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More eco-friendly desalination

May 14, 2025 By EarthWise Leave a Comment

There are about 16,000 operational desalination plants, located across 177 countries, which generate an estimated 25 billion gallons of fresh water daily.

For every gallon of drinking water produced at a typical desalination plant, one and a half gallons of brine are produced. Much of it is stored in ponds until the water evaporates, leaving behind solid salt or concentrated brine for further treatment. There are various other techniques for concentrating brines, but they are energy-intensive and environmentally problematic. The process called electrodialysis uses electrified membranes to concentrate salts.

Water flows into many channels separated by membranes, each of which has the opposite electrical charge of its neighbors. Positive salt ions move towards negatively charged electrodes and negative ions move toward positive electrodes. Two streams result, one containing purified water and one containing concentrated brine.

This eliminates the need for evaporation ponds, but existing electrodialysis membranes either result in leakage of salts into the environment or are too slow, making the process impractical for large-scale use.

Researchers at the University of Michigan have developed a new kind of membrane for electrodialysis. The new membranes don’t leak and are ten times more conductive than those on the market today which means that they can move more salt using less power. The membranes can be customized to suit a broad range of water types, which may help make desalination a more sustainable solution to the world’s growing water crisis.

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Making desalination more eco-friendly: New membranes could help eliminate brine waste

Photo, posted February 4, 2012, courtesy of David Martinez Vicente via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Mining with plants

February 21, 2025 By EarthWise Leave a Comment

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

Where not to plant trees

May 10, 2024 By EarthWise Leave a Comment

Planting huge numbers of trees is often proposed as a way to reduce the severity of climate change. Studies have looked at the potential for Earth‘s ecosystems to support large additional areas of forest and have found that it would be possible to have at least 25% more forested area than we do now. This in turn could capture large amounts of carbon and substantially reduce the amount in the atmosphere.

A recent study by researchers at Clark University in Massachusetts and The Nature Conservancy mapped the climate impact of tree planting across the globe, identifying where it would be most and also least beneficial. The study, published in Nature Communications, found that trees planted in arid, desert regions or in snowy places like the Arctic would, on balance, worsen warming rather than reduce it.

Trees take up carbon dioxide from the atmosphere, which helps to keep warming in check. But trees with dark, green leaves also absorb heat from sunlight. Snow and desert sand, on the other hand, are light-colored and reflect more sunlight back into space. For this reason, trees planted in snowy areas or in the desert will absorb more sunlight than their surroundings. This can negate the climate benefits of soaking up carbon dioxide.

Previous studies only looked at how much carbon dioxide would be removed by planting trees in order to determine how much warming would be prevented. The new study finds that it matters where the trees are planted.

Fortunately, the new study also shows that tree planting projects that are currently underway or that are in the pipeline are largely concentrated in regions where they will indeed help slow global warming.

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This Map Shows Where Planting Trees Would Make Climate Change Worse

Photo, posted April 5, 2022, courtesy of UC Davis Arboretum and Public Garden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic food packaging

May 9, 2024 By EarthWise Leave a Comment

Reducing the use of plastic is an important environmental goal. Plastic is made from fossil fuels and plastic pollutes the land and the oceans. It is estimated that 40% of plastic waste comes from packaging. Plastic packaging is extremely common in the supermarket and there is a growing desire to reduce its use. But it isn’t that easy.

Plastic packaging works well to slow the decay of vegetables and fruit. Its use results in less produce being tossed into the garbage, where it creates almost 60% of landfill methane emissions. In fact, food is the most common material in landfills. The average American family of four spends $1,500 a year on food that ends up uneaten and nearly half of all household food waste is fruits and vegetables.

Products like bagged salads, berries in plastic clamshells, and plastic sealed potatoes and cucumbers are popular with shoppers because they stay fresh longer. They are popular with grocers because the items don’t have to be weighed. But all these things result in plastic waste. It is a tradeoff that is difficult to make between food quality and safety vs. the environmental harm caused by plastic.

