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How climate change will intensify infectious disease

By Shaina Eagle, Global Disease Biology ‘24 & Tammie Tam, Molecular and Medical Microbiology ‘22

Authors’ Note: We decided to partner on this paper after discovering a mutual passion for studying infectious diseases. As editors of a scientific journal and science students, we learn about the effects of climate change on our world regularly. It seemed like a natural progression to explore the effects of climate change on infectious disease.

 

Introduction

A changing climate impacts all living organismsincluding the ones you can’t see. While climate change has made a name for itself through its more visible effects, it is equally affecting a hidden dynamic forceinfectious diseases. Climate change is altering the movement of existing pathogens, fostering the emergence of new pathogens, and in turn, changing host-pathogen interactions. As the level of greenhouse gasses, like CO2, increases, shifts in temperature and precipitation patterns are producing more frequent and intense climate disasters from the raging wildfires burning the West to the floods drowning Southeast Asia [1, 2]. Besides damages from climate disasters, humans are actively destroying habitats and expanding the ecosystem boundaries where humans and the wild interact [4]. As a result, climate change is speeding up biodiversity loss, as zoonotic pathogens are spilling over from one host species to another which is threatening more species, including humans [5]. At the same time, pathogens adapted to warmer, more humid climates are creeping into historically cooler, dryer zones [3]. As sea levels rise, Arctic ice and permafrost thaw and release ancient microbial foes [6]. Consequently, infectious diseases are expected to be on the rise.

By the disease triangle model, an infectious disease event occurs when the right host, pathogen, and environment interact with each other [7]. Climate change is expected to affect all three of these factors. If even one part of the disease triangle is thrown off, the disease cannot take root. However, if complementary components are introduced and complete the disease triangle, the disease can take off and spread. The latter is what researchers are concerned about with how climate change may affect the prevalence and emergence of infectious diseases. For instance, if a new pathogen moves into a region where there is a compatible host and optimal environment, it can devastate an ecosystem unprepared for it. Similarly, if a host is weakened because it becomes unsuitable to the changing environment, an existing pathogen can wreck the current population of the host species and the health of the ecosystem.

While the basis of how infectious diseases arise can be simplified by the disease triangle model, infectious diseases come in a range of different combinations of causative pathogens, host species, transmission methods, and severity of symptoms. For instance, pathogens can be bacterial, viral, parasitic, or fungal and can infect plants, animals, and/or humans. How well they affect their host species, however, depends on the strength of their host’s defense. Once the pathogen is established in a host population, pathogens can be transmitted through many means within and between species, such as: direct contact, aerosolized particles, or through an insect vector acting as the intermediary agent transmitting the pathogen between individuals. Due to all these different factors, climate change will not affect all host-pathogen interactions in the same way, presenting different challenges for scientists to tackle. As a result, researchers are working to predict and understand how different aspects of climate change are affecting different host-pathogen interactions that will impact human society. These aspects include plant pathogens on agriculture, wildlife pathogens in zoonotic events leading to the transmission of disease between animals and humans, and environmental changes on existing human pathogens.

Climate Change Effects on Plant-Pathogen Interactions in Agriculture

Climate change is negatively affecting both ends of plant-pathogen interactions, allowing plant pathogens to pose a significant threat to global food security. While predictive models anticipate an increase in crop yield over the next few decades, they often do not consider the detrimental effects of emerging plant pathogens that may hinder such progress [8]. Plant immunity is expected to be less efficient at higher temperatures, which poses an issue as plants will potentially have to face new pathogens as the planet warms [9]. As temperatures increase with latitude, pathogens adapted for higher temperatures are expected to move poleward, especially those that travel through airborne dispersal or on insect vectors [10].

Climate Change can compromise Plant Immunity

Although plants mainly have nonspecific defense mechanisms capable of fending off a variety of pathogens, climate-change-induced abiotic stressors, such as temperature, may negatively impact a plant’s ability to fight against both existing and novel pathogens. In plants, there are two main lines of immune defense. When plant cell surface receptors detect common features shared by all pathogens known as pathogen-associated molecular patterns (PAMP), PAMP-triggered immunity (PTI) is induced, which initiates a signaling cascade that produces reactive oxygen species to damage the infected cells and upregulates resistance genes to inhibit microbial growth [9, 11]. When receptors within the plant cell detect virulent proteins called effectors, effector-triggered immunity (ETI) is induced, causing resistance genes to be upregulated, and a form of apoptosis called hypersensitive response occurs [9, 11].

The rising temperature and shifting precipitation patterns characteristic of climate change can compromise plant immunity. There have been a few studies on how temperature affects PTI, where elevated temperatures may impair some aspects of PTI but enhance it in other ways [12]. While researchers are still looking into PTI, ETI is better studied and can provide a better idea on how climate change can affect plant immunity. Increasing temperatures and humidity alters ETI-related genes and suppresses the hypersensitive response [9, 12]. For example, tomatoes infected by the fungal pathogen Cladosporium fulvum develop leaf mold, and typically, effectors injected into tomato leaf cells activate ETI which upregulates resistance genes specific against C. fulvum. However, under high temperatures greater than 30oC, ETI is unable to be properly activated [9]. Furthermore, at humidity levels greater than 95 percent, the tomato is not able to respond by ETI and efficiently upregulate its resistance genes against C. fulvum effectors [9]. Therefore, higher temperatures and humidity may find plants to have unfavorable odds against plant pathogens under climate change.

