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Elephants And Global Warming | Earth Wise

March 9, 2023 By EarthWise Leave a Comment

A study by researchers at Saint Louis University has found that elephants play a key role in creating forests that store large amounts of atmospheric carbon and in maintaining the biodiversity of forests in Africa. Since elephants are endangered, their status represents a significant threat to an ecosystem that is very important to the Earth’s climate.

The African rainforest contains trees with both low carbon density (light wood) and high carbon density (heavy wood). High carbon density trees grow more slowly and can be crowded out by the faster growing low carbon density trees rising above them. Elephants affect the relative abundance of these trees by feeding more on the low carbon density trees which are more palatable and nutritious. This thinning of the forest allows the trees that sequester the most carbon to flourish.

Elephants are also excellent dispersers of the seeds of high carbon density trees. Essentially, elephants are the gardeners of the forest. They plant the forest with high carbon density trees and get rid of the weeds – in this case, the low carbon density trees. According to the study, if elephants were to become extinct, the African rainforest – the second largest on earth – would gradually lose between six and nine percent of its ability to capture atmospheric carbon.

Elephants have been hunted by humans for millennia. Gaining support for protecting them has mostly been driven by the argument that everybody loves elephants. Focusing on their role in maintaining forest diversity has not driven much more action. The hope is that the evidence of how important elephants are for climate mitigation will be taken seriously by policy makers to generate the support needed for improved elephant conservation.

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Can Elephants Save the Planet?

Photo, posted March 15, 2008, courtesy of Michelle Gadd/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Turning Carbon Into Stone | Earth Wise

January 31, 2023 By EarthWise Leave a Comment

A start-up company in Oman called 44.01 was recently awarded a $1.2 million Earthshot Prize by Prince William of the U.K. The company, whose name corresponds to the molecular weight of carbon dioxide, is working on speeding up natural chemical reactions that take carbon from the air and lock it into solid mineral form.

The company’s location in Oman is no random occurrence. The mountains of northern Oman and along the coast of the United Arab Emirates are the site of a huge block of oceanic crust and upper mantle that was thrust upward some 96 million years ago. The tilted mass of rock is over 200 miles long and is the largest surface exposure of the Earth’s mantle in the world.

This type of rock, called peridotite, is rich in olivine and pyroxene, which react with water and carbon dioxide to form calcium-based minerals like serpentine and calcite that permanently lock in carbon. Other kinds of rock also are capable of carbon-storing mineralization, but this mantle rock is the most effective for the purpose. It only exists at the Earth’s surface in a few places, including Papua New Guinea and some spots in California and Oregon.

The 44.1 company is planning to use solar-powered direct air capture devices to remove CO₂ from the air, use it to produce carbonated water, and inject the water into the reactive rocks. The company will operate a couple of pilot systems during 2023. Ultimately, the company believes it can scale up the process to be able to permanently sequester as much as a billion tons of CO₂ a year by the year 2040 without needing to inject the gas into deep caverns or find other places to store it.

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With Major Prize, a Project to Turn Carbon Emissions to Stone Gains Momentum

Photo, posted August 10, 2018, courtesy of JM McBeth via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Reducing Emissions From Cement Manufacturing | Earth Wise

December 7, 2021 By EarthWise Leave a Comment

Cement is the basic ingredient of concrete, which is the most widely used construction material in the world. About 8% of global carbon dioxide emissions are associated with cement production.

More than half of these emissions come from making clinker, which is a major component of cement produced by heating ground limestone and clay to a temperature of over 2500 degrees Fahrenheit. Some of the emissions come from burning fossil fuels to heat the materials, but much of them come from the chemical reaction that creates the clinker.

The Portland Cement Association, which represents 92% of US cement manufacturing capacity, has recently released its “Roadmap to Carbon Neutrality”, which lays out a plan to reach carbon net zero across the cement and concrete value chain by 2050.

The plan includes the greater use of alternative fuels to reduce emissions from energy use. It also involves the adoption of newer versions of cement such as Portland limestone cement, which reduces CO2 levels. The industry has already reduced emissions by some shifting to Portland limestone cement, but it still only represents a small fraction of cement production.

The most significant strategy would be the adoption of carbon capture, utilization, and storage (or CCUS) technologies. The idea is to capture the CO2 generated in the production of clinker and inject it into the fresh concrete. It would actually be permanently sequestered in the concrete and would not be released even if a structure is demolished in the future.

It will take a combination of technologies and initiatives for the cement industry to reduce its emissions. Fortunately, the industry appears to be committed to that goal.

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US cement manufacturers release their road map to carbon neutrality by 2050

Photo, posted March 26, 2014, courtesy of Michael Coghlan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Atmospheric Carbon Into Useful Materials | Earth Wise

July 7, 2021 By EarthWise Leave a Comment

Plants have the ability to capture carbon dioxide from the atmosphere and incorporate it into leaves, fruits, wood, and other plant materials. This beneficial process is mostly temporary, as much of this carbon dioxide from plant matter ends up back in the atmosphere through decomposition, or even burning.

Researchers at the Salk Institute have proposed a more permanent fate for captured carbon by turning plant matter into a valuable industrial material called silicon carbide.

In a recent study published in the journal RSC Advances, Salk scientists transformed tobacco and corn husks into silicon carbide and evaluated and quantified the benefits of the process.

