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Turning Food Waste Back Into Food | Earth Wise

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Scientists at the University of California Riverside have discovered that fermented food waste can boost bacteria that increase crop growth, make plants more resistant to pathogens, and reduce the carbon emissions resulting from farming.

Food waste is a serious problem from multiple perspectives.  As much as 50% of food is thrown away in the United States and most of that simply ends up in landfills, taking up more than 20% of America’s landfill volume.  Food waste is a huge economic loss as well as a significant waste of freshwater resources used to produce food.

The researchers studied byproducts from two kinds of food waste readily available in Southern California:  beer mash – a byproduct of beer production – and mixed food waste discarded by grocery stores.

Both types of waste were fermented and then added to the irrigation system watering citrus plants in a greenhouse.  Within 24 hours, the average population of beneficial bacteria was two to three orders of magnitude greater than in plants that did not receive the treatments. This led to improvements in the carbon to nitrogen ratio in crops.  When there are enough so-called good bacteria in plants, they produce antimicrobial compounds and metabolites that help plants grow better and faster.

The results of the study suggest that the use of food waste products in agriculture is beneficial and could complement the use of synthetic chemical additives by farmers, perhaps eliminating it entirely.  Crops would in turn become less expensive.

Making use of food waste in agriculture is a step towards a more circular economy in which we use something and then find a new purpose for it.

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Turning food waste back into food

Photo, posted October 28, 2012, courtesy of Daniel Lobo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Not All Eggs In One Basket | Earth Wise

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Sea turtles lay their eggs in burrows on sandy beaches.  Many species lay their eggs on the exact same beach year after year.  On average, sea turtles lay over 100 eggs in a nest and produce between 2 and 8 nests per season.

Animals that produce such large numbers of eggs have this reproductive strategy because so few survive to adulthood.   Sea turtle eggs and hatchlings face numerous threats including powerful storms, poachers, marauding birds, and more.  Estimates are that only one in thousand sea turtle eggs leads to an adult turtle.

A recent study by the University of South Florida looked at the reproductive strategy of loggerhead sea turtles nesting on Keewaydin Island off the southwestern Gulf coast of Florida.  The researchers found that individual females lay numerous clutches of eggs in locations as much as six miles apart from each other to increase the chance that some of their offspring will survive.

As the saying goes, nesting loggerhead turtles don’t lay all their eggs in one basket.  The researchers compare the turtles’ strategy to investing in a mutual fund.  The female turtles divide their resources among many stocks rather than investing everything in a single stock.

During their 50-year lifetime, a single female loggerhead will produce over 4,000 eggs and scatter them at 40 different sites.  This strategy helps reduce the risk of complete reproductive failure caused by hurricanes and thunderstorms that could wash out or flood all their clutches.  The combination of unpredictable patterns of nests over time and space results in nearly two-thirds of loggerhead sea turtle hatchlings making it into the Gulf of Mexico.  The species still faces significant challenges but it is doing its part to try to survive.

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Not all in one basket: Loggerhead sea turtles lay eggs in multiple locations to improve reproductive success

Photo, posted January 27, 2012, courtesy of Jeroen Looye via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Aircraft Emissions And Climate Change | Earth Wise

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The aviation industry accounts for about 2.4% of global carbon dioxide emissions.  If the aviation industry was a country, it would place sixth in emissions, between Japan and Germany.

According to scientists at the University of Reading in the United Kingdom, aviation industry emissions could be reduced by simply better surfing the wind.  The researchers found that commercial flights between New York and London could have used up to 16% less fuel if they had made better use of the fast-moving winds at altitude.

The study, which was recently published in the journal Environmental Research Letters, analyzed approximately 35,000 flights in both directions between New York and London last winter.  The researchers compared how much fuel was burned during these flights to how much less fuel would have been burned by flying into or around the eastward jet stream air currents. 

They found that taking better advantage of the winds would have saved about 125 miles worth of fuel per flight on average.  The fuel saving per flight was 1.7% when flying west to New York, and 2.5% when flying east to London. 

New satellites will soon allow transatlantic flights to be tracked more accurately.  This should afford aircraft more flexibility in their flight paths, allowing them to better follow tailwinds and avoid headwinds. 

Upgrading aircraft or switching to greener fuels are two other ways that the aviation industry can reduce emissions, but those things are costly and take time to implement.  Optimizing flight paths is cheaper and offers immediate benefits.  

