Golden Medicine: Use of Plasmons for Cancer Therapy

Cancer is an immensely complex disease to treat. The number of mutations and combinations of mutations that can lead to its development make each “cure” more of a patch to a few specific cases. Couple that with the increasing rate of mutation within cancer cells, and it becomes difficult to even diagnose the issue. Plasmon therapy offers the potential for a broadly applicable treatment, and because it couples well with the bodies immune response, offers a therapy that could decrease the chance for metastatic tumor development.

Before we discuss this topic with greater specificity, a few terms should be defined. Plasmons, from the word plasma, are a material that has electrons that flow back and forth in a wave when light shines on them. Plasmas are just gaseous ions, like lightning or neon signs, and in the case of a plasmon, this plasma is confined to the surface of a nanoparticle. You can read more about plasmon theory here.

Nanoparticles abound in modern technologies and are defined by one dimension, the so called “critical dimension”, which is around two hundred nanometers. For reference, that’s roughly one hundred thousand times smaller than a human hair. This size can afford a variety of unique properties to a molecule: distinct colors, uncharacteristic electronic activities, and even the ability to move through a cellular membrane. All these attributes will come into play in how these molecules interact with cancer cells, so they’re important to keep in mind.  Plasmons are nanoparticles that are so small, that the plasma on the surface can be manipulated by light. This rapid movement of plasma gives rise to heat as it collides with surface particles just as your hands generate heat rubbing together. The type of light that does this can be visible or even radio waves, meaning that very low-energy and harmless beams can be used to generate this rapid heat.

The second bit of background knowledge necessary for this discussion is: how is cancer treated in the first place? Many current cancer therapies come from small molecules roughly the size of glucose. Whether they use metals or strictly carbon, small molecule cancer therapies usually rely on interrupting one or a few cellular pathways, like DNA replication or a checkpoint before mitosis (cell splitting). One of the first nanoparticles approved for cancer therapy have been gold nanorods, which are thousands of times larger than a small molecule and have used physical rather than chemical mechanisms for therapy. To clarify, instead of changing some pathway in a cell, these nanorods can selectively heat cancer cells until the cell dies. If you were to think about this in terms of pest control, nanoparticle therapy is like burning a nest of cockroaches. In that same case, using small molecules like cisplatin would be like spraying the cockroaches with the latest bugkiller.

Extending this analogy, it’s fairly obvious that setting a fire inside someone’s body is not a good medicinal practice, so it would be fair to question how plasmon therapy might be helpful. There are two strategies for plasmon cancer therapy: precision lasers and radio waves which can pass through a body. The earliest use of plasmon cancer therapy used a fiber optic that was inserted under the skin to a location near the tumor. Then, beams of light would hit only the tumor. This has the advantage of targeted dosing, but can still be considered fairly invasive. Others have begun using plasmons that generate that intense heat with radio waves so that no procedure is necessary: simply an injection or ingestion of nanoparticles and then stepping into a radio transmitter This can be impractical if the tumor is not in a confined space. Common gold plasmonic nanoparticles would go inside all cells so healthy cells would be damaged just as easily as cancerous ones. Recent work shows that the surface of the nanoparticle can be changed so that the majority of uptake occurs by cancer cells. Cancer cell metabolism makes the charge of cancer cell membranes different from the charge of normal cell membranes, so these nanoparticles can exploit that difference to target only cancer cells.

With this targeted dosing, plasmons show promise as a noninvasive form of therapy that do not harm the patient and would be applicable to most forms of cancer. Even though the safest and most effective nanoparticles will use gold, treatment costs are currently around  $1000, thereby promising a treatment that will not be prohibitively expensive for the future.

Peer edited by Kasey Skinner.

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Midterm Election Ballot Amendments: What’s up with the Right to Hunt and Fish Amendment?

Do you think the right to hunt should be protected by the NC state constitution?

This election cycle, North Carolinians will be voting on six constitutional amendments, one of which is the Right to Hunt and Fish Amendment. The amendment would upgrade hunting and fishing to a constitutional right, designating “public hunting and fishing [to] be the preferred means of managing and controlling wildlife.” Restrictions on hunting and fishing would be prohibited, except to comply with wildlife conservation and management laws.

