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Posts Tagged ‘Global Warming

Science Policy Around the Web September 8th, 2020

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By Andrew Wright, BSc

Image by Heidelbergerin from Pixabay 

Ice sheet melt on track with ‘worst-case climate scenario’ 

While RCP 8.5, or the ‘worst-case scenario’ climate model may be unlikely in its entirety due to global reductions in coal use, at least one factor, glacial melting, is tightly adhering to the most severe model from the Intergovernmental Panel on Climate Change (IPCC) fifth assessment report according to a paper published in Nature Climate Change. Greenland and Antarctica, which are particularly sensitive to global warming, have lost a combined 6.4 trillion tons of ice since 1992 and now account for a third of all sea level rise. Should the rates of glacial ice melt continue to accelerate at their current pace and track with extreme climate models, sea levels are predicted to rise by 17.8 cm by 2100 from ice melt alone. To put that in perspective, since 1993 the ocean has risen by about 8cm and flooding in the United States has increased by over 200%. In addition, glacial lakes, or reservoirs of ice melt are rapidly forming that pose flood dangers to communities at lower elevations.

The Greenland ice sheet may be past the point of no return now that annual snowfall is no longer sufficient to replenish glacial mass lost through warming oceans and higher air temperatures. In addition, extreme melting events where billions of ice are lost in a single day are starting to occur. As the world is faced with at least some level of inevitable sea level rise that will cause trillions of dollars in damage in coastal and river communities, governments will have to invest not only in carbon reduction strategies, but also protective infrastructure. 

(The European Space Agency

Written by sciencepolicyforall

September 8, 2020 at 12:44 pm

Science Policy Around the Web August 27th, 2020

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By Mohor Sengupta, PhD

Image by skeeze from Pixabay 

Why Does California Have So Many Wildfires?

Yet another bout of wildfire season is raging in large forested swathes of California. Firefighters are struggling to bring to control 560 wildfires burning throughout the most populous state in the United States. A beloved redwood forest is directly under attack. The current fires are among the largest wildfires in the history of California. Brought about by lightening strikes, these fires have prompted evacuation orders for 48,000 people residing in Santa Cruz county. The ongoing and relentless pandemic has made evacuees wary of shelters where thousands are expected to stay put. So why are we seeing increasing wildfires in California? Ten largest fires in state records dating back to 1932 have occurred after 2000. Experts point to four basic reasons:

  1. Climate change

California gets most of its rainfall in the fall and winter months. That is when new vegetation springs to life. Over the hot and dry months of the summer, existing vegetation becomes dry, creating highly inflammable material waiting for a random spark, a lightening strike, or some thoughtless human activity, to turn into a smoldering mass that can quickly get out of hand. Gradual climate change has increased general summer temperatures by one to two degrees Fahrenheit, worsening the problem.  

  • Human activities

The Carr fire in 2018 started when sparks flew after a flattened truck tire scraped against the pavement. It was the sixth largest fire on record in California. Over the years people have also moved toward forested areas, which are called urban-wildland interface. Human activities, or results of human habitation, like downed power lines near forests, are a great recipe for fires. 

  • The method of controlling fires

Counterintuitive as it may seem, the long-existing strategy of firefighting that douses all burning vegetation might have caused the accumulation of more burnable material over the years! Experts say that had there been controlled burning, there would be lesser plants to start fires in the zones currently being affected by wildfires. The United States Forest Service has started using controlled burns in recent years to address this issue. 

  • Seasonal winds

A study has suggested that California has two fire seasons. One that is happening now, usually ranges from June through September and targets forested highlands. It is the wildfire season we are familiar with. A second, more devastating fire season is from October through April. That is caused by dry, hot winds, called Santa Ana winds, that blow from the Great Basin area into Southern California. These fires spread a lot faster and wreak havoc in urban areas. Since the last 20 years, this second fire season has caused 80 percent of the total economic damage caused by wildfires in California! 

(By Kendra Pierre-Louis and John Schwartz, The New York Times)

Written by sciencepolicyforall

August 27, 2020 at 2:32 pm

Science Policy Around the Web July 21st, 2020

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By Andrew Wright BSc

Image by Magnascan from Pixabay 

Methane rises to highest level on record 

Methane emissions across the globe have led to record atmospheric concentrations of the potent greenhouse gas, the increase of which tracks with the Intergovernmental Panel on Climate Change’s “doomsday” climate model RCP8.5. According to an article published in Environmental Research Letters, global methane emissions are 9% higher than the average period of 2000-2006 when methane levels were relatively stable. As of 2019, atmospheric methane is approximately 1875 parts per billion (ppb), or two-and-a-half times preindustrial levels, and has contributed to a quarter of gaseous warming (also known as “radiative forcing”).