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Aircraft could cut emissions by better surfing the wind

Photo, posted May 16, 2011, courtesy of Cory W. Watts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Policy Moves on Electric Cars | Earth Wise

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In recent times, there have been several significant events affecting the transition to electric vehicles.  The new administration has made aggressive moves toward fighting climate change.  Wall Street investors have placed more value on Tesla stock than that of GM, Toyota, Volkswagen, and Ford combined.  China, the world’s largest car market, recently mandated that most new cars must be powered by electricity within 15 years.

Against this background, the CEO of General Motors announced in late January that the company will aim to sell only zero-emission cars and trucks by 2035.

This announcement took the rest of the auto industry by surprise.  In the past, the industry tended to present a united message on emissions and other policy issues.  This time around, GM has stepped out in front of the issue.

GM has already committed to spending $27 billion to introduce 30 electric vehicle models by 2025 and is building a plant in Ohio to make batteries for those cars and trucks.

A key driver in the GM decision, no doubt, was an executive order signed by President Biden on his first day of office.  The order directed the Environmental Protection Agency to immediately begin developing tough new tailpipe pollution regulations, designed to reduce the nation’s largest source of greenhouse gas emissions.

Even before the change in administration, five other major automakers – BMW, Ford, Honda, Volkswagen, and Volvo – had already legally bound themselves to tougher fuel economy standards in a deal with California.  Those companies committed to an average fuel economy of 51 miles per gallon in 2026.

While no other large automaker has set a specific target date for selling only electric vehicles, many of them are moving in that direction.  The rapid growth of Tesla is an indicator of where the auto industry is heading.

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G.M. Announcement Shakes Up U.S. Automakers’ Transition to Electric Cars

Photo, posted July 29, 2017, courtesy of Steve Jurvetson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Street Trees And Depression | Earth Wise

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According to a study published in the journal Jama Network Open last fall, the COVID-19 pandemic has tripled the rate of depression in U.S. adults in all demographic groups. 

Previous studies have demonstrated that greenspaces in urban areas can have a positive effect on those people experiencing mental ill health. But most of those studies used self-reporting measures, which makes it difficult to compare results and draw conclusions.

As a result, an interdisciplinary research team from three research organizations in Germany tried to improve upon the work by involving an objective indicator: prescriptions of antidepressants.  To figure out whether greenspaces – in this case street trees – could positively influence mental health, the researchers focused on how the number of street trees and their proximity to homes correlated to the number of prescribed antidepressants.

After analyzing data from nearly 10,000 people living in Leipzig, Germany, and combining the findings with data on city street trees, researchers were able to identify an association between antidepressant prescriptions and the number of street trees.  The results were controlled for other factors known to be associated with depression, such as employment, gender, age, and body weight.

Having more trees within 100 meters of the home was associated with a reduced risk of being prescribed antidepressants.  The association was especially strong for groups of people deprived of street trees. 

Street trees in urban cities can not only serve as a nature-based solution for good mental health, but they can also contribute to climate change mitigation and biodiversity conservation.

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Street trees close to the home may reduce the risk of depression

Photo, posted August 17, 2011, courtesy of Aleksandr Zykov via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Sustainable Polymer From Wood | Earth Wise

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Scientists from the University of Bath in the UK have developed a sustainable polymer using xylose, a sugar found in wood.

The new polymer is a member of the polyether family.  It could be used in a variety of applications, including being a building block for polyurethane, used for example in mattresses and shoe soles. It could also be a bio-derived alternative to polyethylene glycol, a chemical widely used in biomedicine, or in polyethylene oxide, which is sometimes used as an electrolyte in batteries.

Xylose, also known as wood sugar, is one of the most abundant carbohydrates on earth, second only to glucose. Apart from comprising 5-20% of hardwoods, xylose is a major component of straw, corncobs, and many other plant materials.

The new polymer could reduce reliance on crude oil products and its properties can be easily controlled to make the material flexible or crystalline.  Added functionality could be added to it by binding other chemical groups such as fluorescent probes or dyes to the sugar molecule for biological or chemical sensing applications.

Tweaking the physical and chemical properties of bio-derived polymers has previously been a very difficult thing to do.  The Bath researchers discovered that combining two mirror-image chemical forms of xylose results in a stronger and more adaptable material.  They have filed a patent for their technology and are seeking industrial collaborators for further development.

