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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

Self-healing concrete

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Concrete is the most widely used building material on Earth.  It has a dangerous and costly flaw:  it cracks easily.  Cracks in concrete can lead to inconvenient damage or to catastrophic structural failures such as collapses of buildings, bridges, or highways.

Concrete is made by mixing crushed stone and sand with powdered clay and limestone and adding water.  The mixture hardens and once set becomes extremely strong.  However, natural forces like freeze-thaw cycles, drying shrinkage, and heavy loads can cause cracks.  Even very tiny cracks can allow liquids and gases to seep into embedded steel reinforcements causing corrosion and weakness. 

For over 30 years, researchers have investigated microbe-mediated self-healing concrete.  It involves introducing microbial healing agents into cracks and injecting nutrients for the healing agents to produce repair materials.  It is not a very practical solution.

Researchers at Texas A&M University have developed a technique inspired by the behavior of lichen systems. Their system, like lichen, uses a combination of cyanobacteria which turns air and sunlight into food, and filamentous fungi, which produces minerals that seal the cracks. 

In lab tests, the paired microbes were able to grow and produce crack-filling minerals even in challenging environments such as concrete.  If it is possible to produce concrete that can heal itself, it would significantly reduce maintenance costs, extend its longevity, and even protect lives through increased safety.

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Cracking the Code: Deciphering How Concrete Can Heal Itself

Photo, posted May 21, 2009, courtesy of DesignMag via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A biostimulant for wheat

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Feeding a global population projected to reach nearly 10 billion by mid-century is a massive challenge.  Wheat provides a fifth of the calories in the global human diet and is a significant source of protein, minerals, vitamins, and fiber.  Finding ways to increase the yield of wheat crops has great value.  However, wheat has complex genetics, which makes it difficult to improve yields by traditional breeding methods or even by genetic engineering.

Researchers at Oxford University and the nearby Rosalind Franklin Institute have developed a biostimulant that can deliver increased wheat yields of up to 12%.  It is applied as a spray and a four-year study in Argentina and Mexico demonstrated that it delivers major yield improvements irrespective of weather conditions.

The biostimulant is based on trehalose 6-phosphate (T6P), which is a natural molecule that regulates the plant equivalent of blood sugar.  T6P prompts plants to produce more starch and increases the rate of photosynthesis.

Naturally occurring T6P cannot be applied topically because it cannot cross cell membranes.  The researchers developed a membrane-permeable precursor of T6P that releases T6P into a plant in the presence of sunlight.

The biostimulant can be manufactured on an industrial scale and would be inexpensive to use. 

The researchers have created SugaROx, a spinout company whose mission is “to increase the productivity, resilience, sustainability, and profitability of crop production” using active ingredients inspired by powerful natural plant molecules.

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New biostimulant treatment significantly boosts wheat yields, field studies confirm

Photo, posted July 28, 2014, courtesy of Brad Higham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Trapping carbon with rocks

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Many experts say that combating global warming will require both drastically reducing the use of fossil fuels and permanently removing billions of tons of CO2 already in the atmosphere.  Developing practical, large-scale technologies for carbon removal is a significant challenge.

There is a nearly inexhaustible supply of minerals that are capable of removing carbon dioxide from the atmosphere, but they don’t do it quickly enough to make a significant dent in the ever-growing supply in the atmosphere.  In nature, silicate minerals react with water and atmospheric CO2 to form minerals in the process called weathering.  But this chemical reaction can take hundreds or even thousands of years.

Researchers at Stanford University have developed a new process for converting slow-weathering silicates into much more reactive minerals that capture and store carbon quickly.  The new approach resembles a centuries-old technique for making cement.  They combine calcium oxide and another common mineral containing magnesium and silicate ions in a furnace.   The result are new materials that, when exposed to water, quickly trap carbon from the atmosphere.

In their experiments, the carbonation process took weeks to months to occur, thousands of times faster than natural weathering.

The idea would be to spread these materials over large land areas to remove CO2 from the air.  Meaningful use for trapping carbon would require annual production of millions of tons.  But the same kiln designs used to make cement could produce the needed materials using abundant minerals found in many places.  In fact, the required minerals are often common leftover materials – or tailings – from mining.

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Scientists discover low-cost way to trap carbon using common rocks

Photo courtesy of Renhour48 via Wikimedia.

