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Paper Cups Are Not So Great | Earth Wise

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The environmental cost of plastic waste is a highly visible global issue.  The response has been a growing effort to replace plastic items with alternative materials.  One very visible change of this sort has been the replacement of plastic cups with paper cups at coffee shops.  But a new study at the University of Gothenburg in Sweden has found that this solution has problems of its own.

Researchers studied the effects of disposable cups in the environment on the larvae of the butterfly mosquito.  They placed disposable cups made from different materials in wet sediment and water for a few days and observed how the chemicals leached from the cups affected the growth of the larvae.  It turned out that all of the different kinds of cups had negative effects.  The concern is not specifically about mosquito larvae; it is the fact that more environmentally friendly drinking cups are still potentially harmful to living things.

Paper is neither fat nor water resistant, so paper cups need to be treated with a surface coating.  The most common coating is polylactide, which is a type of bioplastic.  It is generally considered to be biodegradable, but the study shows that it can still be toxic.  Bioplastics still contain many different chemicals and the potential toxicity of each of them is not well known.

The UN is trying to develop a binding agreement by the world’s countries to end the spread of plastics in society and nature.  For such an agreement to be effective, the plastics industry will need to clearly report what chemicals all products contain, including such mostly invisible products as the coating on paper drinking cups.

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Paper cups are just as toxic as plastic cups

Photo, posted October 23, 2016, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cryopreserving Corals | Earth Wise

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Recent climate models estimate that if the effects of climate change are not mitigated soon enough, 95% of the world’s corals could die by the mid 2030s.  Given the current rate of greenhouse gas emissions, this is an increasingly likely outcome.  Coral reefs are estimated to have a $10 trillion economic value apart from their essential role in marine ecosystems.

Researchers at the University of Hawaii at Manoa have demonstrated a successful technique for cryopreserving entire coral fragments; in other words, preserving coral using cold temperatures and successfully reviving them.

Existing coral cryopreservation techniques rely on freezing sperm and larvae, which can only be collected during spawning events, which occur only a few days each year for coral species.  This makes it logistically very challenging for researchers and conservationists.

The Hawaiian researchers focused on a process called isochoric vitrification, which is a method of freezing with liquid nitrogen that prevents the formation of ice crystals.  They tested the technique with thumbnail-sized fragments of coral, freezing them in small aluminum chambers which restrict the growth of ice crystals that would otherwise damage delicate polyp tissues.  Once the chambers were warmed, the fragments were transferred to seawater and allowed to recover.  They found that the revived corals behaved the same as those that were never cooled.

The process holds great promise to conserve the biodiversity and genetic diversity of coral.  If the process can be scaled up, it may be possible to preserve as many species of coral as possible by 2030, when it may no longer be viable for them to survive in the warming and acidifying oceans.

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Cryopreservation breakthrough could save coral reefs

Photo, posted June 2, 2023, courtesy of USFWS – Pacific Region via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Lithium In The Salton Sea | Earth Wise

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The Salton Sea is a shallow, landlocked, extremely salty body of water in the southern end of California.  It was formed from an inflow of water from the Colorado River in 1905 in the aftermath of a collapse of a canal during spring floods.  At one time, it was a thriving tourist destination and site of real estate speculation.  It was also a crucial habitat for migratory birds and various aquatic species.

Over the past 20 years, the Salton Sea has become increasingly desiccated and polluted with agricultural runoff and waste.  Rising salinity and the shrinking water supply from the Colorado River has made it uninhabitable for many species.

Recently, the Salton Sea has attracted new attention because of untouched lithium deposits located beneath its shores.  The general area has acquired the moniker “Lithium Valley” and has become a place where major energy companies are exploring advanced mining techniques such as Direct Lithium Extraction (DLE).  This new technique enables lithium to be captured from brine deposits without resource-intensive open-pit mining or evaporation pond processes.

Lithium is crucial for making the batteries that power electric vehicles.  DLE mining has attracted large investments from billionaires like Warren Buffet, Bill Gates, and Jeff Bezos. 

Lithium mining has generated major controversies because of its potential to damage the environment.  Whether the new mining techniques can avoid these problems and tap into the potential resources near the Salton Sea remains to be seen.  According to experts, the aquifers near the Salton Sea hold enough lithium to supply close to 40% of the global demand.

