fresh

Supermarket bargains and food waste

September 3, 2025 By EarthWise Leave a Comment

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

Building better blackberries

June 6, 2025 By EarthWise Leave a Comment

The Human Genome Project is one of the greatest scientific feats in history. It was launched in 1990 and completed in 2003. The international group of researchers wanted to comprehensively study all of the DNA – the genome – from a select set of organisms, foremost of which being that of human beings. The results accelerated the study of human biology and has led to improvements in the practice of medicine.

Every living thing – animal, plant, fungus, and various single-celled organisms – has a genome – a genetic blueprint. A recent study by researchers at the University of Florida has done genome sequencing of blackberries with the hope of being able to achieve more efficient and targeted breeding.

Over the past 20 years, consumer demand for blackberries has increased leading to farmers growing more of the fruit in the United States. The U.S. produces 37 million pounds of processed blackberries and almost 3 million pounds of fresh berries each year.

The Florida researchers made use of a large collection of DNA sequences to computationally piece together the entire genome of the blackberry variety in the study. The genome study uncovered the secrets behind key traits that could lead to growing blackberry plants with no thorns and increasing the production of anthocyanin, which affects the color and health benefits of the fruit.

For Florida, the southeastern United States and regions with similar climates, the genetic research holds the promise of accelerating the process to create blackberry varieties that are better suited to local growing conditions, enhancing both the yield and the quality of the increasingly popular fruit.

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Decoding blackberry DNA: UF study paves way for enhanced breeding strategies

Photo, posted September 18, 2016, courtesy of Theo Crazzolara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Recycling lithium-ion batteries

March 28, 2025 By EarthWise Leave a Comment

Lithium-ion batteries are used to power computers and cellphones and, increasingly, vehicles. The batteries contain lithium as well as various other valuable metals such as nickel, cobalt, copper, and manganese. Like other batteries, lithium-ion batteries have a finite lifetime before they can no longer perform their intended function.

Recycling lithium-ion batteries to recover their critical metals is an alternative to mining those metals. A recent study by Stanford University analyzed the environmental impact of obtaining those metals using lithium-ion battery recycling compared with mining. They found that the recycling process is associated with less than half of the greenhouse gas emissions of conventional mining. The process uses about one-fourth of the water and energy of mining new metals. North America’s largest industrial-scale lithium-ion battery recycling facility is Redwood Materials, located in Nevada, which uses a clean energy mix that includes hydropower, geothermal, and solar power.

These calculated advantages are associated with recycling batteries that have been in use. The advantages are even greater for recycling scrap: defective material from battery manufacturers.

The advantages of recycling are dependent on the sources of electricity at the recycling plant and the availability of fresh water.

At present, the U.S. recycles about half of its available lithium-ion batteries. By comparison, 99% of lead-acid batteries (like those found in cars and trucks) have been recycled for decades. As the supply of used lithium-ion batteries continues to increase, it is important for the availability of industrial-scale battery recycling to keep pace.

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Recycling lithium-ion batteries delivers significant environmental benefits

Photo, posted May 7, 2020, courtesy of Mark Vletter 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

The end of a supergiant iceberg

November 16, 2023 By EarthWise Leave a Comment

In 2017, a supergiant iceberg known as A-68 calved from the Larsen C ice shelf in Antarctica. In 2020, it drifted close to South Georgia, a British island in the South Atlantic Ocean, and then began to break up. This iceberg was enormous – nearly the size of Delaware. When it started to break up, it released huge quantities of fresh, cold meltwater in a relatively small region.

Scientists from the British Antarctic Survey and the University of Sheffield have studied how the melting iceberg has affected the temperature and the salinity of the ocean surface in the area. They found that the water near the surface was 8 degrees Fahrenheit colder than normal and the water only had about two-thirds of its normal saltiness.

The effects from the melted iceberg eventually extended well beyond South Georgia as the colder, less-salty water was carried by ocean currents to form a long plume that stretched more than 600 miles across the South Atlantic. It also took several months to disappear.

The calving of this massive iceberg provided a unique opportunity for scientists to study the impact of iceberg melting on surface ocean conditions. A-68 was one of the largest and most studied of all icebergs. The study has shown that each individual melting giant iceberg can have widespread and long-lasting impacts on ocean conditions, which has consequences for the plant and animal life that lives there.