The reliance of plastics and polymers on fossil fuels is a major problem.  Bio-derived polymers, such as this new one, are an important part of the effort to make plastics sustainable.

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Scientists make sustainable polymer from sugars in wood

Photo, posted January 25, 2017, courtesy of Keith Double via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Can We Tow Icebergs To Use Their Water? | Earth Wise

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At any given time, there are thousands of icebergs adrift in Antarctica that are hundreds or even thousands of feet across.  For at least fifty years, there has been speculation about whether such icebergs could be towed from the Antarctic to places experiencing freshwater shortages.  The feasibility of such a scheme is still the subject of studies that nowadays include sophisticated computer modeling.

Places like the Persian Gulf, Cape Town, South Africa, and Perth, Australia all experience water shortages and could benefit tremendously from having a large iceberg towed to their waters.

How big an iceberg would it take to quench the thirst of a city like Cape Town?  Computer models show that an iceberg 2,000 feet long and 650 feet thick could produce enough water to supply the city for more than a year.  However, with water temperatures in the 60s in the area, even such a large iceberg would melt away within weeks.  So, to get enough water for a year, it would require a much larger iceberg – one at least a couple of miles long.

Daunting problems include figuring out how many and what sort of ships would be required.  An alternative to such giant icebergs would be finding a way to insulate the icebergs so they don’t melt as quickly, thereby allowing much smaller and more towable icebergs to be harvested.

Beyond these issues, there are the ecological issues of the effects of huge amounts of very cold fresh water affecting local marine ecosystems. 

Despite a wide range of challenges, there is continued interest in the idea of using icebergs as a source of very pure fresh water.  In an increasingly thirsty world, it might someday actually happen.

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Can icebergs be towed to water-starved cities?

Photo, posted November 1, 2007, courtesy of M A Felton via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Geothermal Power In The Energy Transition | Earth Wise

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The heat beneath the earth represents a vast repository of energy that in principle could provide for a significant part of our needs.  In some places, geothermal energy is easy to get to and is already being exploited.  California and Nevada operate dozens of geothermal electric generating plants.  Boise Idaho heats 92 of its biggest buildings with the river of hot water that flows 3,000 feet below the city.  In total, the U.S. produces enough geothermal electricity to power more than a million homes.

But all these examples make use of relatively rare local features that are not available to the great majority of locations.  As a result, geothermal energy has generally not been viewed as being able to play a major role in the alternative energy transition.

A number of experts around the world disagree with this assessment.  To a fair extent due to the deep-drilling techniques and knowledge about underground formations developed by the oil and gas industry during the fracking boom, there is growing interest in a type of geothermal energy called deep geothermal that accesses hot temperatures in the earth’s mantle as far down as two or three miles.

Deep geothermal can either access extremely hot water that exists down at those depths or water can be injected into hot rock down there, which is a technology known as enhanced geothermal systems.

There is enormous untapped potential for geothermal energy.  A 2019 report by the U.S. Department of Energy says that by 2050, geothermal could provide 8.5% of the United States’ electricity as well as direct heat.  Geothermal could be an important part of the so-called all-of-the-above future energy strategy.

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Can Geothermal Power Play a Key Role in the Energy Transition?

Photo, posted August 2, 2008, courtesy of ThinkGeoEnergy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Global Warming Could Stabilize | Earth Wise

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The world has been heading toward climate disaster with the effects of greenhouse gas-induced warming looming larger and larger.  But recent analysis published in Nature Climate Change offers hope that rapidly eliminating emissions could stabilize global temperatures just within a couple of decades.

For quite some time, it has been assumed that further global warming would be locked in for generations regardless of the extent of emissions reductions going forward.  This conclusion was based on having a certain carbon dioxide concentration in the atmosphere which would linger for hundreds of years even if emissions were reduced.

Recent analysis takes into account the dynamism of the Earth’s natural systems which could actually reduce atmospheric CO2 content because of the huge carbon absorption capacity of oceans, wetlands, and forests.  The key requirement is to drastically reduce emissions so that these natural systems can take over.

More than 100 countries have pledged to get to net zero emissions by 2050.  That means they will emit no more carbon dioxide than is removed from the atmosphere by such actions as restoring forests.   The UK, Japan, and the European Union are among the countries that have set this zero target, and the United States is joining the club.