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As Companies Eye Massive Lithium Deposits in California’s Salton Sea, Locals Anticipate a Mixed Bag

Photo, posted October 28, 2021, courtesy of Christian Collins via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Recycling Solar Panels | Earth Wise

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Solar panels generally have a useful life of around 20 to 25 years.  The great majority of deployed panels have been installed fairly recently, so they have a long way to go.  But the growth in solar technology dates back to the 1990s, so there are growing number of panels that have already or are shortly coming to their end-of-life.

Today, roughly 90% of solar panels that have lost their efficiency due to age, or that are defective, end up in landfills because recycling them is too expensive.  Nevertheless, solar panels contain valuable materials, including silver, copper, and crystalline silicon, as well as lower-value aluminum and glass. 

The rapid growth of solar technology means that in the coming years, large numbers of retired solar panels will enter the waste stream.  The area covered by solar panels that are due to be retired by 2030 in the U.S. alone would cover about 3,000 football fields.  Clearly, more cost-effective recycling methods are sorely needed.

Engineers at the University of New South Wales in Sydney Australia have developed a new, more effective way of recycling solar panels that can recover silver at high efficiency.  The panel frames and glass are removed leaving just the solar cells themselves.  The cells are then crushed and sieved in a vibration container that effectively separates 99% of the materials contained in them.

Silver is the most valuable material contained in solar cells.  The Australian researchers estimate that between 5 and 10 thousand tons of silver could potentially be recycled from retired solar panels by the year 2050.  But even the other materials contained in solar panels are well worth recovering if it can be done cost-effectively.

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New environmentally friendly solar panel recycling process helps recover valuable silver

Photo, posted November 22, 2008, courtesy of Oregon Department of Transportation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wealth And Greenhouse Gas Emissions | Earth Wise

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A new study led by researchers from the University of Massachusetts Amherst has found that the wealthiest 10% of Americans are responsible for a staggering 40% of the country’s greenhouse gas emissions. The study, which was recently published in the journal PLOS Climate, is the first to link income, especially income derived from financial investments, to the emissions used in generating that income.

The research team suggests that policymakers adopt taxation strategies focused on shareholders and the carbon intensity of investment incomes in order to meet the global goal of limiting temperature rise to 1.5 degrees Celsius.

Historically, environmental policies have focused on regulating consumption, but the researchers argue that this approach misses something important:  carbon pollution generates income, but when that income is reinvested into stocks, rather than spent on necessities, it isn’t subject to a consumption-based carbon tax.  Rather than focus on how emissions enable consumption, they argue that the focus should be on how emissions create income. 

After analyzing 30 years of data, the researchers found that not only are the top 10% of earners in the United States responsible for 40% of the nation’s total greenhouse gas emissions, but that the top 1% alone account for 15-17% of the emissions. Emissions tended to peak in the 45-54 age group before declining.

The researchers highlight the need for an income and shareholder-based taxation strategy to incentivize climate action among high-income earners and industries, which could expedite decarbonization efforts and create tax revenue to support other climate initiatives.

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America’s Wealthiest 10% Responsible for 40% of U.S. Greenhouse Gas Emissions

Photo, posted June 29, 2015, courtesy of Pictures of Money (via Flickr).

Earth Wise is a production of WAMC Northeast Public Radio

The Cost Of Invasive Species | Earth Wise

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According to a new report published by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services for the United Nations, invasive species introduced to new ecosystems around the world are causing more than $423 billion in estimated losses to the global economy every year.  These economic costs are incurred by harming nature, damaging food systems, and threatening human health.

According to the report, these costs have at least quadrupled every decade since 1970 and the estimates are actually conservative because it’s difficult to account for all of the effects of invasive species.

The report estimates that humans have intentionally or unintentionally introduced more than 37,000 species to places outside their natural ranges.  More than 3,500 of them are considered invasive because they are harmful to their new ecosystems.  Invasive nonnative species were a major factor in 60% of known extinctions of plants and animals.

Some species are relocated deliberately by the wildlife trade and international shipping.  Other plants and animals end up hitching a ride with ordinary travelers as they move about by car, boat, plane, or train. 

Invasions can damage human health.  Mosquitos that transmit diseases like malaria, dengue fever, and the Zika virus have become invasive around the world. The wildfires in Hawaii this summer were fueled by invasive nonnative grasses in a warming climate. 

