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A Miracle Tree | Earth Wise

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The world needs to be fed without destroying the environment.   We need to grow more trees to store more carbon on earth and reduce the amount in the atmosphere.  But meanwhile, we decimate rainforests to produce palm oil and grow soybeans.

A startup company in California called Terviva thinks they have a solution.  It’s called pongamia, which is an ordinary looking tropical tree.  It produces beans packed with protein and oil, much like soybeans.  However, it has the potential to produce much more nutrition per acre than soybeans and it is hardy enough to grow on pretty much any kind of land without the use of pesticides, fertilizers, or irrigation.  In short, it is a miracle crop for a hot and hungry planet that is running out of fertile farmland and fresh water.

Pongamia is not a new or rare tree.  It is common in India but grows all over the world.  It is often planted as an ornamental here in the U.S.

The initial idea for making use of the hardy tree was to use its oil as a biofuel.  The seeds of pongamia are known to have a bitter taste and disagreeable odor, which is why the seeds or oil were never used for human or animal feed.  However, Terviva has developed a way to de-bitter pongamia oil.  Once this is done, it becomes a golden-colored substitute for olive oil. It also has enormous potential as a protein for plant-based milks and meats, since it contains all nine essential amino acids.

Terviva has raised more than $100 million to further develop pongamia and is now partnering with Danone, a $25 billion multinational food company, to develop pongamia as a climate-friendly, climate-resilient, non-GMO alternative to soy and palm oil.

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This super-tree could help feed the world and fight climate change

Photo, posted December 15, 2015, courtesy of Lauren Gutierrez via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Carbon Storage In Harvested Wood | Earth Wise

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Trees are an exceedingly important carbon sink on our planet.  For this reason, deforestation is a major contributor to climate change.  But when trees are harvested for wood products like lumber, much of the carbon in that wood continues to be stored.  Even when a wood product is discarded at the end of its useful life, it can keep storing carbon.

Over 90% of new single-family homes in the U.S. are built with wood.  Each year, about 400,000 homes, apartment buildings, and other housing units are lost to floods and other natural disasters.  Others fall apart from decay or are torn down to be replaced with newer structures.  Given how much carbon is stored in houses, it is important to understand what the future trajectory of residential structures will be.

A new study by the USDA Forest Service published in the journal PLOS ONE looks at the future of harvested wood products in residential structures.  According to the study, wood products in these structures will continue to increase the country’s carbon storage for the next 50 years. 

Even after residential structures reach the end of their useful life and much of the materials end up in landfills (which is typical in this country), the wood products do not immediately release their carbon.  It may take decades for that to happen.

The study looked at various scenarios for future home construction.  Although housing starts are projected to decline in the future, residential housing and the need to maintain existing structures are projected to continue to increase carbon storage in wood products for the next several decades.

The role of trees as a carbon sink does not end when they are harvested for their wood.

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Carbon Storage in Harvested Wood Products

Photo, posted January 27, 2022, courtesy of Luke McKernan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Importance Of Wildlife Crossings | Earth Wise

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Highway accidents involving animals are a big problem for both people and animals.  According to the National Highway Traffic Safety Administration, motorists in the United States kill one to two million large animals every year.  About 200 people are killed annually in the U.S. as a result of those collisions with animals.   

These crashes are expensive, too.  Deer-vehicle collisions cost an average of more than $8,000 each; elk-vehicle collisions cost about $25,000; and moose-vehicle collisions cost more than $44,000.

One solution that has been quite effective around the world in reducing car-animal collisions is wildlife overpasses and underpasses.  They are designed to help animals move in search of food and to escape predators and wildfires.  These traffic-spanning bridges and tunnels have been popular in Europe since the 1950s.  They look much like regular overpasses for cars but are decked out with native flora.  The underpasses, which assist shyer and smaller animals, are typically invisible to drivers.

According to a new economic analysis by researchers at Washington State University, wildlife crossings in Washington State save roughly $235,000 to $443,000 every year per structure. 

Wildlife crossing structures range in cost from $500,000 for a tunnel-like underpass to more than $6 million for a broad bridge.  There may soon be many more wildlife crossing structures across the country since $350 million was allotted in the federal Infrastructure Investment and Jobs Act signed into law in 2021.

