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Wildfires And Air Quality | Earth Wise

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People in the Northeast have been dealing with unhealthy air quality in recent times because of smoke from hundreds of wildfires in Canada.  Canada has experienced a much higher than average incidence of blazes this year with nearly 500 fires burning uncontrolled at times.

It turns out that states far away from Canada aren’t necessarily free from the impact of the fires.  Early in October, smoke from a wildfire burning in Quebec made its way south all the way down to Florida and created unhealthy air quality and reduced visibility across much of the state.  Smoke from the same fire had created hazy air in Boston, New York City, and parts of Connecticut before heading south.

It took a rather unusual set of atmospheric conditions to make this happen.  The smoke drifted from Canada into the western Atlantic.  From there, it got trapped behind a cold front and was then pushed south along the east coast until it finally moved inland across Florida. 

Wildfires produce a variety of particles and gases from the burning of vegetation such as organic carbon, black carbon, nitrogen oxides, carbon monoxide and hazardous air pollutants.  The mixture of particles and gases in wildfire smoke is associated with respiratory symptoms like shortness of breath and reduced lung function, as well as dangerous cardiovascular effects.

Smoke from increasingly frequent and increasingly large fires has started to undo decades of gains in air quality brought about by air pollution policies.  According to researchers, wildfires in the United States in recent years have undone about 25% of past progress in cleaning up air pollution in states from coast to coast.

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Wildfire Smoke From Canada Creates Unhealthy Air Quality in Florida

Photo, posted June 8, 2023, courtesy of Anthony Quintano via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Hottest Summer | Earth Wise

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It was a very rainy and relatively cool summer in much of New England as well as in New York’s Capital Region, where Earth Wise originates.  Despite that fact, according to NASA scientists, the summer of 2023 was the Earth’s hottest since global record keeping began in 1880.

The months of June, July, and August taken together were .41 degrees Fahrenheit warmer than any other summer on record as well as being 2.1 degrees warmer than the average summer between 1951 and 1980.

The record summer heat was marked by heatwaves in South America, Japan, Europe, and the US.  The heat exacerbated wildfires in Canada that dumped smoke across much of the northern tier of our country and also led to severe rainfall in Europe.  All sorts of temperature records were set in places across the globe.

According to NASA, exceptionally high sea surface temperatures, fueled in part by the reemergence of El Niño in the Pacific, were a major factor in the summer’s record warmth.

The record-breaking heat of this summer continues a long-term trend of warming.  Scientists around the world have been tracking the warming that is driven primarily by human-caused greenhouse gas emissions.  The combination of this background warming and the marine heatwaves set the stage for new temperature records.  The El Niño was enough to tip the scales. 

In the current environment, heat waves will last longer, be hotter, and be more punishing.  The atmosphere can hold more water producing hot and humid conditions that are harder for the human body to endure.

Scientists are expecting the biggest impacts of El Niño in the early parts of next year.  We can expect to see extreme weather of many kinds over the next year.

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NASA Announces Summer 2023 Hottest on Record

Photo, posted June 8, 2023, courtesy of Anthony Quintano via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Why Was the Summer So Hot? | Earth Wise

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Many places around the world have experienced extraordinary heat waves this summer.  The 31 days of high temperatures 110 degrees or more in Phoenix is a prime example but many other places suffered from extreme and relentless heat.  Why did this happen?

The overarching reason is climate change, which has warmed the Earth by 2.2 degrees Fahrenheit since the preindustrial era.  This change on a global level is enough to make heatwaves far more likely.  For example, the concurrent heatwaves in Europe and North America were 1000 times more likely to have occurred because of climate change.

But there hasn’t been a sudden increase in global temperature that would make this summer so much hotter.  Instead, what really has happened is three other factors all came into play at the same time.

The first is the 2022 eruption of Hunga Tonga-Hunga Ha-apai, which is an underwater volcano in the South Pacific.  That eruption did not produce much in the way of planet-cooling aerosols in the atmosphere.  Instead, it vaporized huge amounts of seawater, sending water vapor into the atmosphere, which helps trap heat.

The second is a change in the amount of energy radiating from the sun.  That actually rises and falls a small amount every 11 years.  Currently, it is in the upswing and will reach its next peak in 2025.

Finally, there is the arrival of the El Niño in the Pacific, whose balmy ocean waters radiate heat into the air.