Climate Change can introduce new Plant Pathogens

Armed with a less effective immune system, plants may also have to face new pathogens to which they are not adapted. Typically, plant microbes, including existing plant pathogens, compete against new plant pathogens and prevent them from establishing. However, with climate change, plant microbes face a changing environment which they are not adapted to, allowing new pathogens more suited to the environment to sweep in. For instance, the bacterial pathogen Agrobacterium tumefaciens is responsible for crown gall disease in many plant species like fruit crops, but when exposed to temperatures greater than 32oC, its virulent genes are downregulated, rendering it nonpathogenic [9]. While this seems great for these fruit crops, they now face the threat of new pathogens that can fill roles vacated by native beneficial and pathogenic microbes that can’t survive well in the new environment. Although new pathogens may not be adapted to the plant hosts of the region, it is possible for them to acquire virulent genes from existing pathogens through horizontal gene transfer, the mechanism where bacteria can share pieces of DNA with other bacteria [13]. Meanwhile, plants can’t adapt as quickly and are limited now by an immune system that has adapted to familiar pathogens but not novel pathogens, providing ample opportunity for the new pathogen to proliferate.

Climate Change can Exacerbate Existing Vector-borne Plant Diseases

Since effectiveness of immunity and susceptibility to new pathogens under climate change do vary by plant species, some plants like cassava, which is a starchy root vegetable grown throughout the tropics that provides nutrition for over half a billion people, are quite hardy and resistant to stressors like changing temperature and precipitation levels [14, 15]. Yet, plants, such as cassava, that are susceptible to diseases transmitted by insect vectors still face a different challenge brought about by climate change. For example, cassava is affected by two major pathogens across Africa, cassava mosaic virus and cassava brown streak virus, which are transmitted by the insect vectors, whiteflies and mealybugs, respectively [16]. As temperature increases, the populations of whiteflies and mealybugs boom, leading to the destruction of cassava crop and ultimately resulting in famine and a collapsed economy for communities that rely on the crop for food and income [17]. 

Combatting Effects of Climate Change on Plant-Pathogen Interaction

As illustrated, climate change impacts many aspects of plant-pathogen interactions, many of which are still unknown but it’s certain from current findings that the impact is most likely large. Fortunately, much of the predicted effects of climate change on plant-pathogen interactions have yet to take root, so it’s pertinent to employ techniques to prevent and manage any negative effects that are already in place. Besides cultivating crop strains resistant against specific pathogenic species, humans have a huge hand in staving off diseases in crops through the use of pesticides and fungicides. To manage and prevent disease, crop growers can switch between different fungicides or use multi-site targeting fungicide to minimize the chance of developing resistance among pests and pathogens [18]. Climate change may also affect pesticide and fungicide uptake. As CO2 concentration increases, plants are expected to grow bigger, so more pesticide and fungicide will be necessary for better uptake [18]. Ideally, once these strategies are properly in place, plant pathogens will no longer be a threat to global food security. 

Climate Change and Wildlife Infectious Disease

Besides threatening global food security, climate change is producing more natural disasters that are intensifying the habitat destruction and biodiversity loss that was initiated by human-driven forces such as urban expansion and wildlife trade. This has increased the prevalence and transmission of existing and novel wildlife infectious diseases [19]. Additionally, with increasing temperatures, pathogens are expanding into new territories. As a result of the increasing interaction between humans and wildlife, zoonotic diseases, a subsection of wildlife diseases capable of infecting humans, are expected to increase in frequency and infect humans at a higher rate.  

Climate change is great for ticks and mosquitoes

All pathogens are adapted to living at certain temperatures. For pathogens that have evolved to live in warmer climates, they may find themselves moving northward as the temperature there rises due to climate change. This particularly affects pathogens that are transmitted by arthropod vectors, which have previously been kept at bay by colder winters and lower average temperatures in the global North [25]. Arthropod vectors, such as ticks and mosquitoes, may harbor new diseases that Northern hosts have never encountered before, and consequently do not have immunity to. Blood-sucking vectors transmit diseases between different species by first feeding on an infected host, and then transferring the disease with a bite directly into the bloodstream of a naive host, which can be a human or another animal [26]. As pathogens adapt to the changing global climate, species across the globe will be threatened.

The thermal mismatch hypothesis explains that species adapted to the cold are at high risk from infectious diseases as their habitats warm, and vice versa [20]. The risk of this increases as parasites and other wildlife pathogens are adapting to survive a wide range of environments. The Arctic is one region especially susceptible to fluctuations in temperature and the spread of disease. The Arctic’s temperature is increasing nearly double anywhere else on the planet, and an unusually warm summer in the Arctic would put local species and the humans that rely on them at risk of zoonotic diseases [21]. Encephalitis, a disease that causes inflammation of the brain, is spreading northward into Arctic Russia as temperatures warm and the ticks that carry the disease can survive for longer periods of the year [21]. Similarly, Lyme disease, normally found in climates like those of the upper Midwest or Northeast of the United States, is now reported in areas of the Russian Arctic, due to a tick species better suited to the cold climate [21].