The researchers used a previously reported method to transform plant matter into silicon carbide in three stages and carefully tracked the carbon utilization at each stage.

Stage one is growing the plants. They used tobacco from seed, chosen for its short growing season. Then the harvested plants are frozen, ground into a powder, and treated with chemicals including a silicon-containing compound. Finally, the powder is subjected to a high-temperature process resulting in the production of silicon carbide.

Their analysis showed that much of the carbon sequestered by growing the plants could be preserved through the full process and the amount of energy required for the production of the silicon carbide (mostly from the high-temperature process) is comparable to current manufacturing processes for the material.

Permanently sequestering carbon from agricultural waste products by incorporating it into a valuable industrial material would be a valuable addition to strategies for reducing greenhouse gases in the atmosphere.

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Transforming Atmospheric Carbon Into Industrially Useful Materials

Photo, posted August 3, 2013, courtesy of AJ Garrison via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tropical Forests As Carbon Sinks | Earth Wise

April 21, 2020 By EarthWise Leave a Comment

Tropical forests are an important part of the global carbon cycle because they take up and store large amounts of carbon dioxide. Because of this, deforestation in the Amazon and other tropical forests is a major contributor to the growing CO2 levels in the atmosphere.

Therefore, climate models need to accurately take into account the ability of tropical forests to sequester carbon. It turns out that this is not such a simple matter. A new study by the International Institute for Applied Systems Analysis sought to determine how much detail about tropical forests is needed in order to make valid assumptions about the strength of forest carbon sinks.

They looked at the role of both biotic factors – differences between plant species that are responsible for capturing more or less carbon from the atmosphere – and abiotic factors – local environmental factors like soil properties that also influence carbon sink strength.

It is generally assumed that more diverse forest communities capture available resources more efficiently as a result of complementary characteristics and preferences of certain species to specific conditions. Factors like soil texture and chemistry are also important. In general, the results show that abiotic and biotic factors interact with one another to determine how much carbon can be stored by the ecosystem.

Traditional projections of the role of tropical forests in storing carbon mostly rely on remote sensing techniques that integrate over large spatial areas. The new study shows that there can be large differences in the carbon storing ability of tropical forests and that more detailed models are needed to produce more accurate projections.

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Shedding light on how much carbon tropical forests can absorb

Photo, posted July 17, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Powerful Case For Protecting Whales

October 24, 2019 By EarthWise Leave a Comment

Efforts to mitigate climate change typically face two major challenges. One is to find effective ways to reduce the amount of atmospheric carbon dioxide. The other is how to raise enough money to implement climate mitigation strategies.

Many proposed solutions to climate change, like carbon capture and storage, are complex, expensive, and in some cases, untested. What if there was a low-tech solution that was effective and economical?

Well, it turns out there is one, and it comes from a surprisingly simple, “no-tech” strategy to capture CO2: increase global whale populations.

According to a recent analysis by economists with the International Monetary Fund, whales help fight climate change by sequestering CO2 in the ocean.

Whales sequester carbon in a few ways. They hoard it in their fat and protein-rich bodies, stockpiling tons of carbon apiece. When whales die, they turn into literal carbon sinks on the ocean floor. While alive, whales dive to feed on tiny marine organisms like krill and plankton before surfacing to breathe and excrete. Those latter activities release an enormous plume of nutrients, including nitrogen, iron, and phosphorous, into the water. These so-called “poo-namis” stimulate the growth of phytoplankton, microscopic marine algae that pull CO2 out of the air and return oxygen to the air via photosynthesis. Phytoplankton are responsible for every other breath we take, contributing at least 50% of all oxygen to the atmosphere and capturing approximately 40% of all CO2 produced.

With other economic benefits like ecotourism factored in, economists estimate that each whale is worth $2 million over its lifetime, making the entire global population possibly a one trillion dollar asset to humanity.

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How much is a whale worth?

Photo, posted June 12, 2013, courtesy of Gregory Smith via Flickr.

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Cloning Ancient Redwoods

January 30, 2019 By EarthWise Leave a Comment

During the 19th and 20th centuries, many of the world’s largest and oldest tress were cut down for their lumber. Some of these coast redwoods were 3,000 years old and measured 35 feet in diameter.

Today, giant stumps of these ancient redwoods dot the landscape from Oregon to northern California and are a remnant of the old-growth forest that once stretched across much of the Pacific Northwest.

An organization called the Archangel Ancient Tree Archive is dedicated to reestablishing ancient redwood forests to help combat climate change. Coastal redwoods are not only huge but can grow an average of 10 feet a year. One of these enormous trees can sequester 250 tons of carbon dioxide over its lifetime, more than 200 times the amount for an average tree.

While many experts thought that the giant stumps were lifeless, arborists at Archangel collected DNA from the stumps of five giant coast redwoods, all larger than the largest tree living today. They then used this genetic material to grow dozens of saplings, which are clones of the ancient trees, in a process that takes about two-and-a-half years.

To date, the Archangel Ancient Tree Archive has planted nearly 100 of these saplings in the Eden Project garden in Cornwall, England, a couple of hundred in Oregon, and most recently, has planted 75 in the Presidio National Park in San Francisco.

According to arborists at the nonprofit organization, these saplings have extraordinary potential to purify our air, water, and soil for generations to come. Their hopes are that the new San Francisco ‘super grove’ will be allowed to grow unmolested by manmade or natural disasters and thus propagate forever.

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