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Bitcoin Mining And The Environment | Earth Wise

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Bitcoin mining, the process by which the prominent cryptocurrency is created, is well-known to be energy intensive, but the environmental impact of it has not been extensively studied.  People have described Bitcoin as ‘digital gold.’  A new analysis by researchers at the University of New Mexico has found that Bitcoin mining shouldn’t be compared to gold mining.  It is more appropriately compared to the creation of much more energy-intensive products such as beef, natural gas, and crude oil.

Furthermore, the study found that rather than becoming more sustainable over time, Bitcoin mining is becoming dirtier and more damaging to the climate as long as it relies upon fossil-fuel generated electricity.  Estimates are that in 2020, Bitcoin mining used 75.4 terawatt hours of electricity, which is more electricity than the entire country of Austria, as well as 150 other nations around the world.

The study looked at the economic cost of the air pollution and carbon emissions associated with Bitcoin mining and found that in many instances, the negative economic impact of creating a single Bitcoin is more than what the resultant coin is worth.

Based on the market value of Bitcoins, the cost of climate damage for that value is a little less that that of electricity produced by natural gas and gasoline produced from crude oil, but actually more than that of beef production.

There are multiple cryptocurrencies.  Ether is one that voluntarily switched away from so-called proof-of-work mining.  Whether Bitcoin or others will act similarly absent potential regulation remains to be seen.  Until such time, Bitcoin mining remains an increasingly dirty and damaging business.

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Technology: UNM researchers find Bitcoin mining is environmentally unsustainable

Photo, posted May 11, 2017, courtesy of Komers Real via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Carbon Inequality | Earth Wise

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Everyone contributes to climate change through the generation of greenhouse gas emissions, but individual contributions vary greatly.   A study at the Paris School of Economics has determined that just 1 percent of the population is responsible for nearly a quarter of global carbon emissions growth since 1990.

The study estimated emissions from individuals’ consumption and their financial investments, and also from government spending in their country.  Individuals are responsible for carbon emissions as a result of their own activities, but they also bear their share of responsibility for the emissions of the firms that they own or invest in. 

In 2019, people living in sub-Saharan Africa produced an average of 1.8 tons of CO2 equivalent per capita.  In North America, the average per capita was more than 10 times higher.  Meanwhile, the top 10% of North America’s emitters produced more than 75 tons each.

From 1990 to 2019, the bottom 50% of emitters was responsible for just 16% of emissions growth, while the top 1% was responsible for 23%.  The top 0.1% saw emissions growth of 80%.

The inequality between rich and poor is driven more by inequality within countries than by inequality between countries.  This is particularly true for wealthy countries.  For example, over the study period, the top 1% saw their emissions grow by 26% while emissions actually declined 5-15% among low and middle earners even in wealthy nations.

Economic inequality drives a lot of the dynamics taking place within many countries around the world, and this even applies to pollution and greenhouse gas emissions.

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Global carbon inequality over 1990–2019

Photo, posted December 11, 2017, courtesy of Bernal Saborio via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Trees Are Growing Bigger | Earth Wise

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The alarming rate of carbon dioxide flowing into the atmosphere is having a real and actually positive effect on plant life. Higher concentrations of carbon dioxide make plants more productive because photosynthesis makes use of the sun’s energy to synthesize sugar out of carbon dioxide and water.  Plants make use of the sugar both as a source of energy and as the basic building block for growth.  When carbon dioxide levels go up, plants can take it up faster, supercharging the rate of photosynthesis.

In a new study published in the journal Nature Communications, scientists at Ohio State University found that trees are feasting on decades of carbon dioxide emissions and are growing bigger as a result. 

The researchers tracked wood volume in 10 different tree groups from 1997 to 2017 and found that all of them except aspens and birches grew larger.  Over that time period, carbon dioxide levels climbed from 363 parts per million to 405 parts per million.  According to the study, each 1% increase in lifetime CO2 exposure for trees has led to more than a 1% increase in wood volume.

In the big picture, the news isn’t so positive.  The global warming caused by increasing carbon dioxide levels increasingly threatens the forests of the world.  It has led to worsening droughts, insect infestations, and wildfires.  So overall, increasing levels of carbon dioxide are by no means a good thing for the world’s trees.  However, since trees are growing bigger more quickly, it means that planting them is an increasingly cost-effective method for fighting climate change because the same number of trees can sequester more carbon.