Shorter, warmer winters and longer, drier summers are easier for cold-blooded ticks and mosquitoes to survive. And as temperatures rise globally, vectors’ viable habitat expands, and thus, so does the range of disease, as mosquitoes and ticks will bring vector-borne diseases into previously temperate locations. The ranges of many vector-borne diseases will shift to higher latitudes and altitudes, where they previously were not found or could not survive. Furthermore, the seasons of transmission in historically warmer and more tropical climates will lengthen [22]. Certain aspects of the ticks’ reproduction, such as developmental cycle and egg production, speed up as temperature increases [22]. This is significant because the number of ticks maturing to be capable of spreading disease and further reproducing will increase, and as tick numbers increase, so will the risk of disease.

Increasing temperatures are expected to increase vector abundance as well as their survival. Changes in precipitation rates will also affect the transmission of vector-borne diseases. More rain creates more puddles, which serve as the perfect breeding ground for mosquitoes, while drought will increase the number of containers storing stagnant water, which if not properly stored can also serve as a vector breeding ground.

Zoonotic diseases and spillover

Over time, thousands of bacterial, viral, and fungal pathogens that once circulated within host species spilled over into the human population, causing illness. Increasing interaction between humans and wildlife and the loss of biodiversity characteristic of climate change will put human populations at the risk of increased emergence and transmission of zoonotic diseases.

Zoonotic diseases are those that are transmitted between animals and humans, such as rabies, Lyme disease, and COVID-19. The transmission of zoonotic diseases, zoonotic spillover, is a significant public health concern for humans as nearly 75 percent of emerging infectious diseases [20] originate from wildlife reservoir species. Reservoir species are those through which a disease circulates without killing it off entirely, thus allowing it to spread to humans if direct or indirect cross-species contact occurs. 

The rates of zoonotic spillover are increased in areas where humans live in close vicinity to wildlife. Factors such as deforestation, land-use change, and increasing population density push humans closer and closer to wildlife species’ habitats [23]. These areas, known as boundary zones, are areas where two or more different ecosystems meet. It has long been hypothesized that boundary zones are associated with the emergence and spillover of zoonotic disease, because they support increased contact of humans and wildlife species as well as species that are more likely to transmit zoonotic pathogens. These bridge species are generalist, meaning that they can move through a wider variety of ecosystems and encounter a wider variety of pathogens. This in turn increases the diversity of zoonoses that have the chance to spill over as well as the rate of spillover in and around these ecosystem boundaries [23].

As discussed, areas of high biodiversity, such as boundary zones between ecosystems, are often attributed to the emergence and spread of zoonotic disease. However, decreasing biodiversity has also been acknowledged as increasing the spread of pathogens in human populations. A new study explains that the reason for this apparent contradiction is that species that are more likely to be host species of zoonotic pathogens are more commonly found in areas where humans live [24]. It is the diversity of host species such as bats, rodents, and livestock that influence zoonotic emergence and spillover, rather than total species diversity. With decreasing biodiversity, the species that are left behindsuch as those with small bodies and fast life histories (early maturation, high rates of reproduction, and mortality)are those likely to transmit zoonotic pathogens [24]. There is also a dilution effect, when the buffer of non-reservoir species declines, meaning that the transmission of zoonotic diseases is increased.

Climate Change on Existing Human Pathogens

Besides the downstream effects of plant and wildlife infectious diseases on human society and health, climate change is expected to also directly affect the human population by impacting existing human-pathogen interactions. In the Arctic, ice and permafrost is melting at an unprecedented rate due to rising temperatures, reviving dormant pathogens, such as anthrax and smallpox, and introducing old and unknown human diseases [6]. Warmer water and more frequent storms are also generating outbreaks of water-borne infectious diseases such as cholera [27]. With warmer winters and hotter summers, climate change is affecting seasonal weather patterns and thus driving the prevalence and severity of certain seasonal infectious diseases like the flu [28]. These are just a few examples, as there are many more climate-related environmental changes and human infectious diseases being similarly affected. 

Arctic ice melting and permafrost thawing brings new and familiar threats

Every decade as the ocean’s temperature rises by 0.13oC, the Arctic ice melts by about 13 percent on average, which is thereby accelerating how fast the nearby Arctic permafrost, or frozen soil, is thawing and reviving dormant microbes [29, 30, 31, 6]. From the thawing permafrost, researchers have found novel viruses and bacteria but none so far that can infect humans [6]. For now, scientists are only aware of known human pathogens that may emerge. In 2016, an anthrax outbreak in Siberia has been linked to thawing permafrost releasing hardy anthrax spores. Besides anthrax, scientists are also worried about other known human pathogens, like smallpox, being released. Since the 1970s, the deadly smallpox has been considered eradicated. However, smallpox may still remain on frozen corpses as the virus can withstand freezing conditions [32]. Although scientists have not been able to isolate viable smallpox viruses, they have been able to extract their viral DNA from previously infected frozen corpses [32]. Nonetheless, the thawing permafrost in the Arctic may still contain threats from old and new human pathogens that have yet to be revealed as researchers continue digging into the matter.