Nearly every country in the world has agreed to participate in a sweeping agreement to preserve biodiversity and reduce invasive species.  It is an essential global goal.

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Invasive Species Are Costing the Global Economy Billions, Study Finds

Photo, posted June 2, 2022, courtesy of Sam Stukel (USFWS) via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Lampshades And Indoor Air Pollution | Earth Wise

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We mostly think of air pollution as an outdoor problem.  Common sources of air pollution include emissions from vehicles, byproducts of manufacturing and power generation, and smoke from wildfires.  What we don’t often spend a lot of time thinking about is indoor air quality. 

Indoor air pollution refers to harmful pollutants within buildings and structures, which can lead to a myriad of health issues.  Sources of indoor air pollution include smoke from tobacco products, as well as volatile organic compounds (VOCs), including acetaldehyde and formaldehyde, emitted from things such as paints, cleaning products, plastics, and cooking. 

A team of scientists from South Korea’s Yonsei University has developed a special coating that when applied to lampshades can convert pollutants into harmless compounds.  Composed of titanium dioxide and a small amount of platinum, this thermocatalyst can be applied to the inside surface of a lampshade and is triggered to break down VOCs when warmed by the lamp’s existing incandescent or halogen bulb.

In lab tests, the coating was applied to the inside of an aluminum lampshade, warmed by a halogen bulb, and then placed into a sealed chamber containing air and acetaldehyde gas.  The researchers found that the material quickly converted the gas into acetic acid, then into formic acid, and finally into carbon dioxide and water. The scientists are now looking for ways to extend the pollutant-destroying-lampshade concept to LED lightbulbs. 

The findings offer a promising and eco-friendly solution to improve indoor air quality and reduce the health risks associated with prolonged exposure to VOCs. 

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Clever coating turns lampshades into indoor air purifiers

Photo, posted March 21, 2009, courtesy of Levent Ali via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Captive Lion Problem | Earth Wise

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In the 1990s, there was rapid growth in South Africa of the private wildlife industry.  Large numbers of cattle, sheep, and goat ranchers replaced their domestic livestock with wild animals that wealthy hunters would pay lots of money to shoot.  Lions were among the most prized targets for these people.  Over time, hundreds of ranchers became involved in the business of breeding large numbers of the big cats in cages or small enclosures.  Wealthy clients paid $25,000 to $40,000 to shoot a captive-bred lion – cheaper than the cost of a true wild lion hunt and much easier too.  The animals were not afraid of humans and were easy to find.

By 2015, about 200 ranches held at least 8,000 captive-bred lions.  Over 600 were trophy-hunted that year, generating about $16 million in trophy fees, mostly from Americans.

Journalists and conservationists exposed poor conditions on many lion farms and many other abuses.  Over time, the South African government cracked down on the export of lion bones and other body parts for taxidermy, traditional Chinese medicine, and other uses.  The days of captive lion breeding seemed numbered but shutting down the lucrative industry is not easy.

Wild lions in South Africa are not endangered.  In fact, existing sanctuaries and preserves have as many lions as they can sustain.  What to do with thousands of captive lions is a real problem.  Some have suggested mass euthanasia, but that appalling idea has garnered very little support.  The future of these animals still hangs in the balance and so far, there are really no truly desirable solutions in the offing.

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If South Africa Ends Lion Breeding, What to Do With Captive Cats?

Photo, posted August 21, 2011, courtesy of Leszek Leszczynski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Too Many Bison | Earth Wise

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In the northern part of Yellowstone National Park, an historically large bison herd is hampering the comeback of quaking aspen trees, whose numbers were greatly diminished by decades of over-browsing by elk.  Restoring the balance of ecosystems at Yellowstone is proving to be a complicated matter.

Long ago, the bison population in the Great Plains was as much as 30 million.  The population sharply decreased in the 1800s.  By the 1830s, there were no bison east of the Mississippi River.  Fifty years later, the Plains bison was nearly extinct.  Several small herds lived near Yellowstone Park when it was established in 1872, but poachers killed off nearly of them by the turn of the century.  Protective measures were taken and by 1925, Yellowstone’s Lamar Valley herd had grown to more than 750.  After that, occasional culling took place for over 40 years. 