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As Carbon Dioxide Grows More Abundant, Trees Are Growing Bigger, Study Finds

Photo, posted September 12, 2015, courtesy of Nicholas A. Tonelli via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wildfire Smoke And Air Quality | Earth Wise

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According to a new study published by Stanford University, the average number of people in the U.S. exposed to unhealthy levels of airborne particulates at least one day a year has increased 27-fold over the last decade as a result of wildfires.

Millions of Americans are now routinely exposed to plumes of wildfire smoke that sometimes travel thousands of miles across the country.  Accumulations of deeply unhealthy air have emerged mainly in the West, where increasingly intense wildfires have become all too common.  Six of the seven largest wildfires in California recorded history have occurred since 2020.

Wildfire smoke has resulted in school closures, flight postponements, and even cancelled concerts.  Overall, the regression in air quality has undone much of the clean air progress that has taken place since the advent of the Clean Air Act in 1970.

Wildfire smoke has added about 5 micrograms of PM 2.5 particles per cubic meter of air on average in many places in the West.  This is a substantial increase from national levels, which are a total of about 10 micrograms per cubic meter and mostly result from emissions from cars, trucks, and power plants.

A decade ago, fewer than 500,000 Americans were exposed to any days of an air quality index of 100 or more due to smoke, which is a level that is deemed unhealthy.  In 2020, 25 million Americans were in areas with such levels at least one day during the year.

Ordinarily, if people don’t live near a highway or power plant, their air quality is likely to be pretty good.  But incursion from wildfire smoke is changing that, and the trend is likely to increase.

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Number of Americans Exposed to Harmful Wildfire Smoke Has Increased 27-Fold

Photo, posted August 19, 2013, courtesy of Mike Lewelling / National Park Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Bengal Water Machine | Earth Wise

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Over the past three decades, the owners of 16 million small farms in the Bengal Basin of Bangladesh have been pumping shallow groundwater during dry seasons to irrigate rice paddies.  By lowering groundwater levels in this way during the dry season, the ability of leakage from rivers, lakes, and ponds to replenish the groundwater was greatly enhanced.   Capturing surface water not only improved the recovery of groundwater levels but only helped to reduce flooding during monsoons.

The net result of this enormous collective groundwater pumping by millions of farmers has been the creation of vast natural reservoirs underground that are comparable to what is contained by many of the world’s largest dams.   This system of sustaining irrigation has transformed what was previously a famine-prone country into a food-secure nation.

The details of this remarkable transformation have been laid out in a study by University College London recently published in the journal Science.  According to the study, over the course of 30 years, more than 75 cubic kilometers of fresh water was captured by this process, which is equivalent to the combined reservoirs of China’s Three Gorges Dam and the Hoover Dam in the U.S.

The authors of the study described the water cycling process as “The Bengal Water Machine” and argue that it can be a sustainable alternative to conventional approaches to seasonal river flow storage for irrigation, which typically involve dams and reservoirs.  Such approaches are difficult to implement in densely populated alluvial plains where sand, silt, and clay are laid down by annual floodwaters. 

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Millions of farmers “replumb” world’s largest delta

Photo, posted February 2, 2010, courtesy of Melanie Ko via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Insects In A Changing Climate | Earth Wise

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Insects can be found in every environment on Earth and are critical components of many ecosystems.  They perform countless important functions, including aerating and fertilizing soil as well as pollinating flowers.  In fact, according to the USDA, 75% of the world’s flowering plants and about 35% of the world’s food crops depend on animal pollinators, the majority of which are insects, to reproduce.

According to a study published in the journal Nature earlier this year, the combination of climate change and intensive agriculture is having a profound impact on both the abundance and diversity of insects.  In regions where substantial warming had occurred and where land had been converted for intensive farming, insects were nearly 50% less abundant and more than 25% fewer species were observed.  Tropical regions were among those most at risk for heavy losses.

According to a new study recently published in the journal Global Change Biology, tropical insects will be even more susceptible to climate change than previously thought.  In a five-year study conducted in Peru, researchers from the Florida Museum of Natural History found that insect populations declined 50% following short periods of drought and following short periods of heavy rainfall.  Insect populations decreased after three months of dry weather, but also decreased after three months of exceptionally wet weather.   