Cholera, algal blooms, and changing tides

Besides melting ice, the warming ocean, home to many water-borne pathogens, is changing tidal patterns and intensifying and increasing the frequency of storms. Moreover, warmer water is also promoting algae bloom, which the bacterial causative agent of cholera, Vibrio cholerae, can be found in [33, 34]. As a result, hurricanes, which are becoming stronger due to warming water, are driving V. cholerae to wash up onto shores and coastal cities and contaminate water sources [27, 35]. Since V. cholerae is transmitted through contaminated food and water, hurricanes and algae blooms have both been linked to cholera outbreaks. During infection, V. cholerae proliferates in the human intestine and produces a toxin that causes diarrhea, vomiting, dehydration, a drop in blood pressure, and, if left untreated, can lead to death within 18 hours [36]. In communities that lack a stable health system, a treatable disease such as cholera may end up fatal when hospitals and clinics are overwhelmed by multiple coinciding disease outbreaks such as COVID-19 [37]. 

Influenza seasons become more severe

On a more global scale, the effects of seasonal changes is expected to worsen the severity of the flu season. Influenza is commonly known for its mild nature and annual appearance in the winter. While a warmer winter may create a milder flu season by making transmission of the virus less effective and thus affecting less individuals, more individuals are set to become susceptible to the flu the next season due to the lack of acquired immunity during the previous season, allowing the following winters to see more severe and earlier flu seasons [28]. Interestingly, during the warmest winters experienced, the 2017-18 flu season had the highest influenza mortality rates in recent history [38]. To account for this, scientists found that climate change is also affecting rapid weather variability in the fall preceding flu season, which is correlated with severe flu seasons [38]. Although COVID-19 restrictions in the past year have led to a dramatic decline in flu cases during the flu season, flu cases are picking back up once again, so the public must continue to remain vigilant and vaccinated if they want to avoid future severe flu seasons [39]. 

Conclusion

There is no more obvious of an example of the interactions between climate change and infectious disease than the last two years. Questions still remain regarding the origin and circulation of SARS-CoV-2 leading up to its explosion into a global pandemic [40], but a World Health Organization investigation distinguished bats as the virus’ reservoir host and identified a wet market in Wuhan as a probable center of outbreak [40]. Many of the underlying causes of climate change, such as deforestation and loss of habitat, are also linked to the emergence of infectious diseases. Researchers suspect the outbreak of COVID-19 could be connected to deforesting the tropics, changing agricultural practices, and increasing contact between reservoir and intermediate species, as well as wild animals and humans [41].

With no corner of the globe untouched by COVID-19, a clear and thorough understanding of how climate change and infectious disease affect each other is necessary for mitigating this pandemic and preventing the next one. Ultimately, any action taken towards reducing climate change will likely have a positive impact on reducing the risks of emerging infectious diseases. Recognizing that climate change and global health are interconnected is necessary for avoiding any future disastrous consequences.

Infectious disease emerges at the intersection of host, pathogen, and environment—and climate change is interacting with all three. This presents a multifaceted challenge, as a solution for plant immunity to fungal pathogens likely will not be the same as a solution for the increasing transmission of vector-borne wildlife viruses. Climate change, from rising greenhouse gasses to biodiversity loss, is dredging up new diseases and making existing ones worse. As host susceptibility, pathogen survival, and environment structures change, it would not be surprising to see more global pandemics in the future.

 

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Inconsistency in climate change education across K-12 grades

By Vishwanath Prathikanti, Anthropology ‘23

Author’s note: I, like many around the world, was alarmed when the Intergovernmental Panel on Climate Change released its sixth assessment report in August 2021 and delivered news of rapid and intensifying climate change. As an undergraduate with a research focus on science education, I was almost equally alarmed to find that the National Center for Science Education reported that 40% of middle and high school teachers teach climate change inaccurately. Furthermore, climate change isn’t required to be taught, or addressed in any capacity, in any state. In an era where climate change is becoming an existential threat to humanity, I wish to highlight the faults in climate change education and explain how it must improve.

 

In schools across the United States, teachers are teaching subjects such as arithmetics, the Revolutionary War, Shakespeare’s plays, and, more recently, climate change. However, not all teachers teach climate change, and the ones who do may be teaching it wrong. 

Before we discuss climate change education, it is important to understand exactly what has caused the degree of climate change in the past few decades. All credible scientists agree that climate change is happening, and it’s human activities that are responsible for causing it. Our atmosphere is designed to keep heat from the sun inside; it’s why we don’t completely freeze at night when the sun isn’t directly on us. Greenhouse gasses, such as CO2 and methane, help our atmosphere keep this heat in. Since the mid-twentieth century, humans have been significantly increasing the amount of greenhouse gasses in our atmosphere, either by driving cars that produce carbon dioxide, raising livestock, which produce methane, or cultivating soil, which produces nitrous oxide [1]. This results in more heat being trapped in the atmosphere, causing increased floods and droughts, the destruction of coral reefs, and the displacement of animal populations.

Considering the fact that the United States had the second greatest carbon footprint in 2021, it is imperative that the next generation understands the reality of climate change [2]. If nothing is done to address climate change, irreversible damage will be dealt to the Earth, such as animal and plant populations going extinct and even human settlements being destroyed or simply deemed uninhabitable due to worsening weather conditions. People must be educated on the severity of climate change so that they may mitigate or prevent such catastrophic events.

