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Return of the frogs

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The mountain yellow-legged frog is a species that lives in the mountains of Southern California.  It is listed as an endangered species for protection by the federal government.   Surveys 20 years ago determined that the frog’s population was declining and on a trajectory toward extinction.  The frogs are severely impacted by water pollution and are vulnerable to the effects of wildfires, floods, disease, and drought.

A collaboration headed by the Scripps Institution of Oceanography at UC San Diego along with the San Diego Zoo Wildlife Alliance, UCLA, and the Big Bear Alpine Zoo has been raising mountain yellow-legged frogs in captivity as part of a long-running recovery program with partners at multiple federal and California state agencies.

In August, more than 350 of the frogs were reintroduced into the wild in Southern California’s San Bernardino Mountains, one of the largest releases of the captive-raised frogs to date.  This represented the first species reintroduction by the Scripps Institution and an important milestone in its growing conservation work.

The frogs were transported in coolers to the mountains where a team then hiked the frogs to three sites along a lake within a protected reserve.  The frogs were microchipped with passive transponder tags that will allow researchers to identify individuals during future surveys.  This will enhance long-term monitoring and inform ongoing conservation efforts.

The goal of these efforts is to help to delist or at least downlist the endangered status of the frogs by enhancing the genetic diversity of both captive and wild populations, optimizing reintroduction efforts, and increasing wild frog populations.

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Hundreds of Mountain Yellow-legged Frogs Leap Back Into the Wild

Photo, posted April 27, 2011, courtesy of Rick Kuyper / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fighting fires with man-made wind

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Researchers at Ohio State University have developed a new portable tool that may help firefighters battle blazes more efficiently and with less risk.

Traditional firefighting methods include chemical foams – which are toxic – and the use of hydrants, which can strain water resources.  The recent fires in Southern California demonstrated the need for efficient fire suppression methods.  The new device works to suppress flames using conductive aerosols, which are small particles that can direct electricity.

The device uses vortex rings – small donut-shaped bands of air – that transform the aerosol particles into short pulses of wind that convert nearby oxygen into ozone.  This accelerated airflow generates rapid turbulence, which disrupts the natural combustion process and quickly extinguishes the target fire.

The device resembles a small bucket, attached to an arm brace.  Firefighters would aim the bucket toward the fire, and it would use bursts of compressed air to deliver aerosols in an electric arc to fight the fire.

Testing identified a coarse copper solution for the vortex ring material and simulations showed that the device would succeed in suppressing fires.  They then worked on optimizing the power and range of the device.

Depending on the size of the fire and number of firefighters, it is likely that several of the devices would be required in a real emergency.  According to the developers, the design of the vortex launcher is actually very simple and is very scalable.  The device is maneuverable in tight spaces and could be taken through doors and indoor environments.  Vortex rings can carry chemical payloads over longer distances than other methods, making firefighters safe by staying further from flames. 

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New device uses electrically assisted wind to fight fires

Photo, posted November 12, 2024, courtesy of the USDA Forest Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

California is the largest emitter of a little-known greenhouse gas

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California is a state known for its aggressive climate policies.  However, and rather ironically, California is also the nation’s greatest emitter of one little-known greenhouse gas: sulfuryl fluoride. 

Sulfuryl fluoride is one of the few treatments to rid buildings of drywood termites, a common regional pest that can be found in wooden structures.  Sulfuryl fluoride is also used at shipping ports to destroy pests before they can hitch a ride to another part of the world. 

But sulfuryl fluoride is also a greenhouse gas that’s several thousand times more effective than carbon dioxide at trapping heat in the atmosphere.    

According to a new study by researchers from Johns Hopkins University, as much as 17% of global emissions of this gas stem from the U.S., and the majority of those emissions can be traced back to just a few counties in Southern California.  In fact, the research team found 60-85% of sulfuryl fluoride emissions in the U.S. come from California, primarily Los Angeles, Orange, and San Diego counties. 

In the paper, which was recently published in the journal Communications Earth & Environment, the researchers attribute approximately 85% of the state’s sulfuryl fluoride emissions to structural fumigation.  Structural fumigation is the practice of sealing an infested structure, pumping this gas into it to kill pests, and then releasing the gas into the atmosphere.  The other 15% of emissions come from agricultural and commodities fumigation.  

Without some form of intervention, the research team warns that sulfuryl fluoride will continue to accumulate in the atmosphere, where it can linger for more than 40 years.

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Researcher sheds light on the main source of a rare but destructive greenhouse gas

California leads U.S. emissions of little-known greenhouse gas

It is very important to save nature in California and we happy that Michael / Armchair Builder via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Winegrowing regions and climate change

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Grapes grown to make wine are sensitive to climate conditions including temperatures and amount of rainfall.  The warming climate is already having visible effects on yields, grape composition, and the quality of wine.  This has significant consequences on the geography of wine production and is of major concern for the $350 billion global industry.

Winegrowing regions are mostly at the mid-latitudes where temperatures are warm enough to allow grapes to ripen but not excessively hot.  The climates are relatively dry so that fungal diseases are not rampant.

