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Harmful algal blooms and climate change

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An algal bloom is a rapid increase in the density of algae in an aquatic system.  Harmful algal blooms occur when bodies of water get overloaded with nitrogen and phosphorus runoff from agriculture and other human activities. These excess nutrients can facilitate the out-of-control growth of cyanobacteria, also known as blue-green algae. 

Some species of blue-green algae produce a toxin called microcystin.  These toxins pose a serious health hazard to people, animals, and the environment.  Microcystin affects liver function and can cause death in animals, as well as humans in rare instances.  A notable incident occurred in the summer of 2014, when cyanobacteria contamination in Lake Erie left 500,000 residents in Ohio and Michigan without water for 72 hours and sickened more than 100 people. 

According to a study led by researchers from Carnegie Science, as climate change warms the earth, higher-latitude regions will be at a greater risk for microcystin produced by algal blooms.  The study found water temperatures of 68 to 77 degrees Fahrenheit as being at the greatest risk for developing dangerous levels of microcystin. 

In the study, which was published in the journal Nature Water, the research team also demonstrated that the areas most susceptible to high toxin concentrations will continue to move northward. And in some areas, researchers say the relative risk of exceeding water quality guidelines will increase by up to 50% in the coming decades.

The research team hopes its findings raise more awareness about water sustainability, and the need to focus on the quality of the water as much as the quantity of water. 

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Geographic redistribution of microcystin hotspots in response to climate warming

Photo, posted October 27, 2010, courtesy of Nara Souza / Florida Fish and Wildlife Commission via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Abandoned farmland and the environment

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Abandoned farmland has been increasing dramatically in recent decades.  Estimates are that a billion acres – an area half the size of Australia – have been relinquished from cultivation globally.  While more and more of the tropics have been cultivated in recent times, the global amount of land used for agriculture has been in decline since 2001.  In the past 30 years, arable land in the United States has declined by almost a sixth.  The situation in Europe is similar.  Huge amounts of the former Soviet Union now lie abandoned. 

Farmland is abandoned for various reasons.  It may suffer from damaged soil so that crop yields are too low to be worth the effort.  Farm owners may become too old or be physically unable to continue farming.  Many younger people head for jobs in the cities and more attractive opportunities.  Wars, natural and man-made disasters, and political turmoil have all contributed.

Another form of largely ignored lands are so-called degraded forests.  These are forests that were logged in the past but are no longer productive and aren’t protected either.  These places also represent unused land with great potential value.

Ecologists point to the potential of these lands as neglected resources for rewilding efforts, improving biodiversity, and for increasing natural ways to capture carbon.  Left to its own devices, nature will usually reclaim abandoned places.  This generally provides benefits for biodiversity and climate.  But mapping, studying, managing, and protecting the increasingly vast tracts of abandoned land could increase their potential to contribute to climate change mitigation and the restoration of species and their habitats.

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Abandoned Lands: A Hidden Resource for Restoring Biodiversity

Photo, posted January 26, 2023, courtesy of Larry Syverson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Supermarket bargains and food waste

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Food waste is a major global problem.  The UN estimates that one third of all food goes to waste.  Apart from the fact that this is happening in a world where many people don’t have enough to eat, food waste is both an economic and a climate problem.

Researchers from the University of Copenhagen and Southern Methodist University investigated how different types of grocery sales strategies affect people’s shopping and food waste.  The result was that bulk offers increase food sales by nearly 20%, but they also lead to increased food waste in people’s homes.

The study analyzed over 43,000 purchases of fresh vegetables in eight Swedish supermarkets.  When customers were offered “two-fer” offers, they bought significantly more than when only single items were available.  The attraction of a special offer can be strong.  But, according to a follow-up survey, food from bulk offers ended up in the trash more often.  People thought they were saving money, but often ended up buying more than they can eat.

The researchers tested two strategies for reducing overbuying.  One was to make the actual savings explicit by displaying the regular price next to the offer.  The second was to put a friendly reminder on the offer sign along the lines of “I’d love to come home with you if you eat me.”  Both of these approaches resulted in reduced sales of 9-11% compared to the original volume offer despite the sale price remaining the same. 