What does climate change education look like now?

Despite climate change being an existential threat to humanity, climate change education isn’t actually required to be taught in schools. Topics discussed in school are left for states to decide, and in many states, including California, teaching climate change is not mandated, despite it aligning with state science education standards [3, 4]. This leads to varying levels of quantity and quality regarding climate change education, as it often falls into the hands of individual schools or teachers themselves to determine how much time they spend and the level of depth when discussing climate change.

A study done by Eric Plutzer and colleagues found that of their sampled high school and middle school teachers, around 75% spent at least an hour per academic year on climate change (87% of high school biology and 70% of middle school science teachers) [5]. Plutzer and colleagues note that this small amount of time dedicated is worrisome by itself, but the quality of education is cause for more concern. Thirty percent of teachers emphasized that recent rises in climate were due to “natural causes” and 12% failed to emphasize human causes. Strangely, 31% admitted to teaching that recent climate change is caused by human activity, but also that many scientists believe it is due to natural causes [5]. Plutzer and colleagues stipulate it may be an attempt to convey both sides of the argument. This is alarming when coupled with the fact that 97% of climate scientists agree that humans are causing global warming and climate change. According to NASA, “international and U.S. science academies, the United Nations Intergovernmental Panel on Climate Change and a whole host of reputable scientific bodies around the world” have expressed this fact [6].

Sarah B. Wise, a professor at University of Colorado Boulder, conducted a similar study earlier, though limited the sample to Colorado public school teachers. Wise found that while 87% of teachers addressed climate change, the method was much more variable as indicated by a free-response section. According to Wise, many teachers only have an “informal discussion” rather than an organized lecture. Meanwhile, among those that did include a formal lesson plan, more than ⅔ of them indicated the lesson was mainly on “emphasizing the ‘nature of science’ (e.g., how scientists gather evidence, arrive at explanations, and engage in peer review) … and acknowledging or discussing the presence of public controversy and skepticism around the topic of global warming” [7]. These methods of teaching climate change often give way to imagining holes in the idea that humans are responsible for climate change. For example, if a student hears the notion that some scientists disagree on climate change, and the nature of science requires us to have skepticism, their perception of climate change being driven by humans weakens. 

While many teachers make sure to emphasize the scientific consensus, the fact that the number is only 54% should be cause for concern.

Why is climate change taught this way?

Plutzer and colleagues suggested that teachers may cover certain aspects of climate change and avoid others due to misinformation in their own lives. While 97% of scientists agree that human activity has been responsible for climate change, the public perception of climate change scientists’ knowledge is poor. According to a 2016 Pew Research poll, only 33% of Americans believe climate change scientists understand whether climate change is occurring or not, 28% believe scientists understand the causes, and 27% believe scientists agree that it is caused by humans [8]. 

When teachers were asked directly in Wise’s study, answers were a bit nebulous. The vast majority reported that a discussion of climate change would not “fit into their curriculum or standards” for various reasons, some being a lack of time, and others citing a limitation of the curriculum itself. Interestingly, unlike a subject such as evolution, very few teachers indicated they felt pressure to avoid teaching the subject by a student or member of the community. Even when teachers were directly discouraged from teaching the subject, free responses indicated it did not affect their decision to include it in the class, through an informal discussion or otherwise.

That being said, the political aspect of climate change should not be ignored. While the extent of the politicization of climate change is a somewhat complicated issue, it is undeniable that many believe climate change is a political subject, and like all political views, it is important to share “both sides” in school. While teachers were found to generally teach climate change, as discussed prior, the discrepancy was with whether they would emphasize human activity or natural causes as the main driving factor. While scientists have recognized there are patterns of climate change that occur naturally, it is also clear that after the mid-twentieth century, when cars became a family staple and humans started producing more greenhouse gas emissions, temperatures spiked much higher than they ever did naturally [9]. It is therefore commonly agreed that in the past few years, human beings are the ones mainly responsible for the increase in temperature.

Wise found that 85% believed teaching both sides was important. When asked why, 25% of teachers said it was because both views held scientific validity and 50% said it was to promote “critical thinking” and “independent decision-making.” Only 25% believed students should learn both, but school curricula should emphasize the scientific consensus that human activity is the driving force [7].

When they asked similar questions to their sample, Plutzer and colleagues found that those who believed it’s “not the government’s business to protect people from themselves” were also most willing to teach both sides [5]. In this sense, Plutzer and colleagues claimed the issue was based more on personal values of the teachers than any formalized curricula that may have been forced onto them.

What needs to be changed

It is clear that education on climate change in America must be made more robust; not only must climate change be required in school curriculums, but it should also emphasize the fact that there is a scientific consensus that human activity is the main cause. Climate change must be standardized at the state level, or at the very least, be mandated to teach. Until there is an established curriculum for climate change, the way it is presented will remain up to teachers. 

While some might argue a solution is to educate teachers and allow them to retain power over the way climate change is taught, because of the personal motivations at play, Plutzer and colleagues do not believe this would solve the issue [5]. In an interview with Time Magazine, Plutzer said, “The goal of climate skeptics is very similar to the goals of evolution skeptics. They’re not attempting to prove their point; they’re merely hoping to raise doubt — enough doubt to delay [changes to education] policies” [10]. 

