remote

Solar-powered desalination

November 7, 2024 By EarthWise Leave a Comment

People in remote, low-income regions far from the ocean often need to meet their water needs from groundwater and groundwater is becoming increasingly saline due to climate change. Desalination of brackish groundwater is a huge and largely untapped source of drinking water, but there are challenges in making the process efficient and reliable.

Engineers at MIT have developed a solar-powered desalination system that requires no batteries or external power sources and is capable of producing large quantities of clean water despite the variations of sunshine throughout the day.

The system is based on the process of electrodialysis and consists of water pumps, an ion-exchange membrane stack, and a solar panel array. What is unique about it is that it makes use of sensors and a control system that predicts the optimal rate at which to pump water through the system based on the output of the solar panels. As a result, it uses nearly all of the electricity generated to produce clean water and does not need stored or grid-based energy.

The MIT engineers tested a community-scale prototype on groundwater wells in New Mexico over a six-month period. The system harnessed on average over 94% of the electricity generated by its solar panels and produced as much as 5,000 liters of water per day despite large variations in weather and sunlight.

The new renewable-powered, battery-free system could provide much-needed drinking water at low cost, especially for communities where access to seawater and to grid power are limited. The team plans to further test and scale up the system so it can supply larger communities and even whole municipalities with low-cost drinking water.

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Solar-powered desalination system requires no extra batteries

Photo courtesy of Shane Pratt.

Earth Wise is a production of WAMC Northeast Public Radio

Biodegradable microplastics

April 10, 2024 By EarthWise Leave a Comment

Ordinary plastics are not biodegradable, but they are also not indestructible. Plastics in the environment can break down into tiny fragments – microplastics – and those, unfortunately, are nearly indestructible. Microplastics have been documented in the oceans and in soil virtually everywhere on Earth including remote frozen wastelands and on top of high mountains. More recently, they have been found in our own arteries, lungs, and even in placentas. Microplastic pollution is a very serious problem.

There is considerable ongoing effort to develop biodegradable plastics from non-petroleum sources. There has been progress but it has not necessarily been aimed at creating bioplastics that do not create microplastic when they break down.

Researchers at the University of California San Diego have developed algae-based polymers that they have shown to degrade when composted. Recently, in work published in the journal Nature Scientific Reports, they have shown that even fine microparticles of their bioplastic are digested by microbes when placed in a compost. What remains are the starting plant materials from which the plastic was made. Products made from this sort of plastic would not only be sustainable beyond their useful lifetime but would also not represent a potential danger to human life.

Creating this eco-friendly alternative to petroleum-based plastic is only the first step toward creating a viable replacement for existing plastics. It is necessary to be able to use the new material on existing manufacturing equipment and for it to have the same mechanical and thermal properties as the materials it is replacing. But the researchers are optimistic that this could be a potential solution to an increasingly serious problem.

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Say Hello to Biodegradable Microplastics

Photo, posted January 17, 2018, courtesy of Bo Eide via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastics In The Air | Earth Wise

October 25, 2023 By EarthWise Leave a Comment

Plastic pollution is a big deal. There are plastics clogging up landfills and waterways and accumulating in the oceans, choking turtles and seabirds. Annual production of plastics has grown from 2 million tons a year in 1950 to more than 450 million tons today.

As if plastic problems weren’t already big enough, it is becoming increasingly clear that there are growing amounts of microplastic particles in the air. Bits of plastic are lofted into the sky from seafoam bubbles and from spinning tires on highways. The particles are so light that they can travel for thousands of miles, far from where they originate.

Studies in recent years documented the presence of plastic particles even in places like the Pyrenees in Europe and in federally protected areas of the US. Other studies have measured the quantity of plastic in the air of various locations and have looked at the origins of the particles.

In the western US, over 80% of microplastics came from roads where vehicles kick up particles from tires and brakes. In remote areas of the Pacific, there is less than a single particle of plastic per cubic meter of air. In cities like London and Beijing, on the other hand, there can be several thousand particles per cubic meter.

Microplastics can act as airborne aerosols, like dust, salt, soot, volcanic ash, and other particles. Aerosols play an important role in the formation of clouds and in temperature regulation on the earth. At low concentrations, such as exist in most places, microplastic aerosols don’t have much of an effect. But there are more in the atmosphere all the time and, at this point, scientists don’t really know what effect they will have.

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Microplastics Are Filling the Skies. Will They Affect the Climate?