Because of the warming climate, harvesting in most vineyards now begins two or three weeks earlier than it did 40 years ago and this affects the grapes and the resultant wines.  Temperature changes affect acidity, wine alcohol, and aromatic signatures.

If global temperature rise crosses the 2-degree level, 90% of all traditional winegrowing areas throughout Spain, Italy, Greece, and southern California may become unable to produce high-quality wines.  Conversely, areas of northern France, the states of Washington and Oregon, British Columbia, and Tasmania will see improved conditions for producing quality wines. 

As the climate warms, winegrowers face new challenges such as the emergence of new diseases and pests as well as an increasing number of extreme weather events.  Wine producers are using more drought-resistant grape varieties and are adopting management methods that better preserve soil water.

The changing climate poses many threats to the quality of wines produced in traditional vineyards.  In the future, the wine industry may look very different in terms of where and how the best wines are produced. 

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A global map of how climate change is changing winegrowing regions

Photo, posted November 14, 2008, courtesy of Curtis Foreman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sponging up a river

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During the first week of February, an atmospheric river dumped enormous amounts of rain on Southern California.  Over the course of four days, Los Angeles received 9 inches of rain.  The average annual rainfall in the city is only 14 inches.

But Los Angeles was not the site of a flooding disaster because the city has spent years preparing for this type of deluge by becoming a “sponge city.”   By installing lots of green spaces and shallow basins with porous soil, Los Angeles was able to soak up 8.6 billion gallons of water during the storm, enough to meet the water needs of 100,000 people for a year.

Cities covered with impermeable concrete sidewalks and paved areas make storm-related flooding worse because they are unable to absorb water.  Instead, the water flows into drains and overwhelms infrastructure.

Natural materials like dirt and plants take in water from storms and can filter it into underground aquifer that cities can then tap into, especially during droughts.  Adding green spaces to cities has many other benefits beyond the ability to absorb large amounts of rainwater.

The so-called sponge-city movement is catching on in many other places.  Philadelphia is revamping its water systems in a 25-year project that includes green spaces to absorb stormwater runoff.  In China, the government has spent more than a decade adding spongy elements to dozens of cities around the country.

Sponge cities are part of a broader effort to combine modern engineering techniques with natural systems.  This is known as green-gray infrastructure.  Nature knows what it is doing when it comes to flood control as well as to pollution control.

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‘Spongy’ LA Soaked Up Tons of Water From Atmospheric River

Photo, posted December 28, 2011, courtesy of Ron Reiring via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

California Trees Are Dying | Earth Wise

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California relies on extensive forests to help reduce the amount of carbon dioxide entering the atmosphere.  But extensive drought and increasingly frequent wildfires have been reducing the state’s tree population for the past three decades.

A comprehensive study by a team of scientists from the University of California Irvine used satellite data to study vegetation changes between 1985 and 2021.  Across the entire state, tree cover area has declined 6.7% over that time period.  The results varied from region to region across the state.

Southern California exhibited the sharpest decline, where 14% of the tree population in local mountain ranges vanished, potentially permanently.  In the Sierra Nevada mountains, tree populations were relatively stable until about 2010.  After that, a severe drought followed by historically large wildfires resulted in a 8.8% die-off of trees.  The northern parts of the state, with higher rainfall and cooler temperatures, fared better, being able to more easily recover from wildfires.

The study goes beyond measuring the tree population of the state and its effects on carbon storage.  The data is also important for understanding how changes in forest cover affects water resources and fire behavior in the state.

The decline of trees in California is affecting the carbon storage abilities of the state.  The satellite survey showed that as the tree populations have dropped, the state’s coverage of shrubs and grasses has risen, possibly indicating that permanent ecosystem shifts are occurring.  The forces contributing to the decline of trees in California are not going away any time soon.  As a result, the threat to California’s ability to mitigate the effects of climate change continues to grow.

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UCI study: California’s trees are dying, and might not be coming back

Photo, posted March 24, 2016, courtesy of David Fulmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Alaskan Icemageddon | Earth Wise

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December saw some wild weather in Alaska.  A combination of record high temperatures and torrential rainstorms resulted in the coining of the term “Icemageddon” to describe what was going on with the weather.

Kodiak Island in southern Alaska saw a high temperature of 67 degrees on December 26, which was warmer than it was in Southern California that same day.  This set an all-time record for the warmest December day in Alaska.  Such a high temperature is amazing considering how little sunlight Alaska gets at this time of year.  And with warmer air comes wetter air, as the atmosphere is capable of holding more water vapor as temperatures increase.

As a result, that same day saw the interior of the state get an inch of rain in just a few hours, something that hadn’t happened for decades.  But then, when temperatures plummeted again, all that rainwater froze.

Huge sheets of ice blocked roads and choked traffic in Fairbanks, Alaska’s second largest city.  Indeed, it was the state’s transportation department that came up with the term icemageddon to describe the situation.