Researchers have known that tropical insects don’t tend to do well when their habitats dry out.  But the researchers were surprised to discover that these insects were equally averse to increased precipitation.  Alarmingly, precipitation is expected to become more frequent and more intense as a consequence of the changing climate. 

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Tropical insects are extremely sensitive to changing climates

Photo, posted June 11, 2016, courtesy of Z. Leng via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Beavers As Climate Change Fighters | Earth Wise

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California is fighting the effects of climate change on multiple fronts.  The state has been grappling with relentless drought, record heat waves, and persistent wildfires.  The California Department of Fish and Wildlife is enlisting the help of beavers in its battle against climate change.

The state has created a beaver restoration unit charged with developing methods for nature-based restoration solutions involving beavers as well as artificial beaver dams. The agency plans to spend at least $3 million over the next two years to oversee a restoration program for the North American beaver.

A 2020 study showed that beaver-dammed corridors were relatively unharmed by wildfires compared with other areas that lacked beaver damming.  The study highlighted the differences between two adjacent corridors – one without a beaver population with a landscape scarred by a recent wildfire and another with beavers that remained a lush wetland after a fire.   The differences in burn severity, air temperature, humidity, and soil moisture between the beaver complex and the adjacent landscape were huge. 

From the 1920s through the 1950s, California actively exported beavers to other parts of the state and country so they could build dams in eroded areas where beaver dams could help evenly distribute water.  Now, the state wants to reintroduce beavers into watersheds where they once flourished.

The Department of Fish and Wildlife’s proposal to the California Legislature called beavers an important keystone species that can be used to combat climate change.   The state has spent enormous amounts of money on wildfire measures with minimal results.  Now they are going to see if beavers can make a difference.

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California says the beaver can be superhero in fighting climate change

Photo, posted September 19, 2021, courtesy of Larry Lamsa via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sinking Cities | Earth Wise

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Sea levels across the globe are rising as a result of the changing climate.  Two factors are largely responsible: the melting of ice sheets in the polar regions and the fact that as the oceans get warmer, the water in them expands.  

Estimates are that by 2050, there will be over 800 million people living in 570 cities that will be at risk from rising sea levels.   The rising waters can drown neighborhoods, put people’s lives at risk, and wreck entire economies.  Unless global emissions can be reduced sufficiently, sea levels will continue to rise.

A new study, published in the journal Nature Sustainability by Nanyang Technical University in Singapore in collaboration with the University of New Mexico, ETH Zurich, and NASA’s Jet Propulsion Lab, has focused on yet another aspect of the threat to coastal cities.  They have found that many densely populated coastal cities worldwide are even more vulnerable to sea level rise because much of their land is sinking. 

The researchers processed satellite images of 48 cities from 2014 to 2020 using a system called Interferometric Synthetic Aperture Radar.  They found that land subsidence varied on a neighborhood and even individual block level but across all the cities studied, there was a median sinking speed of 6/10” a year.  Some places had land that is sinking at 1.7” per year.  Meanwhile, the global mean sea-level rise is about .15” per year.

The increasing prevalence of industrial processes such as the extraction of groundwater, and oil and gas, along with the rapid construction of buildings and other urban infrastructure are leading to the sinking of the urban areas. 

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Rapid land sinking leaves global cities vulnerable to rising seas

Photo, posted October 24, 2015, courtesy of Jeffrey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Why Do Woodpeckers Peck? | Earth Wise

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Most of us have heard the sound of a woodpecker drumming on a nearby tree, or unfortunately, on the walls of our house where it can be very destructive.  We were often told that the birds were hunting for insects inside the wood, or perhaps trying to open up a nest. But a new study at Brown University has found evidence that woodpeckers are just additional musicians in the bird orchestra who happen to be percussionists.

The researchers studied the forebrains of birds and found characteristic gene expression specializations in songbirds.  Songbirds sing to communicate for various reasons – such as staking out territory or seeking mates.  The study looked at birds that are not known to sing, such as the emu, penguin, flamingo, and woodpeckers.  It turns out that among these, only woodpeckers had forebrains that anatomically resembled those of songbirds.  The study is the first time a neural basis has been identified for the communication activities of animals other than primates.