Climate models show that a global temperature rise of 2 degrees Celsius over that of the pre-industrial period would lead to global calamities that include punishing heatwaves, flooding, and mass displacement of people.  The world has already heated up by 1.1 degrees and governments have committed to restrain the rise to less than 1.5 degrees under the Paris Climate Agreement.

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Global Warming Could Stabilize Faster than Originally Thought If Nations Achieve Net Zero

Photo, posted September 10, 2017, courtesy of Ron Cogswell via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

New York Offshore Wind | Earth Wise

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Norwegian energy company Equinor and its strategic partner bp have been selected by New York State to build several offshore wind power installations that will be one of the largest renewable energy projects in the United States to date.  When completed, the projects will provide 1,260 megawatts of offshore wind power from Empire Wind 2 and another 1,230 megawatts from Beacon Wind 1 and these will be added to the 816-megawatt project already awarded to the companies for Empire Wind 1. 

The two phases of Empire Wind are located 15-30 miles southeast of Long Island and span 80,000 acres. Beacon Wind is located 60 miles east of Montauk Point and 20 miles south of Nantucket and covers 128,000 acres.  The overall development will provide 3.3 gigawatts of homegrown, renewable electricity to New York.

The projects will comprise up to $8.9 billion in investments including $664 million provided by the state.  As part of the award from NYSERDA, the companies will partner with the State to transform two New York ports – the South Brooklyn Marine Terminal and the Port of Albany – into large-scale offshore wind working industrial facilities that position New York to become an offshore wind industry hub.

In Albany, Equinor will join forces with wind industry companies Marmen and Welcon to help the port become America’s first offshore wind tower and transition piece manufacturing facility, where it will produce components for Equinor’s projects.

New York’s goal is to have 9 gigawatts of offshore wind capacity by 2035.  The Equinor projects will contribute more than one-third of that goal. 

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New York Selects Equinor for Largest US Offshore Wind Award

Photo, posted March 24, 2016, courtesy of TEIA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Restoring Environmental Rules Will Take Time | Earth Wise

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Over the previous four years, the Trump administration weakened or rolled back more than 100 rules and regulations on air, water, public lands, endangered species, and climate change.  The Biden administration has vowed to review these changes and restore the environmental protections that were removed or weakened.

The process of restoring environmental protections generally fall into a few broad categories.  Some changes can happen by executive order.  The President can cancel individual fossil fuel infrastructure projects or reinstate federal protection of specific places.  On his first day in office, President Biden rescinded the construction permit for the Keystone XL pipeline.

The President is also expected to restore federal protection to the Bears Ears and Grand Staircase-Escalante national monuments in Utah, which the Trump administration opened up to mining, logging, and drilling.

However, it could take two years or more to restore Obama-era climate change regulations including limits on emissions, rules on industrial emissions of toxic pollutants such as mercury, and protections on wetlands and waterways.

Reinstating comprehensive regulations on air, water, and climate pollution will take years because the Trump administration, rather than eliminating rules entirely, often replaced them with weaker regulations.  Replacing the weak regulations cannot just happen by executive order.  The process involves scientific and economic analysis, and that takes time.

After four years of shrinking budget and shrinking staff, the Environmental Protection Agency has a lot of catching up to do and will need to prioritize its actions in order to deal with the most damaging consequences of the previous administration.

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Restoring Environmental Rules Rolled Back by Trump Could Take Years

Photo, posted September 25, 2012, courtesy of Tar Sands Blockade via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Understanding How To Enhance Desalination | Earth Wise

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Desalination is the process of removing mineral components – notably salt – from saline water, generally seawater.  Over 16,000 desalination plants operate across 177 countries, generating 25 billion gallons of fresh water each year.  Currently, desalination accounts for about 1% of the world’s drinking water.

The leading process for desalination in terms of installed capacity as well as new installations is reverse osmosis that makes use of a thin-film composite membrane based on ultra-thin polyamide.

Despite the fact that these membranes are widely used for desalination, they are actually rather poorly understood.  It has not been known exactly how water moves through them.  As a result, much of the progress made on the technology over the decades has been essentially based on guesswork.