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Wildlife crossings potentially save millions annually in Washington state

How wildlife bridges over highways make animals—and people—safer

Photo, posted March 24, 2017, courtesy of Jeffrey Beall via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Colorful Solar Panels | Earth Wise

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More and more buildings and public spaces are incorporating solar panels and not only just on rooftops.  Some buildings are incorporating power-generating structures all over their facades.

Using solar panels in this way puts some design constraints on buildings because solar panels are typically a deep black color.  This is because solar panels need to absorb light and making them any other color decreases their ability to do so and generate power.  But the problem is that people don’t necessarily want a black building.

One alternative to traditional solar panel design is to use structural sources of color that include microscopic shapes that only reflect specific light frequencies, like the scales on butterfly wings.  But this approach generally leads to iridescence – which might not be what is wanted – and is often quite expensive to implement.

A team of researchers at a university in Shanghai has now demonstrated a way to give solar panels color that is easy and inexpensive to apply and that does not reduce their ability to produce energy efficiently.

The technique involves spraying a thin layer of a material called a photonic glass onto the surface of solar cells.  The photonic glass is made of a thin, disorderly layer of dielectric microscopic zinc sulfide spheres.  Even though most light can pass through the photonic glass, certain colors are reflected back, depending on the sizes of the spheres.  By varying that size, the researchers created solar panels that were blue, green, or purple with only a very small drop in solar panel efficiency.

The solar panels made this way maintained their color and performance under durability testing.  With this new technology, there may soon be colorful solar panels on our buildings.

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Colorful solar panels could make the technology more attractive

Photo, posted December 15, 2021, courtesy of Pete via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Pacific Bluefin Tuna On The Rebound | Earth Wise

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The Pacific Bluefin Tuna is a commercially valuable species that is especially prized in Japan.  The fish is particularly valued for sashimi and sushi and large specimens have been known to fetch enormous prices at seafood auctions.

Aggressive fishing reduced the bluefin biomass through the late 1990s and 2000s to only a few percent of its potential unfished levels.  Beginning in 2011, The Western and Central Pacific Fisheries Commission began management measures that reduced the catch of smaller bluefin as well as limited the catch of larger bluefin.  The goal was to allow more fish to grow to maturity.  The Inter-American Tropical Tuna Commission adopted similar resolutions a year later.  Despite these efforts, increasing concern about declining bluefin levels led to a petition to list the species as endangered.  The National Oceanic and Atmospheric Administration’s Fisheries organization determined that while the population was near historical lows, the remaining 1.6 million fish was a sufficient number to avoid the risk of extinction and that the measures in place were sufficient.

A new assessment of the bluefin population has shown that the species is now increasing and includes many younger fish that will help accelerate its rebound.  The assessment by NOAA showed that the bluefin stock was greater than the first rebuilding target set for 2019. 

According to the NOAA Fisheries biologists that performed the assessment, the species has responded exactly as predicted given the actions that were taken.  The bluefin tuna is an amazingly resilient fish and it is continuing to demonstrate that fact.

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International Actions Pay Off For Pacific Bluefin Tuna as Species Rebounds at Accelerating Rate

Photo, posted June 1, 2022, courtesy of Philippe Yuan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Propane Refrigerants | Earth Wise

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About 10% of the world’s total electricity supply is used for air conditioning.  If current temperature trends continue, the energy demands for space cooling will more than triple by the year 2050.  Air conditioning is a double threat to the environment.  Apart from using lots of energy, ACs also make use of halogenated refrigerants that are extremely powerful greenhouse gases.

The most common space cooling appliances are split-air conditioners, which use an indoor unit and an outdoor unit connected by pipes.  These split ACS mostly utilize HCFC-22 and HFC-410 as refrigerants, which have global warming potential scores as high as 2,256 – meaning they trap 2,256 times more heat than carbon dioxide. 

A study by the International Institute of Applied Systems Analysis in Austria has shown that propane is a far better choice as an air conditioning refrigerant.  Its global warming potential is actually less than 1 meaning it traps less heat than carbon dioxide.  According to the study, if air conditioners switched to propane refrigerants, the world would avoid about a tenth of a degree Celsius of additional warming, which is a significant contribution to meeting the goals of the Paris climate agreement.

Propane-based split-ACs are already available commercially in China and India.  Elsewhere, many national regulations prohibit their use, primarily due to codes restricting the use of refrigerants with higher flammability.  Given the increasingly urgent need for climate action, it seems to be time to reconsider regulations on refrigerants.