The increases in methane emissions were uneven, both geographically and by industrial sector. While China saw the largest increase, the rest of Asia, Africa, the Middle East, and North America (largely driven by the United States) also demonstrated large increases in methane emissions, while Europe saw a modest decrease. The largest contributor to Asian and African methane levels were agricultural practices, whereas the United States created increases largely from hydraulic fracturing (or fracking) and other fossil fuel utilization. 

This suggests that policies could be tailored by region. In Africa, where food security is affected by farming practices and is recursively vulnerable to climate change, agricultural policies that diversify and make farming sustainable could be beneficial. In the United States, policies could be put in place to reduce fossil fuel use and exploration while also managing the increasing burden of natural gas leaking from abandoned wells. Policies that have been effective in Europe such as those that reduce emissions from landfills could also be applied more broadly.

(Jonathan Watts, The Guardian

Written by sciencepolicyforall

July 21, 2020 at 10:55 am

Science Policy Around the Web May 5th 2020

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By Hannah King, PhD

Image by Free-Photos from Pixabay 

Renewable power surges as pandemic scrambles global energy outlook, new report finds

The current coronavirus pandemic and resultant economic instability have led to a sharp drop in global energy use, and consequently, carbon emissions. A new report from International Energy Agency posits that this may transform global energy use even beyond the end of this pandemic.

In countries with strict lockdowns in place, energy use has declined by 25% week-to-week with an estimated 6% global decline across 2020. This decline has been driven by high carbon emitting energy sources, such as coal which has declined by 8% and oil which has declined by 5%. This may be due to the difficulties in storage and supply chains required for these fossil fuels. In contrast, renewable energy use has risen by 1.5% in the first 3 months on 2020, and overall renewable energy demand is expected to increase by 1% this year.

While this trend may wane as economies begin to re-open, some countries, such as South KoreaGermany and the U.K., have indicated they wish to invest in technologies to reduce climate change as part of their economic recovery plans. Fatih Birol, the executive director of the International Engery Agency, has urged other governments to follow suit and place renewable energy investments “at the heart of their plans for economic recovery”, while predicting that “the energy industry that emerges from this crisis will be significantly different from the one that came before”.

(Warren Cornwall, Science)

‘Autistic voices should be heard.’ Autistic adults join research teams to shift focus of studies

Autistic people are increasingly being included in research teams studying autism, especially in adults, a population sometimes overlooked in autism research. The focus of such research is also shifting from medically-oriented studies attempting to find either a medical cause or cure for autism, towards research into strategies to assist autistic individuals succeed in society and the workplace.

One example is a recently published study assessing burnout in autistic workers that demonstrated such burnout is often due to the accomodations autistic workers need to perform to mask autistic behaviours, which are associated with chronic exhaustion. The authors suggest the onus should fall on workplaces to introduce solutions, such as not pressuring autistic workers to appear “neurotypical” and providing flexible working arrangements. 

By including autistic researchers in the design and implementation of studies, researchers such as Christina Nicolaidis, who has an autistic adult son, say that this inclusion has helped them to better design studies to obtain reliable and rigorous data. Nicolaidis contends that failing to get this input is “like doing research in Spanish and not having anybody who’s Latino on your team.”

This philosophy is exemplified by the new journal Autism in Adulthood which publishes quarterly issues. Here, several members of the editorial team are austistic researchers, and at least one reviewer for each article submitted is autistic. These reviewers provide valuable input, such as ensuring the accessibility of language used in manuscripts. TC Waisman, an autistic member of the editorial team, summarizes the importance of this inclusion with “autistic voices should be heard and acknowledged first and foremost”.

(Emily Willingham, Science)

A Strange Dinosaur May Have Swum the Rivers of Africa

A fossil dinosaur tail found in Morocco may indicate the existance of a predatory dinosaur able to swim and hunt underwater. This dinosaur is Spinosaurus aegyptiacus, a 40 foot long, 6.5 tonne creature with crocodile-like jaws. The newly discovered tail fossil, described in the journal Nature, has long fins rising vertically from it, suggesting the tail may be capable of undulating side-to-side to swim underwater, placing the morphology of Spinosaurus aegyptiacus like a cross between a lizard and an eel.