When gray wolves and cougars were removed from the park, elk populations boomed, and the elk gradually decimated the growth of quaking aspen, cottonwood, willow, and berry-producing shrubs.  Both elk and bison were regularly culled until 1968 when public and congressional outcry intervened.

The return of wolves and cougars to the park made some progress in restoring ecosystem balance, particularly with respect to the elk population which has dropped from 20,000 to 5,000.  But bison numbers have grown to over 4,000 over past 20 years and the damage once caused by elk is now continuing from bison.

Park administrators are faced with complex management decisions about how to best preserve the ecosystems at Yellowstone National Park.

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Bison in northern Yellowstone proving to be too much of a good thing

Photo, posted October 6, 2016, courtesy of Christian Collins via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Deadly Heatwaves On The Rise | Earth Wise

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The European heatwave in the summer of 2003 resulted in at least 30,000 deaths with more than 14,000 in France alone. At the time, such a heatwave was considered to be a once-in-a-hundred-year event. But the warming climate is dramatically changing the odds for deadly heatwaves.

A new study by the ETH Institute in Zurich has found that the risk of fatal heatwaves has risen sharply over the past 20 years, and in the future, such extreme weather will become more frequent and heat-related excess mortality will increase, particularly in Europe.  According to a paper published in Nature Medicine, more than 61,000 deaths in Europe could be blamed on the heat during the summer of 2022, which was the hottest summer on record for the continent.  When the readings from this summer are analyzed, that record is likely to be surpassed.

Heatwaves lead to excess deaths due to dehydration, heat stroke, and cardiovascular collapse.  They are particularly deadly for the elderly, the sick, and the poor.  The ETH researchers analyzed comprehensive data from 748 cities and communities in 47 countries.   They determined the relationship between increased temperature and excess mortality.  Their models look at how excess mortality would develop with an average global temperature increase of 0.7 degrees Celsius (the value in 2000), 1.2 degrees (the value in 2020), and both 1.5 degrees (the limit sought by the Paris Agreement) and 2 degrees.

Even with the current global temperature, heatwaves that were a once-in-a-century event are now expected to occur every 10 years.  With 2 degrees of warming, such heatwaves could happen every 2 to 5 years.

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Heatwaves are becoming more frequent and more deadly

Photo, posted July 22, 2009, courtesy of Matt McGee via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Grid-Scale Gravity Energy Storage | Earth Wise

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As wind and solar energy play a growing part in our energy system, the need for grid-scale energy storage is growing as well.  An historic form of energy storage and still the largest in installed capacity is pumped hydro storage, which makes use of the potential energy contained in having water sitting at a higher elevation where it can be released downward to operate turbine generators.  This is an effective system but is limited to places where geography cooperates.

For the past five years, a company called Energy Vault has been developing a system that uses the same principle to generate electricity but instead of pumping water to a higher elevation, it uses mechanical devices to lift heavy objects such as concrete blocks to an appropriate height.  Lowering the blocks back to the ground drives generators.

To date, Energy Vault has only built demonstration systems with a fraction of the storage capacity needed for grid-scale operation. Their EV1 Tower in Switzerland was successfully grid interconnected in 2020 and demonstrated round-trip efficiency (the fraction of the energy stored that was produced by the generators) above 75%.  Their improved EVx system is expected to do better than 80%.

This year the company, along with partners Atlas Renewable and China TIanying, is now in the first phases of commissioning a grid-scale system located outside of Shanghai, China.  The 25-MW system is built adjacent to a wind farm and a national grid interconnection site

This is the first grid-scale gravity energy storage system and is expected to be fully online in the fourth quarter of this year.  A second, similar system is now under contract to be built elsewhere in China.

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First grid-scale gravity energy storage system undergoes commencement in China

Photo courtesy of Energy Vault.

Earth Wise is a production of WAMC Northeast Public Radio

Trouble For Emperor Penguins | Earth Wise

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Emperor penguins are the tallest and heaviest of all living penguin species.  The loss of sea ice in Antarctica last year has led to unprecedented breeding failure in some emperor penguin colonies.

In a study published by the British Antarctic Survey, researchers found that no chicks survived from four of the five known emperor penguin colonies in the central and eastern Bellinhausen Sea.   Satellite images showed the loss of sea ice at breeding sites, well before chicks would have developed waterproof feathers.