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Propane — a solution for more sustainable air conditioning

Photo, posted March 24, 2021, courtesy of Phyxter Home Services via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Food For The Future | Earth Wise

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Researchers predict that climate change will negatively impact most staple food crops, including rice, corn, and soybeans.  Therefore, climate resilient food crops – those that are salt, drought, and heat resilient – will have an important role to play in global food security.  Examples of climate resilient crops include quinoa, kernza, amaranth, millet, and tepary beans.    

According to a new study by researchers from Northwestern University, breadfruit – a starchy tree fruit native to the Pacific Islands – will be relatively unaffected by climate change.  Because breadfruit is climate resilient and well-suited to grow in regions with high levels of food insecurity, the research team suggests breadfruit could be a part of the solution to global hunger.

While it has ”fruit” in its name, breadfruit is more like a potato.  It’s starchy and seedless, and is closely related to jackfruit.  Breadfruit is nutrient-rich, and high in fiber, vitamins, and minerals.  It can be steamed, roasted, fried, fermented, and even turned into flour.  People in tropical regions around the world have been eating breadfruit for thousands of years. 

In the study, which was recently published in the journal PLOS Climate, researchers determined the climate conditions necessary to cultivate breadfruit and then looked at how these conditions are predicted to change in the future.  They examined two future climate scenarios: one that reflects high greenhouse-gas emissions and another in which emissions stabilize.

In both scenarios, the regions suitable for breadfruit cultivation were mostly unaffected.  Additionally, the researchers identified new suitable land where breadfruit cultivation could expand.   

As the climate continues to change, breadfruit might soon be on a table near you.

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Climate-resilient breadfruit might be the food of the future

Photo, posted August 11, 2007, courtesy of Malcolm Manners via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Resurrecting The Tasmanian Tiger | Earth Wise

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Tasmanian tigers earned their nickname because of the stripes along their back, but they were not felines.  In fact, they were carnivorous marsupials, the type of Australian mammal that raises its young in a pouch.

Tasmanian tigers, also known as thylacines, were once native to the Australian mainland, as well as the islands of Tasmania and New Guinea.  Dog-like in appearance, Tasmanian tigers were extensively hunted after European colonization.  The last known Tasmanian tiger died in captivity in 1936.

Nearly 100 years after its extinction, the Tasmanian tiger may live once again.  Scientists in Australia and the United States have launched an ambitious multimillion dollar de-extinction project to genetically resurrect the Tasmanian tiger.

In order to bring back the animal, researchers will have to take stem cells from a living species with similar DNA – like the fat-tailed dunnart – and use gene editing techniques to turn them into “Tasmanian tiger” cells – or the closest approximation possible.  The team will need new assisted reproductive technologies to use the stem cells to make an embryo, which will then have to be transferred into an artificial womb or a dunnart surrogate to gestate.  The research team is optimistic that there could be a hybrid baby Tasmanian tiger in 10 years. 

The ambitious project is a partnership between scientists at the University of Melbourne and the Texas-based company Colossal Biosciences.  This is the second de-extinction undertaking by Colossal Biosciences, which announced last year it planned to use its technology to recreate the woolly mammoth, and return it to the Arctic tundra.

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Scientists want to resurrect the extinct Tasmanian tiger

Tasmanian tiger: Scientists hope to revive marsupial from extinction

Photo credit: E.J. Keller, from the Smithsonian Institution archives, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Pumped Hydro Storage In Switzerland | Earth Wise

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Pumped hydro energy storage is still by far the largest form of energy storage in the world, representing more than 90% of storage capacity worldwide.  The theory behind it is simple.  Water is pumped into an upper reservoir (that is, one at a higher elevation), and when electricity is needed, the water is allowed to flow downhill to power turbines and then is collected in a lower reservoir.   When there is excess electricity, it is used to pump water back uphill for use later.

Pumped hydro installations can’t be built just anywhere.  Geography and hydrology have to be suitable, which means high voltage transmission lines need to be constructed to link electricity sources like wind and solar farms with the storage location.  But in those situations where pumped hydro makes sense, it is a great solution to the energy storage problem.