At UNC’s Science Policy Advocacy Group (SPAG), we highlighted the quoted language from the amendment, wondering: Are voters being asked to make a decision motivated by wildlife conservation science or by politics? While the U.S. Fish and Wildlife Services claims that hunting is a wildlife management tool, this largely depends on local context based on hunting regulation and the species in question.

To answer this question in North Carolina, we consulted resources at the NC Wildlife Resources Commission. While NC has a Deer Management Assistance Program, a recent publication on the Wildlife Restoration Program states that the primary contribution of hunters is financial. In addition to the state taxes we all pay, hunters contribute to conservation funds through hunting licenses and excise taxes on arms, ammunition, and equipment. The Wildlife Commission uses those funds to purchase and manage habitat lands, restore wildlife species, conduct research, and survey wildlife populations. In fact, the increase in game populations (turkey, quail, fox, black bear, etc) is desirable because it incentivizes a growth in the popularity of hunting, which would in turn maintain revenue streams for conservation. The report does not mention hunting’s impact on wildlife population control in NC, and a search of academic literature yielded no results on the topic.

So hunting is an important financial tool for wildlife management, rather than a tool for wildlife population control. However, there’s also no evidence that anyone wants to reduce hunting licenses. If anything, because of the important funds generated by hunting, NC has a Hunter Heritage program to try to reverse declines in the number of people who hunt.

Which brings us back to the ballot amendment – what are we really voting for?

A “yes” vote supports creating a state constitutional right to hunt, fish, and harvest wildlife, affording it the same protection as free speech. This would mean the NC General Assembly would have the sole power to regulate hunting and fishing. In comparison, a “no” vote opposes codifying this right in the state constitution, maintaining having a license as a privilege.

In the end, it’s unclear what exactly this amendment would accomplish besides adding another amendment. Of all the ballot amendments, this is the one toward which state legislators feel the most ambivalent. Some democratic state representatives believe the amendment is politically motivated to draw more conservative voters to the polls who may misunderstand the amendment to mean that their ability to hunt and fish is vulnerable. This would help shore up votes for Republicans across the state.

This article is not a referendum on hunting, which, it turns out, is a prime example of how recreational activities can be leveraged to support conservation and science. However, we find this amendment uses misleading language about the efficacy of hunting itself as a wildlife management tool in NC to create unnecessary legislation.

Peer edited by Izzie Newsome.

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Stop Insulting Anglerfish Sex

http://www.photolib.noaa.gov/htmls/expl5923.htm

A deep sea anglerfish called a goosefish and is a member of the Lophiidae family – Sladenia remiger.  Image Credit: NOAA Okeanos Explorer Program, INDEX-SATAL 2010

You may have seen the anglerfish sex video floating around the Internet recently, with titles like “The worst sex in the world is anglerfish sex, and now there’s finally video.” While the video is worth a watch, I think most behavioral ecologist would beg to differ with the main assertion: there’s a lot of bad sex in the animal kingdom.

Why is anglerfish sex supposedly so terrible? A male anglerfish bites a females when he finds her, and then hangs onto her for the rest of his life, essentially turning into a living sac of sperm. But hey, at least he’s alive. In contrast, some species of male widow spiders somersault into the mouths of females as they mate, impaling themselves on their mates’ fangs. It sounds like an evolutionary enigma–why would an organism ever willingly sacrifice itself?–but turns out that that self-sacrifice can increase a male’s chances of fathering the female’s offspring.

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The female bed bug (the larger of the two) is traumatically inseminated by the male (bottom) through her abdomen.

Traumatic insemination” is another great example of not-so-great sex. In this case, bed bug females are the ones getting royally screwed, because traumatic insemination is a nice way of saying males stabbing females through the abdomen with their penises. The sperm then travels through the female’s hemolymph (the insect equivalent of blood), until reaching the ovaries and fertilizing the eggs. Males mate with all available females, because the last male to mate with any given female has the best chance of fathering her offspring. However, females who are subjected to these multiple matings pay a high cost: they have shortened lives and reduced reproductive output, because they have to allocate energy to healing the wounds and dealing with any resulting infections.

People often assume that two organisms mating with one another have the same “goals.” After all, both males and females are presumably invested in having as many healthy offspring as possible. But this is only true up to a certain point. Female widow spiders don’t need males to remain alive after mating, and in fact gain an advantage from eating the male (a ready source of nutrients that will help her with her next clutch!). In contrast, male widow spiders obviously benefit from not being eaten, and instead living to mate another day. Similarly, mating multiple times via traumatic insemination is costly to female bed bugs, who only need enough sperm to fertilize their eggs, while male bedbugs benefit from mating as many times as possible.