Emperor penguins are dependent on stable sea ice that is firmly attached to the shore from April through the end of the year.  Arctic sea ice reached an all-time low in December 2022 with the most extreme loss seen in the central and eastern Bellinghausen Sea where there was a 100% loss of sea ice late the year.

This year, the sea ice extent in Antarctica is still far below all previous records for this time of year.  As of August, when oceans normally are freezing up, there were still areas that were ice-free.

Emperor penguin populations have not had to contend with large-scale hunting, habitat loss, overfishing, or other human-caused problems in the modern era, but climate change may be their undoing.  They have previously responded to incidents of sea ice loss by moving to more stable sites in the following year.  But this strategy will not be successful if the sea ice habitat is affected across entire regions of Antarctica.

Scientists are predicting that 90% of emperor penguin colonies will be quasi-extinct by the end of the century, assuming current global warming trends continue.

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Loss of sea ice causes catastrophic breeding failure for emperor penguins

Photo, posted October 7, 2017, courtesy of Christopher Michel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Aphids And Monarchs | Earth Wise

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Last year, the monarch butterfly was officially designated as endangered by the International Union for Conservation of Nature.  Estimates are that the overall population of the species has dropped between 20% and 90% over the past several decades. 

The migratory western population of monarchs is at the greatest risk of extinction, having declined by as much as 99.9% between the 1980s and 2021.  Legal and illegal logging and deforestation to make space for agriculture and urban development has destroyed much of the butterflies’ winter shelter in Mexico and California and pesticides and herbicides throughout the butterflies’ range kills both the butterflies and the milkweed that their larvae feed on.

A new study by the University of Florida has found that aphids feeding on the milkweed that grows across the southern portions of the US causes the butterflies to lay fewer eggs on the plants and the caterpillars developing on those plants were slower to mature.  The study showed that monarch laid three times as many eggs on aphid-free plants as they did on aphid-infested plants.

For years, there have been efforts to plant milkweed in urban areas to support monarch populations.  However, aphids and other insect pests often reach high densities on plants in urban settings. 

The researchers are advising home gardeners in the southern U.S. who want to conserve monarch butterflies to make use of safe techniques to limit aphid populations such as insecticidal soap.  This may not always be an option and the researchers are investigating other options to keep aphids at low levels that aren’t harmful to monarchs.

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Aphids make tropical milkweed less inviting to monarch butterflies, study finds

Photo, posted October 12, 2018, courtesy of Renee Grayson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Better Plastic Recycling | Earth Wise

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Many of us are careful to put our plastic trash into the appropriate recycling bins hoping that we are helping to stem the global tide of plastic waste.  But many plastics are not recyclable at all and recycling those that are is not even always a good thing.  Breaking down plastics can generate polluting microplastics that are themselves a major environmental problem.  And perhaps the biggest problem for recycling efforts is that they are not cost effective and generally incur huge losses.

Chemical engineers at the University of Wisconsin-Madison recently published a study in the journal Nature outlining a new technique for turning low-value waste plastic into high-value industrial chemicals. 

The technique makes use of two existing chemical processing techniques.  The first is pyrolysis, which is high-temperature heating in an oxygen-free environment.  Heating waste plastic in this way produces pyrolysis oil, a liquid mix of various compounds that includes large amounts of olefins.  Olefins are simple hydrocarbons that are a central building block of many chemicals and polymers.  Olefins are most often produced by energy-intensive processes like steam cracking of petroleum. 

The UW-Madison process takes the olefins and subjects them to a process called homogenous hydroformylation catalysis, which converts them into aldehydes, which can then be further reduced into important industrial chemicals. 

The payoff is that the process can take waste plastics, which are only worth about $100 a ton, and turn them into high-value chemicals worth $1,200-$6,000 a ton.  If the process can be optimized and otherwise made ready for industrial-scale use, it would be a real game-changer in the battle against plastic waste.

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New recycling process could find markets for ‘junk’ plastic waste

Photo, posted September 16, 2015, courtesy of Oregon State University via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

More Offshore Wind Proposed For New Jersey | Earth Wise

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There have been three offshore wind projects previously approved by utility regulators in New Jersey.  New Jersey is vying to become an East Coast leader in the fast-growing offshore wind industry and now developers have proposed four new projects off the New Jersey Shore.