Switzerland has just completed one of the largest pumped hydro facilities in the world.  The Nant de Drance installation makes use of the Emosson reservoir, which is an artificial lake built high in the Alps near the French border.  Over the past 14 years, 10 miles of tunnels have been dug into the mountains to connect the Emosson reservoir to the Vieux Emosson reservoir to the south.

In between the two reservoirs is a giant underground cavern where six of the largest water-driven turbines in the world are spun from the water rushing down from above.  The turbines have a capacity of 900 megawatts, making Nant de Drance one of the most powerful generating plants in Europe.  In terms of storage capacity, the installation has a maximum capacity of 20 gigawatt-hours, and can store that energy indefinitely, which is challenging for other storage technologies.

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14 Years In The Making, 20 GWh Pumped Hydro Storage Facility Comes To Switzerland (With Video)

Photo, posted September 7, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rewilding The American West | Earth Wise

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Oregon State University scientists have proposed a series of management changes for western federal lands aimed at re-establishing ecosystems there.  Their proposal would result in more gray wolves and beavers in nearly 200,000 square miles of federal lands in 11 states.

In each of those states, the researchers identified areas containing prime wolf habitat.  Gray wolves were hunted to near extinction in the West but have been gradually reintroduced in some areas starting in the 1990s.  Wolf restoration offers significant ecological benefits by helping to naturally control the population of grazing animals such as elk.  This in turn facilitates the regrowth of vegetation species such as aspen, which ultimately supports diverse plant and animal communities.

Beaver populations, which used to be robust across the West, declined roughly 90% after settler colonialism and are now nonexistent in many areas.  By felling trees and shrubs and constructing dams, beavers enrich fish habitat, increase water and settlement retention, maintain water flows during droughts, and increase carbon sequestration.

According to the researchers, the biggest threat to these western lands is livestock grazing, which has degraded ecosystems to a great extent.  They recommend the removal of grazing on about 30% of the federal lands being used for that purpose and instead would have rewilding efforts go on. 

The American West is going through a period of converging crises including extended drought and water scarcity, extreme heat waves, massive fires, and loss of biodiversity.  Rewilding is a way to reestablish long-standing ecosystems.

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More wolves, beavers needed as part of improving western United States habitats, scientists say

Photo, posted October 1, 2020, courtesy of Tina DaPuglet via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Death Valley Flooding | Earth Wise

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Furnace Creek in Death Valley is the driest place in North America.  Its average annual rainfall is under two inches.  On August 5th, a thousand-year rainfall event dropped 1.46 inches of rain – about three-quarters of a year’s precipitation.  The all-time record for a single day is 1.47 inches, set in April 1988.  The storm did break the record for the most rain ever recorded in August, which averages just over a tenth of an inch of rain for the entire month.

The flash flood washed debris over roads, swept away and buried cars, knocked a water facility offline, damaged buildings, and stranded about a thousand visitors and staff in Death Valley National Park. By the next day, the flood water had mostly receded, and stranded visitors could be escorted out of the park by National Park personnel.

Death Valley sits at 282 feet below sea level.  If it were not for the extremely arid climate there, Death Valley would likely be filled with water.  However, humid air masses traveling east from the Pacific Ocean have to cross four mountain ranges before they reach the desert valley.  Those air masses lose their moisture in the form of rain on the western slopes of the mountain, leaving a dry area, or rain shadow, on the eastern sides.  By the time the air masses reach Death Valley, they are bone dry.  On rare occasions, the lowest spot in the valley fills with water forming a wide, shallow lake, known as Lake Badwater. 

The extreme heat and aridity of Death Valley evaporates the temporary lake quickly, returning the valley to its usual state.  Furnace Creek still holds the record for the highest air temperature ever recorded:  134 degrees Fahrenheit.

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Death Valley Flash Flooding

Photo, posted April 7, 2021, courtesy of Matthew Dillon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Cheap Material For Carbon Capture | Earth Wise

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The recently passed Inflation Reduction Act includes significant support for carbon capture technologies. Eliminating fossil fuel burning is essential for halting climate change, but in the interim, methods for capturing emissions of carbon dioxide and either storing it or turning it into usable products are increasingly necessary.

There are a variety of techniques being developed for carbon capture but at this point, none of them are commercially viable.  The best technique in use today involves piping flue gases through chemicals called liquid amines, which bind CO2.  The process requires large amounts of energy to release the bound carbon dioxide so it can be concentrated and stored.  As a result, it is complicated and expensive.