Earth Wise is a production of WAMC Northeast Public Radio

Mining with plants

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Plants absorb nutrients and minerals from the soil as they grow and incorporate them into their leaves and stems.  Such plants can be used to remove toxic elements from soil.  Cleaning soil in this way is called phytoremediation. 

Researchers at the University of Massachusetts Amherst are trying to go beyond phytoremediation and do phytomining, in which hyperaccumulated minerals from the soil can be harvested from plants for use in industrial or manufacturing applications.

One mineral that is critically needed for modern technology is nickel.  There are trace amounts of nickel in nearly one million acres of topsoil in the US, making the soil inhospitable for most crops, but the economics and environmental impact of extracting it make doing it impractical. 

A common plant, Alyssum murale, is a nickel hyperaccumulator; in fact, up to 3% of the plant’s biomass can be made up of nickel.  But the plant is slow-growing and difficult to manage and is also considered an invasive species

Another common plant, Camelina sativa, does not have the downsides associated with Alyssum and is also a rich source of valuable biofuel.  The Amherst researchers are working to determine which genes and proteins are responsible for Alyssum’s nickel hyperaccumulation and hope to genetically engineer Camelina sativa to have the same ability.

The researchers believe there is enough nickel in barren soil in the US to supply 50 years of phytomining.  It wouldn’t supply all the nickel the economy needs, but it could account for 20 to 30 percent of the projected demand.

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Scientists at UMass Amherst Engineer Plant-based Method of ‘Precious’ Mineral Mining

Photo, posted July 10, 2017, courtesy of Matt Lavin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Deep sea mining

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Deep sea mining is the extraction of minerals from the ocean floor at depths greater than 660 feet and as much as 21,000 feet below the surface.  Active or extinct hydrothermal vents on the ocean floor create sulfide deposits which collect metals such as silver, gold, copper, manganese, cobalt, and zinc.  This forms polymetallic nodules – potato-sized rocklike deposits containing these valuable minerals.  There are literally trillions of these things scattered over wide areas of ocean floor.  The largest of these deposits are in the Pacific Ocean between Hawaii and Mexico in the Clarion Clipperton Fracture Zone.

Mining companies argue that land-based sources for valuable metals are running out and are critically needed for green technologies like batteries for electric vehicles and manufacturing solar panels and wind turbines.  They also claim that mining in the deep sea will be less environmentally damaging than land-based mining.

The deep sea is viewed by many as kind of a watery desert but there are actually diverse and rich ecosystems down there.  Most of the animals living in the depths are tiny, but that doesn’t make them any less important.  Many can live for a very long time.  Some invertebrates live for thousands of years.

There are currently no commercial deep sea mining operations underway.  Many countries have outlawed them.

The deep seas are the last mostly unexplored part of the Earth.  Deep sea mining will unquestionably be highly destructive to these environments.  We don’t really know what the impact of widespread deep sea mining might be, but the world continues to edge ever closer to allowing it to happen.

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Can We Mine the World’s Deep Ocean Without Destroying It?

Photo, posted March 30, 2018, courtesy of the NOAA Office of Ocean Exploration and Research via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Dark chocolate is not so dangerous

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Last year, Consumer Reports published a story stating that a third of chocolate products contain potentially dangerous amounts of heavy metals, in particular lead and cadmium. Since it contains much more cacao, dark chocolate was singled out as the most worrisome product.  Needless to say, chocolate lovers found this report quite alarming.

A new study by Tulane University published in Food Research International employed a larger sample size, expanded the scope of testing to 16 metals, and included a risk assessment of toxic metals as well as accounted for the nutritional contribution of essential minerals.

The conclusions of the study were that dark chocolate poses no adverse risk for adults and contains nutritionally beneficial levels of essential minerals.  Some risks remain for very young children, but only from a very small number of chocolate products and only when large quantities are consumed.

The study sampled 155 dark and milk chocolates from various global brands sold in the United States.  It modeled the risk of eating one ounce of the chocolate per day or two large whole bars a week.

Only one brand exceeded the international limit for cadmium; four had cadmium levels that could pose a risk for a child weighing less than 33 pounds.  Only two bars contained lead levels above California interim standard, but neither posed adverse risks for anyone.

Lead in chocolate comes from post-harvest processing; cadmium comes from the soil.  South American chocolates generally have higher levels of metals than chocolates from Asia and West Africa.  Most dark chocolate in the U.S. is sourced from West Africa.