Instead, Plutzer and colleagues suggest the process of educating teachers will need to draw on science communication research, and specifically help science teachers “acknowledge resistance to accepting the science and addressing its root causes.” A failure to approach educators properly may actually lead to the strengthening of views that seek to teach both sides equally [5].

Until personal biases in teachers regarding climate change can be resolved, some researchers have turned towards extracurricular activities and games to increase climate change knowledge and bridge the partisan gap. Juliette Rooney-Varga and colleagues created a simulation for secondary (grades 6-12) and post-secondary students in which participants role-play as UN delegates who are tasked with saving the world from climate change. The researchers found that of the 2042 participants, 81% reported an increase in their desire to “combat climate change.” In particular, they pointed out the effectiveness in convincing Americans who were “somewhat or strongly opposed to free-market regulation.” This label applied to 40% of all participants, who, prior to the study, indicated lower beliefs “that climate change is caused by human activities,” “lower levels of knowledge about CO2 accumulation dynamics,” and lower levels of “a sense of Urgency” [11]. After the study, their views on climate change “showed no statistically significant differences” when compared to their fellow Americans who favored government regulation.

Similar to how schools still face difficulties teaching evolution, it is unclear exactly how much resistance teachers, schools, and textbook authors will face when incorporating a stronger climate change curriculum into K-12 education. However, with the help of educators and researchers with a desire to foster better science communication, the next generation of students may be better equipped to address climate change in society.

 

References:

  1. NASA. The Causes of Climate Change. Accessed January 30, 2022. Available from: https://climate.nasa.gov/causes/ 
  2. World population review. Carbon footprint by country. Accessed Jan 30, 2022. Available from: https://worldpopulationreview.com/country-rankings/carbon-footprint-by-country 
  3. Johnson S. October 18, 2019. Teachers and students push for climate change education in California. Ed source. https://edsource.org/2019/teachers-and-students-push-for-climate-change-education-in-california/618239 
  4. U.S. Department of Education. The Federal Role in Education. Accessed January 30, 2022. Available from: https://www2.ed.gov/about/overview/fed/role.html 
  5. Plutzer E, Mccaffrey M, Hannah AL, Rose J, Berbeco N, Reid AH. February 12, 2016. Climate confusion among U.S. teachers. Science. 351(6274):. 664-665. https://www.science.org/doi/10.1126/science.aab3907 
  6. NASA. Do scientists agree on climate change? Accessed January 30, 2022. Available from: https://climate.nasa.gov/faq/17/do-scientists-agree-on-climate-change/ 
  7. Wise SB. January 31, 2018. Climate Change in the Classroom: Patterns, Motivations, and Barriers to Instruction Among Colorado Science Teachers. Journal of Geoscience Education. 58(5): 297-309. https://www.tandfonline.com/doi/abs/10.5408/1.3559695 
  8. Pew Research Center. October 4, 2016. Public views on climate change and climate scientists. Available from: https://www.pewresearch.org/science/2016/10/04/public-views-on-climate-change-and-climate-scientists/ 
  9. Denchak M,  Turrentine J. September 1, 2021. Global Climate Change: What You Need to Know. Natural Resources Defense Council. https://www.nrdc.org/stories/global-climate-change-what-you-need-know 
  10. Worland J. February 11, 2016. Why U.S. Science Teachers Struggle to Teach Climate Change. Time. https://time.com/4214388/science-teachers-climate-change/
  11. Rooney-Varga JN, Sterman JD, Fracassi E, Franck T, Kapmeier F, Kurker V, Johnston E, Jones AP, Rath K. August 30, 2018. Combining role-play with interactive simulation to motivate informed climate action: Evidence from the World Climate simulation. PLoS ONE 13(8): e0202877. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0202877

The Technological Impact on Coffee Growing in the Face of Climate Change

By Anushka Gupta, Genetics & Genomics, ‘20

Author’s Note:  Climate change is an important topic and must be discussed in order to mitigate the severe consequences. Unbeknownst to most people, however, coffee is also heavily impacted by climate change due to the sensitive conditions necessary for proper cultivation. I hope I can bring to light some of the less serious impacts of climate change and how something normal, like coffee, may become extinct without interference. 

 

Over fifty percent of Americans enjoy a daily cup of coffee, with over 500 million cups of coffee  served everyday. Unfortunately, with the increasing temperatures due to climate change, coffee is at high risk of extinction. However, with new advances in technology, coffee can now be grown in a wider range of environmental conditions. Specifically, the integration of modern technology to pre-existing growing practices and the use of artificial intelligence have both contributed to making a future with coffee a possibility.  

To understand the new developing technologies, it is crucial to understand the severity of climate change and how it specifically affects the coffee production business. Given the rapidly increasing rate of global temperatures, coffee will likely be much more expensive and be of a much lower level of quality within just 30 years. On top of this, the amount of land that is available for coffee growing will be cut in half by 2050, according to Climate Institute, a company in Australia. Coffee is grown mostly in tropical regions, like Honduras and Brazil, which also happen to be the regions hardest hit by climate change. In fact, the top countries that are most affected by climate change are the same countries where the majority of the world’s coffee beans are grown. 