The combination of all these factors when added to the already warming climate is a recipe for temperatures to soar to uncharted highs.  We can expect more heat waves, forest fires, flash floods, and other sorts of extreme weather.

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It’s Not Just Climate Change: Three Other Factors Driving This Summer’s Extreme Heat

Photo, posted February 27, 2017, courtesy of Giuseppe Milo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wildfire Smoke And Global Weather | Earth Wise

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In 2019 and 2020, wildfires burned 72,000 square miles in Australia, roughly the same area as the entire country of Syria. During the nine months when the fires raged, persistent and widespread plumes of smoke filled the atmosphere.

These aerosols brightened a vast area of clouds above the subtropical Pacific Ocean.  Beneath these clouds, the surface of the ocean and the atmosphere cooled.  The effect of this was an unexpected and long-lasting cool phase of the Pacific’s La Niña-El Niño cycle.

A new modeling study by the National Center for Atmospheric Research in Boulder, Colorado quantified the extent to which aerosols from the Australian wildfires made clouds over the tropical Pacific reflect more sunlight back towards space.  The resultant cooling shifted the cloud and rain belt known as the Intertropical Convergence Zone northward.  These effects may have helped trigger the unusual three-year-long La Niña, which lasted from late 2019 through 2022.

The impacts of that La Niña included intensifying drought and famine in Eastern Africa and priming the Atlantic Ocean for hurricanes.  2020 was the most active tropical storm season on record, with 31 storm systems, including 11 that made landfall in the U.S.

The study highlights widespread multi-year climate impacts caused by an unprecedented wildfire season.  The wildfires set off a chain of events that influenced weather far from where the fires occurred.  In the future, climate experts will need to include the potential effects of wildfires in their forecasts.

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How Wildfire Smoke from Australia Affected Climate Events Around the World

Photo, posted December 19, 2019, courtesy of Simon Rumi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Europe Is Warming Faster Than The Rest Of The Planet | Earth Wise

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A new study by researchers at Stockholm University has found that the warming during the summer months in Europe has been much faster than the global average.  The findings, published in the Journal of Geophysical Research Atmospheres, are that the climate across the European continent has become drier, particularly in southern Europe, leading to worse heat waves and an increased risk of fires.

Warming over land areas occurs much faster than over oceans.  The global average warming to date is 1.6 degrees Celsius over land and 0.9 degrees over oceans.   This means that the global emissions budget to keep warming below 1.5 degrees has already been used up over land.  The new study in fact shows that the emissions budget to avoid 2 degrees of warming has already been exceeded over large parts of Europe during the summer half-year (April to September).

This accelerated warming in Europe has led to more frequent heat waves.  These, in turn, increase the risk of fires, such as the devastating fires in southern Europe this past summer.

Southern Europe has been experiencing a positive feedback situation in which the ongoing warming has been amplified because of drier soil and decreased evaporation.  Added to that, there has been less cloud coverage over large parts of Europe, probably as a result of less water vapor in the air.

The study also looked at the impact of aerosol particles on temperatures in Europe.  As the amount of relatively short-lived aerosol particles has decreased with the reduction of coal-fired power plants, the temporary cooling effects of those particles partially masking the underlying warming trend have diminished.  In contrast, carbon dioxide emissions stay in the atmosphere for centuries.

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Large parts of Europe are warming twice as fast as the planet on average

Photo, posted April 18, 2020, courtesy of Roman Ranniew via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Saving Giant Sequoias | Earth Wise

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Last year, the KNP Complex Fire burning in Sequoia National Park drew global attention as the General Sherman, the world’s largest tree, was wrapped in tinfoil-like material in order to repel the flames from the fire.  Hundreds of firefighters labored for weeks trying to save giant redwood trees.  Despite these efforts, the U.S. Forest Service estimates that wildfires killed 13% to 19% of the world’s giant sequoias in 2020 and 2021.

This past July, the Washburn Fire burned through part of Yosemite’s Mariposa Grove and the giant sequoias there were surrounded by automated sprinklers trying to shelter them from the flames.

For a century, government agencies have worked to extinguish all natural wildfires and prohibited Native people in the region from lighting the fires they traditionally used to manage their lands.  As a result, forests have grown far thicker with trees that can fuel fires.  The Sierras are now home to more than three times as many trees as when they were managed by indigenous communities.  But more than 100 million of those trees had died by 2016 because of drought.

Add to this massive amount of kindling the effects of climate change – a hotter and drier environment – and there is the perfect storm for megafires among the giant sequoias.