However, other paleontologists have contested the plausibility of these claims. David Hone, a paleontologist at Queen Mary University of London in England commented “I’m extremely unconvinced by some of the ecological interpretations that they placed on it”. Another researcher Donald M. Henderson, from the Royal Tyrrell Museum in Alberta, Canada instead believes this species of dinosaur lived a lifestyle much more similar to a grizzly bear, living near the edge of the water and eating fish. The study’s authors are receptive to these criticisms, and plan to continue their research. Despite, or possibly because of this discussion, it certainly seems true, as author Dr. Stephanie E. Pierce of Harvard says, that “it’s going to lead to all sorts of cool analyses.”

(Kenneth Chang, New York Times

Climate Change and Human Health

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By Sanjay Gautam, PhD

Image by Pete Linforth from Pixabay 

The World Health Organization recently listed climate change as one of the ‘urgent global health challenges’ for upcoming decades. A healthy planet offers every living being a better place to live. The effect of climate change on human health is obvious and anyone who ignores this fact are ‘fooling themselves’ (George Benjamin, Executive director of American Public Health Association). Climate change essentially refers to an increasing rate of global temperature commonly referred to as global warming. This happens when there is an imbalance between incoming solar radiation to the earth’s surface and its exit with greenhouse gases (carbon dioxide, methane and nitrous oxide) being the sole culprit.  So, how does this affect the epidemiology of infectious diseases? 

There are multiple mechanisms described to relate the increasing incidence of communicable diseases and earth’s raising temperature. For example, warmer air retains more moisture and causes heavy rainfall in some places and drought in others. Increased availability of stagnant water and temperature above 16°C allows the malaria transmitting mosquitoes to breed increasingly well. In contrast, places with drought will have increased numbers of West Nile virus infection as water scarcity brings its primary host mosquito and bird in close proximity resulting in disease transmission.  As the environment gets warmer, the spread of flu is not limited to a single season, but rather continues year-round (William Schaffner, Vanderbilt University). An investigation by Towers and colleagues investigated the pattern of Influenza seasons in the United States between 1997 to 2013 and concluded that severe epidemic and early onset of the disease is preceded by warmer winters (Towers et al., PLoS Curr, 2013). Similarly, countries with cooler climate are getting record number cases of vector borne diseases (for example, dengue, chikungunya) and spread of diarrheal illnesses in colder seasons. 

The effect of climate change makes live, livelihood and economy vulnerable and therefore warrants a coordinated approach which fortunately is within the reach. A strong political will is key to recognize the depth of the issue and prioritize the measures to mitigate the effects of adverse environmental phenomenon. The Centers for Disease Control and Prevention (CDC)has issued a policy on climate change and health with an objective to place the system to detect and track the adverse health effects with no delays; and, work towards effectively managing and responding the public health challenges. The impact of climate change in human health can be predictable or not and may vary with regions and communities.  The CDC’s priority area for public health preparedness includes, credible dissemination of information, tracking the data, model and predict the health effects, scientific capacity building, identification of communities at high risk, establish partnership with stakeholders, provide leadership, implement preparedness and response plans, provide technical assistance and promoting the workforce development. Similarly, American Public Health Association and the World Health Organization are actively prioritizing the discussions on global warming, health and  policy action agenda to adequately prepare to mitigate the human health challenges due to change in rising global temperature. There is an urgent need to develop and implement sustainable development programs and educate young generations the effects of poor climate, for example through incorporating the issues of climate change in curriculums.  

Written by sciencepolicyforall

March 20, 2020 at 4:01 pm

Wildfire reduction policies after a summer of Australian burning

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By Hannah King, PhD

Image by skeeze from Pixabay 

As an Australian watching the wildfires burn across my country from afar, I have been filled with grief at all the damage that has occurred. Like many people around the world I am confused as to how an event of such scale happened. I have been filled with questions about how, both on a policy and individual level, such large-scale burning events can be prevented, or their effects mitigated in the future.