These are examples of what biologists call sexual conflict. While the source of conflict is obvious in the widow spiders’ and bed bugs’ cases, sexual conflict occurs anytime male and female genetic interests don’t align. In fact, the only time there is absolutely no potential for conflict is when males and females have exactly the same lifetime reproduction, so that each is equally invested in all of their shared offspring, with no opportunities for having offspring with other partners. In contrast, conflict can arise whenever one sex has the opportunity to improve their chances of having more, or better, offspring. This can happen in many different ways, such as: eating your partner, mating multiple times with the same partner, or even mating with multiple partners.

As a result, sexual conflict isn’t likely in anglerfish, at least those species which only have one mate for their entire lives. Although there are genera of anglerfish where females can have up to 8 males hanging off of her! So there’s potential for sexual conflict there, since the males will presumably compete to father her offspring and could do so in ways that are harmful to the female. However, anglerfish are incredibly hard to study because they generally occur in the deep sea. Frankly, male anglerfish have way more going for them than you might’ve ever thought–keep that in mind next time someone’s making fun of them.

 

Peer edited by Karen Setty.

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Mimicking Electric Eels to Provide Power to Medical Devices

https://www.flickr.com/photos/ryanready/4593249712

The electric organ of eels has inspired researchers to develop biocompatible power sources that could be used to power medical devices

While the shock of an electric eel sounds like more of a medical nightmare than a fortunate asset, researchers at the University of Michigan were inspired to simulate the power of these slick creatures in hope of creating power sources for a variety of medical devices. With society’s heavy reliance on technology, it’s not surprising that medical treatments have continued to rely more and more on electrical devices including wearable and implantable sensors, pacemakers, and prosthetics. Just as with any piece of technology, these devices require an electrical power source. However, medical devices face the added requirement of being biocompatible, meaning they must function safely and effectively in the human body. Eel-inspired power sources may achieve this goal of being biocompatible while supplying medical devices with the electricity they need to function.  

The inspirational efficiency with which an eel uses its electrical shock, to help catch prey and protect itself against predators, is the result of natural selection. Electrophorus electricus, know commonly as a knifefish or an electric eel, possesses an electric organ that extends through the back 80% of its body. The organ contains parallel stacks of special cells called electrocytes. When a situation arises that warrants a shock from the eel, its nervous system generates an electric current by activating thousands of electrocytes at the exact same time. As the cells are activated, the positively charged sodium and potassium ions, in and around the cells, move toward the head of the eel. The movement of these ions allows each of the electrocytes to act like small batteries. The activated end that lost the ions has a negative charge, while the opposite side that acquired the sodium and potassium ions carries a positive charge. The battery-like cells can each generate a small, innocuous voltage (less than that of a AAA battery). But when combined, the eel’s shock can be over 600 volts! For reference, a US household outlet supplies 120 volts. While a significant portion of this voltage is lost to the water around the eel, its prey or attacker will still get a nasty shock.

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By developing this work further, researchers hope to successfully use their artificial electric organ to run medical devices like pacemakers

The University of Michigan team has successfully created an artificial electric organ that can potentially be used by humans to power devices. To make the electrical power supply biocompatible, it was necessary to efficiently mimic the features of the eel’s electric organ. This was achieved by preparing hydrogel membranes that could be layered to replicate the structure of the organ. To mimic the movement of ions in and out of the cells, the hydrogels were filled with dissolved table salt, which is made of sodium and chlorine ions. Half of the cells were designed to allow only positively charged sodium ions out and the other half would only allow negatively charged chlorine ions to exit. The gels containing the salt water were alternated on the membrane sheet with gels containing pure water, which allows the sodium and chlorine to move in opposite directions. This flow of ions generates an electric charge with an electrical potential of 110 volts. While this voltage is less than that of the inspirational eel organ, in its current state the artificial organ may be sufficient to power some low-power devices.

Though pleased with the engineering of a potentially biocompatible power source, the researchers acknowledge that there are plenty of opportunities to improve its design. By increasing the efficiency of these artificial organs, researchers believe their utility will increase, as they will become more suitable for use in combination with implantable devices.

Peer edited by Erika Van Goethem.