The extreme warmth in December is related to the same weather pattern that brought cold, wintry weather to the Pacific Northwest and Northern California.  Those weather conditions resulted in hundreds of cancelled flights in Seattle, where temperatures dropped into the 20s, and in massive amounts of snowfall in the Sierra Nevada mountains in California.  A strong area of high pressure anchored in the Northern Pacific resulted in a clockwise flow around it drawing warmer, more tropical air from the Pacific up to Alaska.

Climate change continues to push the envelope on what sort of weather is possible all over the world.

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Alaska faces ‘Icemageddon’ as temperatures swing wildly

Photo, posted April 30, 2015, courtesy of Naql via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Food Waste Back Into Food | Earth Wise

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Scientists at the University of California Riverside have discovered that fermented food waste can boost bacteria that increase crop growth, make plants more resistant to pathogens, and reduce the carbon emissions resulting from farming.

Food waste is a serious problem from multiple perspectives.  As much as 50% of food is thrown away in the United States and most of that simply ends up in landfills, taking up more than 20% of America’s landfill volume.  Food waste is a huge economic loss as well as a significant waste of freshwater resources used to produce food.

The researchers studied byproducts from two kinds of food waste readily available in Southern California:  beer mash – a byproduct of beer production – and mixed food waste discarded by grocery stores.

Both types of waste were fermented and then added to the irrigation system watering citrus plants in a greenhouse.  Within 24 hours, the average population of beneficial bacteria was two to three orders of magnitude greater than in plants that did not receive the treatments. This led to improvements in the carbon to nitrogen ratio in crops.  When there are enough so-called good bacteria in plants, they produce antimicrobial compounds and metabolites that help plants grow better and faster.

The results of the study suggest that the use of food waste products in agriculture is beneficial and could complement the use of synthetic chemical additives by farmers, perhaps eliminating it entirely.  Crops would in turn become less expensive.

Making use of food waste in agriculture is a step towards a more circular economy in which we use something and then find a new purpose for it.

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Turning food waste back into food

Photo, posted October 28, 2012, courtesy of Daniel Lobo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recovering Condors | Earth Wise

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The California condor is the largest North American land bird.  Its wingspan is nearly 10 feet and its weight of up to 26 pounds nearly equals that of the trumpet swan, the heaviest native North American bird.  California condors can live up to 60 years, making them among the world’s longest-living birds as well.  But California condors became extinct in the wild in 1987.

Lead poisoning is the primary threat to condors.  The birds are scavengers and feeding on the carcasses of dead animals that contain fragments of lead rifle ammunition is responsible for half of all condor deaths.

Condors historically occupied California’s Sierra Nevada mountains and were known to nest in the cavities of giant sequoia trees.  By 1982, the wild population was reduced to just 22 birds, and all of those were eventually trapped and brought into captivity to prevent extinction of the species.

A captive breeding program was undertaken at the Los Angeles Zoo and the San Diego Wild Animal Park.  With the success of that program, in 1992 the U.S. Fish and Wildlife Service began releasing condors back into the wild in the mountains of Los Padres National Forest in Southern California.  That flock has grown to about 100 birds through both wild reproduction and additional release of captive-bred birds.

The Southern California flock continues to expand its range with birds in 8 California counties and even in Arizona, Utah, and Baja California in Mexico.  The total wild population of condors is now estimated to be about 340 birds.  Recently, condors have been spotted in Sequoia National Park, a part of its historic range where the birds have been absent for nearly 50 years.

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California Condors Spotted in Sequoia National Park, First Time in Nearly Half a Century

Photo, posted May 20, 2005, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Trouble On The Colorado

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The 1450-mile-long Colorado River begins in the Rocky Mountains and wends its way to the Gulf of California, creating the Grand Canyon along the way, and providing water to some 40 million people.  The amount of Colorado River water promised to users is far more than actually flows between its banks, and that amount is dropping.

An unrelenting drought since 2000 has resulted in the water levels of the two largest reservoirs of Colorado River water – Lake Mead and Lake Powell – being at all-time lows.

Lake Mead, just outside of Las Vegas, is the reservoir of Hoover Dam, which provides power for millions of people in Southern California, Nevada, and Arizona.  The last time Lake Mead was full was in 1983.  It has slowly declined and now is 40% full.

If the lake level drops another 7 feet to 1075 feet above sea level, it will trigger a Tier 1 declaration, mandating cuts to water allocations to Arizona and other states.  If the level drops to 1050 feet, it would reach Tier 2 at which point Hoover Dam would have to stop generating electricity because water levels would be too low to flow through it.  If the lake level drops all the way to 895 feet, it would be below the level at which water can be piped out of it.  This is known as the “dead pool”.

These scenarios are no longer doomsday fantasies.  Water managers in the Southwest see the writing on the wall and are busy making contingency plans and developing ways to use less water from the Colorado River.  The booming city of Phoenix in particular is hard at work finding alternative ways to provide water for its millions of citizens.  On the Colorado, drought in the new normal.

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On the Water-Starved Colorado River, Drought Is the New Normal

Photo, posted October 24, 2016, courtesy of Sharon Mollerus 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...)