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A dark side to dark chocolate? New study finds very minimal risk for kids from metals in chocolates

Photo, posted February 19, 2012, courtesy of Bodo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Minerals from seawater

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There are about 18,000 desalination plants around the world that take in 23 trillion gallons of water each year.  The plants produce more than 37 billion gallons of brine – enough to fill 50,000 Olympic-size swimming pools – every day.  Disposing of this brine is an ongoing challenge.  Dumping it into the ocean can damage marine ecosystems.  Inland desalination plants either bury this waste or inject it into wells, adding further cost and complexity to the already expensive process of desalination.

According to researchers at Oregon State University, this waste brine contains large amounts of copper, zinc, magnesium, lithium, and other valuable metals.  A company in Oakland, California called Magrathea Metals has started producing modest amounts of magnesium from waste brine in its pilot projects.  With support from the U.S. Defense Department, it is building a larger-scale facility to produce hundreds of tons of the metal over two to four years. 

Most of the world’s magnesium supply comes from China, where producing it requires burning lots of coal and utilizing lots of labor.  Magrathea’s brine mining makes use of off-peak wind and solar energy and is much less labor intensive.

No large-scale brine mining operations currently exist and when there are some, they might end up having negative environmental impacts.  But in principle, the process should produce valuable metals without the massive land disturbance, acid-mine drainage, and other pollution associated with traditional mining.  Brine mining could turn a growing waste problem into a valuable resource.

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In Seawater, Researchers See an Untapped Bounty of Critical Metals

Photo, posted February 18, 2017, courtesy of Jacob Vanderheyden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Geologic Hydrogen | Earth Wise

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There is great interest in the potential use of hydrogen as a fuel or an energy storage medium.  Unlike hydrocarbon-based fuels, pure hydrogen combustion produces nothing but water as an emission.  But most hydrogen used at present is made by reforming natural gas, which is a process that results in carbon dioxide emissions.  Thus, the search goes on for cost-effective and energy-efficient ways to make “green hydrogen” that doesn’t result in greenhouse gas emissions.

Researchers at Colorado University Boulder are investigating the potential effectiveness of coaxing hydrogen from subterranean rocks – a commodity known as geologic hydrogen.

When water mixes with iron-rich minerals deep in the earth’s crust, ensuing chemical reactions can generate pockets of hydrogen gas. 

The questions are whether it is possible to bring these deposits up to the surface without harming the environment or human communities in the process and whether they can be extracted in large enough quantities to meet growing global energy demands.

The Colorado researchers will conduct experiments both in the lab and hundreds of meters below the earth’s surface to see if it is possible to induce the subterranean rock to make more hydrogen than it normally does.  If the hydrogen-producing reactions can be accelerated, then geologic hydrogen could become a clean and abundant energy source.

Geologists have known about hidden underground deposits of hydrogen for a long time, but recent research has found that there may be a lot more of it than once thought.  According to a 2022 report by the US Geological Survey, there may be enough hydrogen below ground to supply humanity’s need for fuel for hundreds of years.

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Can rocks produce abundant clean energy? New project to explore

Photo, posted December 26, 2013, courtesy of Juozas Šalna 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

Great Salt Lake In Danger | Earth Wise

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Utah’s Great Salt Lake has been plagued by excessive water use and extensive drought conditions.  As of January, the lake dropped to record-low water levels, losing 73% of its water and exposing 60% of its lakebed. According to scientists, the lake could disappear entirely within five years.

Great Salt Lake is what is known as a “terminal lake,” which means that it is fed only by rain, snow, and runoff and has no rivers that take water to the ocean.  As a result, salt and minerals build up over time.  With so much salt in the water, only brine flies and shrimp can survive in it.  The unique ecosystem supports 10 million migratory birds.  As the lake continues to dry up, the water is becoming too salty for even algae and microbes to survive.  With shallow mud replacing previous shallow water, the nests of the 80,000 white pelicans that annually come to the lake are endangered by predators that can simply walk over to the eggs.

The historic low water levels have exposed 800 square miles of lakebed.  This lakebed holds centuries of natural and manmade toxins like mercury, arsenic, and selenium.  The exposed mud ultimately turns to dust that is carried off into the air.  This is contributing to what is already some of the worst winter air pollution in the nation.  Scientists warn that the unfolding ecological disaster may become a human health disaster.