Researchers at UC Berkeley, Stanford, and Texas A&M University have developed a carbon capture method using melamine, which is an inexpensive polymer used to make Formica, as well as low-cost dinnerware, industrial coatings, and other plastics.  Porous melamine itself adsorbs CO2 to a limited extent.  But the researchers discovered that adsorption could be much improved by adding the chemical DETA (diethylenetriamine) to bind the CO2.  In addition, adding cyanuric acid increased the melamine pore size and radically improved CO2 capture efficiency even more.

The result is a material that is more efficient even than exotic carbon capture materials like metalorganic frameworks and is much cheaper and easier to make. The researchers aim to design equipment that can used in industrial facilities, attached to buildings and other structures, or even to the tailpipes of gas-powered vehicles.

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A simple, cheap material for carbon capture, perhaps from tailpipes

Photo, posted June 10, 2006, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Plant-Based Foods And CO2 Emissions | Earth Wise

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We often hear how eating locally-sourced food is a way to minimize the carbon footprint of our diet.  But from a climate impact perspective, this only has a significant impact if transportation is responsible for a large portion of a food’s final carbon footprint.  In many cases, the greenhouse gas emissions related to transportation make up only a small portion of the total emissions from food, and what we eat is far more important.

In general, beef and lamb have the biggest climate footprint per gram of protein.  Plant-based foods tend to have the smallest impact. Pork and chicken are somewhere in the middle. 

According to new research, U.S. food production could reduce its agricultural carbon footprint between 2.5% and 13.5% by embracing plant-based alternatives to beef.  The study, from researchers at Cornell University, Johns Hopkins University, and international partners, found that most of the reduction would be achieved by decreasing the number of cows needed for beef production by two to twelve million animals.  The research was recently published in the journal Lancet Planetary Health.

However, the researchers also found that acting to reduce climate change in this manner could have unintended consequences.  For example, economic models from the research team show that the growth in popularity of plant-based beef could disrupt the agricultural workforce, threatening more than 1.5 million jobs. 

But in the big picture, doing nothing will cost much more than doing something to slow climate change.  Shifting diets away from meat and other animal products and towards more plant-based foods will help shrink carbon footprints and mitigate climate change.  It’s a win-win for the planet and for human health. 

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Plant-based ‘beef’ reduces CO2 but threatens ag jobs

Photo, posted November 27, 2018, courtesy of Sarah Stierch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Law To Tackle Climate Change | Earth Wise

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The Inflation Reduction Act signed into law in mid-August is the most comprehensive U.S. legislation addressing climate change ever enacted.   It contains $369 billion in funding for clean energy and electric vehicle tax breaks, domestic manufacturing of batteries and solar panels, and pollution reduction.

The legislation for the most part makes use of carrots rather than sticks to coax American consumers and industry away from reliance on fossil fuels.  Rather than establishing more carbon taxes, mandates, and penalties, the law largely makes use of tax credits to provide incentives for the use of clean energy.

The law provides a large mix of tax breaks intended to bring down the costs of solar, wind, batteries, electric cars, heat pumps, and other clean technology.  For example, consumers will get a $7,500 credit for purchasing many new electric car models and about $4,000 for buying a used vehicle.

On the stick side of the ledger, oil and gas companies that emit methane above certain threshold levels will incur fees that escalate over time.  The law also increases the cost to the oil industry for extracting fossil fuels from public lands.

The act provides $60 billion for overall environmental justice priorities, including $15 billion targeted specifically for low-income and disadvantaged communities. There are many other provisions in the law addressing multiple climate-related issues.

According to three separate analyses by economic modelers, the investments from the Inflation Reduction Act are likely to cut pollution by about 40% below 2005 levels by the year 2030.

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The US finally has a law to tackle climate change

Photo, posted December 15, 2021, courtesy of Mario Duran-Ortiz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Decreasing Forest Area Per Capita | Earth Wise

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Over the past 60 years, global forest area has decreased by 315,000 square miles, an area about twice the size of California. Combined with global population growth over that period, this has resulted in more than a 60% decline in global forest area per capita.

The continuous loss as well as degradation of forest affects the integrity of forest ecosystems and reduces their ability to generate and provide essential services and sustain biodiversity.  It impacts the lives of at least 1.6 billion people worldwide – primarily in developing countries – who depend upon forests in multiple ways.