Photo, posted August 28, 2014, courtesy of Alan Levine via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic In Lakes | Earth Wise

August 28, 2023 By EarthWise Leave a Comment

We are always talking about the millions of tons of waste plastic that finds its way into the oceans and about the challenges of trying to remove it. A new multinational study has found that the concentration of plastics and microplastics in some lakes is even worse than in the so-called garbage patches in the oceans and some of these lakes are even in remote places around the world

Scientists from institutes in multiple countries collected water samples from 38 lakes and reservoirs in 23 countries across six continents. The samples were then all analyzed by the University of Milan to assess the presence of plastic particles more than a quarter millimeter in size.

The study found that two types of lakes are particularly vulnerable to plastic contamination: lakes and reservoirs in densely populated and urbanized areas and large lakes with elevated deposition areas, long water-retention times, and high levels of human influence.

Lakes found to have the highest concentration of plastic included some of the main sources of drinking water for communities and were also important to local economies. These included Lough Neagh in Northern Ireland, Lake Maggiore in Italy, and Lake Tahoe on the California/Nevada border. Not all the lakes studied contained large amounts of plastic. For example, Windermere, the largest lake in England, had very low concentrations of plastic in surface water.

This was the first global survey of the abundance and type of plastic pollution in lakes and reservoirs and the scale of freshwater plastic pollution is sobering indeed. There is widespread concern that plastic debris is having harmful effects on aquatic species and ecosystem function and clearly is not limited to marine ecosystems.

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Plastic pollution is higher in some lakes than oceans

Photo, posted May 27, 2019, courtesy of Jonathan Cook-Fisher via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic Eating Fungus | Earth Wise

May 26, 2023 By EarthWise Leave a Comment

More than five billion tons of plastic have accumulated on land and sea including the most remote regions of the planet as well as in the bodies of animals and humans. There is a compelling need to recycle as much plastic as possible but doing so is a major challenge. Plastic comes in many varieties and breaking it down for reuse requires different methods for each.

Polypropylene is one of the biggest challenges for recycling. It is a very common plastic used for all sorts of products including food containers, coat hangers, plastic wrap, toys, and much more. It accounts for roughly 28% of the world’s plastic waste, but only 1% of it is recycled.

Polypropylene is seldom recycled because it generally has a short life as a packaging material, and it often becomes contaminated by other materials and plastics. Thus, it generally ends up in landfills.

Researchers at the University of Sydney in Australia have discovered that two common strains of fungi were able to successfully biodegrade polypropylene. The fungi species – with unavoidable Latin names of Aspergillus terreus and Engyodontium album – are typically found in soil and plants.

The researchers found that the fungi were able to break down polypropylene after it had been pre-treated with either UV light or heat, by 21% over 30 days, and by 25-27% over 90 days. This seems rather slow but compared with the nearly endless life of polypropylene in landfills, it is a major improvement.

The hope is that methods like this could ultimately reduce the amount of plastic polluting the environment by encouraging plastic to biodegrade naturally under the appropriate conditions.

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Fungi makes meal of hard to recycle plastic

Photo, posted March 5, 2010, courtesy of Kevin Krejci via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Mauna Loa Eruption And Climate Tracking | Earth Wise

January 9, 2023 By EarthWise Leave a Comment

Mauna Loa, the largest active volcano in the world, erupted for the first time in nearly 40 years in late November. A 124-foot aluminum tower at the top of the volcano has been the site of carbon dioxide measurements for over 60 years but the eruption cut off power to the site, stopping the monitoring.

Carbon dioxide measurements on Mauna Loa began in 1958. The project was started by geochemist Charles Keeling and eventually taken over by his son Ralph Keeling upon his father’s death in 2005. It is the longest continuous record of the rising levels of carbon dioxide in the world.

Mauna Loa is an ideal location for carbon dioxide monitoring because it is a remote location away from both carbon dioxide sources like dense population centers and roads, and carbon sinks like areas of heavy vegetation.

There are hundreds of carbon dioxide monitoring stations around the world, including more than 70 operated by the National Oceanic and Atmospheric Administration, so the interruption will not stop global recordkeeping. But Mauna Loa holds significant symbolism as the first and most frequently sited source of carbon dioxide data.

There have been other interruptions in the measurements. Federal budget cuts in 1964 paused them for about 3 months. A 1984 eruption also cut off power to the facility and shut it down for about a month.

When the facility first started operating, the average carbon dioxide concentration was measured at 313 parts per million. Most recently, levels have peaked at around 421 parts per million, the greatest concentration in at least 4 million years.

Power will be restored to the Mauna Loa facility and its measurements will resume.