There are over 200 species of woodpeckers around the world and each species has its own characteristic drumming speed and rhythms.  Woodpecker drumming may well have evolved through a form of vocal learning, which is the way songbirds learn to make their own melodious sounds.  And like the calls of songbirds, these drumming patterns change depending on what the birds want to communicate and to whom.

So, the little downy woodpecker that is poking holes in your walls is probably not hunting for insects.  It is more likely to be telling another woodpecker to get out of its territory.

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Why do woodpeckers peck? New discovery about bird brains sheds light on intriguing question

Photo, posted June 15, 2021, courtesy of Tony Oldroyd via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

visit site by the doctor who prescribed the drug. Prescription. If the drug is sold in Russia without a prescription, it is necessary to make sure that the drug will also be sold abroad without it. You can find out in advance and, for example, write a letter to a specific pharmacy abroad, or you can be reinsured and ask to make a prescription form for the drug from your doctor.

Climate Change And The Color Of Lakes | Earth Wise

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According to a new study recently published in the journal Geophysical Research Letters, blue lakes around the world are at risk of turning green-brown if climate change continues unabated. 

For the study, the research team used over five million satellite images of more than 85,000 lakes and reservoirs around the globe between 2013 and 2020 in order to determine each lake’s most common water color.  Since lake color can change seasonally, the researchers assessed the most frequent lake color during those seven years. 

Algae and sediments affect the color of lakes.  But the study found that precipitation, air temperature, lake depth, and elevation also play major roles in determining a lake’s most common water color. 

The research team found that blue lakes account for less than one-third of lakes worldwide.  Blue lakes tend to be deeper and are often found in cool, high latitude regions with high precipitation and winter ice cover.  Meanwhile, green-brown lakes, which account for 69% of all lakes, are found in drier regions, continental interiors, and along coastlines. 

As global temperatures rise, lakes will warm, and warmer water produces more algal blooms.  As a result, the researchers expect the changing climate to decrease the percentage of blue lakes, many of which are found in the Rocky Mountains, northeastern Canada, northern Europe and New Zealand. 

Water color is a simple but viable way to measure water quality that can be done on a global scale using satellites.  This approach provides researchers with a way to study how lakes – even the remote ones – are changing.  

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Climate change is making lakes turn green-brown

Photo, posted August 27, 2011, courtesy of Paul Schultz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Decarbonizing Could Save Trillions | Earth Wise

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Scientists have long been calling for a transition to clean energy to prevent catastrophic impacts of climate change.  For much of that time, many people and, specifically, many of those in power, were skeptical of the need to do something about the warming climate.  But even as the facts about the changing climate became increasingly undeniable, there continued to be fears that the transition to clean energy sources would be unacceptably expensive and harmful to the economy.

A recent study published by Oxford University shows that the opposite is true:  a concerted effort to convert to green energy technologies such as solar, wind, and batteries, will save the world enormous amounts of money.

The Oxford study shows that a transition to nearly 100% clean energy by 2050 results in a lower-cost energy system that provides energy access to more people around the world.  The energy transition is expected to save the world at least $12 trillion compared to continuing our current levels of fossil fuel use.

The cost of renewable energy sources has been going down for decades and they are already cheaper than fossil fuels in many situations.  It is expected that they will become cheaper than fossil fuels across almost all applications over time.  Accelerating the transition will allow renewables to become cheaper faster.

The study made use of probabilistic models to estimate the costs of various possible future energy systems based on past data.  Even the most pessimistic models showed that scaling up green technologies is likely to drive their costs down so far that they will generate net cost savings and that the faster the transition goes, the more will be saved.  The result will be a cleaner, cheaper, more energy secure future.

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Decarbonising the energy system by 2050 could save trillions

Photo, posted July 12, 2010, courtesy of Tom Shockey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electrifying Delivery Vehicles | Earth Wise

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Most of the buzz about electric vehicles relates to passenger cars as the auto industry is making a major transition away from gasoline power.  Recently, pickup trucks have started to get some attention as well as Ford’s electric version of the F-150 truck has hit the streets and the long-awaited Tesla Cybertruck will be introduced next year.  There hasn’t been as much talk about delivery vehicles, but there should be.