Two of the projects would be located far out to sea where they would not be visible at all from the shore.  One of them, called Community Offshore Wind, would be built 37 miles offshore from Long Beach Island.  It aims to generate enough electricity to power 500,000 homes.

A second project, called Leading Light Wind, would be located 40 miles off Long Beach Island and would consist of up to 100 turbines that would generate enough electricity to power 1 million homes.

The two companies that are building the already-approved Atlantic Shores Wind Farm have submitted a bid for a new project located 10 to 20 miles offshore.  In addition, a fourth application to the New Jersey Board of Public Utilities has also been submitted, but there is yet no public information about it.

Existing offshore projects have drawn intense opposition from homeowners in part because they are close enough to the Atlantic City and Ocean City shorelines to be seen by beachgoers, albeit as tiny objects on the horizon.  The new proposed projects located far offshore would not have this problem.

The new projects can take advantage of existing federal tax credits, but the bidders say they will not seek the tax breaks from New Jersey that the earlier project received as they have also been the subject of legal challenges by opponents of offshore wind.

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4 new offshore wind power projects proposed for New Jersey Shore; 2 would be far out to sea

Photo, posted March 25, 2016, courtesy of TEIA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Top Fish Predators And Climate Change | Earth Wise

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Climate change is taking its toll on forests, farms, freshwater sources, and the economy, but ocean ecosystems remain the epicenter of global warming.  In fact, oceans have absorbed more than 90% of the excess heat from greenhouse gas emissions since the 1970s.

As a result, many marine fish species are responding to ocean warming by relocating towards the poles.  According to new research recently published in the journal Science Advances, climate change is causing widespread habitat loss for some of the ocean’s top fish predators, driving these species northward.

The research team studied 12 species of highly migratory fish predators, including sharks, tuna, and billfish, such as marlin and swordfish, inhabiting the Northwest Atlantic Ocean and the Gulf of Mexico.  These two regions are undergoing rapid changes in sea surface temperatures, and are among the fastest warming ocean regions on earth.

The research, which was led by researchers from Woods Hole Oceanographic Institution in Massachusetts, with collaboration from San Diego State University, NOAA, and several other U.S. institutions, found that most species will encounter widespread habitat losses by 2100.  Some species could lose upwards of 70% of suitable habitat by that year.  Areas offshore of the Southeast United States and Mid-Atlantic coasts were identified as likely hotspots of multi-species habitat loss. 

According to the researchers, strategies for managing fish have historically been static. But marine systems need to be treated as dynamic and changing.  This study helps provide the scientific data needed for marine conservation and fisheries management efforts.

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Top fish predators could suffer wide loss of suitable habitat by 2100 due to climate change

Photo, posted March 18, 2015, courtesy of Kenneth Hagemeyer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Lakes Are Shrinking | Earth Wise

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A study by the University of Colorado Boulder has found that more than half of the world’s largest lakes have shrunk over the last three decades.  This is a very big problem because about one-quarter of the Earth’s population lives in the basin of a drying lake.  People depend on lakes for drinking water and irrigation and lakes are central to the survival of local ecosystems as well as migrating birds.  Lakes cover only about 3% of the planet, but they hold nearly 90% of the liquid surface freshwater.

The study used satellite observations from 1992 to 2020 to estimate the area and water levels of nearly 2,000 freshwater bodies.  These account for 96% of Earth’s total natural lake storage and 83% of that in man-made reservoirs.  About 53% of the world’s lakes have clearly shrunk, while only 22% have gained water.  The study estimates that about 160 trillion gallons of water has been lost over the 28-year period.  That’s about 17 times the maximum capacity of Lake Mead, the largest reservoir in the United States.

Many of the world’s most significant lakes have been shrinking. The dramatic declines in Lake Mead have been headline news for years.  The Caspian Sea, which is the world’s largest inland body of water – has long been declining.

The main causes of the decline in natural lakes are climate change and human consumption.  Reservoirs face an additional major problem of sediment buildup which reduces their storage capacity and diminishes their benefits of water supply, flood control, and hydropower.

Lake loss is a big problem.

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More than half of the world’s largest lakes are drying up

Photo, posted April 10, 2018, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Planting Rocks To Capture Carbon | Earth Wise

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Getting humanity to stop dumping carbon dioxide into the atmosphere continues to be very challenging regardless of how increasingly apparent the need to do so becomes.  For this reason, climate change mitigation strategies increasingly include interventions in the form of removing carbon dioxide that is already there.  There are a variety of ways to draw carbon dioxide out of the atmosphere, but they face a host of technological, economic, and even environmental difficulties.