There are a variety of alternatives to plastic packaging of food that are being explored. They range from biodegradable, organic coatings that can take the place of plastic films, to cardboard and paper produce packaging.

But practically, there is yet no affordable and biodegradable plastic alternative that keeps fruits and vegetables safe and fresh. Solving the food packaging problem is not easy.

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So Much Produce Comes in Plastic. Is There a Better Way?

Photo, posted July 1, 2007, courtesy of Brian via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Positive tipping points and climate

January 29, 2024 By EarthWise Leave a Comment

We often hear about tipping points and climate change. Tipping points are critical thresholds that, when crossed, lead to large, accelerating, and often irreversible changes. Some of the ones of concern with the climate are thawing permafrost, melting glaciers and ice sheets, and global temperatures reaching certain levels. These are all tipping points that are essential to avoid.

A study published in the journal One Earth by researchers at the University of Exeter in the UK contends that in order to avoid the severe consequences of climate change, we need to trigger some positive tipping points.

Many climate-friendly changes are happening too slowly. Triggering positive tipping points is a way to rapidly reach the high levels of decarbonization required to avoid triggering the negative tipping points of great concern.

Reaching a positive tipping point is a way that beneficial changes can rapidly gain momentum. One example is the adoption of electric vehicles. It has clearly reached a tipping point across Scandinavia and has happened rapidly. Norway has managed to transition the market share of electric vehicles from under 10% to nearly 90% in less than 10 years. At some point, everybody wanted an electric car. This is evidence that positive tipping points can happen.

Many of the other forms of decarbonization need to move from their current level of adoption to rapid expansion. A combination of affordability, attractiveness, availability, and political will are needed to trigger tipping points. Exactly what those tipping point are is not necessarily known, but unless something accelerates the current pace of change, it will be very difficult to prevent negative climate tipping points from changing the world in destructive ways.

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Positive tipping points must be triggered to solve climate crisis

Photo, posted July 8, 2023, courtesy of Michael Swan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The slow decline of coal

January 25, 2024 By EarthWise Leave a Comment

Despite the fact that coal is the dirtiest and most climate-harmful energy source we have, the global demand for it hit a record high in 2023. The demand for coal grew by 1.4% worldwide, according to an analysis by the International Energy Agency.

Coal use grew by 5% in China and 8% in India. The two countries are the world’s largest producers and consumers of coal. Meanwhile, coal use in the U.S. and the European Union fell by 20%.

Despite this discouraging news, the IEA forecasts that coal use will decline over the next two years. There have been declines in coal demand a few times before, but they were driven by unusual events such as the collapse of the Soviet Union and the Covid-19 crisis. But the IEA says that the forthcoming decline is different. It will be driven by the formidable and sustained expansion of clean energy technologies.

According to the IEA, global coal demand will fall by 2.3% by 2026 even in the absence of new policies to curb coal use. Forces at play will be increased hydropower in China as it recovers from drought and puts new wind and solar projects online. China is responsible for more than half of global coal demand, but it is also responsible for more than half of the planned renewable power projects coming online over the next three years. Experts believe that with these forthcoming projects, Chinese emissions may have peaked in 2023.

The projected drop in coal demand is still far short of what is required for the world to avoid catastrophic warming. Much greater efforts are needed to meet international climate targets.

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After a Record 2023, Coal Headed for Decline, Analysts Say

Photo, posted August 25, 2015, courtesy of Jeremy Buckingham 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

Electrifying The Federal Fleet | Earth Wise

October 7, 2021 By EarthWise Leave a Comment

The federal government owns and operates about 645,000 vehicles. Among them are about 200,000 passenger vehicles, 78,000 heavy-duty trucks, 47,000 vans, 847 ambulances, and three limousines. About 225,000 vehicles are operated by the Postal Service.

Each year, these vehicles are driven about 4.5 billion miles and use about 400 million gallons of gasoline, producing 3.5 million tons of greenhouse gases.

