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Manatees are not Florida natives

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Florida is very proud of its manatees.  It has a county named after them and has pictures of them on license plates.  These gentle creatures are part of Florida culture.  But recent research indicates that manatees – also known as sea cows – might only be relatively recent residents of the Sunshine State.

Manatees have been spotted in Florida waters for several centuries but might have only been tourists visiting briefly before returning to their home waters in the Caribbean in places like Cuba.

The new research suggests that manatees might not have actually taken up residence in Florida until after Europeans colonized the area in the 1500s.  There is a rarity of manatee bones on archaeological sites that date back further.  It was particularly striking that Crystal River, which is an epicenter for modern manatee populations, had little evidence of their presence in earlier times.

Even into the early 1900s, Florida newspaper reports treated manatee sightings as a spectacle rather than a common occurrence.  In the 1920s and 1930s, there started to be more routine sightings in places like yacht basins and canal harbors.  In the 1950s, manatees became more plentiful in Tampa Bay and Crystal River. The warming waters and human activities creating shallow warm water refuges increased manatee populations, particularly near places like power plants.

The current Florida manatee population is between 8,000 and 12,000 and is classified as threatened under the Endangered Species Act, an improvement over its previous endangered status.  But pollution is killing a lot of the seagrass that they eat, and their safety is by no means assured.

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Why manatees are likely not Florida natives

Photo, posted March 25, 2012, courtesy of David Hinkel / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Greenhouse Gas Emissions Are Still Increasing | Earth Wise

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Recent research has found that the level of greenhouse gases emitted by human activity has reached an all-time high level of nearly 60 billion tons a year.  Despite increasing public attention, policy measures, and adoption of green technologies, the pace at which these changes have been taking place has simply not kept up with the ongoing burning of fossil fuels by increasingly industrialized societies.  The rate at which greenhouse gas emissions has increased over time has indeed slowed, but emissions need to start decreasing and as soon and as much as possible.

Human-induced warming has reached a ten-year average from 2013-2022 of 1.14 degrees Celsius above pre-industrial levels, up from a 1.07 degrees average between 2010-2019. 

Scientists have calculated a carbon budget that describes how much more carbon dioxide can be emitted before global warming exceeds the threshold of 1.5 degrees Celsius that is widely predicted to lead to potentially catastrophic changes to the climate.  In 2020, the Intergovernmental Panel on Climate Change calculated that the remaining carbon budget was about 500 billion tons of carbon dioxide.  Over the past three years, nearly half of that carbon budget has already been exhausted by the continuing onslaught of carbon emissions.

Researchers describe their study as a timely wake-up call that the pace and scale of climate action to date has been insufficient and that we need to change policy and approaches in light of the latest evidence about the state of the climate system.  Time is no longer on our side in trying to stave off the worst effects of climate change.

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Greenhouse gas emissions at ‘an all-time high’, warn scientists

Photo, posted September 18, 2015, courtesy of In Hiatus via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Emissions From Global Computing

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A recent study from Lancaster University in the UK has concluded that global computing is likely to be responsible for a greater share of greenhouse gas emissions than previously thought and that share is continuing to grow.

Previous calculations of the contributions from information and communications technology (or ICT) estimated that globally it accounts for 1.8 to 2.8% of total emissions.  According to the new study, these estimates likely fall short of the sector’s real climate impact because they only show a partial picture.

Prior estimates do not account for the full lifecycle and supply chain of ICT products and infrastructure.  They do not include the energy expended in manufacturing the products and equipment, the carbon cost associated with all the components in the products, and the operational carbon footprint of the companies producing those components. 

The study argues that the true contribution of ICT to global greenhouse gas emissions could be between 2.1 and 3.9%, which is more than the aviation industry.  Furthermore, the study warns that new trends in computing and ICT such as the use of big data and artificial intelligence, the so-called Internet of Things, and the use of blockchain and cryptocurrencies, risk driving further substantial growth in ICT’s greenhouse gas footprint.

It has been a commonly held believe that ICT and computing technologies lead to greater efficiencies across many other sectors, leading to savings in net greenhouse gas emissions.  According to the new study, the historical evidence indicates the opposite.  ICT has driven wide-ranging efficiency and productivity improvements, but the net result in emissions has been that they have been growing steadily.

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Emissions from computing and ICT could be worse than previously thought

Photo, posted March 13, 2018, courtesy of Flickr.