According to the new study published in the journal Environmental Research Letters, forest losses have been occurring primarily in lower-income countries in the tropics while forest gains have occurred in higher-income countries in the mid-latitudes or extratropics. 

More than half of the world’s forest losses were in Brazil, home to the Amazon rainforest.  In the past 60 years, that country has had a net loss of 170,000 square miles of forest.  While most high-income countries had net forest gains, Canada actually had a net loss of about 11,000 square miles of forest.

Economic growth has a stronger association with net forest gain than with net forest loss.  Therefore, the study highlights the need to strengthen the support given to lower income countries, especially in the tropics, to help improve their capacity to minimize or curtail their forest losses.  To help address this ongoing displacement of forest losses to lower income countries, higher-income nations need to reduce their dependence on imported tropic forest products.

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New study finds global forest area per capita has decreased by over 60%

Photo, posted April 19, 2011, courtesy of ©2011CIAT/NeilPalmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar-Powered Desalination | Earth Wise

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About two-thirds of humanity is affected by water shortages.  In the developing world, many areas with water shortages also lack dependable sources of electricity.  Given this situation, there is widespread research on using solar heat to desalinate seawater.  To date, many approaches to this face problems with fouling of equipment with salt buildup.  Tackling this issue has proven to add complexity and expense to solar desalination techniques.

A team of researchers from MIT and China has recently developed a solution to the problem of salt accumulation that is more efficient than previous methods and is less expensive as well.

Previous attempts at solar desalination have relied on some sort of wick to draw saline water through the device.  These wicks are vulnerable to salt accumulation and are difficult to clean.  The MIT-Chinese team has developed a wick-free system instead.  It is a layered system with dark material at the top to absorb the sun’s heat, and then a thin layer of water that sits above a perforated layer of plastic material.  That layer sits atop a deep reservoir of salty water such as a tank or pond.  The researchers determined the optimal size for the holes in the perforated plastic.

The 2.5 millimeter holes are large enough to allow for convective circulation between the warmer upper layer of water above the perforated layer and the colder reservoir below.  That circulation naturally draws the salt from the thin layer above down into the much larger body of water below.

The system utilizes low-cost, easy to use materials.  The next step is to scale up the devices into a size that has practical applications.  According to the team, just a one-square-meter system could provide a family’s daily needs for drinking water.

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Solar-powered system offers a route to inexpensive desalination

Photo, posted February 13, 2017, courtesy of Jacob Vanderheyden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Some Good News For The Great Barrier Reef | Earth Wise

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It seems like there has been nothing but dire news from Australia’s Great Barrier Reef.  Earlier this year, there was yet another mass bleaching event – the fourth in seven years and the first ever to strike during a cooler La Niña phase in the Pacific.  But this bleaching event was less severe than other recent ones, which makes it possible for parts of the reef to bounce back.

In particular, in the northern and central stretches of the reef, scientists have recorded the most extensive coral cover seen in 36 years of study.  In areas where coral cover has expanded, it is mostly fast-growing Acropora corals driving the growth.  That isn’t the best outcome, given that Acropora are particularly vulnerable to strong waves, highly susceptible to bleaching, and are the preferred target of crown-of-thorns starfish.

Those creatures are a major problem for the Great Barrier Reef.  In contrast to the upper stretches of the reef, the southern third actually saw coral cover drop from 38 to 34 percent over the course of the past year.  Scientists blame the decline on an outbreak of crown-of-thorns starfish, which prey on corals.  The starfish grow faster and eat more in warmer, more acidic waters.   Carbon emissions are both raising ocean temperatures and turning waters more acidic.

The large increases in hard coral cover in the reef are certainly good news, but it is important to understand that they can be quickly negated by disturbance on reefs where Acropora corals predominate.  Warming temperatures and mass bleaching events continue to pose a critical threat to all reefs, especially when there are crown-of-thorns starfish outbreaks and increasing frequency of tropical cyclones.

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Parts of Great Barrier Reef See Most Extensive Coral Cover In 36 Years

Photo, posted July 15, 2019, courtesy of Kenneth Lu via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tepary Beans | Earth Wise

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Tepary beans are an ancient crop native to the northern part of Mexico and the southwestern part of the U.S..  They have been grown in those places by native peoples since pre-Columbian times.  They are still grown in Native American reservations in Arizona’s Sonoran Desert.  One can purchase them from some small farms in that region. 