Wildfires, or bushfires as they are known in Australia, are large, powerful fires that burn out of control. Wildfires play an important role in many ecosystems, clearing debris to allow smaller and younger plants to flourish, increasing soil fertility by returning nutrients, creating new habitats and germinating seeds from some plants, such as many species of pine trees. Conversely, when they occur in or near populated areas wildfires can claim lives, damage property and cause health effects from smoke inhalation. Wildfires can kill wildlife or contribute to habitat loss for many species (e.g. koalas in Australia, orangutans in Indonesia and jaguars in Brazil), be a means of deforestation (either intentional or unintentional) and result in increases to the global level of greenhouse gasses, resulting in further climate changes.

As humans have spread across the globe and shaped their surrounding environment, they have concurrently changed both wildfire frequency and severity. Moreover, in the last few decades wildfires have become increasingly prevalent, due to changes in heat and moisture levels from climate change, changes in the flora comprising ecosystems to more fire-sensitive species, and the deliberate starting of fires by humans or accidental starting of fires via human-produced technologies (e.g. power lines). In Australia, scientists have predicted that the hot and dry conditions that were present in the 2019/2020 fire season are 8 times more likely to occur if 2°C global warming occurs. Already this year in the Australian wildfires, many occurred in normally cool and wet areas that typically do not burn.

A major policy question therefore is what interventions can be implemented to reduce the incidence and severity of wildfires? Two strategies that are often employed are controlled burning and thinning of vegetation. Both of these strategies aim to reduce fuel loads, and thereby either prevent fires from occurring or reduce their severity and the speed of their spread. Despite the seemingly similar goals of these strategies, they result in distinctly different outcomes. Controlled burning can be difficult to execute safely and is not always politically popular due to concerns about the potential for these deliberately lit blazes to escape control and damage people or property. Additionally, as any kind of burning will destroy flora and fauna, controlled burning is often avoided in areas of conservation importance, such as the habitats of endangered animals and plants. As a result, controlled burning is only appropriate for certain environments and in certain weather conditions. Forest thinning, in contrast, does not pose the risk of creating out-of-control blazes, enabling it to be applied in more settings increasing its popularity. Moreover, the wood by-products from this process can also be sold to industry, thereby creating a profit or offsetting some of the associated costs.

However, vegetation thinning often breaks up larger debris into smaller pieces which remain on the forest floor, providing a source of fuel that can increase the spread and severity of forest fires. In addition, given that fires provide benefits to many ecosystems as discussed above, fire management strategies that try to suppress all fire can risk disturbing the natural ecosystem balance. Because of this, in environments where it can be performed safely, controlled burning may be the more appropriate – and most overall beneficial – option. To mitigate the risks of controlled burning, further research into how fires spread in different landscapes and weather conditions will decrease the risks of controlled burns escaping control.  Additionally, in areas where endangered species live, the use of a “mosaic” burning pattern – in which only patches or swathes of land are burnt, leaving surrounding areas fire-free – will still provide the benefits of controlled burning in reducing fire spread, but also allow havens of wildlife to remain untouched.

As well as prescribed burns and careful forest management, there are other strategies and policy initiatives which could help reduce wildfires. Due to human intervention and a changing climate, many forests around the world are losing biodiversity and may be comprised of increased proportions of fire-sensitive species. Changing forest composition to increase biodiversity could both increase ecosystem health and reduce the spread of wildfires.

An further strategy that may aid fire management efforts is the inclusion of Indigenous Fire Stewardship within organized fire management efforts. Many indigeous peoples around the globe practiced extensive fire management strategies prior to colonization to modify their environment, increase the abundance of desired resources and reduce the severity of subsequent wildfires. Today many indigenous groups live in environments highly vulnerable to the threat of wildfires, yet today often have little representation within state or national fire management bodies. Cultivating and including indigenous knowledge and practices within forest management strategies may help us find ways to live with fire, thereby gaining the benefits it provides to many ecosystems, instead of fighting it. In the Northern Territory of Australia, the use of cultural burning has reduced destructive wildfires by 40% over the last decade

Another factor affecting wildfire severity, especially its effects on human health and property, is the continued encroachment of human settlements into forested areas. If wildfires continue to increase in severity, a necessary – but contentious – policy solution may be to discourage building of new infrastructure in extremely wildfire-prone areas, similar to policies discouraging building in flood-prone areas. This would reduce the resources needed to respond to fires when they do occur, as human settlements often, and rightly, take priority for protection by fire services. In addition, increases in government spending not only on wildfire response, but on prevention programs, such as controlled burning, and national or multinational preparedness efforts (rather than piecemeal local efforts), may reduce the severity and frequency of wildfires.