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Has Wheat Changed for the Worse? | Earth Wise

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In recent years, the number of people affected by celiac disease, wheat allergies, or gluten or wheat sensitivity has increased dramatically.  Why this should be is not well understood.  One theory is that modern wheat varieties contain more immunoreactive protein than those used in the past.  Researchers at two German research institutions investigated this issue in detail. 

Wheat grains contain about 70% starch.  Proteins constitute 10 to 12% of wheat, and nearly 80% of that protein is gluten.  Gluten is a compound mixture of two types of protein subgroups:  gliadins and glutenins.

The researchers investigated the protein content of 60 preferred wheat varieties in use during the period between 1891 and 2010, making use of an extensive seed archive.  They selected 5 leading wheat varieties for each decade over that 120-year period and cultivated the plants under the same geographical and climate conditions.

The results were that the modern wheat varieties actually contain slightly less protein than old ones.  Gluten content itself has been essentially constant over the 120 years, although the proportion of gliadins (which are the prime suspect for causing undesired immune responses) was actually 18% lower while the proportion of glutenins was 25% higher.

Overall, they found no evidence that the immunoreactive potential of wheat has changed over the years as a result of the cultivation factors.

The researchers note that some of the other, less significant proteins in wheat have not been investigated with regard to their physiological effects, so there is more work to be done.  But so far, the culprit for increasing wheat sensitivity has not been found.

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Is modern wheat off the hook?

Photo, posted July 3, 2009, courtesy of Clare Black via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Hidden Source Of Arctic Carbon | Earth Wise

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Researchers from the University of Texas at Austin, the U.S. Fish and Wildlife Service, and Florida State University have published a paper presenting evidence of significant and previously undetected concentrations and fluxes of dissolved organic matter entering Arctic coastal waters.  The source of the organic matter is groundwater flow atop the frozen permafrost.  The groundwater moves from land to sea unseen, but the new research reveals that it carries significant concentrations of carbon and other nutrients to Arctic coastal food webs.

Globally, groundwater is important for delivering carbon and other nutrients to oceans, but in the Arctic, where much water is trapped in the permafrost, its role was thought to be minimal.  But the new research reveals that groundwater may be contributing an amount of dissolved organic matter to the Alaskan Beaufort Sea that is comparable to what comes from neighboring rivers during the summer.

The researchers found that shallow groundwater flows beneath the surface and picks up new, young organic carbon and nitrogen, but it also mixes with layers of deeper soils and thawing permafrost, picking up and transporting century-to-millennia old organic carbon and nitrogen.  This material is unique because it is directly transported to the ocean without seeing or being photodegraded by sunlight and may be valuable as a food source to bacteria and higher organisms that live in Arctic coastal waters.

The study concluded that the supply of leachable organic carbon from groundwater amounts to as much as 70% of the dissolved organic matter that enters the Beaufort Sea from rivers during the summer.  The role that groundwater inputs play in Arctic coastal ecosystems will be an area of active research for years to come.

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Hidden Source of Carbon Found at the Arctic Coast

Photo, posted June 14, 2015, courtesy of Eugen Marculesco via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Air Pollution And Bone Health | Earth Wise

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Many of the negative effects of air pollution are well documented.  Studies have shown that exposure to air pollution is associated with an increased risk of lung cancer, stroke, respiratory and cardiovascular diseases, and so on. 

Now, according to a new study in India led by the Barcelona Institute for Global Health (ISGlobal), exposure to air pollution is also associated with a higher risk of developing osteoporosis.  Osteoporosis, which literally means porous bone, is a disease in which the density and quality of bone is reduced. As bones become more porous and fragile, the risk of fracture is greatly increased. 

The study, which surveyed 3,700 people from 28 villages in southern India, was recently published in the medical journal Jama Network Open.     

The researchers used a model to estimate air pollution by fine particulate matter (commonly referred to as PM2.5) and black carbon at each participant’s residence.  The research team then assessed bone health using a special type of radiography (called dual-energy x-ray absorptiometry) that measures bone density.  They measured bone mass of the participants’ left hip and at the lumbar spine.

The results showed that exposure to air pollution, particularly fine particulate matter, was associated with lower levels of bone mass.  Annual average exposure to PM2.5 was 32.8 micrograms per cubic meter, well above the maximum levels recommended by the World Health Organization (10 micrograms per cubic meter) and the U.S. EPA (12 micrograms per cubic meter).   

The researchers say their findings add to a growing body of evidence that indicates that particulate air pollution is relevant for bone health. 