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Science Communication, Advocacy and the Federal Budget

https://www.flickr.com/photos/library_of_congress/8470008043

Scientific societies, such as ASBMB, provide opportunities for trainees to travel to Washington, D.C. and meet with policymakers.

Recently, the federal budget for the fiscal year (FY) 2019 (beginning October 1st, 2018) was released. Shockingly, the initial plan called for brutal cuts to basic research funding agencies—slashing the budget of the National Institutes of Health (NIH) and the National Science Foundation (NSF) by 27% and 29%, respectively. While Congress subsequently lifted spending caps to compensate for these losses, the budgets of both the NIH and NSF will now remain stagnant at levels for FY2017.

Although catastrophic funding losses have been avoided, these flat budgets are still worrisome. When adjusted for inflation, a stable budget equates to a decrease in funding.  Furthermore, three health research institutes currently located in the Agency of Healthcare and Human Services and the CDC will be terminated and their successors will be created within the NIH. The relocation of these institutes without an increase in NIH funding will further strain the budget.

Numerous scientific societies have responded with criticism to the federal government’s budget proposal. A statement from The Society for Neuroscience (SfN) highlighted the public’s support for scientific research funding and emphasized that adequate funding is critical to combat devastating diseases, such as Alzheimer’s. Likewise, a press release from the American Society for Biochemistry and Molecular Biology (ASBMB) expressed concern regarding America’s ability to lead in science and innovation amidst stagnant funding.

Educating elected officials on the importance of scientific research is a key focus of scientific societies. ASBMB sponsors an opportunity for graduate students and postdocs to travel to the capital and meet with Congress through their annual Hill Day. Societies also encourage local action. For example, the American Society for Cell Biology (ASCB) compiles an advocacy toolkit to guide members through the process of contacting local representatives, scheduling meetings and organizing lab tours. On the UNC campus, the Science Policy Advocacy Group (SPAG) is a resource for graduate students and postdocs to gain skills in science communication and advocacy through outreach events, workshops and seminars.     

At the core of science advocacy is the ability to communicate why science is necessary. While the significance of developing new cancer therapies is clear, the importance of basic science research is still often misunderstood. Basic science research is often described as “curiosity-driven” and asks fundamental questions such as: “How do cells move?” This basic research provides a thorough understanding of cellular processes that is critical for later medical innovations. In the 1990s, Yoshinori Ohsumi observed an unusual structure in yeast cells when he starved them. His work in yeast was essential for uncovering the mechanism behind autophagy, a recycling pathway in the cell. Today, researchers know that defects in autophagy result in cancer, Parkinson’s Disease and Type 2 Diabetes, and Ohsumi was awarded the Nobel Prize in Medicine in 2016.

Ohsumi’s story demonstrates that breakthroughs in basic science are critical for breakthroughs in medicine. Yet, proper funding must be secured before further innovations in either field can occur. As a result, it is critical to create a culture that both understands and values scientific research.

Peer edited by Kelsey Miller.

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Space Travel is Possible with the Sound of Light

https://commons.wikimedia.org/wiki/File%3ASpace_travel_195807.jpg

Optical communication devices may be the first step in space travel.

Technology moguls dream of human colonies on other planets. For this dream to become reality, science needs to develop new spacecraft capable of transporting people and cargo to the outer reaches of our galaxy. Another challenge is how to find a route to these other planets.  We can’t just use Google Maps. Space travelers would have to navigate around comets, space debris, or orbiting planets.  Complex models and communications developments would be needed to move through galaxies safely and quickly.

Light-based communication is desirable because it can transmit more data per second while producing significantly less heat. This means that less energy is spent cooling equipment, making the it more efficient to run compared to conventional electron-based communication.

Similar to how electronic devices maneuver electrons through a computer chip, photonic devices maneuver light for optical communication. Normally, a magnetic field is required to produce a change in optical properties necessary for one-way light propagation. However, the size of magnets are too large to be incorporated efficiently into nanoscale devices. To address this problem, University of Illinois researchers created a nanoscale photonic device called an optical isolator, using sound waves instead of magnets for one-way light guidance.