Climate change is likely to lead to more giant iceberg calving in the future. It is important to monitor these events to assess their future impacts on ocean circulation, biology, and even seafloor geology.

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Supergiant iceberg makes surrounding ocean surface colder and less salty

Photo, posted October 24, 2018, courtesy of Jefferson Beck / NASA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Greenland Becoming Darker | Earth Wise

July 5, 2021 By EarthWise Leave a Comment

According to research published by Dartmouth University, a weather pattern that pushes snowfall away from parts of Greenland’s ice sheet is causing the continent to become darker and warmer.

Reducing the amount of fresh, lighter-colored snow exposes older, darker snow on the surface of Greenland’s ice sheets. Fresh snow is the brightest and whitest. The reflectivity of snow decreases fairly quickly as it ages. This decrease in albedo – or reflectivity – allows the ice sheet to absorb more heat and therefore melt more quickly.

The research attributes the decrease in snowfall in Greenland to a phenomenon called atmospheric blocking in which persistent high-pressure systems hover over the ice sheet for up to weeks at a time. Such systems have increased over Greenland since the mid-1990s. They push snowstorms to the north, hold warmer air over Western Greenland, and reduce light-blocking cloud cover.

All of this contributes to Greenland melting faster and faster. According to research cited in the study, the Greenland ice sheet has warmed by nearly 5 degrees Fahrenheit since 1982. Overall, Greenland is experiencing the greatest melt and runoff rates in the last 450 years, at the minimum, and quite likely the greatest rates in the last 7,000 years.

The Greenland ice sheet is the second largest ice body in the world, after the Antarctic ice sheet. It is 1,800 miles long and about 700 miles wide at its greatest width. Its thickness is between 1.2 and 1.9 miles. If the entire sheet were to melt, it would lead to a global sea level rise of 24 feet. So, the darkening of Greenland is a source of great concern.

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Greenland Becoming Darker, Warmer as Snow Changes

Photo, posted April 3, 2012, courtesy of Francesco Paroni Sterbini via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Can We Tow Icebergs To Use Their Water? | Earth Wise

February 23, 2021 By EarthWise Leave a Comment

At any given time, there are thousands of icebergs adrift in Antarctica that are hundreds or even thousands of feet across. For at least fifty years, there has been speculation about whether such icebergs could be towed from the Antarctic to places experiencing freshwater shortages. The feasibility of such a scheme is still the subject of studies that nowadays include sophisticated computer modeling.

Places like the Persian Gulf, Cape Town, South Africa, and Perth, Australia all experience water shortages and could benefit tremendously from having a large iceberg towed to their waters.

How big an iceberg would it take to quench the thirst of a city like Cape Town? Computer models show that an iceberg 2,000 feet long and 650 feet thick could produce enough water to supply the city for more than a year. However, with water temperatures in the 60s in the area, even such a large iceberg would melt away within weeks. So, to get enough water for a year, it would require a much larger iceberg – one at least a couple of miles long.

Daunting problems include figuring out how many and what sort of ships would be required. An alternative to such giant icebergs would be finding a way to insulate the icebergs so they don’t melt as quickly, thereby allowing much smaller and more towable icebergs to be harvested.

Beyond these issues, there are the ecological issues of the effects of huge amounts of very cold fresh water affecting local marine ecosystems.

Despite a wide range of challenges, there is continued interest in the idea of using icebergs as a source of very pure fresh water. In an increasingly thirsty world, it might someday actually happen.

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Can icebergs be towed to water-starved cities?

Photo, posted November 1, 2007, courtesy of M A Felton via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protecting Fresh Produce | Earth Wise

May 26, 2020 By EarthWise Leave a Comment

Fresh fruits and vegetables can sometimes become contaminated by microorganisms during their long journey from fields to restaurants and grocery stores. Contaminated produce can spoil other produce, which increases the number of fruits and vegetables in the supply chain that can cause illnesses.