This becomes problematic as coffee beans are also extremely sensitive to temperatures outside of their ideal growing temperature. Most coffee beans will only grow in the range of 18°C to 21°C at high altitudes. They also require a perfect amount of rain, as anything outside of these optimal conditions will damage or even kill the plants. Climate change has already had its effects on coffee production around the world. Heavy rains in Columbia, droughts in Indonesia, and coffee leaf rust (a fungus that attacks coffee bean leaves) in Central and South America have significantly decreased the coffee yield in the past few years. These are only a few of the many examples of how coffee growers are struggling to maintain their crop yield each year [1]. 

One way coffee growers are preparing for climate change is by engineering a new resistant strain of coffee beans. Currently, only one type of coffee bean, Arabica, dominates the entire industry. Arabica is known for its high quality flavor and aroma, but lacks genetic diversity, commonly leaving it susceptible to coffee leaf rust [2]. The coffee leaf rust fungus preys on the leaves of coffee plants, and eats away at the leaf until an orange-brown color is left instead of the previous green leaf, thus destroying the plant’s ability to make its own energy [3]. The lack of genetic diversity allows for this fungus to spread rampantly across coffee bean farms. For instance, if one strain of the fungus affects a particular variety of Arabica, it is also extremely likely that other Arabica plants will also be afflicted [2]. With increasing temperatures already posing a greater threat to plants, the leaf rust fungus is expected to have an even more apparent impact on coffee yield. In addition, the availability of farmable land is decreasing, as coffee plants only grow in a narrow range, a range that is shrinking due to increasing global temperatures. However, creating a hybrid coffee bean can resolve this problem by choosing strains in hopes of achieving a desired quality, such as coffee leaf rust resistance [2].  

Coffee breeder William Solano works at the tropical agricultural research and higher education center (CATIE) in Costa Rica doing just that. He works on creating coffee hybrids by combining genetically distant yet complementary coffee strains in hopes to achieve a product that takes in characteristics from each parent coffee strain [3]. At CATIE, he created the Centroamericano coffee bean, a cross between the Ethiopian landrace variety Rume Sudan and another coffee bean called T5296, which is known for its coffee leaf rust resistance [2]. On its own, the Centroamericano has proven to be twenty percent more productive than other coffee beans and is tolerant to coffee leaf rust. However, it soon became clear that it fares better against the effects of climate change as well, as it can survive temperatures below freezing. This was an especially surprising find as the plant was originally designed with only disease resistance in mind [3].  

On top of changing the coffee bean, scientists are also finding a way to use new technologies to make coffee farming more efficient. The most promising example seen so far has been the implementation of artificial intelligence (AI) to the coffee growing business. AI technology now allows farmers to accurately analyze soil fertility properties and compute an estimation of coffee yields [4]. The American technology company IBM has developed an AI-powered device that does just that. The device, called the AgroPad, is portable and about the size of a business card. This device has the capability to quickly analyze the soil to check for chemical composition, allowing coffee farmers to make educated decisions on how to manage their crops. Coffee growers can improve sustainability of their crops as well as save money since they know the amount of water and fertilizer that would be most beneficial to the crop to maximize yield. 

To activate the device, only a small sample size is needed. The sample can either be a drop of water or a liquid soil extract that is produced from a pea-sized clump of dirt, depending on the type of analysis needed. Within about 10 seconds, the device will generate a report using a microfluidics chip inside that performs data analysis. The device can give accurate information on the pH, and amount of various chemicals, such as nitrite, aluminum, magnesium, and chloride. This information is given in the form of circles that correlate to the soil composition. These circles give colorimetric test results, where each circle will represent the amount of a specific chemical that is in the sample [6]. The figure below shows what a sample report may look like. Once this output is given out by the AgroPad, the farmer can use an app to take a picture of the output where the app will read the data. The implementation of this device could allow coffee to be grown in more parts of the world as it will be evident what specifically must be done to ensure the productive growing of coffee in these fields [5]. 

 

Dedicated mobile app scanning of a sample report created by AgroPad

Fig. 1. Peskett, Matt. “IBM’s Instant AI Soil Analysis – the AgroPad.” Food and Farming Technology, 28 Jan. 2020, www.foodandfarmingtechnology.com/news/soil-management/ibms-instant-ai-soil-analysis-the-agropad.html. 

 

Technology has the potential to save some of these coffee plants in the face of climate change, however, at the current rate of climate change, it is difficult to say how the world will look like thirty or even fifty years in the future, and if coffee will be a part of that world. Hopefully, more technological advances will continue to rise over the years giving hope to both coffee growers and coffee drinkers alike around the globe. 