Erika Van Goethem

Cartoon of optical device

The optical isolator device is made from aluminum nitride. A radio frequency driver (RF driver) generates a radio frequency signal that is used to create a sound wave. The RF signal is applied to an IDT, consisting of two interlocking comb-shaped arrays of metallic electrodes that convert electrical signals into surface sound waves. The grating couplers allow the light, generated by a laser, to enter into the device from one direction.  The light travels along the optical waveguides and is transferred from one optical band to another, interacting with the previously converted sound waves. Light is able to pass through the device when the shape of the light wave matches the shape of the sound wave going in the same direction. However, light waves going in the opposite direction of sound waves are absorbed by the device and are unable to pass through, thus maintaining the one-way propagation of light.

This new device allows for a more reliable and sensitive transfer of information that can be used in devices such as atomic clocks and GPS.  Such innovations may be the first step toward developing deep space navigation and travel.

Peer edited by Portia Flowers.

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Cloned Monkeys: Another Human Creation

http://english.cas.cn/head/201801/t20180123_189488.shtml Image credited to Qiang Sun and Mu-ming Poo, Institute of Neuroscience of the Chinese Academy of Sciences

First cloned none-human primates: Zhong Zhong and Hua Hua (Image credited to Qiang Sun and Mu-ming Poo, Institute of Neuroscience of the Chinese Academy of Sciences)

Cloned primates are here! Over three decades have passed since the birth of Dolly, the sheep, scientists have now tackled cloning mammals that are even closer to us on the evolutionary tree: macaque monkeys. What does this mean for a society that witnesses dramatic changes day by day: computers are outperforming doctors in calling out heart abnormalities in patients; 3D-printed organs are bringing us one step closer to tissue restoration; genome sequencing has become an online product easily available for anyone curious about their ancestry, bodybuilding, or just simply wine tastes. Breakthroughs in science and technologies are so prevalent in our life that by now, we probably shouldn’t be surprised by any new discovery. Yet when the two cute, little, cloned monkeys were born, the whole world was, once again, shaken.

Published in Cell on January 24th, 2018, a study from a group of scientists in China reported their methods in generating two non-human primates that are genetically identical. To clone the two identical macaque monkeys, the scientists applied Somatic Cell Nuclear Transfer, the same method that generated Dolly in 1996. The key idea behind cloning is that a new organism, be it sheep or monkey, is generated without sexual reproduction. Asexual reproduction is not as uncommon as one would think, plenty of plants do so. For example, Bryophyllum shed plantlets from the edge of the leaves to produce new plants. Some insects, such as ants and bees, also exploit asexual reproduction to clone a huge working class army. Since asexual reproduction is essentially an organism duplicating itself, the offsprings are all genetically identical. Evolution, however, doesn’t favor asexual reproduction as identical offsprings don’t prevail in a fast changing environment. On the other hand, sexual reproduction combines different sperms and eggs to create diverse offsprings, of which some may survive. To combat challenges from the mother nature, higher organisms, such as mammals, almost exclusively reproduce sexually. This is why a cloned monkey, an anti-evolution human creation, is mind blowing.

https://commons.wikimedia.org/wiki/File:Kalanchoe_plantlets.JPG

The succulent, genus Kalanchoe, uses asexual reproduction to produce plantlets.

To clone mammals, scientists came up with the idea of transferring the nucleus of a somatic cell to an enucleated egg (an egg that lacks nucleus). Unlike  germ cells (sperm and eggs), somatic cells refer to any cells that don’t get passed onto the next generation. These cells have the full genome of an organism that is split equally in germ cells during sexual reproduction. Carrying half of the genome, sperm and egg need to fuse their genetic materials to make one viable embryo. Technically, the nucleus of a somatic cell holds all the genetic information an organism needs. Thus, by inserting the somatic cell nucleus into an egg, scientists could generate a functional embryo. But why not into a sperm? Evolution has trimmed mammalian sperm tremendously so that it can accomplish its only job better: swim faster to fertilize the egg. As a result, not much other than the sperm’s genetic information is incorporated into the fertilized egg and the embryo relies on the cellular machinery from the egg to finish development. Using this technology, the scientists generated over 300 “fertilized” embryos. Of these embryos, 260 were transferred to 63 surrogate mothers to finish developing. 28 surrogate mothers became pregnant, and from those pregnancies, only 2 healthy monkey babies were born. Although they were carried by different surrogate mothers, every single piece of their genetic code is the same as the the somatic nucleus provider, a real-life demonstration of primate-cloning. Followed by millions of people since their debut to the world, these two macaque superstars are the living samples of a revolutionary breakthrough in our science and technologies.