The measures outlined above aim to stop individual fires from occurring, however the main factor leading to an increased risk of fires is changes in weather patterns due to human-created climate change. The primary solution to globally reduce the severity and frequency of wildfires is to seriously address climate change. As individuals, we can both advocate for better wildfire prevention policies and funding, but also urge governments to step-up their response to climate change. By depoliticizing climate change and investing heavily in existing renewable energy technologies and research to develop the renewable energies of tomorrow governments can create real and lasting change. This will have the benefit of not only reducing wildfires, but also reducing the incidence of other extreme weather events such as drought and flooding, increasing food security, improving economic outcomes, reducing sea level rise, and preventing further degradation of the environment and the planet we call home.

Written by sciencepolicyforall

March 14, 2020 at 7:54 pm

Science Policy Around the Web February 25th, 2020

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By Andrew Wright BSc

Image by CheapStockImage_com from Pixabay

Humans are a bigger source of climate-altering methane, new studies suggest

One of the holes in modern climate research is an appropriate estimate of newly emerging positive-feedback loops and their planetwide impact. One such phenomenon that has been previously put forward is the “clathrate gun” hypothesis, which theorizes that an increasingly warm environment will be capable of releasing crystallized methane frozen in arctic permafrost and shallow waters. This would, in turn, lead to more warming and more methane release, potentially causing a catastrophic runaway warming event. However, recent studies have suggested that arctic deposits of ocean-bound methane are less sensitive to warming than previously thought and new data from the University of Rochester seems to confirm that idea in terrestrial deposits of crystalline methane as well.

In order to assess the effect of different global average temperatures on release of methane from natural sources, researchers took advantage of radioactive carbon isotope levels (like carbon-14) in ice core samples that marked the last climate transition; during the most recent ice age thousands of years ago. Since carbon-14 is formed by solar radiation, if methane was released from large underground and underwater sources following the last warming it should have shown a smaller percentage of carbon-14 than methane sampled from when the earth was much cooler. Instead, levels of carbon-14 were similar across samples, suggesting that an increase in release of crystalline methane did not occur.

 Importantly, another study was able to demonstrate with the same technique that the large increase in methane emissions following the industrial revolution were almost entirely anthropogenic. In fact, they demonstrated that the amount of naturally generated methane was generally in agreement with the estimates of those levels from the last ice age, which would mean that most modern methane release is from human consumption. While this does provide stark evidence of the increasing level of methane that is being released from industrial sources, it also means that ultimately the amount of methane that acts as a greenhouse gas can be controlled though inter-governmental policy corrections.   

(Warren Cornwall, Science)

African killifish may hold key to stopping aging in humans

While many forms of anti-aging research have focused on telomerases and stem-cell therapies, an increasing emphasis is being put on diapause, the phenomenon of biological suspension. When diapause is induced, often during developmental periods and in response to environmental pressure, organisms largely cease cellular activity and do not age. The mechanisms of this process were generally unknown, but research from Stanford University has started to elucidate them. Here, researchers focused on the African killifish, the eggs of which can enter diapause in response to months-long droughts.

After inducing diapause in killifish embryos, researches analyzed which genes and proteins were more active. They found that a particular protein called CBX7 was greatly increased.  To determine the function of this protein, researchers generated a genetically modified killifish with impaired CBX7-encoding genes using the gene-editing tool CRISPR-Cas9.  Genetically modified animals showed changes in genes that regulated metabolism, muscle development and maintenance, hormones, and neurotransmitters. They also experienced muscle atrophy within a month of diapause and were not able to maintain diapause for as long. 

While this research is far from being applicable in humans, it is a step closer than nematodes like C. Elegans, or the beloved extremophile known as the tardigrade, or “waterbear”.  Still, the study raises the prospect of another avenue of research that might limit or pause aging in other living systems. 

(Nicola Davis, The Guardian

Written by sciencepolicyforall

February 25, 2020 at 11:14 am

Science Policy Around the Web January 16th, 2020

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By Andrew H. Beaven, PhD

Facts & Figures 2020 Reports Largest One-year Drop in Cancer Mortality

On January 11, 1964, the U.S. Surgeon General reported that cigarette smoking is a cause of lung cancer and laryngeal cancer in men, a probable cause of lung cancer in women, and the most important cause of chronic bronchitis. This led to the Federal Cigarette Labeling and Advertising Act of 1965 and the Public Health Act of 1969 that required warnings on cigarette packages, banned cigarette advertising in broadcasting media, and called for an annual report on the health consequences of smoking. 

