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The dangers of deep sea mining

April 21, 2025 By EarthWise Leave a Comment

The White House is considering an executive order that would fast-track permitting for deep-sea mining in international waters and allow mining companies to bypass a United Nations-backed review process.

Deep sea mining is the extraction of minerals from the seabed in the deep ocean. Most of the interest is in what are known as polymetallic nodules, which are potato-sized mineral deposits that have built up in layers over thousands of years. They are located several miles below the surface, primarily in what is called the Clarion-Clipperton zone, which is an environmental management area of the Pacific Ocean about halfway between Mexico and Hawaii.

A new multiyear study led by UK’s National Oceanography Center and published in the journal Nature found that the site of a deep-sea mining test in 1979 still showed lower levels of biodiversity than in neighboring undisturbed sites 44 years later.

Much is not known about the undersea nodules. We know that they produce oxygen. If the nodules are removed, will that reduce the amount of oxygen in the deep sea and affect the organisms that live there? If mining occurs, what effect will the metal-containing sediment plumes churned up by the mining process have?

The nodule fields sustain highly specialized animal and microbial communities. More than 20 billion tons of nodules are estimated to lie on the seabed of the Clarion-Clipperton Zone. If large-scale mining takes place, and there is much interest in that happening, it is important to find out what the impact will be on the ocean and its ecosystems because it is likely to be largely irreversible.

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Deep sea mining for rare metals impacts marine life for decades, scientists say

Photo, posted September 4, 2014, courtesy of James St. John via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cloud brightening

June 17, 2024 By EarthWise Leave a Comment

Solar geoengineering is a type of climate intervention: deliberate actions designed to affect the climate. There are several ways to try to reduce the amount of sunlight reaching the surface of the earth and all of them are controversial. Perhaps the least controversial approach is cloud brightening.

The idea is based on something called the Twomey effect, which is that large numbers of small droplets in the atmosphere reflect more sunlight than small numbers of large droplets. Spraying vast quantities of minuscule aerosols into the sky, thereby forming many small droplets, could change the reflective properties of clouds. If clouds are more reflective, then less sunlight reaches the surface, and the temperature goes down.

This form of geoengineering is thought to be less risky because it can be performed on a localized basis and can use relatively benign materials such as sea salt.

In early April, scientists from the University of Washington started testing a device that sprays tiny sea-salt particles into the air from the deck of a decommissioned aircraft carrier in Alameda, California. The test was simply to see whether the machine propelled a mist of suitable size.

Within two weeks, Alameda officials ordered a stop to the experiment, citing potential health and environmental risks. After a month-long investigation, Alameda ruled that the experiment does not generate a measurable risk to health, wildlife, or the environment.

But before more ambitious experiments take place, there are potential side effects of cloud brightening that need to be studied. It may turn out to be a useful tool in fighting global warming, but in any case, such technology should not be viewed as a substitute for moving away from fossil fuels.

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A Test of Cloud-Brightening Machines Poses No Health Risk, Officials Say

Photo, posted September 8, 2011, courtesy of Justin Ladia via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tracking down PFAS toxins

December 5, 2023 By EarthWise Leave a Comment

PFAS – per- and polyfluoralkyl substances – are a group of organic compounds that have been extensively used to provide water-, oil-, and dirt-resistance to a wide range of products ranging from non-stick pans, clothing, and packaging to paint, car polish, and fire-suppressant foam. Exposure to specific PFAS compounds is associated with multiple adverse health effects, including altered immune and thyroid function, liver disease, kidney disease, poor reproductive and developmental outcomes, and cancer. PFAS compounds do not break down in the environment and therefore, over time, become concentrated in plants, animals, and people.

Government agencies such as the EPA in this country and the EU have set strict limits for allowable levels of PFAS in drinking water. Testing water for the trace amounts of PFAS that constitute the limits is time-consuming and expensive and requires complex equipment and experienced personnel.

Researchers at MIT have now introduced a technique for making a portable, inexpensive test that can easily and selectively detect PFAS in water samples. The test makes use of a special polymer containing fluorinated dye molecules that cause the polymer to fluoresce red. If PFAS are present in the sample, they enter the polymer and displace the dye molecules and switches off the red fluorescence.

The new technique is suitable for on-site detection in highly contaminated regions. Detecting smaller concentrations can be achieved with sufficient precision after pre-concentrating the samples using the process of solid-phase extraction.

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Tracking down Environmental Toxins

Photo, posted October 16, 2021, courtesy of Nenad Stojkovic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cryopreserving Corals | Earth Wise

October 3, 2023 By EarthWise Leave a Comment

Recent climate models estimate that if the effects of climate change are not mitigated soon enough, 95% of the world’s corals could die by the mid 2030s. Given the current rate of greenhouse gas emissions, this is an increasingly likely outcome. Coral reefs are estimated to have a $10 trillion economic value apart from their essential role in marine ecosystems.

Researchers at the University of Hawaii at Manoa have demonstrated a successful technique for cryopreserving entire coral fragments; in other words, preserving coral using cold temperatures and successfully reviving them.

Existing coral cryopreservation techniques rely on freezing sperm and larvae, which can only be collected during spawning events, which occur only a few days each year for coral species. This makes it logistically very challenging for researchers and conservationists.

The Hawaiian researchers focused on a process called isochoric vitrification, which is a method of freezing with liquid nitrogen that prevents the formation of ice crystals. They tested the technique with thumbnail-sized fragments of coral, freezing them in small aluminum chambers which restrict the growth of ice crystals that would otherwise damage delicate polyp tissues. Once the chambers were warmed, the fragments were transferred to seawater and allowed to recover. They found that the revived corals behaved the same as those that were never cooled.

The process holds great promise to conserve the biodiversity and genetic diversity of coral. If the process can be scaled up, it may be possible to preserve as many species of coral as possible by 2030, when it may no longer be viable for them to survive in the warming and acidifying oceans.

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Cryopreservation breakthrough could save coral reefs

Photo, posted June 2, 2023, courtesy of USFWS – Pacific Region via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Houseplants And Indoor Air Quality | Earth Wise

April 11, 2022 By EarthWise Leave a Comment

Many of us have houseplants in our homes and offices. The foliage and flowers add beauty and comfort to our indoor spaces. But it turns out that there are health advantages as well.

Many studies have demonstrated that indoor houseplants can help keep you happier and healthier by improving your mood, reducing fatigue, lowering stress and anxiety, and improving focus. Houseplants can also improve indoor air quality.

According to a new study by researchers from the University of Birmingham in the U.K. in partnership with the Royal Horticultural Society, ordinary houseplants can potentially make a significant contribution to reducing indoor air pollution.

The researchers tested three types of houseplants commonly found in homes in the U.K: Peace lily, corn plant, and fern arum. These plants are easy to maintain and not overly expensive.

In the study, the research team exposed these houseplants to nitrogen dioxide, which is a common indoor pollutant. The plants were isolated in a test chamber containing levels of nitrogen dioxide comparable to what might be in an office situated next to a busy road. The researchers found that all the plants were able to remove about half of the nitrogen dioxide in the chamber in just one hour.

In a poorly ventilated small office with high levels of air pollution, the researchers calculated that five houseplants would remove up to 20% of the nitrogen dioxide. In a larger space, the effect would be smaller – around 3.5% – although this figure could be increased by adding more plants.

Bringing nature indoors is one way to breathe cleaner air.

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