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Mauna Loa Eruption Threatens a Famous Climate Record

Photo, posted November 29, 2022, courtesy of L. Gallant / USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electric Cars And The Remote Road Test | Earth Wise

August 18, 2022 By EarthWise Leave a Comment

One reason many people are hesitant about switching to an electric car is range anxiety, the fear that their car’s battery will die on them in the middle of a trip. It is pretty much the same thing as running out of gas, but somehow it seems like more of a danger.

Perhaps this was true when charging stations were few and far between and electric cars couldn’t go very far on a charge, but these days, the average electric car can drive about 200 miles on a charge and there are charging stations all over the place.

A big difference between gas cars and electric cars is that many people can charge their cars at home and start every day with the equivalent of a full tank. With an electric car, there is little reason to use up all nearly all the charge before filling up the tank again.

The truth is that most people don’t drive all that much on the average day anyway. In the US, the average driver goes about 39 miles a day. In Europe, is it considerably less. Yes, there are some people who drive 200 miles a day, but they are few and far between.

Remote and regional Australia is a place where distances between essential services can be very large. But a new study from the Australian National University found that even under those trying conditions, the vast majority of residents, about 93%, can go about their business even with the lower-range electric vehicles available on the market without having to recharge en route.

Electric cars may not be practical for some drivers, but for most, they are already a great choice.

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Electric vehicles pass the remote road test

Electric car range and 5 reasons why your range anxiety is unwarranted

Photo, posted May 21, 2022, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Nanoplastics In The Air | Earth Wise

December 17, 2021 By EarthWise Leave a Comment

The world is awash in plastic. Discarded plastic litters our roadways, woodlands, and beaches. It piles up in landfills. Plastic enters the oceans by the millions of tons. And plastic is finding its way even to remote and supposedly pristine parts of the world.

A team of researchers has found nanoplastics at the isolated high-altitude Sonnblick Observatory in the Austrian Alps. This is the first time the particles were found in the area. The researchers were looking for certain organic particles and only found the nanoplastics by chance.

The detected plastic particles were less than 200 nanometers in size, about one hundredth the width of a human hair. It is highly unlikely that such particles originated in remote Alpine areas.

The researchers were looking for organic particles by taking samples of snow or ice, evaporating them, and then burning the residue to detect and analyze the vapors. They described the detection method as essentially like a mechanical nose. In this case, the nose smelled burning plastics in the form of polypropylene and polyethylene terephthalate.

Looking into the issue, the researchers found a strong correlation between high concentrations of nanoplastics and winds coming from the direction of major European cities – especially Frankfurt and the industrial Ruhr area of Germany, but also the Netherlands, Paris, and even London.

Modeling supports the idea that nanoplastics are transported by air from distant urban places. This is particularly worrisome because it means that there are likely hotspots of nanoplastics in our cities and in the air that we are breathing. Plastics appear to be everywhere.

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Nanoplastics found in the Alps, transported by air from Frankfurt, Paris and London

Photo, posted July 1, 2013, courtesy of Robert J. Heath via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bomb Cyclones | Earth Wise

December 2, 2021 By EarthWise Leave a Comment

It seems like we are hearing about new weather phenomena pretty frequently these days. One name that has popped up lately is “bomb cyclones.” Bomb cyclones, it turns out, are storms that undergo “bombogenesis.” What that means is a low-pressure area (in other words, a storm) that undergoes rapid strengthening and can be described as a weather bomb, or popularly, a bomb cyclone.

These things usually take place over remote tropical ocean areas but a really intense one struck the Pacific Northwest on October 24th. The storm off the coast of Washington, with a barometric pressure reading equivalent to a category 4 hurricane, was the second extreme low-pressure storm in the North Pacific in a single week. Both storms involved pressure drops of more than 24 millibars in 24 hours, making them bomb cyclones.

These storms brought high winds and extreme precipitation that doused wildfires and provided some relief to the extreme drought in Central and Northern California. Along with these positive effects, however, the storms also caused power outages, flooding, landslides, and mud and debris that washed out roads.

The October 24-25 event brought 16.55 inches of rain to Mount Tamalpais in Marin County, California in a 48-hour period. Sacramento got 5.44 inches of rain, breaking a 140-year-old record. And the city had just broken another extreme weather record for the longest dry spell in history.

The storms directed streams of moisture from north of Hawaii toward the West Coast in long, narrow bands of moisture known as atmospheric rivers. We are learning about all sorts of unfamiliar weather phenomena as extreme weather events become increasingly common.