Fifty-six years later, lung cancer is still the leading cause of cancer mortality in the U.S. – accounting for almost one-quarter of all cancer deaths. However, with an ever-increasing understanding of how to treat cancer and America’s general cessation, the American Cancer Society announced a 2.2% drop in the American cancer death rate between 2016 and 2017, the largest single-year drop in cancer mortality (statistics are reported in the American Cancer Society’s peer-reviewed journal, CA: A Cancer Journal for Clinicians). This substantial mortality rate decrease is primarily attributed to a decrease in lung cancer deaths. Coincidentally, the report aligns with recent legislation raising the age to buy tobacco products from 18 to 21 years old. This legislation was included in the federal year-end legislative package, passed by both houses of Congress, and signed into law on December 20, 2019 by President Donald Trump. The goal of the legislation is to keep tobacco out of teenager’s hands, with the hope that if teens do not start using tobacco early, they will never start using tobacco products.

(Stacy Simon, American Cancer Society)

NASA, NOAA Analyses Reveal 2019 Second Warmest Year on Record

New, independent analyses by U.S. federal agencies NASA and NOAA demonstrate Earth’s continuing warming. Global surface temperatures in 2019 were the second hottest since 1880 when modern recordkeeping began. These results, posted online January 15, continue the concerning trend – the past 5 years have been the warmest of the last 140 years (the hottest year was 2016). NASA and NOAA report temperature on a relative scale based on the mean temperature between 1951–1980. The 2019 anomaly was 1.8 ºF (0.98 ºC) warmer than the 1951–1980 mean. The report makes special note that average global warming does not imply that all areas experience the same warming. For example, NOAA reported that the contiguous 48 U.S. states experienced the 34th warmest year on record, simply giving it a “warmer than average” classification. Meanwhile, Alaska experienced its warmest year on record.

To account for biases, the scientists take into account the varied spacing of the temperature stations, urban heat island effects, data-poor regions, changing weather station locations, and changing measurement practices. Through continuing modeling and statistical analyses, scientists continue to conclude that this rapid uptick in temperature is because of increased greenhouse gas emissions caused by human activities.

(Steve Cole, Peter Jacobs, Katherine Brown, NASA)

Written by sciencepolicyforall

January 16, 2020 at 9:38 am

Science Policy Around the Web August 16th, 2019

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By Neetu M. Gulati PhD

Image by vegasita from Pixabay 

How Eating Less Meat Could Help Protect the Planet from Climate Change

A recent report by the United Nations climate science body, the Intergovernmental Panel on Climate Science (IPCC), warns that now is a moment of reckoning for how humans use the planet. The report highlights how the planet has been impacted by land-use practices, deforestation, agriculture, and other activities. These threaten our ability to limit the global temperature increase as outlined by the 2015 Paris climate agreement. The report further outlines how humans can help stop the impacts of climate change by drastically changing what food we eat as well as how it is produced.

Explaining this logic, Debra Roberts, the co-chair of the IPCC Working Group II, commented, “some dietary choices require more land and water, and cause more emissions of heat-trapping gases than others.” If people eat more sustainably grown and produced foods, as well as more plant-based diets, this could provide opportunities to adapt and mitigate the potential climate issues. Meats like beef and lamb are particularly taxing on the environment for the amount of meat obtained, partially because such livestock require a large space to graze. Reducing the amount of land to produce meat and also using that land more efficiently through sustainable farming practice will be imperitive to ensure that land remains usable as the planet warms. 

While a lot of the world already eats majority plant-based diets, the countries that eat a lot of meat tend to be wealthier countries. As countries with lesser meat consumption gain wealth, there is a risk that they will eat more meat and put a greater strain on the environment. While not every country will stop eating meat, the recent popularity of meatless products is encouraging, and hopefully the public will begin to focus on the fact that food and agriculture are important in the fight against climate change.

(Abigail Abrams, Time)

“Qutrit” Experiments are a First in Quantum Teleportation

Many believe that quantum information science is a key avenue of research for future technologies. Now, for the first time, researchers have used this technology to teleport a qutrit, a tripartite unit of quantum information. This is an important advance for the field of quantum teleportation, previously limited to the quantum equivalent of binary bits of information known as qubits. The two research teams who independently achieved this feat first had to create qutrits from photons, a challenge in and of itself. Because qutrits can carry more information and have more resistance to noise than qubits, these experiments may mean that qutrits become an important part of future quantum networks.