What sets tepary beans apart from other beans is that they are among the most drought- and heat-tolerant legume crops in the world.  They can be grown without irrigation under conditions that are not viable for other crops.  They can be consumed by people like many other kinds of beans, and they can also provide forage for livestock with better nutrition content than many other plants.  They seem to be a very attractive option for a crop in the changing climate.  What is lacking, at present, is large supplies of tepary seeds to be planted.

Researchers at Texas A&M have been funded to bring tepary beans into modern cropping systems and diets.  The goal is to develop tepary bean cultivars with high biomass and yield that are still well-suited to drought and heat conditions.  Getting the beans to the point of widespread commercialization will take several years.  The end result should be of interest to pulse growers, seed industries, and food companies across the U.S.

Tepary beans are higher in fiber and protein than most other beans.  They come in several different colors, each of which has unique flavor and texture characteristics.  The white ones have a naturally sweet flavor.   The brown beans are slightly nutty in flavor and are similar to pinto beans.  If the Texas program is successful, we may all be eating tepary beans some day.

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Tepary Beans Offer Producers A Low-Input, Climate-Resilient Legume Alternative

Photo, posted August 25, 2017, courtesy of Katja Schulz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar Windows | Earth Wise

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Solar windows are an attractive idea.  It is very appealing to have the vertical surfaces on the outside of almost any building generate electricity.  The challenge is to have a transparent window be able to function as an efficient-enough solar panel.

Most conventional solar panels use silicon solar cell technology, which is not based on a transparent material.  Transparent solar cells use dye-sensitized technology, which has been the subject of research for decades but has yet to achieve widespread use.

Researchers at the University of Michigan have recently published work on a new process to manufacture solar windows that can be large (over six feet in each dimension) and efficient at electricity production.

The windows make use of dye-sensitized cells which are connected to lines of metal so small that they are invisible to the naked eye.  The individual cells are fairly small but the connection technology allows the construction of large windows.

The solar window has an efficiency of 7%, meaning 7% of incoming sunlight energy is converted to electricity.  The researchers believe that 10% efficiency should be attainable with their technology.  Conventional solar panels have efficiencies of 15% or more.

However, the goal is not necessarily to compete with silicon solar panels.  The real opportunity is to be able to generate electricity when rooftop solar is not practical or to produce additional electricity even when there is already a solar roof.

Going forward, the goals of solar window development are to increase efficiency and to reduce costs to where installing the windows is economically attractive.  Estimates are that the windows currently would cost about twice as much as a conventional window but would pay for the difference in two to six years depending on such things as the level of sun exposure.

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Inside Clean Energy: What’s Hotter than Solar Panels? Solar Windows.

Photo, posted April 17, 2017, courtesy of Shelby Bell via Flickr.

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The Great Salt Lake Is Disappearing | Earth Wise

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Utah’s Great Salt Lake is the largest saltwater lake in the western hemisphere.  According to data from the US Geological Survey, the surface water elevation of the Great Salt Lake has fallen to the lowest level since records began in the mid-1800s.  The average elevation is now 4,190 feet above sea level.   With this drop in water level, the surface area of the lake is little more than half of its historical size.  The lower water level has exposed about 700 square miles of previously submerged lakebed.

The lake now contains about a quarter of the volume of water that it did at its high point in 1987.  The precipitous drop in water is a result of water usage from the lake coupled with climate change-fueled drought.   Increased water demand is due to the rapidly growing population of metropolitan Salt Lake City.  Utah’s population is projected to increase by almost 50% by 2060.

The Great Salt Lake goes though seasonal cycles of water loss and replenishment.  Rain and snow generally refill its level.  However, because of the ongoing megadrought in the West, water evaporation and depletion continue to exceed the amount of water entering the lake.  The water levels are expected to further decrease until fall or early winter, when incoming water is expected to equal or exceed evaporation.

The decline of the Great Salt Lake is a serious threat to the economy, ecology, and people of northern Utah.  The lake generates snowpack, is a refuge for hundreds of migratory birds and other wildlife and generates millions of dollars in the economy through mineral extraction and tourism.

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Utah’s Great Salt Lake is disappearing

Photo, posted October 6, 2020, courtesy of Julie Girard via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)