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Extratropical Cyclones Drench West Coast

Photo, posted January 4, 2018, courtesy of NOAA/CIRA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Plastic Pollution And The Galapagos Islands | Earth Wise

July 12, 2021 By EarthWise 1 Comment

The proliferation of plastics remains one of the world’s most challenging environmental problems. Plastic pollution can be found in some of the most remote regions of the planet, including atop the world’s tallest mountains and in the deepest depths of the ocean. Even the Galapagos Islands, a volcanic archipelago in the Pacific Ocean, are no exception.

According to a new study by researchers from the University of Exeter, the Galapagos Conservation Trust, and the Galapagos Science Center, plastic pollution has been found in seawater, on beaches, and inside marine animals at the Galapagos Islands.

In the most polluted hotspots, more than 400 plastic particles were found per square metre of beach. The researchers found that only 2% of macroplastic pollution – plastic fragments larger than five millimeters – was identified as coming from the Galapagos islands. All seven of the marine invertebrate species examined – 52% of individuals tested – were found to contain microplastics.

Significant accumulations of plastic were also found in key habitats, including rocky lava shores and mangroves. In fact, plastics were found in all marine habitats at the island of San Cristobal, which is where Charles Darwin first landed in Galapagos.

Most of the plastic pollution in the Galapagos appears to arrive via ocean currents. According to the research team, the highest levels of plastic pollution were found on east-facing beaches, which are exposed to pollution carried across the ocean on the Humboldt Current.

The pristine images of the Galapagos, a world-famous biodiversity haven, might give the impression that the region is protected from plastic pollution. But clearly that is not the case.

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Plastic in Galapagos seawater, beaches and animals

Photo, posted April 12, 2012, courtesy of Ben Tavener via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Radar Satellites And Hazard Mitigation | Earth Wise

May 26, 2021 By EarthWise Leave a Comment

Scientists have concluded that the changing climate is primarily the result of increased human-caused greenhouse gas emissions. Some of the effects of global climate change include melting glaciers, warming oceans, intensifying storms, and rising seas.

Another consequence of global climate change is natural disasters like floods and wildfires. Climate change is increasing the frequency and severity of wildfires and increasing the odds of record-breaking floods in many parts of the United States and all around the world.

As a result, scientists in Australia have turned to technology for better assistance in keeping tabs on these climate change-driven natural disasters. Researchers from Curtin University in Perth, Australia have found that satellites can improve the ability to detect, monitor, prepare for, and withstand natural disasters, including floods, wildfires, and earthquakes.

The research team used Synthetic Aperture Radar (SAR) data, which was acquired by the European Space Agency Sentinel-1 satellite. The researchers also used data acquired by other satellites to evaluate these Australia-specific case studies.

According to the researchers, SAR data provides remote monitoring capabilities of Earth’s surface around the clock and in all weather, which is something that traditional optical Earth Observation (EO) imagery cannot do. The ability to function through fog, clouds, rainfall, and smoke is what makes SAR so valuable.

The research team says that the data can be used to improve how people track and respond to natural disasters, by precisely mapping topography, tracking movements of the ground, and mapping damage to infrastructure.

As the climate continues to change, the ability to mitigate hazards like floods and wildfires will be increasingly important.

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Radar satellites can better protect against bushfires and floods

Photo, posted May 11, 2007, courtesy of Bert Knottenbeld via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Even The Deep Sea Is Warming | Earth Wise

November 17, 2020 By EarthWise Leave a Comment

Approximately 75% of the area covered by ocean is deep, dark, and cold. This is known as the deep sea. But even in these remote regions of the planet things are heating up.

According to a new study published in the journal Geophysical Research Letters, researchers analyzed a decade of hourly temperature readings at four depths in the Atlantic Ocean’s Argentine Basin, off the coast of Uruguay. The research team selected recording depths that would best represent the average depth of the ocean, which is just over 12,000 feet.

The researchers found that deep sea temperatures fluctuate more than was previously known. They also detected a warming trend at the bottom of the ocean. In fact, all recordings indicated a warming trend of 0.02 to 0.04 degrees Celsius per decade between 2009 and 2019. This is a significant warming trend in the deep sea because temperature fluctuations are typically measured in thousandths of a degree.

Researchers say this increase is consistent with warming trends in the shallow ocean associated with anthropogenic climate change. However, they say more research is needed to better understand what is driving the warming temperatures in the deep sea.

A better understanding of what is driving these changes could have far-reaching implications. Since oceans absorb a significant amount of the world’s heat, learning about the oceans’ temperature trends could help researchers better understand temperature fluctuations in the atmosphere as well.

The researchers hope their findings will demonstrate the need to survey deep ocean temperatures annually in order to better identify the long-term trends.

