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Planting trees to cool the planet

July 16, 2025 By EarthWise Leave a Comment

Planting lots of trees is one of many strategies being pursued to combat climate change. Forests absorb carbon dioxide, provide shade, and help regulate temperatures. They also support biodiversity and improve air and water quality.

According to a new study by researchers from the University of California – Riverside, restoring forests to their pre-industrial extent could reduce global average temperatures by 0.34 degrees Celsius. That’s equivalent to about 25% of the warming the Earth has already experienced.

The study models restoring 4.6 million square miles of forest. While previous studies have focused on the role trees play in removing carbon, this research adds that trees also alter atmospheric chemistry in ways that boost their cooling impact.

Trees release natural chemicals called BVOCs – biogenic volatile organic compounds – which interact in the atmosphere to form particles that reflect sunlight and promote cloud formation. These effects enhance the cooling impact of forests, especially in climate models that take these chemical reactions into account.

But not all reforestation is created equal. The benefits of reforestation vary by region, with tropical forests offering stronger cooling and fewer drawbacks. Importantly, the researchers emphasize that meaningful climate benefits don’t require restoring every lost forest. Small, localized efforts can still shift regional climates.

While forest restoration can meaningfully aid climate efforts, the researchers stress that it must complement – not replace – fossil fuel reductions.

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Does planting trees really help cool the planet?

Photo, posted May 20, 2005, courtesy of Ben Britten via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Saharan dust and solar power

May 29, 2025 By EarthWise Leave a Comment

The world is a big place but even things that are far away can have serious local consequences. The effects of distant Canadian wildfires on air quality in Florida is a good example.

Europe is increasingly becoming reliant on solar energy to meet its targets for climate change mitigation and energy security. According to new research by four Hungarian universities, mineral dust carried on the wind from the Sahara Desert is not only reducing electricity generation from solar power across Europe but it is also making it harder to predict what gets generated.

The Sahara releases billions of tons of fine dust into the atmosphere each year. Tens of millions of tons reach European skies where the tiny particles scatter and absorb sunlight, reduce the amount of light reaching the surface, and even promote cloud formation. All of these things reduce the output of photovoltaic systems.

In addition, conventional weather forecasting tools don’t consider the effects of Saharan dust events, so that scheduling of solar power for the energy system becomes less reliable. Incorporating these events into new forecast models will be essential.

Apart from the atmospheric effects of the dust, there are also long-term impacts due to dust contaminating and eroding the physical infrastructure of solar panels thereby further reducing their efficiency and increasing maintenance costs.

Over time, south-to-north transport of Saharan dust is likely to become more pronounced due to a steeper thermal gradient. Currently, the quantities of atmospheric dust, the dynamics of its transport, and the physical properties of the dust itself are not very well understood. Understanding these things will be crucial for Europe’s energy future.

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The shadow of the wind: photovoltaic power generation under Europe’s dusty skies

Photo, posted March 11, 2023, courtesy of Mark Wordy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Reducing emissions from cement

November 14, 2024 By EarthWise Leave a Comment

Cement production accounts for about 7% of global carbon emissions. It is one of the most difficult challenges for emissions reduction. The emissions associated with producing cement come from both the energy used to provide heat for the process and from the chemical reactions that take place in the formation of cement. Cement is an essential building block of society, and its use is not expected to decline over time.

A German company called Heidelberg Materials is embarking on an ambitious project to reduce carbon emissions from a cement plant in Norway. They are building a facility to use absorbent chemicals to capture large quantities of carbon dioxide emitted through cement production. More than half a ton of carbon dioxide arises from every ton of cement produced at the plant.

Once the carbon dioxide is captured it will be chilled to a liquid, loaded onto ships, and carried to a terminal farther up the Norwegian coast. From there, it will be pumped into undersea rocks located 70 miles offshore and a mile and a half below the bottom of the North Sea.

With all of this complicated process going on, cement from the plant is likely to be quite expensive. It might even be two or three times the price of ordinary cement. Heidelberg Materials is counting on customers’ willingness to pay much more for cement that comes with green credentials.

Can this be economically viable? Heidelberg estimates that cement accounts for only about 2% of the cost of a large building project but as much as 50% of the emissions. As a result, using carbon-free cement could be a relatively inexpensive way for builders to reduce emissions.

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Cement Is a Big Polluter. A Plant in Norway Hopes to Clean It Up.