State officials and university researchers have formed a “Great Salt Lake Strike Team” looking for ways to get more water to the lake.  There are a number of so-called moonshot proposals to save the lake.  It remains to be seen what will be done, but the clock is ticking.

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Great Salt Lake will disappear in 5 years without massive ‘emergency rescue,’ scientists say

Scientists fear a Great Toxic Dustbowl could soon emerge from the Great Salt Lake

Photo, posted September 19, 2009, courtesy of John Morgan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Mining Metals From Water | Earth Wise

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Researchers at the Department of Energy’s Pacific Northwest National Laboratory in Richland, Washington are working with industry to develop a method of extracting valuable materials from various sources of water.  The technique is the 21st-century equivalent of panning for gold in rivers and streams.

The patent-pending technology makes use of magnetic nanoparticles that are surrounded by an absorbent shell that latches on to specific materials of interest that are found in certain water sources.  These sources could include water in geothermal power plants (known as geothermal brines), water pulled from the subsurface during oil or gas production, or possibly effluents from desalination plants.  Extracting valuable materials from geothermal brines could greatly enhance the economics of geothermal power plants.

The initial focus of the development is on lithium, which is an essential element in many high-technology applications, especially in the batteries that power cell phones, computers, and electric cars.  The global market for lithium is projected to reach over $8 billion a year by 2028 and very little of it is currently produced in the United States.

The tiny particles are added to the water and any lithium is drawn out of the water and is bound to them.  Using magnets, the nanoparticles can be readily collected.  Once the particles are no longer suspended in liquid, the lithium can easily be extracted, and the nanoparticles can be reused.

PNNL is developing the technology in partnership with a company called Moselle Technology as well as with other commercial partners.  This new technology offers the promise of extracting critical materials in a quick, cost-effective manner.

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Tri-Cities Scientists “Magically” Mining Metals From Water

Photo, posted June 4, 2012, courtesy of Tom Shockey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Insects On The Menu | Earth Wise

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According to the World Food Programme, a record 349 million people across 79 countries are facing acute food insecurity.  This constitutes a staggering rise of 200 million people compared to pre-pandemic levels.  Nearly one million people globally are fighting to survive in famine-like conditions, which is ten times more people than just five years ago.  

As a result, many experts contend that alternative or so-called novel food sources – such as lab-grown meats, seaweed aquaculture, and insects – will be necessary to help fight global hunger and global food insecurity. 

Insects already form a significant part of diets in many cultures around the world.  Insects are great sources of nutrients, including protein, vitamins, and minerals.  But insects have yet to be embraced in any substantial way in western cultures… but that may be changing. 

In fact, the European Union has now certified four types of bugs as food fit for human consumption.  The larvae of lesser mealworms and house crickets recently became the third and fourth insects approved for sale as food in the EU, joining yellow mealworms and grasshoppers. Eight more applications are awaiting approval.

Insects are already a delicacy in many high-end restaurants around the world, and a normal and healthy part of diets in countries like Mexico and Thailand.  Embracing insects as a food of the future will not only help in the fight against global hunger, but will also help to reduce greenhouse gas emissions and to slow species extinction. 

In Western food markets, the so-called “yuck factor” remains the biggest hurdle to cross.  But as the world population grows, the need for sustainable solutions in the food industry grows with it. 

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Insects on the menu as EU approves two for human consumption

World Hunger Surged in 2020, U.N. Says

A global food crisis

Photo, posted April, 2014, courtesy of Shankar S. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Onshore Algae Farms | Earth Wise

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According to some estimates, food production will need to increase by 50% by 2050 in order to feed a projected global population of 10 billion people.  How can this be achieved?  

One solution, according to researchers at Cornell University, could be to grow nutritious and protein-dense microalgae in seawater-fed onshore aquaculture systems.

According to the research, which was recently published in the journal Oceanography, growing algae onshore could close a projected gap in society’s future nutritional demands while also improving environmental sustainability.  

Climate change, environmental degradation, limited arable land, and lack of freshwater will all constrain the amount of food that can be grown in the coming decades.  Wild fish stocks are already heavily exploited, and there are limits to how much finfish, shellfish, and seaweed aquaculture can be produced in the coastal ocean. 