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Air pollution can worsen bone health

Photo, posted November 15, 2019, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

We’re Still Eating The Wrong Things

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A new study published in the Journal of the Academy of Nutrition and Dietetics has found that despite efforts to increase public awareness of health issues related to diet, the amount of processed meat consumed by Americans has remained unchanged in the past 18 years.  Furthermore, our intake of fish and shellfish has not increased.  One quarter of US adults are still eating more unprocessed read meat than the recommended level, and less than 15% meet the current guidelines for fish and shellfish consumption.

About the only positive note is that Americans are eating less beef and more chicken than they did 18 years ago and, in fact, for the first time, the consumption of poultry exceeds that of unprocessed red meat.

Accumulating evidence has linked excessive consumption of processed meat to increased risk of obesity, diabetes, cardiovascular diseases, and some cancers.  The study’s authors speculate that public awareness of these linkages is not widespread enough to affect change and, in any case, factors other than health – social, cultural, and economic – have greater influence over Americans’ food choices.  The top five consumed processed meats are luncheon meat, sausage, hot dogs, ham, and bacon.

The low consumption of fish and shellfish among U.S. adults could be due to high retail prices, lack of awareness of the health benefits, and concerns about mercury contamination in certain types of fish.

Future research is needed to identify barriers to reducing processed meat consumption and increased seafood consumption.  Policies such as nutrition quality standards, excise taxes, health warning labels, and other interventions need to be explored.

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Americans still eat too much processed meat and too little fish

Photo, posted January 28, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

One Million Extinctions

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A group of 145 expert authors from 50 countries has produced a report based upon a review of 15,000 scientific and government sources that is the first comprehensive look at the state of the planet’s biodiversity in 15 years.  The conclusions are alarming.

Thanks to human pressures, one million species may be pushed to extinction in the next few years, something with serious consequences for human beings as well as the rest of life on earth.

Based upon scientific studies as well as indigenous and local knowledge, the evidence is overwhelming that human activities are the primary cause of nature’s decline.  The report ranked the major drivers of species decline as land conversion, including deforestation; overfishing; bush meat hunting and poaching; climate change; pollution; and invasive alien species.

The tremendous variety of living species on our plant which number at least 8.7 million and perhaps many more – biodiversity – constitutes a life-supporting safety net that provides our food, clean water, air, energy, and more.

In parts of the ocean, little life remains but green slime.  Some remote tropical forests are nearly silent because insects have vanished.  Many grasslands are becoming deserts.  Human activity has severely altered more than 75% of Earth’s land areas and has impacted 66% of the oceans.  The world’s oceans increasingly are characterized by plastics, dead zones, overfishing, and acidification.

The main message of the 1,500-page report is that transformative change is urgently needed.  In order to safeguard a healthy planet, society needs to shift from a sole focus on chasing economic growth.  This won’t be easy, but we must come to the understanding that nature is the foundation for development before it is too late.

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One million species at risk of extinction, UN report warns

Photo, posted January 1, 2014, courtesy of Eric Kilby via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Science And False Beliefs

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There are sizeable numbers of people who hold to beliefs that run counter to overwhelming contrary evidence. Flat Earthers and Holocaust deniers are well-known examples and, more recently, people – some of them in high places – who reject the evidence for climate change.

New research published in the journal Open Mind by developmental psychologists at UC Berkeley suggest that feedback, rather than hard evidence, boosts people’s sense of certainty when learning new things or trying to tell right from wrong.  People’s beliefs are more likely to be reinforced by the positive or negative reactions they are exposed to than by logic, reasoning, and scientific data.

People’s learning habits can limit one’s intellectual horizons.  According to the study, if you think you know a lot about something, even though you don’t, you’re less likely to be curious enough to explore the topic further and will fail to learn how little you know.

This phenomenon plays out in social media and cable-news echo chambers and explains how some people are easily duped by charlatans.  Receiving positive feedback for what they are saying can make people believe they know more than they actually do.  This confidence makes them less likely to seek out and learn more information about the subject, as well as take into account contradicting opinions or facts.

Another factor is that what influences people’s certainty is that their confidence tends to depend on what they heard most recently rather than on long-term cumulative data.  A few pieces of recent information tend to get much more attention than an extensive body of data.  If a crazy theory is able to make a correct prediction a few times, people tend to get fixed in their belief in that theory and be less open to other information.

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Here’s Why People Advocate False Beliefs, Conspiracy Theories Despite Evidence

Photo, posted February 2, 2007, courtesy of Tim J. Keegan via Flickr. 

Earth Wise is a production of WAMC Northeast Public Radio.

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)