Clearly, small changes in marketing can make a big difference.  Supermarkets play a big role in the occurrence of food waste and they have the ability to help nudge consumers into better behavior.

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Good deals – bad for the climate: Supermarket volume discounts lead to food waste

Photo, posted November 13, 2006, courtesy of Josh Hallett via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Recycling solar panels

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The use of solar energy has been growing by leaps and bounds in recent years. It is the fastest growing source of energy in the U.S.   Solar panels have a useful life of about 25 to 30 years and there are growing numbers that have been around that long.  They contain valuable materials, including silver, copper, and aluminum, as well as some hazardous materials, so just committing them to landfills is a bad idea from many perspectives.

Recycling solar panels is a relatively new but increasingly important business.  At the present time, roughly 90% of panels that have lost their efficiency due to age or that are defective end up in landfills because that is much cheaper than recycling them.  The best option is to reuse them where their reduced efficiency is acceptable.  This includes in developing nations or in other places that are able to make use of the lower power in exchange for lower installation cost.

Estimates are that the area covered by solar panels in the U.S. that are due to retire by 2030 would cover about 3,000 football fields.   The amount of potential waste contained in all of those panels is quite substantial.

There are new companies dedicated to solar panel recycling such as one called SolarCycle that are trying to change this situation.  It is much more expensive to have SolarCycle take away solar panels than to send them to landfills, but it is difficult to find landfills that accept panels and many clients want to minimize the environmental impact of their old panels.

Only 10% of retired solar panels are currently recycled. That that is likely to change as economics and regulations continue to evolve.

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As Millions of Solar Panels Age Out, Recyclers Hope to Cash In

Photo, posted November 23, 2024, courtesy of Mussi Katz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Air pollution and human health

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Climate change is making air quality worse in many parts of the world. Rising temperatures increase ground-level ozone, and more frequent wildfires release harmful smoke and particulates into the air. These changes, combined with ongoing pollution from sources like vehicle exhaust and industrial emissions, lead to longer and more intense episodes of unhealthy air.

A new study led by researchers from the University of Toronto in Canada examined more than 600 people and found that long-term exposure to air pollution is associated with early signs of heart damage.  The research, which was recently published in the journal Radiology, indicates that fine particulate matter in the air may contribute to diffuse myocardial fibrosis, a form of scarring in the heart muscle that can precede heart failure. 

Cardiovascular disease is the leading cause of death worldwide. 

Long-term exposure to common air pollutants is also linked to a significantly higher risk of dementia.  A separate study by researchers from the University of Cambridge in the UK analyzed data from nearly 30 million people and found that for every 10 micrograms of fine particulate matter per cubic meter of air, the risk of dementia increases by 17%.  The study, which was recently published in The Lancet Planetary Health, found that exposure to nitrogen dioxide and soot was also strongly associated with an increased risk of dementia.

Dementia is estimated to affect more than 57 million people worldwide, a number that is expected to swell to 152 million by 2050.

Strengthening efforts to reduce air pollution could make a real difference for the environment and human health.

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Even low levels of air pollution may quietly scar your heart, MRI study finds

Is the air you breathe silently fueling dementia? A 29-million-person study says yes

Photo, posted February 25, 2017, courtesy of CCO Bay via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Seaweed and concrete

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Modern civilization is pretty much made of concrete.  People use more concrete than any other substance apart from water.  But concrete is made from cement, and cement is the source of 10% of all carbon dioxide emissions worldwide.

Researchers at the University of Washington and Microsoft have developed a new kind of concrete made by mixing dried, powdered seaweed with cement.  By fortifying cement with seaweed, the global warming potential of the concrete is reduced by 21% without weakening it. 

This novel recipe for concrete was developed using machine learning models, arriving upon it in a fraction of the time it would have taken by traditional experimentation.

Producing cement leads to carbon emissions from the fossil fuels used to heat raw materials and from a chemical reaction called calcination that occurs during the production process.  Seaweed is a carbon sink that pulls carbon dioxide out of the air and stores it while it grows.  By replacing some of cement in concrete, the resultant product has a much smaller carbon footprint.