As a result, the researchers argue for expanding algae production in onshore aquaculture facilities.  The research team’s models found that the best locations for onshore algae farming facilities are along the coasts of the Global South, including desert environments. 

Algae can grow as much as ten times faster than traditional crops.  Algae can also be produced in a manner that is more efficient than agriculture in its use of nutrients.  In addition to its high protein content, algae also provides nutrients lacking in vegetarian diets, such as essential amino acids, minerals, and omega-3 fatty acids.

Algae could become the breadbasket of the Global South.

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Onshore algae farms could feed the world sustainably

Photo, posted June 17, 2011, courtesy of NOAA Great Lakes Environmental Research Laboratory via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Food For The Future | Earth Wise

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Researchers predict that climate change will negatively impact most staple food crops, including rice, corn, and soybeans.  Therefore, climate resilient food crops – those that are salt, drought, and heat resilient – will have an important role to play in global food security.  Examples of climate resilient crops include quinoa, kernza, amaranth, millet, and tepary beans.    

According to a new study by researchers from Northwestern University, breadfruit – a starchy tree fruit native to the Pacific Islands – will be relatively unaffected by climate change.  Because breadfruit is climate resilient and well-suited to grow in regions with high levels of food insecurity, the research team suggests breadfruit could be a part of the solution to global hunger.

While it has ”fruit” in its name, breadfruit is more like a potato.  It’s starchy and seedless, and is closely related to jackfruit.  Breadfruit is nutrient-rich, and high in fiber, vitamins, and minerals.  It can be steamed, roasted, fried, fermented, and even turned into flour.  People in tropical regions around the world have been eating breadfruit for thousands of years. 

In the study, which was recently published in the journal PLOS Climate, researchers determined the climate conditions necessary to cultivate breadfruit and then looked at how these conditions are predicted to change in the future.  They examined two future climate scenarios: one that reflects high greenhouse-gas emissions and another in which emissions stabilize.

In both scenarios, the regions suitable for breadfruit cultivation were mostly unaffected.  Additionally, the researchers identified new suitable land where breadfruit cultivation could expand.   

As the climate continues to change, breadfruit might soon be on a table near you.

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Climate-resilient breadfruit might be the food of the future

Photo, posted August 11, 2007, courtesy of Malcolm Manners via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Healthy Soil Is Healthy For People | Earth Wise

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A new study by researchers at the University of Washington looked at the impact of regenerative farming practices on the nutritional content of the food that is grown. 

Regenerative agriculture involves farming practices that not only “do not harm” to the land but actually improve it by regenerating and revitalizing the soil.  The practices focus on topsoil regeneration, increasing biodiversity, improving the water cycle, and enhancing ecosystem services.  Examples are soil-building techniques that minimize plowing, the use of cover crops, and the planting of diverse crops rather than monocultures.

The study included 10 farms across the U.S. that followed soil-friendly practices for at least five years. The results were that the crops from those farms had a healthier nutritional profile than the same crops grown on neighboring, conventional farms.  In particular, there was a boost in certain minerals, vitamins and phytochemicals that are beneficial to human health.  Across the board, regenerative practices resulted in crops with more anti-inflammatory compounds and antioxidants.

The participating farms grew one acre of a test crop – peas, sorghum, corn, or soybeans – for comparison with the same crop grown on a neighboring farm using conventional agriculture.  Analysis showed that the farms practicing regenerative agriculture had healthier soils, as measured by their organic matter – or carbon – content and by other tests. 

Organic farms avoid chemical pesticides, but they operate with a variety of farming processes.  Nonetheless, they have also been found to produce crops with higher levels of beneficial nutrients.  The biology of the soil in which crops are grown is an important factor for human health.  It isn’t just what we eat that matters; it is how we grow it.

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Farms following soil-friendly practices grow healthier food, study suggests

Photo, posted January 10, 2020, courtesy of Les via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Offsetting Reef Acidification | Earth Wise

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The Great Barrier Reef is the world’s largest coral reef system.  It is composed of nearly 3,000 individual reefs and 900 islands covering an area of more than 130,000 square miles.  In recent times, it has been under unprecedented stress from ocean warming, tropical cyclones, sediment and nutrient runoff, marine pests, and ocean acidification.

Among these stressors, ocean acidification is one of the most significant threats to the long-term viability of the reef because acidification affects the ability of corals to rebuild and repair their structures and recover from bleaching events.