A new study at Yale University evaluated a type of climate intervention called enhanced rock weathering.  Rock weathering is a natural chemical process by which certain minerals absorb carbon dioxide over time.  Enhanced rock weathering is simply speeding up weathering such so it can have beneficial results soon enough to make a difference.

The study explored the potential of applying crushed basalt, which is a fast-weathering rock that forms when lava cools, to agricultural fields around the world.  Basically, the idea is for farmers to mix the crushed rocks into their fields. There is no real downside to doing this.  In fact, adding crushed basalt to fields rejuvenates depleted soils and helps counter ocean acidification.

The study simulated the results of enhanced rock weathering on 1,000 agricultural sites around the world.  Over a 75-year period, these sites would remove 64 billion tons of carbon dioxide from the atmosphere.  This is roughly the amount climate scientists believe is needed to take out of the atmosphere. 

Enhanced rock weathering has been used on a small scale on farms around the world.  Perhaps it is time to ramp up its use.

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‘Planting’ rocks in farms, along with emissions reductions, could help meet key IPCC carbon removal goal

Photo, posted January 14, 2023, courtesy of Ron Reiring via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Air Pollution And Insects | Earth Wise

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Insects can be found in every environment on Earth and play critical roles in the planet’s ecosystems.  Insects pollinate more than 80% of plants, including those that we eat and those that provide food and habitat for other species.  Without insects, we wouldn’t have the rich biodiversity that supports life on earth today.

But the world is experiencing a decline in overall insect populations as well as a collapse in insect diversity.  According to researchers from the University of Melbourne in Australia, Beijing Forestry University in China, and the University of California – Davis, air pollution particles may be the cause of the dramatic decline.  They found that an insect’s ability to find food and a mate is reduced when their antennae are contaminated by particulate matter. 

In the study, which was recently published in the journal Nature Communications, the research team exposed houseflies to varying levels of air pollution for just 12 hours and then placed the flies in a Y-shaped tube ‘maze’. Uncontaminated flies typically chose the arm of the Y-maze leading to a smell of food or sex pheromones, while contaminated flies selected an arm at random, with 50:50 probability.

Using a scanning electron microscope, the researchers also found that as air pollution increases, more particulate material collects on the sensitive antennae of houseflies. 

Insect antennae have olfactory receptors that detect odor molecules emanating from a food source, a potential mate, or a good place to lay eggs.  If an insect’s antennae are covered in particulate matter, a physical barrier is created between the smell receptors and air-borne odor molecules.

Air pollution poses a significant threat to insect populations around the world.   

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Air pollution particles may be cause of dramatic drop in global insect numbers

Photo, posted June 13, 2008, courtesy of Allen Watkin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Saving Florida’s Corals | Earth Wise

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When corals are exposed to extended periods of excess heat, they are subject to bleaching, which occurs when they expel the algae that live within their structure.  Bleaching can lead to coral death.

This summer, temperatures in the Florida Keys crossed the bleaching threshold in mid-June and remained above it for extended periods of time.  This cumulative heat exposure leads to widespread bleaching and significant die-offs.  The last major mass bleaching event in the Florida Keys occurred in 2014 and 2015.

The Coral Restoration Foundation has been receiving reports ranging from partial bleaching to mass coral mortality throughout the keys.  Several coral restoration sites in the lower Keys have been totally lost already.

The National Oceanic and Atmospheric Administration and its state agency, university, and non-profit partners have initiated actions to try to save Florida’s corals.

They have halted all restoration-related planting and are evacuating some of their nursery-grown stock to climate-controlled labs.  They are considering interventions such as shading coral nurseries or even high-value reef sites.  They are also considering feeding nursery and wild corals until the waters cool off enough for algae to return.

Modeling indicates that there is a 70-100% chance that the extreme heat in the North Atlantic will persist through September-October.  NOAA and its partners will continue to do what they can to save Florida’s Coral Reef for the marine and human communities that depend on them.

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NOAA and partners race to rescue remaining Florida corals from historic ocean heat wave

Photo, posted April 19, 2012, courtesy of U.S. Fish and Wildlife Service Southeast Region via Flickr.

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