 

Sources

  1. Campoy, Ana. “Another Species Threatened by Climate Change: Your Morning Cup of Coffee.” Quartz, Quartz, 3 Sept. 2016, qz.com/773015/climate-change-will-kill-coffee-by-2100/. Accessed 1 Jun. 2020.
  2. Mu, Alejandra, and Hernandez. “Coffee Varieties: What Are F1 Hybrids & Why Are They Good News?” Perfect Daily Grind, Perfect Daily Grind, 20 Apr. 2020, perfectdailygrind.com/2017/06/coffee-varieties-what-are-f1-hybrids-why-are-they-good-news/#:~:text=Centroamericano%20is%20a%20cross%20between,high%20yielding%20and%20rust%2Dresistant.&text=SEE%20ALSO%3A%20Bourbon%20vs%20Caturra,Variety%20%26%20Why%20Should%20I%20Care%3F. Accessed 1 Jun. 2020.
  3. Ortiz, Arguedas. “The Accident That Led to the Discovery of Climate-Change-Proof Coffee.” MIT Technology Review, MIT Technology Review, 2 Apr. 2020, www.technologyreview.com/2019/04/24/135937/the-accident-that-led-to-the-discovery-of-climate-change-proof-coffee/. Accessed 1 Jun. 2020.
  4. “The Future of Coffee: 3 Technologies to Be on the Lookout for in 2019.” Royal Cup Coffee, 28 Dec. 2018, www.royalcupcoffee.com/blog/articles/future-coffee-3-technologies-be-lookout-2019. Accessed 1 Jun. 2020.
  5. “Enveritas Pilots IBM’s AI-Powered AgroPad to Help Coffee Farmers.” IBM Research Blog, 10 Dec. 2019, www.ibm.com/blogs/research/2019/12/enveritas-pilots-ibms-ai-powered-agropad-to-help-coffee-farmers/. Accessed 1 Jun. 2020.
  6. “No Farms, No Food.” IBM Research Blog, 7 Mar. 2019, www.ibm.com/blogs/research/2018/09/agropad/. 
  7. “IBM’s Instant AI Soil Analysis – the AgroPad.” Food and Farming Technology, 28 Jan. 2020, www.foodandfarmingtechnology.com/news/soil-management/ibms-instant-ai-soil-analysis-the-agropad.html.

The Consequences of Tropical Deforestation

By: Wincy Yu, Biological Sciences, ‘17

Author’s Note:

In light of climate change and environmental talks among world leaders, as well as rising media attention for endangered species around the world, I realized that people were concerned about the consequences, but may not have paid attention to the underlying reasons. Inspired by an ecology class I took last year, I wrote this piece to discuss one of the reasons for climate change and ecosystem loss, which is deforestation.

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UC Davis Hosts DataRescue Event To Archive Climate Research

By N. J. Griffen, English, ‘17

Author’s Note:

“I chose to write about this topic as a response to one of the many uncertainties that exists under our newly elected president, Donald Trump. More specifically, this article is meant to encompass the nationwide effort by scientists, professors, researchers and archivists to safeguard, backup and protect work conducted in the realm of climate science. This topic, I believe, should be integrally important to most residents of this planet; due to the fact that we have no choice but to live the entirety of our lives here on earth. Therefore, my interview of the archivists at UC Davis seeks to uncover the motives and connotations that the DataRescue Davis event assumes.”

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Learning from Drought in California: Past and Present

By Marisa Sanchez, Molecular and Cellular Biology, ’15

The most current drought in California is considered to be one of the worst droughts in the past century, and many wonder if this severity is due to climate change. However, California has had a long history of unpredictable weather fluctuations, and is familiar with severe droughts. Many droughts can have devastating effects, particularly in the agricultural industry and the hydropower industry. Most Californians have also experienced the effects of a drought first-hand, such as having enforced water rationing. Even though, California’s history has shown that most droughts have devastating effects, droughts can also great learning experiences.

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When the Last Frog Croaks

By Renata Vidovic, Evolution and Ecology ’15

To some, the phrase climate change evokes images of dry lakes, melting icebergs, and rising oceans. However, the effects of global warming are not simply cataclysmic geological changes. There are links between all biotic and abiotic features of an ecosystem. Unsurprisingly, climate change has an immense impact on frog populations around the world. Home range, abundance, breeding cycles, pathogen epidemics, and physical degradation in frogs are all affected by the changing climate.

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Grass-fed or grain-fed?

By Jenny Cade, Biochemistry & Molecular Biology ’15

Eating grass-fed beef and pasture-raised chicken is the eco-friendly thing to do–right? Maybe not, according to a recent paper published in the Proceedings in the National Academy of Science. The study proposes that intensifying livestock production by transitioning from pure grazing to mixed systems–where animals are fed high-energy food like grains–could reduce livestock greenhouse gas emissions by 23% by 2030. Currently, livestock account for 14.5% of all anthropogenic greenhouse gas emissions, so such a reduction would be significant.

In contrast, a comment piece that appeared in Nature last month calls for increasing grazing to make livestock systems more sustainable. Of eight strategies that the authors outline to reduce the environmental and economic costs of raising livestock, “Feed animals less human food” is number one.

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Climate Engineering: Worth the Risk?

By Ashley Chang, Genetics ’15

Researchers at the GEOMAR Helmhotltz Centre for Ocean Research Kiel are studying the long-term effects of “climate engineering” methods that could help to preserve the climate and protect from rising temperatures. This winter every part of the world except the eastern United States reported record breaking high temperatures. Although political agreements have been made to reducing greenhouse gas emissions, the effects may be too slow as levels of CO2 and other greenhouse gases continue to rise. This is especially important as populous countries, such as China and India, become increasingly industrialized and consequentially raise their greenhouse gas emissions. (more…)