New research from CSIRO, Australia’s national science agency, studied the impact of artificial ocean alkalinization on the acidity of the waters in the Great Barrier Reef.  The idea is to inject a source of alkalinity into the ocean, an accelerated version of a natural process that occurs from the chemical weathering of minerals under the sea.

The results of the study, published in the journal Environmental Research Letters, are that injecting an alkalinizing agent into the ocean along the length of the Reef would make it possible to offset ten years’ worth of ocean acidification based on the present rate of human-generated carbon emissions.  Such an effort could use an abundant mineral resource like olivine, which is already mined near the Great Barrier Reef.  Releasing 30,000 tons a day of the alkalinizing agent from an existing shipping line from a bulk carrier would reach almost the whole of the Great Barrier Reef.

In response to the declining health of coral reef ecosystems, many different intervention concepts and technologies are under consideration.  The goal of these would be to minimize environmental pressures and enhance the resilience of the ecosystems.

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Projected acidification of the Great Barrier Reef could be offset by ten years

Photo, posted August 4, 2019, courtesy of Larry Koester via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Red Hot Chili Solar Panels | Earth Wise

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The majority of solar panels in use today are made from either single-crystal or polycrystalline silicon, the same stuff used to make the ubiquitous chips in computers, cell phones, and countless other devices.  In addition, a growing fraction of solar panels utilize thin-film technology, which offers cost and flexibility advantages.

Monocrystal silicon still provides the highest efficiency and longest lifespan in commercially available panels, but the lower costs and some other features of thin-film solar panels are growing that market over time.

More recently, perovskite solar cell technology has been a source of great interest in the research community.  Perovskites are a class of minerals with a specific crystalline structure that already have uses in various applications.  As a solar cell material, perovskites offer the potential for converting more sunlight to electricity, being manufactured far more cheaply using no exotic or expensive materials, being more defect-tolerant, as well as a having number of other advantages.  They also have the potential for having very high efficiency. 

Recently, a group of researchers in China and Sweden published results of studies demonstrating that the addition of a novel ingredient has increased the efficiency of perovskite solar cells to nearly 22%, which is better than most commercial silicon solar cells.  The ingredient is capsaicin, the chemical that gives chili peppers their spicy sting.  Adding capsaicin expands the grains that make up the active material of the solar cell, allowing the more effective transport of electricity. 

Why did the researchers think of adding the active ingredient of hot peppers to a solar cell in the first place?  So far, they aren’t saying.

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Solar panels capture more sunlight with capsaicin – the chemical that makes chili peppers spicy

Photo, posted August 16, 2019, courtesy of Pedro via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Understanding How To Enhance Desalination | Earth Wise

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

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

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

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

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

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

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Nanoscale control of internal inhomogeneity enhances water transport in desalination membranes

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

Earth Wise is a production of WAMC Northeast Public Radio.

Electronic Waste On The Decline | Earth Wise

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A new study published in the Journal of Industrial Ecology has found that the total mass of electronic waste generated by Americans has been declining since 2015.  Given that electronic devices are playing an ever-growing role in our lives, this finding seems rather surprising.  It also seems like pretty good news, but the underlying facts should dampen our level of enthusiasm.

The main reason for the decline is the disappearance of large, bulky cathode-ray tube televisions and computer monitors.  Since about 10 years ago, CRT displays have been on the decline in the waste stream, thereby leading to an overall decline in total e-waste mass.

Many state regulations with respect to e-waste recycling have targets based on product mass.  The regulations were typically designed to keep electronics with high levels of lead and mercury out of landfills.

At present, the more pertinent concern is how to recover valuable elements like cobalt (from lithium-ion batteries) and indium (from flat-panel displays).  These elements are not so environmentally toxic, but rather are relatively scarce in the earth’s crust. 

The main conclusion to be drawn from the declining mass of electronic waste is not that we are necessarily winning the battle against generating it but rather that e-waste is changing and regulations concerning it need to be rethought.  Focusing regulations on capturing critical elements not only would have significant economic benefits but also would be important in addressing geopolitical uncertainties that potentially could threaten what could be termed the mineral security of the U.S.

E-waste recycling is regulated at the state level and only half the states have e-waste recycling laws.  It may be time for more uniform policies across the country.

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Electronic Waste on the Decline, New Study Finds

Photo, posted January 22, 2013, courtesy of Thorsten Hartmann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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