A team of researchers at the University of Texas, Austin has used advanced microscopy techniques to solve some of the mysteries of reverse osmosis membranes.  By mapping membranes at very high resolution – less than half the diameter of a DNA strand – they gained a much better understanding of what makes a membrane better at reverse osmosis.

They found that desalination membranes are inconsistent in mass distribution and density and that these inconsistencies can impair membrane performance.  It turns out that inconsistencies and dead zones in membranes play a bigger role than membrane thickness.  By making the membranes more uniform in density at the nanoscale, they were able to increase desalination efficiency 30 to 40 percent, therefore cleaning more water with less energy and at lower cost.

Producing fresh water is not just essential for public health, it is also crucial for use in agriculture and energy production.

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Nanoscale control of internal inhomogeneity enhances water transport in desalination membranes

Photo, posted February 13, 2017, courtesy of Jacob Vanderheyden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Positive Tipping Points And Climate | Earth Wise

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A tipping point is a moment when a small change triggers a large and possibly irreversible response.

There has been much discussion of various tipping points that could accelerate climate change in catastrophic ways.  A recent paper from researchers at the University of Exeter in the UK discusses a couple of tipping points that could accelerate positive progress on mitigating climate change.

Electric vehicles account for only 2-3% of new car sales globally. In Norway, this figure is more than 50%, mostly thanks to policies that make electric cars the same price to buy as conventional cars.   According to the Exeter study, when EVs cost the same to manufacture as conventional cars, it will be a global tipping point.  China, the EU, and California together are responsible for half of the world’s car sales and each of these has targets to rapidly decarbonize their economies and policies in place to speed the transition to electric vehicles. 

Decarbonizing electric power is the other potential positive tipping point.  In Europe, carbon taxes on top of increasing renewable energy generation have tipped coal into unprofitability as they have led to the irreversible destruction of coal plants.  Globally, renewables are already generating electricity cheaper than fossil fuels in many countries.  Decarbonizing global power generation would in turn help accelerate decarbonization of large parts of transportation, heating and cooling, and industry.

These potential positive tipping points are by no means inevitable.  Appropriate policies are needed to overcome various barriers to the clean energy transition.  But major changes in transportation and electric power would have a tremendous impact on the global effort to combat climate change.

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Positive ‘tipping points’ offer hope for climate

Photo, posted July 14, 2020, courtesy of Jim Champion via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildfire Smoke And Dangerous Microbes | Earth Wise

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The worsening severity of wildfires across the globe is a major public health concern.  The pulmonary and cardiovascular consequences of wildfire smoke inhalation have been well researched and have been an increasing focus for officials in places like California, other western states, and Australia.  More recently, another public health concern has emerged related to the fact that wildfire smoke can carry microbes that cause infectious diseases.

A new analysis, published in the journal Science, points out that the risk of potential infection from airborne microbes has not been the subject of much research.

The fungus coccidioides, for example, becomes airborne when soils are disturbed by fire. When this fungus is inhaled, it can cause Valley fever, an infection with flu-like symptoms that sometimes progresses to pneumonia or meningitis.  Inhalation risk of these microbes is highest closest to fires, so coccidioidomycosis is listed as a professional risk for firefighters.

A recent study found an increase in cases of invasive mold infection, aspergilliosis, as well as cases of coccidioidomycosis at hospitals within 200 miles of major wildfires in California.

Wildfire smoke has been shown to carry airborne particles of fungal and bacterial cells, hitching a ride on water vapor or charred carbon, over thousands of miles.  Some microbes in soil appear to be tolerant of or even thrive under high temperatures following wildfires.

A multidisciplinary research collaboration is needed to better understand the relationship between microbes, wildfire, and public health.  Such knowledge is increasingly vital as severe wildfires become seasonal norms in parts of the world such as the United States and Australia.

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Wildfire Smoke Can Carry Dangerous Microbes Thousands of Miles, Scientists Warn

Photo, posted September 9, 2020, courtesy of Christopher Michel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Not Enough Buzz For Bees | Earth Wise

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The dramatic worldwide decline in bees and other pollinating insects represents a serious threat to the global food supply, but it isn’t really getting much attention in the mainstream news.  Close to 75% of the world’s crops for human consumption depend, at least in part, on pollinators for sustained production, yield, and quality.