President Biden signed an executive order in January directing federal officials to devise a plan for converting the entire fleet to clean and zero-emission vehicles. So far, the work has been slow.

According to a new report from Atlas Public Policy, accelerating the push for electric vehicles in the federal fleet could save taxpayers billions of dollars.

Electric vehicles have lower fueling and maintenance costs as well as a smaller environmental impact. According to the report, the government could replace 40% of its light-duty vehicles and buses not owned by the Postal Service with cheaper plug-in alternatives by 2025. By 2030, it could replace 97% of such vehicles with EVs for a lifetime savings of more than $1 billion. Furthermore, by 2025, it would be possible to replace nearly all mail trucks with EVs for a savings of $2.9 billion.

The federal fleet represents an opportunity to encourage transportation electrification to happen much more quickly. Apart from the economic and environmental benefits, having an electrified federal fleet would increase public awareness of the practicality and benefits of electric vehicles.

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Push to Electrify Federal Fleet Could Yield Billions in Savings by 2030

Photo, posted May 14, 2015, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hyping Electric Cars | Earth Wise

March 13, 2020 By EarthWise Leave a Comment

During this year’s Super Bowl, at least three car companies – GM, Porsche, and Audi – ran commercials for plug-in cars. This is a sign that automakers are ramping up their efforts to persuade the public that electric cars really are the future.

The auto industry is investing billions of dollars to develop electric vehicles, spurred by stricter emissions rules in places like California and concerns about climate change. In fact, more than 100 new plug-in models are expected to become available in the United States over the next five years.

In Europe, electric cars are increasingly popular. Norwegians, for example, buy more electric cars than gas cars. And several European countries have banned the sale of gas cars starting in 2025.

But in the US, enthusiasm for electric cars has been slow to build. Automakers sold fewer than 330,00 electric vehicles in the US in 2019 and more than half of those were from Tesla, which actually does not even advertise its vehicles.

The auto industry spent nearly $9 billion in national and local advertising in the US last year, but less than half a percent of that went toward promoting electric vehicles.

A big part of the problem is that car dealers are not very enthusiastic about selling electric cars, which require far less maintenance than conventional cars and have far fewer costly replacement parts to sell. As a result, the industry’s efforts to speed the transition to electric cars has been ambivalent at best.

World-wide, Tesla has sold about a million cars, mostly in the past 4 years, so there is clearly a growing demand for electric vehicles. It is up to the rest of the industry to create demand for the new cars they have committed to produce.

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Super Bowl Ads Hyped Electric Cars. But Will Anyone Buy Them?

Photo, posted October 6, 2018, courtesy of Mike Fonseca via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Predicting Lightning Strikes

November 19, 2019 By EarthWise Leave a Comment

Lightning is one of the most unpredictable phenomena in nature. Approximately 100 lightning bolts strike earth’s surface every second, and each lightning bolt can contain up to one billion volts of electricity. Lightning regularly kills both people and animals and sets homes and forests on fire. It’s also been known to ground airplanes.

Researchers at EPFL – a research institute and university in Switzerland – have developed a novel way to predict where and when lightning will strike. The system relies on a combination of standard data from weather stations and artificial intelligence to predict lightning strikes to the nearest 10 to 30 minutes and within a radius of less than 20 miles. The simple and inexpensive system was outlined in a research paper recently published in Climate and Atmospheric Science, a Nature partner journal.

According to researchers, the current systems for predicting lightning strikes are slow, expensive, and complex, relying on external data acquired by satellite and radar. The new inexpensive system from EPFL uses real time data that can be obtained from any weather station, meaning it can cover remote regions that are out of radar and satellite range and where communication networks are lacking. The quick predictions from the system allow alerts to be issued before a storm has even formed.

The system uses a machine-learning algorithm that’s been trained to recognize conditions that lead to lightning. The researchers took into account atmospheric pressure, air temperature, relative humidity, and wind speed, among other things. After training the algorithm, the system was able to predict lightning strikes accurately nearly 80% of the time.

This system is a simple way to predict a complex phenomenon.

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