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The Plight Of Monarch Butterflies | Earth Wise

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The monarch butterfly is one of the world’s best-known butterflies and has become the symbol for a whole class of imperiled pollinators.  Populations of the iconic orange-and-black insects have declined dramatically in recent decades. 

According to the U.S. Fish and Wildlife Service, the eastern monarch population has dropped 88% between 1996 and 2020.  Habitat loss, pesticide use, and global climate change are some of the factors driving monarch butterfly population declines. 

According to a new study led by scientists at Emory University, monarch butterflies are also increasingly plagued by a debilitating parasite.  The study, which was recently published in The Journal of Animal Ecology, reviewed 50 years of data on the infection rate of wild monarch butterflies by the protozoan Ophryocystis elektrosirrha (or O.E.).  The research team found that the O.E. infection rate had increased from less than 1% of the eastern monarch population in 1968 to as much as 10% today.

The O.E. parasite invades the gut of monarch caterpillars.  If the adult butterfly leaves the pupal stage with a severe parasitic infection, it begins oozing fluids from its body and dies. If the infection is lighter and the butterfly survives, it will not fly as well or live as long as uninfected butterflies.  

The study found that one of the contributors to the rise in parasitism is the increased density of monarchs in places where they lay their eggs.  The increased density may be due to several factors, including the loss of habitat, the widespread planting of non-native milkweed, and by people raising large numbers of monarchs in confined spaces. 

If the infection rate continues to increase, monarch butterfly populations will likely continue to plummet. 

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Monarch butterflies increasingly plagued by parasites

Plight of the Monarch

Saving The Monarch Butterfly

Photo, posted September 18, 2008, courtesy of Roy Niswanger via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solid State Batteries For Cars | Earth Wise

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Today’s electric cars run on lithium-ion batteries, the same sort that power our phones, computers, and many other consumer electronic devices.  These batteries are far superior to the batteries of the past, offering long-life, high-energy density, and recyclable components.

Lithium-ion batteries do have their drawbacks.  They may be lighter than older battery technologies, but because the electrolytes in the batteries are liquid, they are still fairly heavy.  The huge number of them in an electric car adds up to a considerable amount of weight.  In addition, the flammability of the electrolytes can lead to explosions or fires if the batteries are damaged or exposed to extreme temperatures.

Solid-state batteries are an alternative technology that contain a solid electrolyte.  Such batteries are lighter, have higher energy density, offer more range, and recharge much more quickly than lithium-ion batteries. They have been used for years in some small devices like cardiac pacemakers, RFIDs, and some wearable devices.

For all these benefits, scaling up production to the level needed to be used in cars is an expensive and challenging endeavor.  The hope is that with sufficient effort, the result will be smaller, lighter battery packs for cars that can be charged in minutes and provide extended range.

Nissan Motor Company has recently announced that it is investing $17.6 billion over the next five years towards developing solid-state batteries for cars.  No doubt other companies will also be working on the technology.

Lithium-ion batteries have proven to be quite practical for powering vehicles.  But if solid-state batteries can meet the challenges of scaled up production, the lithium-ion era might end up being a relatively brief one.

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Nissan to Spend $18 Billion Developing a Cheaper, More Powerful EV Battery

Photo, posted November 13, 2018, courtesy of FirstEnergy Corp via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Roads And Chimpanzees | Earth Wise

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The chimpanzee is a species of great ape native to tropical regions of Central and West Africa.  Chimpanzees are highly social animals and can live to be over 50 years old.  In fact, chimpanzees are our closest cousins.  We share about 98% of our genes with chimpanzees. 

According to the African Wildlife Federation, it’s estimated that at most only 300,000 chimpanzees remain in the wild today.  They face a myriad of challenges, including habitat degradation and hunting. 

According to new research from the University of Exeter in the U.K., roads have a negative impact on chimpanzee populations that can extend for several miles.  In the study, which was recently published in the journal Conservation Letters, the researchers analyzed the impact of major and minor roads on wild western chimpanzee numbers in the eight African countries in which they live.  They found that negative impacts extended an average of 10.7 miles from major roads, and 3.4 miles from minor roads.  The researchers found that the density of chimpanzee populations dropped steadily from the edges of these areas to the lowest value alongside the roads.  Only 4.3% of the chimpanzees’ range remains unaffected by roads. 

While the study did not investigate why roads affect chimpanzee numbers, the research team did offer some clues.  In addition to noise and roadkill, roads provide access to unexploited areas for industries that often reduce or remove chimpanzee habitats.  Roads can also restrict chimpanzee movements, and provide easier access for hunters. 

The researchers hope their findings will bring about more effective guidelines to mitigate the impact of roads on wildlife.   

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Roads have far-reaching impact on chimpanzees

Photo, posted August 12, 2014, courtesy of Rod Waddington via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon From 25 Cities | Earth Wise

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There are roughly 10,000 cities in the world, defined as places with at least 50,000 inhabitants with a sufficient population density.  Roughly half the world’s population lives in cities.