There are about 15 million delivery vehicles in the U.S., and they are a significant contributor to greenhouse gas emissions.   The post office alone has a quarter million of them.  Such vehicles are especially attractive candidates for electrification.  Most travel relatively consistent and short routes, which makes it easier for companies to be able to charge them and keep them charged.

Electrifying delivery vehicles in cities is especially important because the vehicles travel into and through residential neighborhoods, spreading pollution and particulates as they go.

Some provisions of the Inflation Reduction Act provide credits for the purchase of commercial vehicles.  Light-duty vans and trucks qualify for a credit of as much as $7,500.  Medium- and heavy-duty trucks qualify for credits as high as $40,000.  In addition, substantial tax credits are available for the installation of charging equipment.

According to a study by the Rocky Mountain Institute, sixty percent of new truck sales could be electric by 2030.  By 2035, the trucking industry could cut its emissions in half.

American companies are already stepping up to the plate.  Amazon plans to deploy 100,000 electric delivery vehicles from new automaker Rivian.  Walmart, UPS, FedEx, and others have also committed to electrified trucks.

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The Climate Bill Will Electrify More Delivery Vans and Trucks

Photo, posted August 1, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Coping With Climate Change | Earth Wise

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Extreme weather events including prolonged drought and heavy rainfall are becoming more common and more severe as global temperatures rise.  As the climate continues to change in the coming decades, how will animals respond? 

Researchers from the University of Southern Denmark have examined how different mammals react to climate change. They analyzed data on population fluctuations from 157 mammal species around the world.  They compared these fluctuations with weather and climate data from the same time period.  The research team had 10 or more years of data for each species studied. 

The researchers found that mammals that live for a long time and/or produce less offspring –  like llamas, elephants, bears, and bison – are more climate resilient than small mammals with short lives — like mice, possums, lemmings, and rare marsupials. 

For example, large, long-lived mammals can invest their energy into one offspring, or simply wait for better times if conditions become challenging.  On the other hand, small, short-lived mammals like rodents have more extreme population changes in the short term. In the event of a prolonged drought, large portions of their food base may rapidly disappear, and they are left to starve because they have limited fat reserves.

However, the research team notes that the ability of a species to withstand climate change must not be the only factor when assessing a species’ vulnerability.  In fact, in many cases, habitat destruction, poaching, pollution, and invasive species pose a larger threat to animal species than climate change. 

While the study only examined 157 species, the findings enable researchers to also predict how animals they know less about will react to climate change.

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Which animals can best withstand climate change?

Photo, posted July 8, 2018, courtesy of Ray via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tracking Small-Scale Fishers | Earth Wise

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About half of all global seafood is caught by artisanal fishers.  These are individuals who operate on a small scale – often on a subsistence level – and typically fish only a short distance from shore.  Over 85% of the estimated 2.5 million motorized fishing vessels in the world are less than 12 meters in length.  Compared with large-scale commercial fishing operations, these enterprises are very small.  However, they are essential to the food security and livelihoods of their communities.   Because of their sheer numbers, artisanal fishers are an important sector to monitor, manage, and advocate for.  They may be small-scale, but their importance and impact are huge.

Large ships make use of vessel tracking systems, which were originally conceived to prevent maritime collisions.  Over time, VTS technology has become useful for other purposes including monitoring fishing activity in sensitive marine areas and looking out for forced labor on the high seas.

Among small fishing vessels, only an estimated 0.4% are equipped with VTS technology.  So, a massive number of vessels accounting for a big part of the global catch cannot be monitored.

Researchers at UC Santa Barbara surveyed hundreds of artisanal fishers in Indonesia and Mexico to see if they were willing to pay to participate in a VTS program, or participate for free, or be paid to participate.  Having the equipment would provide multiple benefits to the fishers including increased safety and better fisheries management.  Two-thirds of the survey participants said they were willing to pay for the technology.  The study is the first effort to explore the potential for encouraging wide adoption of VTS technology among artisanal fishers.

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Tracking Small-Scale Fishers

Photo, posted November 30, 2014, courtesy of Bernard Spragg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Timber Cities | Earth Wise

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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

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

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

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.

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