 

Despite the extremely low success rate, this technology erects another monument in the history of mankind’s creations. Carrying identical genetic information, cloned monkeys like these two can be a very powerful tool in biomedical research and diseases studies. Co-author Mu-ming Poo, director of the Chinese Academy of Sciences’ Institute of Neuroscience in Shanghai, said that these monkeys could be used to study complicated genetic diseases where environmental factors also play a significant role, such as Alzheimer’s and Parkinson’s diseases. While there are ethical concerns on this technology and its easy application to human cloning, it is worth noting that almost all human creations (explosives, GMO food, the internet, etc.) are double-sided swords. It is up to the hand that wields this sword to decide whether to do good or bad. It is wise to be cautious with the development of new technologies, but it’s also important not to constrain our creativity. After all, it is our creative minds that drive us toward creating a better life for everyone.

Peer edited by Cherise Glodowski.

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Bonnethead Shark: The Newest Veggie Lovers of the Sea

Vegetarian sharks.

If you love a cheesy sci-fi movie as much as I do, the word shark probably brings a few images to mind; swimmers rushing to shore, a huge, hungry, Great white, ready to devour anything in its sights. You may have even started humming the iconic Jaws theme. But you might be surprised to hear that off the big screen, not all sharks are out for blood. In fact, one shark prefers a leafy, green, salad.

We often think of sharks as strict meat eaters, but researchers at the University of California-Irvine are turning the meat hungry shark stereotype on its head with their (mostly) vegetarian Bonnethead sharks. The Bonnethead shark is a small type of hammerhead shark often found in warm, shallow waters of the Northern hemisphere. Bonnetheads get their name from their distinct shovel-like head shape.

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The Bonnethead shark’s unique head shape distinguishes it from its hammerhead cousins.

 

Though distinct in appearance, the characteristic that makes the Bonnethead shark truly unique is its diet. Sharks are infamous meat-eaters. The Bonnethead, however, prefers its meat with a side of veggies. Studies on the diet of the Bonnethead began in 2007 when large amounts of seagrass were found in the stomach of a shark in the Gulf of Mexico. For many years, it was thought the seagrass was indigestible and eaten on accident while the sharks were hunting for shrimp, mollusks, and small fish in the seagrass ridden waters. Recent research now suggests Bonnethead sharks can digest the seagrass they eat and could use it as a source of nutrients.

As the first seagrass-eating shark be discovered, there are still many questions surrounding this veggie-loving shark. Does the Bonnethead eat seagrass on purpose? Or is it accidentally consumed while hunting for creatures on the ocean floor? Perhaps the most puzzling question is how  the Bonnetheads are able to digest seagrass? Because Bonnethead sharks have short intestines that are typical of a strict meat eater, scientists suspect bacteria living in the gut give the Bonnethead the ability to digest seagrass. More research is needed to discover which, if any, bacteria help the Bonnethead digest its dinner.

Although questions remain, one thing is certain; the Bonnethead shark is a unique and remarkable creature with much to teach their human neighbors about what constitutes a five-star meal under the sea.

Peer edited by Zhiyuan Liu.

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Understanding the 2017 Climate Science Special Report

Earlier this year, the U.S. government released the Climate Science Special Report.  This document describes the state of the Earth’s climate, specifically focusing on the U.S.  If you are someone who is interested in environmental science or policy, you may have thought about reading it.  But where to start? The report contains fifteen chapters and four additional appendices, so reading it may seem daunting.  We published this summary of the report to provide a brief introduction to climate change, and to provide a starting point for anyone who wants to learn more.  

https://www.nps.gov/articles/glaciersandclimatechange.htm

Retreating of Lyell Glacier (Yosemite National Park) in 1883 and 2015. Park scientists study glaciers to understand the effects of climate change in parks serviced by the National Parks Service. 1883 Photo: USGS Photo/Israel Russell 2015 Photo: NPS Photo/Keenan Takahashi

 

 

 

 

 

 

 

 

 

 

 

 

What is Climate Change?      

“Climate change” is a phrase that has become ubiquitous throughout many aspects of American and global society, but what exactly is climate change?

Like weather, climate takes into account temperature, precipitation, humidity, and wind patterns.  However, while weather refers to the status of these factors on any given day, climate describes the average weather for a location over a long period of time.  We can consider a climate for a specific place (for example, the Caribbean Islands have a warm, humid climate), or we can consider all of Earth’s climate systems together, which is known as the global climate.

