chicago Press, about the science and business of turning waste into wealth and health. You can find her on http://linazeldovich.com/ and @linazeldovich.