In order to prevent this cross-contamination between produce, researchers from Texas A&M University have designed a coating that can be applied to food-contact surfaces, like buckets, rollers, and conveyor belts. The newly-created dual-function coating is both water-repellent and germicidal. In other words, it can both repel and kill. Without water, the researchers say bacteria can’t stick or multiply on surfaces, drastically reducing contamination.

To make this dual-function coating, the researchers chemically-attached a thin layer of silica to an aluminum sheet. They then added a mixture of silica and lysozyme, a naturally-occurring germicidal protein found in egg whites and tears. Together, the silica-aluminum and the silica-lysozyme formed microscopic bumps and crevices. According to the research team, this rough texture, albeit microscopic, is the key to the coating’s superhydrophobic properties.

The researchers tested the coating’s effectiveness at curbing the growth of two strains of disease-causing bacteria: Salmonella and Listeria. Upon review, the number of bacteria found on the dual-coating surfaces was 99.99% less than what was found on the uncoated surfaces.

Despite the success in preventing bacterial spread, the research team said more research needs to be done to see how well the coating works for mitigating viral cross-contamination. Since the coating would need to be reapplied after a certain amount of use, the researchers also plan to develop more permanent, dual-function coatings.

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New dual-action coating keeps bacteria from cross-contaminating fresh produce

Photo, posted April 14, 2012, courtesy of U.S. Department of Agriculture via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fresh Water Under The Sea

July 18, 2019 By EarthWise Leave a Comment

A new survey of the sub-seafloor off the U.S. Northeast coast has revealed the existence of a gigantic aquifer of relatively fresh water trapped in porous sediments lying beneath the salty ocean. This appears to be the largest such formation ever found.

The newly-discovered aquifer stretches from the shore at least from Massachusetts to New Jersey and extends more-or-less continuously out about 50 miles to the edge of the continental shelf. The deposits begin at around 600 feet below the ocean floor and bottom out at about 1,200 feet. If all that water was found on the surface, it could create a lake some 15,000 miles in area. The researchers estimate that the region holds at least 670 cubic miles of fresh water.

Researchers made use of innovative measurements of electromagnetic waves to map the water, which had not been detected by other technologies. It was already known that fresh water existed in places under the sea bottom as a result of oil drilling as far back as the 1970s. But there was previously no hint of the extent of the undersea aquifer.

The water probably was trapped by sediments deposited during the last ice age when sea levels were much lower. But modern subterranean runoff from land sources might also be a contributor.

If water from the aquifer was to be withdrawn, it would still have to be desalinated for most uses, but the cost would be much less than processing ordinary seawater. There is probably no need to do this in the Northeastern US, but the discovery suggests that such aquifers probably lie off many other coasts worldwide and could provide desperately needed water in places like southern California, Australia, the Mideast or Saharan Africa.

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Scientists Map Huge Undersea Fresh-Water Aquifer Off U.S. Northeast

Photo, courtesy of August 1, 2015, courtesy of Michael Vadon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Sensor For Spoiled Milk

June 20, 2019 By EarthWise Leave a Comment

A new sensor technology developed at Washington State University may eventually make expiration dates on milk a thing of the past. The sensor essentially can ‘smell’ whether milk is still good or has gone bad.

The sensor consists of chemically coated nanoparticles that react to the gas produced when bacterial growth on milk has taken place. When such bacteria grow, they produce a volatile compound that doesn’t smell good. So, when we open a carton of milk that has begun to spoil, our noses tell us so immediately.

The new sensor does not have to be in contact with the milk. It detects the volatile gases produced by the bacteria and it changes color. So far, it has only been demonstrated in a controlled lab environment.

To really be useful, the sensor would ideally be able to show how long the milk has before it spoils. Currently, it only shows whether it is ok or already spoiled. The researchers are working on the enhanced version of the sensor.

The researchers envision working with the dairy industry to integrate the sensor technology into a milk bottle’s plastic cap so that consumers can easily see how much longer the milk will stay fresh. Current expiration dates on milk are based on best-case scenarios. They are only accurate if the milk has been stored at the correct temperature the entire time. Unfortunately, milk can inadvertently spend time above refrigerator temperature during shipment or transportation home from the store. If the new sensor technology can be successfully developed, it will be possible to know for sure whether that bottle of milk is good.

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