Depending on where you live, you may have seen how weather can change from day to day.  It may be sunny one day, but cool and rainy the next.  Climate change differs from changes in weather because it describes long-term changes in average weather. For example, a place with a changing climate may be traditionally warm and sunny, but over many years, become cooler and wetter.  While weather may fluctuate from day to day, climate change is due to gradual changes that occur over long periods of time.  Climate is viewed through an historical lense, comparing changes over many years. Though we may not notice the climate changing on a daily basis, it can have drastic effects on our everyday lives.  It can impact food production, world health, and prevalence of natural disasters.

https://commons.wikimedia.org/wiki/File:Effects_of_global_warming,_plotted_against_changes_in_global_mean_temperature.png

Summary of the potential physical, ecological, social and large-scale impacts of climate change. The plot shows the impacts of climate change versus changes in global mean temperature (above the 1980-1999 level). The arrows show that impacts tend to become more pronounced for higher magnitudes of warming. Dashed arrows indicate less certainty in the projected impact and solid arrows indicate  a high level of certainty.

What Causes Climate Change? 

The major factor determining the Earth’s climate is radiative balance.  Radiation is energy transmitted into and out of the Earth’s atmosphere, surface, and oceans.  Incoming radiation most often comes from light and heat energy from the Sun.  Earth can lose energy in several ways.  It can reflect a portion of the Sun’s radiation back into space.  It can also absorb the Sun’s energy, causing the planet to heat up and reflect low-energy infrared radiation back into the atmosphere.  The amount of incoming and outgoing radiation determines the characteristics of climate, such as temperature, humidity, wind, and precipitation.  When the balance of incoming and outgoing radiation changes, the climate also changes.

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Scientists agree that it’s extremely likely that human activity (via greenhouse gas emissions) is the dominant cause of the increase in global temperature since the mid-20th century.

There are some natural factors that can influence climate.  The main ones are volcanic eruptions and the El Niño Effect.  Volcanic eruptions emit clouds of particles that block the Sun’s radiation from reaching the Earth, changing the planet’s radiative balance and causing the planet to cool. The El Niño Effect is a natural increase in ocean temperature in the Pacific Ocean that leads to other meteorological effects.  The increase in ocean temperature off the coast of South America leads to higher rates of evaporation, which can cause wind patterns to shift, influencing weather patterns worldwide. Together, these factors influence climate, so when they differ from the norm, they can contribute to climate change.

It is true that climate change can occur naturally and it is expected to happen slowly over long periods of time.  In some cases, the climate can change for a few months or years (such as in the case of a volcanic eruption), but the effects of these events are not long-lasting.  However, since the Industrial Era, the factor contributing most to climate change has been an anthropogenic driver, meaning one that is being caused by human activity. The primary cause of climate change since the Industrial Era has been the presence of greenhouse gases in the atmosphere.  The main greenhouse gases are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).  These gases are problematic because they remain in the Earth’s atmosphere for a long time after they are released.  They trap much of Earth’s outgoing radiation, leading to an imbalance of incoming and outgoing radiation energy.  Because the Earth’s atmosphere is holding on to all that energy while still receiving irradiation from the Sun, the planet heats up.  This is called the greenhouse effect, because it is similar to what happens in a greenhouse—the Sun’s energy can get in, but the heat cannot get out.  The greenhouse effect has intensified due to the greenhouse gases that are released during our modern industrial processes.  This has caused the Earth’s climate to begin to change.

 

Who contributed to the Climate Science Special Report?

The report was written by members of the American scientific community, including (but not limited to) the National Science Foundation, the National Aeronautics and Space Administration (NASA), the US Army Corps of Engineers, and multiple universities and national labs.  They analyzed data from articles in peer reviewed scientific journals—that is, other scientists read these articles before they were even published to check for questionable experiments, data, or conclusions—as well as government reports and statistics and other scientific assessments.  The authors provided links to each source in citation sections at the end of each chapter. They combined everything they learned into this one comprehensive document, the Climate Science Special Report.

What can we learn from this report?      

