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Timber Cities | Earth Wise

October 3, 2022 By EarthWise 2 Comments

More than half of the world’s population lives in cities and by 2100, this percentage is predicted to be much higher. This means that more homes will be built with steel and concrete, which both have very large carbon footprints. According to a study by the Potsdam Institute in Germany, housing a growing population in homes made of wood instead could avoid more than 100 billion tons of carbon dioxide emissions over the remainder of the century. This is about 10% of the remaining global carbon budget for staying below the 2-degree Celsius climate target.

The study presents the alternative of housing new urban populations in mid-rise buildings – no more than 4-12 stories high – that are substantially made of wood. Wood is a renewable resource that carries the lowest carbon footprint of any comparable building material. Trees take up CO₂ from the atmosphere to grow. Producing engineered wood releases far less CO₂ than production of concrete and steel and the finished product continues to store carbon.

The study shows that sufficient wood for new mid-rise urban buildings can be produced without a major impact on food production. The wood would come from timber plantations as well as natural forests. The study also looked at biodiversity impacts and ways that ecosystems could be protected while still providing the necessary timber.

Overall, the Potsdam study demonstrates that urban homes made out of wood could play a vital role in climate change mitigation based on their long-term carbon storage potential coupled with the reduced utilization of the carbon-intensive concrete and steel industries.

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Living in timber cities could avoid emissions – without using farmland for wood production

Photo, posted May 24, 2005, courtesy of Stig Anderson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

What Is Healthy Soil? | Earth Wise

August 30, 2022 By EarthWise Leave a Comment

Soil supports life by providing many critical ecosystem services. For example, soil acts as a water filter, a growing medium, and provides habitat for billions of organisms. Soil is also the foundation of our cities and towns, and the basis of global agroecosystems, which provide humans with feed, fiber, food, and fuel.

For all of these reasons and many more, having healthy soil is vital. But what does soil health mean? And how should it be measured?

According to new analysis by researchers from Cranfield University and Nottingham University in the U.K., how we think about, measure, and study soil must change in order to better understand how to manage this resource effectively.

While the term ‘soil health’ is widely used, it means different things to different people. There is no single agreed upon way to gauge the overall health of soil.

Current approaches to assess soil health measure individual soil properties and use findings to assign a single number giving an overall score. But according to the research team, this does not reflect the wider system perspective that’s needed to fully evaluate the health of soil over time.

Instead, the researchers propose a new system to assess soil health based on a hierarchical framework that takes in several measures, including signs of life, signs of function, signs of complexity, and signs of emergence, which is the extent to which soils recover from multiple stressors.

This new approach, which can be applied to all soils, moves us closer to an interdisciplinary understanding of the whole picture of soil health. After all, healthy soil is fundamental to our survival.

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We need to change how we think about soil

Photo, posted April 8, 2008, courtesy of Brian Boucheron via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wind And Solar And Meeting Climate Goals | Earth Wise

May 20, 2022 By EarthWise Leave a Comment

According to a new report from the climate think tank Ember, the rapid growth that has been going on for solar and wind power could allow the global electricity sector to do its part in limiting global warming to 1.5 degrees Celsius.

In 2021, solar power grew by 23% worldwide and wind power grew by 14%. The Netherlands, Australia, and Vietnam had the largest gains in renewable energy. Solar power in Vietnam grew by 337%.

The trends over the past decade, if continued across the globe, would result in the power sector being on track for meeting climate goals. But not all the news is good. The overall power sector has not been adequately reducing emissions. Coal power actually grew by 9% last year as a result of increased demand for power during the rapid economic recovery in the easing of the pandemic shutdowns. A spike in natural gas prices made coal more cost-competitive.

In order for the power sector to do its part in keeping warming below 1.5 degrees, wind and solar power will need to provide 40% of the world’s power by 2030 and nearly 70% by 2050. Today, they supply only 10% of the world’s electricity.

With rising gas prices during Russia’s war with Ukraine, there is real danger of increased use of coal, threatening the gains made by renewable energy.

Nonetheless, a study published in Oxford Open Energy modeled various scenarios for the growth of renewable energy and found that it is feasible to meet climate goals. In order to achieve this, countries’ policies will need to stimulate significant increases in energy and resource efficiency and rapid deployment of low-carbon technologies, promote strong environmental actions, and encourage low population growth.