Machine learning was used to predict the ideal mixture of cement and seaweed to yield concrete with a reduced carbon footprint that still passed mechanical strength tests.  Finding the right mixture would have taken 5 years ordinarily, but the machine learning process took only 28 days.

The researchers plan to generalize their work to different kinds of algae and even to food waste or other natural materials in order to create local, sustainable cement alternatives around the world. 

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Seaweed-infused cement could cut concrete’s carbon footprint

Photo, posted June 29, 2009, courtesy of Peter Castleton via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Facemask pollution

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During the height of the Covid-19 pandemic, the global usage of disposable facemasks reached a staggering 129 billion per month. Most of these masks are manufactured from petroleum-based non-renewable plastics like polypropylene and the disposal of these masks results in serious pollution problems.  These include the loss of ecological integrity from buried waste in landfills, air pollution from increased waste incineration, and microplastic pollution. 

Recent research by engineers at Washington University in St. Louis investigated the multipronged pollution problem brought about by discarded facemasks.  The study in particular looked at the chemical changes that occur when facemasks are exposed to sunlight, water, and trace metal ions.

Masks littering the environment degrade into nanoplastics and produce reactive oxygen species.  These chemical agents interact with trace metal ions in the environment within hours.  The result is oxides of metals like manganese and iron, which can drive various biogeochemical reactions.

Abandoning and forgetting about plastics like facemasks is an unsustainable practice.  Plastics not only cause physical damage, but also introduce unpredictable and potentially dangerous chemical changes into environmental systems.

Plastic waste is a global problem that has continued to grow and become an increasingly serious threat over decades.  Understanding the nature of the effects of billions of facemasks in the environment is essential to efforts to address the challenges created by them.

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Sun exposure changes chemical fate of littered face masks

Photo, posted August 21, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Better blue LEDs

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LEDs have become the standard source of energy-efficient lighting.  They make use of semiconductors to turn electricity into light.  Depending upon the materials used to make them, LEDs produce different colors.  In the early 1990s, the first blue LEDs were discovered, ultimately earning the Nobel Prize in physics, and enabling LEDs to produce white light, which is essential for general lighting applications.

Blue LEDs have shortcomings.  Some have issues with stability, scalability, cost, efficiency, complexity in manufacturing, or have environmental concerns because of the use of toxic components. 

Researchers at Rutgers University in collaboration with scientists at several other institutions have found a way to make blue LEDs more efficient and sustainable.  These LEDs use a new type of hybrid material that is a combination of copper iodide with organic molecules.  The impressive performance of these LEDs was achieved through an innovative technique called dual interfacial hydrogen-bond passivation.  This new manufacturing technique boosts the performance of LEDs by a factor of four.

The material has several advantages.  It has a very high photoluminescence quantum yield, which means that it converts nearly all the photoenergy it receives into blue light.  The LEDs last longer than many others and they work well in larger-scale applications, maintaining high efficiency.  The materials are eco-friendly and cost-effective.

According to the researchers, this new approach could be a versatile strategy for generating high-performance LEDs that can pave the way for better, brighter, and longer-lasting LEDs.

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Scientists Develop Deep-Blue LEDs Expected to Greatly Enhance General Lighting

Photo, posted February 1, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An anti-malaria breakthrough

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The deadliest animal in the world is the mosquito.  Mosquitos infected 263 million people with malaria in 2023, leading to 600,000 deaths, 80% of which were children.  Malaria is caused by infection from Plasmodium parasites.  The parasites are transmitted to humans from the bite of infected female mosquitos.

Researchers at the University of California San Diego, Johns Hopkins University, UC Berkeley, and the University of Sāo Paulo have developed a new method that genetically blocks mosquitos from transmitting malaria.

The study was published in the journal Nature.  They used gene editing to change a single molecule within mosquitos.  The genetically altered mosquitos can still bite people with malaria and can still acquire parasites from their blood, but the parasites can no longer be spread to other people.  The switching of one specific amino acid known as L224 with a genetic alternative called Q224 prevents malarial parasites from reaching the salivary glands of the mosquito, thereby preventing the spread of infection.  In extensive tests, the researchers found that while the genetic switch disrupted the parasite’s infection capabilities, the mosquitos’ normal growth and reproduction remained unchanged.