First of all, the report reveals that the Earth is getting warmer.  The average global surface temperature has increased about 1.8°F (1.0°C) since 1901.  This may seem like a small change, but this increase in temperature is enough to affect the global climate.  Sea levels have risen about eight inches since 1900, which has led to increased flooding in coastal cities.  Weather patterns have changed, with increased rainfall and heatwaves.  While the increased rainfall has been observed primarily in the Northeastern U.S., the western part of the U.S. has experienced an increase in forest fires, such as those that have devastated California this year.  Such changes in weather patterns can be dangerous for those who live in those areas.  They can even damage infrastructure and affect agriculture, which impacts public health and food production.  These changes mainly result from greenhouse gases, namely CO2, that humans have emitted into the atmosphere.

Where can I go to read the report myself?  

You can find a link to the main page of the report here.  There is also an Executive Summary, which was written for non-scientists.   While the rest of the report contains some technical language, it is generally accessible, and contains visuals to help readers understand the data.  If you are interested in gaining a better understanding of Earth’s climate and how it’s changing, we encourage you to take a look at the Climate Science Special Report to learn more.  

 

Peer edited by Amanda Tapia and Joanna Warren.

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Looking for a New Year’s Resolution? Shrink Your Plastic Footprint!

Plastics are nearly unavoidable. From the plastic bottle of water you grab walking into a meeting to the money in your wallet, plastics are ubiquitous. However, evidence is accumulating that heavy plastic use takes a hefty toll on the environment, especially the world’s oceans, which are the repository of nearly 4.8-12.7 million tons of plastic each year (about five bags of plastic for every foot of coastline in the world). Much of this marine plastic comes from litter that washes down storm drains into the oceans, but it can also be blown from landfills to end up in the ocean. Marine wildlife including fish, birds, seals, turtles and whales consume startling amounts of plastics, not only because these plastics look like dinner but because they often smell like it too. Dangers of plastics to marine animals include entanglement and intestinal perforation or blockage which can cause nutrient starvation—marine animals starving on a stomach stuffed with plastic. Researchers estimate that 90% of sea birds and half of all sea turtles have consumed plastics.

https://pixabay.com/en/rubbish-seaside-beach-waste-1576990/

Millions of tons of plastic waste winds up in the ocean each year.

More recently, the alarm has been raised about microplastics, small plastics and plastic fibers less than 5 mm in size. Microplastics can come from the degradation of larger plastics and from washing clothing containing synthetic fibers. Microplastics act like magnets for chemicals the U.S. Environmental Protection Agency (EPA) calls “Persistent Bioaccumulative and Toxic Substances” (PBTs). PBTs build up in the bodies of marine organisms and can harm us when we consume seafood. Though other potential dangers of microplastics to the environment are not clear yet, it has been shown that the decomposition of plastics can release toxic chemicals including bisphenol A (BPA),  a chemical which disrupts hormone balances and may be linked to human health concerns including diabetes, behavioral disorders like ADHD, and cancer. Researchers at the University of Missouri-Columbia have shown that some of the same adverse health effects occur in fish exposed to BPA, indicating a risk to marine food chains and ecosystems.  It is clear that we do not yet know the full impact of plastics in our oceans—but that the dumping of plastic waste into marine ecosystems is not without consequences.

Although some solutions to the plastic crisis have been floated (excuse the pun) including giant plastic-collecting booms which collect large plastic debris in the ocean and plastic-munching bacteria, these approaches are only beginning to be implemented and have limitations. This is where we come in — preventing more plastics from getting into the ocean is an important first step. Simply recycling our plastics may not be enough: one professor of economics cites plastics as one of the least valuable recyclable items due to the high energy and resource costs of processing them. As a result, it is imperative to focus on reducing, rather than recycling plastics.

Here are 100 ways to reduce your plastic use, ranging from reusable coffee cups to making your own deodorant to avoid the use of plastic packaging—an idea that doesn’t stink. Another way to track your plastic use is to accept the Plastic-Free Challenge—a social media challenge that lets you share your commitment to reducing your plastic footprint with all your followers. A good way to get started is to keep track of how much plastic you use and strive to reduce this amount every week. If you want to think bigger than your own plastic footprint, you can call your representatives about measures like plastic bag bans in your city and about funding research for equipping water treatment facilities to deal with microplastic-contaminated effluent. This year, I’ll be making it my New Year’s resolution to reduce my plastic consumption: a small change in habits that can add up. Let’s face it, I was never going to make it to the gym, anyway.

Peer edited by Erica Wood.

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