In quantum science, the states of entangled particles have a connection. Thus, in quantum teleportation, the state of one entangled particle, for example the spin of an electron particle, influences the second particle instantaneously, even if far apart. While this sounds like something out of a science-fiction story, this milestone may have important real-world implications. Quantum teleportation may be important for secure communications in the future. In fact, much of the quantum teleportation research is funded because of its importance for the future of cybersecurity.

The qutrit teleportation experiments were independently performed by two research teams. One team, led by Guang-Can Guo at the University of Science and Technology of China (UTSC), reported their results in a preprint paper in April 2019. The other team, co-led by Anton Zeilinger of the Austrian Academy of Sciences and Jian-Wei Pan at the UTSC, reported their findings in a preprint paper in June 2019 that has been accepted for publication in Physical Review Letters. The two teams agree that each has successfully teleported a qutrit, and both have plans to go beyond qutrits, to at least ququarts (four level systems). Other researchers are less convinced, saying the methods used by the two teams are slow and inefficient, and therefore not suited for practical purposes. In response, one of the authors of the paper by Zeilinger and Pan’s team, Chao-Yang Lu, said, “science is step by step. First, you make the impossible thing possible. Then you work to make it more perfect.”

(Daniel Garisto, Scientific American

 

Written by sciencepolicyforall

August 16, 2019 at 3:15 pm

Homegrown Apocalypse: A Guide to the Holocene Extinction

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By: Andrew Wright BSc

Homegrown Apocalypse: A Guide to the Holocene Extinction

One of the unifying factors of mass extinctions is a rapid change in global average temperature. The end-Ordovician extinction, the second largest, occurred when newly forming mountains made of silicate rock quickly absorbed atmospheric CO2. The global average temperature plunged, leading to the formation of enormous glaciers, drastically lower ocean levels, and much colder waters. Since complex life was still relegated to the oceans, this killed 86% of all species. The most well-known extinction is the end-Cretaceous or K-Pg event caused in part by a massive asteroid impact in Chicxulub, Mexico. The immediate impact, roughly one billion times stronger than the atomic bombings of Japan, was devastating in its own right. However, the subsequent ejection of sulfate-bearing rock into the atmosphere was the real killer, dropping global temperatures by 2-7°C, inhibiting photosynthesis, and acidifying the oceans. Coming right after a period of global warming, this extinction killed about 76% of all species.

            These extinctions pale in comparison to the end-Permian extinction, also known as the Great Dying. When Pangea was the sole continent, an enormous pool of lava called a flood-basalt plain slowly erupted over what is modern-day Siberia. Over 350,000 years, magmatic rock up to a mile thick solidified and covered an area roughly half the size of the United States. This igneous cap forced underground lava to move sideways and spread in paths called sills. As the lava traveled, it vaporized increasing amounts of carbonates and oil and coal deposits, leading to an immense build-up of CO2. Once the sills reached the edge of the cap, these gases were violently expelled, ejecting up to 100,000 gigatons of CO2. The immediate effect was a global average temperature increase of roughly 5°C. Subsequently, oceanic methane hydrate (or methane clathrate) crystals, which become unstable at high temperatures, broke down. Since methane is 20-80 times more potent than CO2as a greenhouse gas, global average temperature increased a further 10°C, bringing the total to 15°C. This left the planet barren, desertified most of Pangea, strongly acidified the oceans, killed 96% of marine life, and 90% of all life on Earth.

            We are currently living through the beginnings of the sixth mass extinction event, known as the Holocene. Species are dying off 10-100 times faster than they should and that rate is accelerating. Insects, including pollinators, are dying off so quickly that 40% of them may disappear within decadesOne in eight birds are threatened with extinction, 40% of amphibians are in steep decline, and marine biodiversity is falling off as well. At current rates, half of all species on Earth could be wiped out by the end of the century. 