The hope is that the replacement of a single amino acid in mosquitoes that prevents them from being infected with malarial parasites is a beneficial trait that can spread throughout a mosquito population.  The researchers believe that the trait can be spread across diverse mosquito species and populations and can pave the way for adaptable, real-world strategies to control malaria.

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Stealth Genetic Switch in Mosquitoes Halts Malaria Spread

Photo, posted June 20, 2014, courtesy of John Tann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A hidden cost of climate change

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Climate change is dramatically impacting food production by altering rainfall patterns, increasing temperatures, and triggering more frequent extreme weather events.  These changes make crops more vulnerable to droughts, floods, heatwaves, pests, and diseases, leading to lower yields and greater uncertainty for farmers worldwide.

But climate change isn’t just reshaping our planet.  It’s also changing what’s on our plates.  According to a new study by researchers from Liverpool John Moores University in the UK, rising carbon dioxide levels and warmer temperatures may be making food less nutritious.

The research team focused on popular leafy vegetables, including kale, rocket, and spinach.  The researchers simulated future UK climate conditions in growth chambers to study how the crops responded to hotter, CO2-rich environments.

The research team found that elevated CO2 levels help crops grow faster and bigger, but not healthier.  Over time, the crops showed a reduction in key minerals like calcium and certain antioxidant compounds.  These changes were exacerbated by increases in temperature.  In fact, the combination had complex effects.  The crops did not grow as big or fast, and the decline in nutritional quality intensified.

This nutritional imbalance poses serious human health implications.  Rising CO2 levels can increase sugar in crops while reducing essential nutrients, leading to calorie-rich but nutrient-poor diets. This shift may raise the risk of obesity, diabetes, and nutrient deficiencies, especially in vulnerable populations.

The challenge ahead isn’t just to grow enough food to feed a growing population, but to preserve the quality of that food in a changing climate.

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Bigger crops, fewer nutrients: The hidden cost of climate change

Photo, posted May 25, 2010, courtesy of Jason Bachman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Trouble for psychedelic toads

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Back in the 1960s, it was discovered that secretions from toads native to the Sonoran Desert have psychedelic properties.  The information did not have much impact for over 40 years but about ten years ago, the story started having widespread exposure in U.S. media outlets and there was increasing publicity for the fact that the toad’s dried secretions could be smoked to produce a brief but intense high.

There was also a false narrative spreading around that this so-called toad medicine was part of an ancient practice of indigenous tribes in the Sonoran Desert.  The active agent in the toad secretion is a compound called 5-MeO-DMT and it became an increasingly popular item being sold by self-described shamans, new-age healers, and other underground practitioners. 

5-MeO-DMT is mostly banned as a controlled substance in the U.S., but many Mexican ranchers have been amassing the toads to sell to foreigners to take back home.  Despite the fact that 5-MeO-DMT has been successfully synthesized, the mystique surrounding the toads makes potential users want to use the natural version.

Researchers have found that trapping the toads in Mexico has decimated several populations of the amphibians and has sent others into steep decline. The species currently has no protections in Mexico.  These desert toads play key roles as both predators and prey and as their population declines, there are likely to be some serious ecological problems.  There is already anecdotal evidence that in many places in the desert, crop-eating insect populations have surged in recent years.

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These Toads Have Psychedelic Powers, but They’d Prefer to Keep It Quiet

Photo, posted December 12, 2017, courtesy of K.S. Black via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Disappearing wetlands

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More than 170 countries gathered recently to discuss how to save wetlands, which are critical ecosystems.  However, the U.S. was a no-show for most of the summit and Russia said it will withdraw from the wetlands treaty.

Wetlands are a crucial element of all life on Earth, supplying fresh water, oxygen, habitat, and food.  The Ramsar Convention, an international treaty focused on the conservation and wise use of wetlands, is the oldest modern global environmental agreement, adopted in 1971. 