A new study by researchers at the University of Illinois Urbana-Champaign looked at nearly 25 million news items from six prominent sources, including The New York Times, The Washington Post, the Associated Press, as well as three overseas English-language news services.  The study found “vanishingly low levels of attention to pollinator population topics”, even compared with what many people consider to be the limited coverage of climate change.

The study made use of the Global News Index, which is a unique database of millions of news items from thousands of global sources published over decades.  It may be the largest academic study of the evolving nature of news coverage ever performed.

Even though the entomological community is highly focused on the impending pollinator crisis, the public is not paying much attention.  It is not even indifference; it is just that people don’t even know about it.

The majority of studies on pollinator decline have been done in Europe and North America, which means we don’t even know how serious the problem is given that most insect biodiversity is in the tropics.

Public awareness is important because individuals can make a difference by their decisions about what flowers to plant in their gardens, which weeds to tolerate in their yards, and how to manage insect pests.

The loss of pollinators is a very serious problem, and it is not likely to get enough attention if people don’t know about it.

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Pollinators not getting the ‘buzz’ they need in news coverage

Photo, posted December 28, 2006, courtesy of Alpha via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rivers Changing Color | Earth Wise

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A recent study, published in Geophysical Research Letters, found that one-third of large American rivers have had significant changes of color over the past 30 years.  Rivers can appear to be shades of blue, green, and yellow and we tend to expect healthy rivers to have colors in shades of blue.  According to the new study, only 6% of American rivers are dominantly blue.

The study looked at 235,000 Landsat images taken from 1984 to 2018.  The results are that 56% of rivers studied were dominantly yellow, 38% dominantly green, and 6% blue.  Over the 34 years studied, 33% of the rivers had significant changes in color. About 21% became greener and 12% more yellow. 

The chief causes of color changes in rivers are farm fertilizer runoff, dams, efforts to fight soil erosion, and climate change.  Climate change increases water temperature and rain-related runoff.

Color changes are not necessarily a sign of poor river health, but dramatic changes could point to issues that need attention.  A river can change color based on the amount of sediment, algae, or dissolved organic carbon in the water.   If a river becomes greener, it can often mean large algae blooms are present that cause oxygen loss and can produce toxins.  On the other hand, rivers that are getting less yellow demonstrate the success of regulations to prevent soil erosion.

The study of river colors can pinpoint which rivers are undergoing rapid environmental change.  What the study does not provide is information on water quality.  Water quality measurements will be important to determine the health of many of the rapidly changing rivers.

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One Third of U.S. Rivers Changed Their Color, Three Decades of Satellite Images Show

Photo, posted July 6, 2016, courtesy of Jeffrey Beall via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Why Have Crocodiles Changed So Little Over Time? | Earth Wise

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Crocodiles today look very similar to ones from the Jurassic period some 200 million years ago.  In fact, there are very few species of crocodilians alive today – approximately two dozen to be exact.  Many other species have achieved a diversity of many thousands of species in the same amount of time. 

During prehistoric times, many more types of crocodiles roamed the earth, including some as big as dinosaurs and other serpentine forms that lived in the sea.  

According to findings by scientists at the University of Bristol in the U.K., a stop-start pattern of evolution could explain why crocodiles have changed so little over time. In the study, which was recently published in the journal Nature Communications Biology, researchers describe how crocodiles follow a pattern of evolution known as “punctuated equilibrium.”  In other words, crocodiles’ rate of evolution is generally slow, but occasionally picks up because the environment has changed.     

According to the research team, this slow rate of evolution is how crocodile diversity became so limited.  It appears crocodiles arrived at a body that was efficient and versatile.  They didn’t need to continue to change in order to survive.

This efficiency and versatility could be an explanation for why crocodiles survived the meteor impact that wiped out the dinosaurs.  Since crocodiles can’t control their body temperature and rely on the environment for warmth, they generally fare better in warm conditions.  During the age of dinosaurs, the climate was warmer than it is today, which could explain why crocodile diversity was higher.  

The scientists next step is to try to figure out why some prehistoric crocodiles died out while others did not. 

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Why crocodiles have changed so little since the age of the dinosaurs

Photo, posted December 26, 2012, courtesy of Nicholas Smith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cell-Based Meat And Seafood | Earth Wise

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We have heard about laboratory meat for a number of years, generally in terms of something that may happen at some point in the indeterminate future. But at least for a couple of California companies, that future is now.