Urban carbon emissions are one of the world’s biggest problems with respect to the climate.  A new study has determined that just 25 cities globally are responsible for 52% of urban greenhouse gas emissions.

The study gathered data on greenhouse gas emissions in 167 cities in 53 countries.  The results were that megacities in Asia, such as Shanghai and Tokyo, were among the biggest total emitters, and that major cities in Europe, the US, and Australia tended to have larger per capita emissions.  Several Chinese cities, however, matched levels seen in developed countries.  Researchers tracked emissions over time in 42 of the cities studied.  Some cities saw declining emissions in the period between 2005 and 2016.  These included Oslo, Houston, Seattle, and Bogota.  Others saw large increases, including Rio de Janeiro, Johannesburg, and Venice.

The largest sources of emissions are power generation, industry, and transportation.  In a third of the cities, road transportation alone accounted for over 30% of emissions.  (Railways, waterways, and aviation combined only accounted for less than 15% of total emissions).

Half of the world’s population lives in cities, but cities are responsible for more than 70% of greenhouse gas emissions.  Thus, cities have a big responsibility for the decarbonization of the global economy.  Of the 167 cities in the study, 113 have set emission-reduction targets.  But as the study shows, cities have much more work to do to meet the goals of the Paris Climate Agreement.

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Two Dozen Large Cities Produce 52 Percent of Urban Carbon Emissions

Photo, posted December 1, 2017, courtesy of Hector Galbis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Transmission Lines And Wildlife Habitat Connectivity | Earth Wise

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Electrical transmission lines and their support towers tend to be a blight on the landscape but are something modern society cannot avoid.  Power transmission networks – with towers every 200 meters or so of line – are in place throughout the world’s developed nations.  Another common feature of developed nations is the fragmentation of animal species caused by human activity breaking up their natural habitats.

It is important for biodiversity conservation for animals to get their environments connected.   It turns out that transmission line infrastructure can provide an important tool for reconnecting wildlife habitats.

In a study conducted in Spain’s Andalusia region, scientists planted native shrubs and seedlings under six towers along power lines running through cereal cropland.  The area of each tower base was 100 square meters.

Compared to four control sites, the researchers measured increased population density and diversity among arthropods and small mammals observed in the four-year study. 

Enhancing connectivity through networks of habitat corridors or stepping-stone patches has become a key concept in conservation biology and landscape ecology.  Renting or buying large parcels of land to connect protected natural areas to one another would be cost prohibitive but planting suitable native shrubs and other flora under existing transmission line networks can provide many of the same benefits.

In general, power companies pay rent to landowners – often farmers or agribusinesses – for the rights to place towers on their land.  Because it is difficult to work the areas under towers with farm equipment, that space is typically unused, which opens the door to low-cost efforts by environmentalists.

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Electrical transmission lines have power to enhance habitat connectivity for wildlife

Photo, posted April 29, 2018, courtesy of Georgi Todorov/digitalnovas.com via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Food Waste And Access To Groceries | Earth Wise

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One-third of all food produced is wasted, which turns out to be a major contributor to carbon emissions.  Most of the carbon emissions associated with food waste are related to the production of the food.  Reducing waste would trickle through the supply chain over time and ultimately less food would be produced.

A study at Cornell’s SC Johnson College of Business looked at a particular strategy for reducing food waste’s environmental impact:  opening more grocery stores.

It turns out that the more stores there are, the lower food waste will be.  Cornell Professor Elena Belavina created a model that incorporates data from the grocery industry, the U.S. Census Bureau, and other academic studies.

When applied to Chicago, which is typical of many American cities, the model predicts that by adding just three or four markets within four-square-mile area, food waste would be reduced by 6 to 9 percent.  This would achieve an emissions reduction comparable to converting more than 20,000 cars from fossil fuels to electric power.  According to the model, not only would food waste be reduced, but so would grocery bills.  By trimming food waste and travel costs, consumers would spend up to 4% less.

Most big cities are well below their ideal density of grocery stores that would minimize food waste. When consumers can purchase perishable goods nearby, they shop more often but buy less each time.  There is less food sitting at home, so there is a much lower likelihood that food will spoil.

New York City, which has an abundance of produce stands and neighborhood markets, comes close to having the ideal density of markets.  Basically, the way to reduce food waste is to bring less groceries home.

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Better access to groceries could reduce food waste, emissions

Photo, posted March 22, 2009, courtesy of Nick Saltmarsh 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.

Improving Energy Storage

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The transition to sustainable energy sources faces many challenges.  One important one is to make those sources as reliable as conventional energy systems.  For technologies like solar and wind power, which can’t operate around the clock, an enabling element is effective energy storage.   Energy storage is critical for both the electricity grid and for transportation.

[Read more…] about Improving Energy Storage

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