Photo, posted May 7, 2016, courtesy of Phillip Pessar via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An active hurricane season

May 13, 2024 By EarthWise Leave a Comment

The Atlantic hurricane season officially runs from June 1st until November 30th. Forecasters at Colorado State University have issued forecasts of Atlantic basin hurricane activity since 1984 based on the pioneering work of Professor William Gray. This year’s forecast, issued in April, predicts a higher-than-average number of Atlantic storms. In fact, it may be one of the most active seasons on record.

On average, there are 14 named storms each season. This year, the prediction is for 23 of them. On average, there are 7 hurricanes each season. This year, the prediction is for 11. The prediction is for 5 major hurricanes among them. These predictions are among the highest on record, although in 2020 they predicted 12 hurricanes. In fact, that year there were 14 that actually took place.

Among the factors at play are that the El Niño that was occurring last year has dissipated and there is a good chance of a La Niña forming, which suppresses upper-level winds thereby making conditions ideal for hurricane formation and intensification. But the overarching factor is global warming which is driving ocean temperature rise. The water in the Atlantic, especially in the eastern Atlantic where most hurricanes form, has seen record-breaking warmth. More warm water means more chances for storms.

Other research groups echo the predictions from Colorado State and, in some cases, see ever greater chances for an extremely active hurricane season. The University of Pennsylvania forecast calls for 33 named storms.

The overall forecast is for a well above-average probability for major hurricanes making landfall along the continental United States coastline and the Caribbean.

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Weather tracker: US experts predict one of most active hurricane seasons on record

Photo, posted September 5, 2017, courtesy of NASA/NOAA GOES Project via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A giant underground battery

February 5, 2024 By EarthWise Leave a Comment

Two up-and-coming energy technologies are coming together near a tiny town in central Utah. Outside of the town of Delta, population 3,600, two caverns, each as deep as the Empire State Building, are being created from an underground salt formation to be used to store hydrogen gas. The gas will be used as a fuel in a new electricity generation plant.

The plant will replace an aging local coal-fired power plant. The new plant will burn a mixture of natural gas and hydrogen – green hydrogen produced without emitting greenhouse gases. To produce the hydrogen, the facility will operate 40 giant electrolyzers that will use excess solar and wind power generated at times of low demand to split water molecules into hydrogen and oxygen.

The caverns were created by a process called solution mining in which high-pressure water is pumped down into salt deposits that are dissolved. The resulting caverns are 200 feet in diameter and 1,200 deep and lie 3,000 to 4,000 feet below the surface. Hydrogen cannot escape through the thick salt layers.

The amount of energy that can be stored in the form of hydrogen fuel in these caverns is massive – far more than all the battery storage installed in the U.S. to date. Chevron has a majority stake in one of the projects and will supply the natural gas. The facility is expected to go online in 2025.

While this will produce far fewer emissions than existing coal plants, it is not carbon-free. Currently, turbine technology cannot operate with pure hydrogen fuel. The Delta plant will run on only 30% hydrogen. The hope is that turbine technology will improve in the future and permit operation on pure hydrogen.

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A Huge Underground Battery Is Coming to a Tiny Utah Town

Photo, posted September 9, 2013, courtesy of Scott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Superstrong Nanofibers | Earth Wise

March 5, 2021 By EarthWise Leave a Comment

Self-assembly is a ubiquitous process in the natural world that leads to the formation of the DNA double helix, the creation of cell membranes, and to many other structures. Scientists and engineers have been working to design new molecules that assemble themselves in water for the purpose of making nanostructures for biomedical applications such as drug delivery or tissue engineering. For the most part, the materials created in this way have been chemically unstable and tended to degrade rapidly, especially when the water is removed.

A team at MIT recently published a paper describing a new class of small molecules they have designed that spontaneously assemble into nanoribbons with unprecedented strength and that retain their structure outside of water.

The material is modeled after a cell membrane. Its outer part is hydrophilic (it likes to be in water) and its inner part is hydrophobic (it tries to avoid water.) This configuration drives the self-assembly to create a specific nanostructure and by choosing the appropriate chemicals to form the structures, the result was nanoribbons in the form of long threads that could be dried and handled. The resultant material in many ways resembles Kevlar. In particular, the threads could hold 200 times their own weight and have extraordinarily high surface areas. The fibers are stronger than steel and the high surface-to-mass ratio offers promise for miniaturizing technologies for such applications as pulling heavy-metal contaminants out of water and for use in electronic devices and batteries.

The goal of the research is to tune the internal state of matter to create exceptionally strong molecular nanostructures. The potential for important new applications is considerable and exciting.

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Researchers construct molecular nanofibers that are stronger than steel

Photo, posted June 19, 2007, courtesy of Andrew Hitchcock via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.