Despite this agreement, since 1970 more than 35% of wetlands have been lost or degraded.  A recent report compiled by more than 60 experts from around the world issued a dire warning that the decline of wetlands spells trouble for global food security, climate stability, and even the capacity for life on Earth to persist.

Sadly, geopolitics have overtaken even the instinct for survival.  Because of a prior resolution to monitor Ukranian wetlands harmed during Russia’s ongoing war there, Russia now intends to withdraw from the treaty.  Meanwhile, the U.S. delegate to the wetlands summit only showed up near the end of the meeting to demand that conference documents make no mention of climate change, diversity equity and inclusion, gender, UN sustainable development goals, or zero growth.

Disengagement by the United States from the world’s increasing and shared environmental problems is a global crisis that only worsens existing global crises.

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Earth’s Wetlands Are Disappearing and Global Efforts to Save Them Are Unraveling

Photo, posted October 8, 2013, courtesy of Marek Kusmin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

AI and energy

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MIT recently hosted a symposium on the subject of artificial intelligence being both a problem and a solution for the clean energy transition.

AI-powered computing centers are expanding rapidly, creating an unprecedented surge in electricity demand.  Electricity demand in the US had been relatively flat for decades but now these computing centers consume about 4% of the nation’s electricity.  Some projections say that this demand could rise to 12-15% in the next five years. 

The power required for sustaining some of the AI large-language models is doubling every three months.  The amount of electricity used by a single ChatGPT conversation is as much as it takes to charge a phone and consumes the equivalent of a bottle of water for cooling. 

The MIT symposium focused on the challenges of meeting these growing energy needs but also on the potential for AI to dramatically improve power systems and reduce carbon emissions. 

Research shows regional variations in the cost of powering computing centers with clean electricity.  The central United States offers lower costs due to complementary solar and wind resources but would require massive battery deployments to provide uninterrupted power.

Because of data center demand, there is renewed interest in nuclear power, often in the form of small modular reactors, as well as efforts in long-duration storage technologies, geothermal power, or hybrid approaches.

Artificial intelligence offers both great promise and great peril.  It will take real intelligence to steer it in the right direction.

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Confronting the AI/energy conundrum

Photo, posted August 31, 2024, courtesy of Jefferson Lab via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The benefits of agroecology

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Agroecology focuses on sustainably managing agricultural systems by applying ecological principles.  The goal is to optimize the interactions between plants, animals, humans, and the environment.

A four-year study by the UK Centre for Ecology and Hydrology found that incorporating nature-friendly practices within farming increases biodiversity, pollination by bees, natural pest control, and the numbers of earthworms. 

The study compared three agricultural systems:  typical intensive agriculture, enhanced ecological farming, and maximized ecological farming.  Enhanced ecological farming involves planting wildflower field margins to provide habitat for bees, beetles, and spiders, and sowing overwinter cover crops to capture carbon and retain soil nutrients.  Optimized ecological farming adds planting in-field strips of wildflowers to attract beneficial insects and adding organic matter such as farmyard manure to improve soil health.

The ecological systems had increased populations of earthworms and pollinators, as well as natural predators of crop pests. 

The study concluded that while there are multiple benefits in terms of biodiversity, soil carbon, and crop yield when ecological farming systems are used, many farmers will be deterred from adopting agroecological farming practices and system because of the reduced profitability.  They argue that financial incentives such as subsidies are needed and are well worth it for the long-term sustainability of agriculture.

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Nature-friendly farming boosts biodiversity and yields but may require new subsidies 

Photo, posted July 27, 2023, courtesy of Judy Dean via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The demise of American offshore wind

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Europe has 37 gigawatts of offshore wind capacity. China is catching up rapidly.  Across the globe, offshore wind is an increasingly important source of clean, renewable power.  The United States had previously set ambitious goals to join the international effort.  But in the aftermath of the 2024 election, offshore wind in the US is basically dead in the water, pun intended.

The Bureau of Ocean Energy Management announced at the end of July that it is rescinding all designated Wind Energy Areas on the U.S. Outer Continental Shelf, effectively ending all offshore wind development across the Gulf of Mexico, the Gulf of Maine, the New York Bight, California, Oregon, and the Central Atlantic.  Additional policy measures announced by the Department of the Interior ended special treatment for what it called “unreliable energy sources, such as wind.” 