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Rapid Growth of Wind and Solar Could Help Limit Warming to 1.5 degrees C

Photo, posted October 11, 2011, courtesy of Michael Coghlan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar Canopies | Earth Wise

December 31, 2021 By EarthWise Leave a Comment

There are plenty of solar panels on residential rooftops but there are also increasing numbers of arrays of them on croplands, arid lands, and grasslands. Large solar arrays are mostly built in open spaces like these rather than in developed areas. The reason is that it is cheaper to build on undeveloped land than on rooftops or construct covered parking lots.

However, building on undeveloped land is not necessarily the smartest idea. Undeveloped land is a dwindling resource that is needed for many different things: growing food, sheltering wildlife, storing and purifying water, preventing erosion, and sequestering carbon.

Putting solar panels on parking lots has the appeal that they are abundant, close to electricity customers, and are on land that already has been stripped of much of its biological value.

Putting a solar canopy over a parking lot can produce large amounts of electricity and has the added benefit that it would provide shade for cars. For example, a typical Walmart supercenter might have a five-acre parking lot, which is enough to support a 3-megawatt solar array. If Walmart put solar canopies on all of its 3,500+ super centers, it would provide 11 gigawatts of solar power – as much as a dozen large coal-fired power plants.

Solar canopies are still pretty uncommon, but some examples are ones at four DC Metro rail stations, one at JFK Airport, and a large one at the Rutgers University Piscataway campus.

Building parking lot solar canopies is much more expensive than putting solar arrays on open space, but they do eventually pay for themselves. Despite active opposition by utility and fossil fuel interests, solar canopies may eventually be a common sight.

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Why Putting Solar Canopies on Parking Lots Is a Smart Green Move

Photo, posted January 10, 2020, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Possible Storage Breakthrough: Solar Energy | Earth Wise

January 10, 2020 By EarthWise 2 Comments

Solar energy is a nearly unlimited resource, but it is only available to us when the sun is shining. For solar power to provide for the majority of our energy needs, there needs to be a way to capture the energy from the sun, store it, and release it when we need it. There are many approaches to storing solar energy, but so far none have provided an ideal solution.

Scientists at the Chalmers Institute of Technology in Sweden have developed a way to harness solar energy and keep it in reserve so it can be released on demand in the form of heat—even decades after it was captured. Their solution combines several innovations, including an energy-trapping molecule, a storage system, and an energy-storing laminate for windows and textiles.

The energy-trapping molecule is made up of carbon, hydrogen, and nitrogen. When hit by sunlight, the molecule captures the sun’s energy and holds on to it until it is released as heat by a catalyst. The specialized storage unit is claimed to be able to store energy for decades. The transparent coating that the team developed also collects solar energy and releases heat. Using it would reduce the amount of electricity required for heating buildings.

So far, the team has concentrated on producing heat from stored solar energy. It is unclear whether the technology can be adapted to produce electricity, which would be even more valuable. In any event, the team does not yet have precise cost estimates for its technology, but there are no rare or expensive elements required, so the economics seem promising. There is much more work to be done, but this could be a very important technology for the world’s energy systems.

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An Energy Breakthrough Could Store Solar Power for Decades

Photo courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hydrogen From The Ocean

November 15, 2019 By EarthWise Leave a Comment

Hydrogen is frequently touted as an excellent source of clean energy that could be used as a fuel in vehicles, or as a storage medium for energy generated by wind and solar power. The challenge is that hydrogen is rather difficult and expensive to attain, and the most economical methods are not clean and green.

Most industrial hydrogen is produced by reforming natural gas, which has the drawback that carbon dioxide is generated in the process. The environmentally friendly way to produce hydrogen is via electrolysis, in which a chemical reaction is triggered by a catalyst enabling electricity to split water into its constituent elements of oxygen and hydrogen.

The best performing catalyst for electrolysis is platinum, but its high price is a big drawback for the economics of making hydrogen. Researchers at the Pacific Northwest National Laboratory have found a pairing of minerals that may solve the problem. Testing a molybdenum-phosphide catalyst with wastewater in a small reactor called a microbial electrolysis cell revealed that the new catalyst actually worked better than platinum.

Even better, the molybdenum-phosphide catalyst worked well with seawater. If hydrogen can be produced using seawater, there would be a pretty much unlimited resource for making it. By eliminating the use of platinum catalysts, it may be possible to reduce the cost of hydrogen made by electrolysis to a competitive level.

Hydrogen as a vehicle fuel currently costs about twice as much as gasoline on an energy-equivalent basis. Given that running cars from batteries is considerably cheaper than using gas, the cost of hydrogen needs to come down considerably for it to be a viable vehicle fuel.

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