What is the commonality between our present circumstances and the past? As with previous mass extinctions, global average temperature has increased. Since 1880, global average temperature has increased by 0.8°C and the rate of warming has doubled since 1975. This June was the hottest month ever recorded on Earth, with global average temperature reaching 2°C above pre-industrial levels. Greenland lost two billion tons of ice in one day. This increase in temperature is because we are currently adding 37.1 gigatons of CO2 per year to the atmosphere, and that number is rising

            From the most recent International Panel on Climate Change (IPCC) report, we know that the best outcome is to keep the increase in global average temperature below 1.5°C. Instead, let us consider what would happen if current trends stay the same and CO2 emissions continue to increase at similar rates until 2100. This is known as the RCP 8.5 model. Under this paradigm, atmospheric CO2 levels will rise from 410 parts per million (ppm) to 936 ppm. The global average temperature will increase by 6°C from pre-industrial levels. That puts the Earth squarely within the temperature range of previous mass extinction periods. 

Given this level of warming the following can be expected to occur: first and foremost, the extreme heat on the planet will massively decrease glaciation, causing a surge in ocean levels. Since water expands as it gets warmer, ocean levels will increase even further to about 12ft higher than current levels. This means most coastal areas will perpetually flood while others will be completely underwater. Unfortunately, non-coastal areas won’t be free from hardship as high air temperature will cause desertification, crop die-off, drought, and widespread wildfires. Secondly, as the ocean absorbs CO2 from the atmosphere, it will become increasingly acidic. So far, the pH of the ocean has only changed by 0.1, but under an RCP 8.5 model, that decrease could be as high as a 0.48 reduction in pH. Since this measurement is on a logarithmic scale, this means that the oceans will be acidic enough to break down the calcium carbonate out of which shellfish and corals are built. Warmer water cannot hold oxygen as effectively as cold, meaning many water-breathing species will suffocate. In combination, these two factors will serve to eliminate a huge source of the human food supply. Finally, since weather patterns are based on ocean and air currents and increasing temperatures can destabilize them, massive hurricanes, dangerously cold weather systems, and flood-inducing rainfall will become the norm. 

One parallel to the end-Permian extinction might result as well. Over millions of years, methane clathrate re-stabilized in the permafrost of Siberia and in the deep ocean floor. But in what has been termed the clathrate gun hypothesis, if methane clathrate destabilizes again at high temperatures, then the resultant methane emissions and planetary warming could form a positive-feedback loop, releasing even more crystallized methane until we end up in another “great dying”. While short-term warming probably won’t cause a runaway temperature increase, a 6°C increase in global average temperature might. New research suggests methane release may not even be necessary as the ocean is reaching a critical point in the carbon cycle where it could rapidly expel an amount of CO2on par with flood-basalt events. Moreover, like the end-Permian extinction, anthropogenic climate change is occurring on a near instantaneous geological time scale and species, including our own, will not have the requisite time to adapt.

Of course, none of these effects exists in a vacuum. They will be alongside increasing deforestation for agriculture, plastic and chemical pollution, and resource extraction. The end result would be a planet with less space, little food, mass migration, and devastating weather. So, what can be done to stop this scenario from coming true? The latest IPCC report essentially places humanity at an inflection point. Either CO2output is cut in half by 2030 and humans become carbon neutral by 2050, or the planet is irrevocably thrust past the point of no return. 

This timeframe may seem short, but it takes into account that even if civilization were to completely stop emitting greenhouse gasses today, it would take hundreds of years for global average temperature to  go back down since it takes time for the ocean to absorb CO2from the atmosphere. Like any problem of scale, there is no one solution to reaching carbon neutrality and it will take a multivariate approach. Some solutions include enacting carbon tax measures, subsidizing and implementing renewable energy (while divesting from new coal and oil production), an increased reliance on nuclear power, large-scale reforestation, livestock reduction, and carbon-sequestration technology. Some of these efforts have come a long way and some have gone in the wrong direction.

This is, of course, a global problem to be solved. At a time when the United States has signaled its intention to withdraw from the Paris Climate Accord as soon as possible and states are rejecting carbon cap-and-trade measures, other nations are moving ahead with unprecedented boosts in renewable energy and bold commitments to reducing greenhouse gas emissions. India, the third-largest polluter after the United States, is on track to surpass its Paris Accord commitments. Should the United States re-engage with and lead the international effort to tackle what is an existential threat, then it is not improbable that the end of this century could be a pleasant one. So, if the idea of living through a global extinction event is disconcerting, one can be assured that the problem is still just barely a solvable one. 

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Written by sciencepolicyforall

July 11, 2019 at 4:24 pm