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The deep sea is slowly warming

Photo, posted July 1, 2018, courtesy of NOAA Ocean Exploration and Research via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cost of Cleaning Up Ocean Plastic | Earth Wise

October 7, 2020 By EarthWise Leave a Comment

Small island developing states increasingly find themselves with large amounts of plastic waste. A recent study looked at the financial cost for removing it.

Aldabra Atoll is a UNESCO World Heritage Site in the Seychelles. It is the world’s second-largest coral atoll and is the home of 307 species of animals and plants, including the largest population of giant tortoises in the world. Aldabra has been called one of the wonders of the world and one of the crown jewels of the Indian Ocean.

Last year, a team from the University of Oxford and the Seychelles Island Foundation, spent five weeks removing litter that had washed up on Aldabra’s shores. In total, they removed 25 tons of plastic litter which, to their surprise, was dominated by waste from the fishing industry. The researchers now estimate that over 500 tons of litter remain on the island, 83% of which consists of buoys, ropes, nets, and, of all things, over 300,000 individual flipflops. This is the largest accumulation of plastic waste reported for any single island in the world.

According to the study, the cost to clean up the entire island would be nearly $5 million, requiring 18,000 person-hours of labor. A project of this magnitude is beyond the capacity of non-profit organizations like the Seychelles Islands Foundation.

The plastic pollution in Aldabra is related to the fishing industry in Seychelles, which provides tuna to high-income markets around the world. The research highlights how even remote highly protected island ecosystems are impacted by global pollution and how difficult and costly it is to remedy.

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Millions of dollars to clean up tuna nets and flip flops from island state

Photo, posted December 27, 2016, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A High-Tech Fire Alarm | Earth Wise

July 23, 2020 By EarthWise Leave a Comment

In recent years, wildfires have been a global problem, notably in California, Brazil, and Australia. It has become increasingly important to be able to respond to new fires as soon and as quickly as possible. Such response can make the task of extinguishing them easier, thereby reducing the amount of damage and the loss of property and life.

Traditional methods for detecting forest fires include satellite monitoring, ground patrols, and watch towers, all of which have high labor and financial costs but suffer from low efficiency. Remote sensing technologies are becoming increasingly common but rely on batteries for power, requiring servicing in remote locations to replace depleted batteries. Solar cells represent an alternative to batteries, but it is challenging to use them in forests because of shading and foliage coverage.

A team of researchers at Michigan State University has developed a remote forest fire detection and alarm system powered by nothing more than the movement of tree limbs in the wind. The device is known as an MC-TENG, which is an acronym for multilayered cylindrical triboelectric nanogenerator. The triboelectric effect is a phenomenon where certain materials become electrically charged when they separate from a second material with which they were previously in contact. In the new device, two cylindrical sleeves fit within one another – one anchored and the other free to slide. The device is tied to a tree branch and when the branch sporadically moves in the wind, electricity is generated and stored in a carbon-nanotube-based micro supercapacitor. This powers a sensing system that can continuously monitor environmental conditions without requiring any maintenance.

A combination of carbon monoxide and temperature sensors provides a high-tech fire alarm that can operate continuously in the most remote forest.

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Self-Powered Alarm Fights Forest Fires, Monitors Environment

Photo, posted August 3, 2012, courtesy of Lukas Schlagenhauf via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Powering Cars With Cactus Juice

June 24, 2019 By EarthWise Leave a Comment

Back in 2016, a company called Nopalimex, located in Micoacan, central Mexico, built the world’s first cactus-powered energy plant. The facility utilizes a biodigester to make biogas from nopal, also known as prickly pear cactus. The nopal plant has been called the ‘Green Gold of Mexico’ and is a staple in Mexican diets, medicine and cosmetics.

Nopalimex is now using the cactus to make biofuel for vehicles.

The fruit of the cactus is pureed, mixed with manure, and then left to decompose, producing methane. The methane produced – about eight tons a day – fuels the biodigester which powers the company’s corn chip and cactus chip production and is being tested in a fleet of government vehicles.

The biogas will cost just 65 cents per liter, which is about a third cheaper than the cost of regular gasoline. Using prickly pear as a feedstock for biofuel is attractive because it can be grown in places where traditional energy crops cannot. One can imagine vast fields of cacti in remote, arid areas of the country where normal crops cannot grow. It would not suck up the resources or space needed to feed people, which is an ongoing criticism of current bioenergy crops.

As long as the nopals are regularly replanted, the process is almost entirely sustainable, producing only water and nopal waste, which can be used to fertilize other crops.

Finding sustainable ways to produce fuel while doing minimal damage to the environment is an important challenge for countries around the world. In Mexico, harnessing the power of the prickly pear cactus is a unique and clever solution.

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