These high-tech companies are producing products – real meat and seafood – that are originally cultured from animal cells but are made without the actual animal.

San Francisco-based Eat Just makes chicken nuggets that have recently gained regulatory approval in Singapore and are now available to order at a downtown restaurant.  San Diego’s BlueNalu creates cell-based seafood fillets including yellowtail, mahi-mahi, red snapper, and tuna.

The companies use stem cells obtained from actual animals and cultivate them in steel tanks with the same nutrients that living animals consume.  The original cell donor is not sacrificed.  The harvested cells multiply and are eventually shaped to form meat or fish that cooks, looks, and tastes just like its natural counterpart.

The “mouth feel” of conventional meat or fish can be mimicked by recreating the same proportions of muscle, fat, and connective tissue in the cell-based product.  Eat Just says their product cooks, looks, and tastes like chicken because it is chicken.  BlueNalu says their product has all the same characteristics as fish because it is fish.

These products have major environmental, safety, and ethical advantages.  The big question is whether people will eat them.  Is there an “ick factor” to overcome?  Ultimately, the key thing is how they taste.  If they pass muster on that score and cell-based meats and seafood are scaled up and accepted, we can have the nutritional and sensory advantages of meat proteins without the environmental, ethical and safety disadvantages.

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Can We Enjoy Meat and Seafood and Save the Planet?

Photo, posted February 1, 2012, courtesy of Andrea Parrish-Geyer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A New Fishway Technology | Earth Wise

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Freshwater fish populations have declined by more than 80% over the past forty years across the globe.  This is in part due to hundreds of thousands of dams, weirs, and barriers stopping their movements.  These river barriers have disrupted fish reproduction cycles the world over by preventing river fish from migrating to spawn.

Fishways or fish ladders are waterways constructed on or around obstructions in order to provide passageways for fish and other aquatic species.  Often, they consist of a series of small overflow weirs and pools constructed in the form of steps.  Fish need to jump from one pool to another to migrate to the upstream.  Such fish ladders require a large space to construct.  These and several other types of fishways tend to be expensive to install and maintain and are not always successful in allowing fish to get to where they need to go.

Researchers at the University of New South Wales in Australia have come up with an ingenious new type of fishway.  Called a “tube fishway”, it is a low-cost and low-energy installation that works by pumping fish at high velocity – protected by a cushion of bubbly water – through a tube running over the obstructing barrier to deliver them safely into the water on the other side.

They successfully demonstrated a prototype system on a rugged slope behind a campus building that transported fish from one tank to another about 25 feet up the slope.

Fish are attracted into the chamber by suitable geometry and the system uses the energy available from the upper reservoir to lift the fish.  Modeling shows that the system will work for pipes as large as three feet in diameter and could lift fish more than 300 feet vertically. 

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New fishway technology to get fish up and over those dam walls

Photo, posted October 19, 2019, courtesy of Andrew Harvey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Grid-Scale Battery Storage is on the Rise | Earth Wise

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Driven by steeply falling prices and improving technology, grid-scale battery storage systems are seeing record growth in the U.S. and around the world. Battery storage is a way to overcome one of the biggest obstacles to renewable energy:  the cycling between oversupply when the sun shines or the wind blows, and shortage when the sun sets or the wind drops.  Storing excess energy in battery banks can smooth imbalances between supply and demand.

In California, a 300-megawatt lithium-ion battery plant is being readied for operation with another 100 megawatts to come online in 2021.  The system will be able to power roughly 300,000 California homes for four-hour periods when energy demand outstrips supply.  It will be the world’s largest battery system for a while until even larger systems in Florida and in Saudi Arabia come online.

Nationwide, a record 1.2 gigawatts of storage were installed last year and that number is projected to jump dramatically over the next five years to nearly 7.5 gigawatts in 2025.

The price tag for utility-scale battery storage in the U.S. has plummeted, dropping nearly 70% just between 2015 and 2018.  Prices are expected to drop by a further 45% over the next decade.  Battery performance has continued to improve dramatically with increased power capacity and the ability to store and discharge energy over ever-longer periods of time. 

Favorable energy policies including renewable energy mandates coupled with continued price drops will drive the widespread expansion of battery energy storage.

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In Boost for Renewables, Grid-Scale Battery Storage Is on the Rise

Photo, posted November 17, 2016, courtesy of Steve Ryan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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