The two significant offshore wind projects underway in the US are both under serious attack by the administration and by newly emboldened special interests.  Vineyard Wind in Massachusetts, with 17 turbines already in operation, is under assault by tourist town forces and fishing groups.  Empire Wind, in New York, which resumed construction after efforts by Governor Kathy Hochul, is under pressure by various special interest groups that are urging President Trump to halt the project.

The current administration has very public and very pronounced antipathy towards wind power in general and towards offshore wind in particular.  And this has brought to a rapid halt billions of dollars in investments and will eliminate tens of thousands of jobs.

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US offshore wind, long ‘dead,’ now really dead

Photo, posted September 15, 2016, courtesy of Lars Plougmann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Soda can hydrogen

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Hydrogen is an ideal climate-friendly fuel because it doesn’t release carbon dioxide when it is used.  But most hydrogen is produced in ways that result in significant carbon emissions. Thus, the search for green hydrogen goes on. 

Last year, engineers at MIT developed a new process for making hydrogen that significantly reduces the carbon footprint of its production.  The recipe uses seawater and recycled soda cans. 

Pure aluminum reacts with water, breaking up the water molecules to produce aluminum oxide and pure hydrogen.  But when aluminum is exposed to oxygen, it forms a shield-like layer that prevents the reaction.

The MIT researchers found that the shield can be removed by treating aluminum with a small amount of gallium-indium alloy.  Mixing the pure aluminum with seawater not only produces hydrogen, but the salt in the seawater precipitates out the gallium-indium, making it available for reuse.

The research team carried out a “cradle-to-grave” life cycle assessment of the process, taking into account every step in using the hydrogen-production process at an industrial scale.  They found that using recycled aluminum – chopped-up soda cans – is environmentally and economically superior to using “primary” aluminum, mined from the earth. The cans would be shredded into pellet and treated with the gallium-indium alloy.  The pellets would be processed near a source of seawater where they would be combined to generate hydrogen on demand.

According to their analysis, the hydrogen produced would be at least competitive economically and environmentally with other potential methods of producing green hydrogen.

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Study shows making hydrogen with soda cans and seawater is scalable and sustainable

Photo, posted July 29, 2020, courtesy of Bruce Dupree via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

New Orleans is sinking

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As climate change accelerates, rising sea levels are putting coastal communities at greater risk of flooding and storm surge. Driven by melting glaciers and warming oceans, global sea levels are rising at an increasing rate. For low-lying cities like New Orleans, even small increases can have serious consequences. And that risk is compounded by another factor: the land itself is sinking.

Much of New Orleans already sits at or below sea level, and parts of the city and its surrounding wetlands are gradually sinking. While most of the city remains stable, a new study by researchers from Tulane University suggests that sections of the region’s $15 billion post-Katrina flood protection system may require ongoing upgrades to keep pace with long-term subsidence.

The study, recently published in the journal Science Advances, used satellite data to track changes in ground elevation across Greater New Orleans between 2002-2020.  The researchers found that some areas – including neighborhoods, wetlands, and even concrete floodwalls – are sinking by more than an inch each year. In some spots, the land is dropping by nearly two inches annually.

Alarmingly, some of the concrete floodwalls and levees built to protect the city after Hurricane Katrina are themselves sinking. In a few cases, they are losing elevation faster than sea levels are rising, reducing their capacity to block storm surges.

The study highlights how satellite monitoring can play a critical role in guiding infrastructure maintenance and urban planning – not just in New Orleans – but in vulnerable coastal cities around the world.

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Vertical land motion in Greater New Orleans: Insights into underlying drivers and impact to flood protection infrastructure

Photo, posted September 22, 2010, courtesy of U.S. Army Corps of Engineers via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Reducing emissions from ocean shipping

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Ocean shipping is a significant contributor to global carbon emissions, accounting for about 3% of the total.  It is a key part of international trade, moving goods like electronics, automobiles, and oil.  It relies on fossil fuels, and, without significant changes, shipping’s emissions could more than double by 2050.  Ocean shipping is one of the world’s most difficult to decarbonize industrial sectors.

Scientists at the University of Southern California and Caltech, collaborating with a startup company called Calcarea, have developed a shipboard system that could remove up to half of the carbon dioxide emitted by shipping vessels. The system is fairly simple and scalable.

The process mimics a natural chemical reaction that takes place in the ocean.  As a cargo ship moves through seawater, the CO2 from the ship’s exhaust is absorbed into water that is pumped onboard.  This makes the water more acidic.  The treated water is then passed through a bed of limestone, where it reacts with the rock to form bicarbonate, which is a stable compound that already exists naturally in seawater.  The treated seawater, now stripped of the carbon dioxide, is dumped back into the ocean.

Sophisticated ocean modeling examined what would happen when the bicarbonate-rich water is released back into the sea over a hypothetical 10-year period.  The model showed a negligible impact on ocean pH and chemistry.

The researchers estimate that widespread adoption of the technique could reduce shipping-related carbon dioxide emissions by 50%.  The startup company Calcarea is working to bring the technology to market and is in early discussions with commercial shippers.

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USC technology may reduce shipping emissions by half

Photo, posted November 14, 2017, courtesy of Bernard Spragg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

More trouble for bees

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Honeybees are a critical resource for American agriculture.  The western honeybee, Apis mellifera, pollinates more than 130 types of nuts, fruits, and vegetables, adding up to $15 billion worth of crops every year.  Honeybee health has been harmed by a combination of factors:  weather extremes, habitat loss, pesticides, and disease.  One of the biggest problems has been a parasite called varroa destructor, which is a Southeast Asian mite that first entered the United States in the 1980s.  The mites spread viruses to the bees.

The past year has been a particularly bad one for the bees.  Nearly 56% of managed honeybee colonies died off in the past year, the worst rate since annual reporting began in 2011. 

Even while American beekeepers seek solutions to the varroa problem, a potentially worse threat is on the horizon.  Another Southeast Asian mite, tropilaelaps, has been making its way across Asia and into Europe. If these mites arrive in North America, the results would be disastrous, wreaking havoc on honeybees and ravaging the nation’s food supply.

Western honeybees are the only honeybee species that is not native to Southeast Asia.  As the cradle of development of the bees, Southeast Asia has given rise to a bounty of parasites and viruses that are dependent upon them.  In turn, bees native to that region have had time to evolve defenses against these pathogens.  Western honeybees have not.

Beekeepers and authorities are taking measures to delay or prevent the arrival of tropilaelaps mites.  The stakes are very high.

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After Devastating Winter Losses, Another Threat Looms for U.S. Beekeepers

Photo, posted April 14, 2013, courtesy of Paul Rollings via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wildfires and water quality

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Hotter and drier conditions driven by climate change are leading to an increasing number of wildfires in North America and around the world. The damage wildfires cause – to forests, homes, and communities – is well-known. But long after the flames are gone, the effects can linger, especially in rivers and streams, where water quality may suffer for years.

A new study by scientists at the CIRES institute at the University of Colorado Boulder analyzed more than 100,000 water samples from more than 500 sites across the Western U.S. and found that wildfires can degrade water quality for up to eight years after a fire. The research, which was recently published in the journal Nature Communications Earth & Environment, found elevated levels of organic carbon, nitrogen, phosphorus, sediment, and turbidity – the cloudiness of water – in basins affected by fire.

This large-scale analysis reveals watersheds take longer to recover from wildfires than previously thought, with widespread, long-lasting impacts often going undetected for years.

Organic carbon, phosphorus, and turbidity remain elevated for one to five years after a fire. Nitrogen and sediment levels stay notably high for up to eight years. Fire-driven impacts are worse in more forested areas.

Each watershed in the study responded differently depending on local conditions.  In some places, sediment levels surged to as much as 2,000 times normal levels, while others remained relatively unchanged.

The research team hopes its findings can help guide future planning efforts to improve wildfire resilience.

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Wildfires threaten water quality for years after they burn

Photo, posted April 6, 2017, courtesy of Bonnie Moreland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

WAMC Northeast Public Radio

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