There is federal legislation pending that would provide resources for prescribed burning and other forms of active forest management.  It is controversial.  It has attracted support from the Nature Conservancy, the Save The Redwoods League, and others, but also opposition from more than 80 environmental groups.

What is not controversial is that the Giant Sequoias are in the midst of a crisis and urgent action is needed.

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In California, a Race to Save the World’s Largest Trees From Megafires

Photo, posted December 10, 2014, courtesy of Laura Camp via 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.

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 Wildfires | Earth Wise

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Alaska is on a pace for a record fire season this year.  As of mid-July, more than 2.7 million acres had burned, which is more than 10 times the total area burned in all of 2021.

Alaskan fires have been spurred on by warm temperatures, a diminished snowpack, and an unusually large number of lightning strikes.  May was one of the warmest and driest on record leading to lots of fires in June.  More than 300 wildfires ignited during June.  Many were sparked by nearly 5,000 lightning strikes early in the month.

There have already been some very large fires, including the East Fork Fire, near the Yukon Delta which had burned more than 250,000 acres by the beginning of July, and the Lime Complex Fire, in the southwest part of the state, which had burned more than 865,000 acres by mid-July.

The all-time record fire season in Alaska was 2004, when more than 6 million acres went up in flames.   Wildfires are a natural part of the Boreal North ecosystem: the great northern forest region.  But the fires occurring now are very different from those of a century ago and more.   The combination of more fuel in the form of dry vegetation, more lightning strikes, higher temperatures, and lower humidity leads to fires that burn hotter and burn deeper into the ground.  Such fires don’t just scorch trees and burn the undergrowth.  They consume everything leaving a barren landscape of ash.  Million-acre fires occur more than twice as often as they did before 1990.

The state may set a new record for wildfire acreage before the season is over.  Nearly 6,000 firefighters and support personnel continue to battle blazes across the state.

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Alaska Is on Track for a Record Fire Season

Photo, posted June 18, 2022, courtesy of Ryan McPherson/BLM Alaska Fire Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fires Are Larger And More Frequent | Earth Wise

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According to a new study by the University of Colorado Boulder, wildfires have gotten much larger and much more frequent across the United States since the year 2000.  The rise in wildfires in recent years has been attributed to the changing climate and the new research shows that large fires have become more common and have been spreading into new areas that previously did not burn.

The researchers analyzed data from over 28,000 fires that occurred between 1984 and 2018 using satellite imagery along with detailed state and federal fire history records.

The results are that there were more fires across all regions of the contiguous U.S. from 2005 to 2018 compared to the previous 20 years.  In the West and East, fire frequency doubled, and in the Great Plains, fire frequency quadrupled.  The amount of land burned each year at least tripled in those regions.

The team discovered that the size of fire-prone areas increased in all regions of the contiguous U.S. in the 2000s, meaning that the distance between individual fires has been getting smaller than it was in previous decades and the fires have been spreading into areas that did not burn in the past.

This comprehensive study confirms what has been assumed by the media, public, and firefighting officials.  The results also align with increasing risk trends such as the growing development of natural hazard zones. Projected changes in climate, fuel, and ignitions suggest that there will be more and larger fires in the future.  More large fires plus intensifying development mean that the worst fire disasters are still to come.

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U.S. Fires Four Times Larger, Three Times More Frequent Since 2000

Photo, posted May 3, 2013, courtesy of Daria Devyatkina via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fire And Ice | Earth Wise

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In recent years, there have been countless stories about the effects of the changing climate.  Many of those stories have been about the dwindling sea ice in the Arctic and many others have been about the worsening wildfires in the western United States.   According to a recent study published by the Pacific Northwest National Laboratory, those two things are very much related.

As sea ice in the Arctic melts from July to October, sunlight warms the surrounding land and sea surfaces.  The resulting differences in air pressure create and strengthens a vortex in the atmosphere above the heated area which spins counterclockwise like a cyclone.

The powerful vortex pushes the polar jet stream out of its typical pattern and diverts moist air away from the western United States.  With the jet stream moved off its usual course, a second vortex, this time spinning clockwise, forms under the ridge of the polar jet stream above the Western U.S.  This second vortex brings with it clear skies and dry conditions:  fire-favorable weather.

Arctic sea ice has continually declined at least since the late 1970s.  It is predicted that there will be periods of entirely iceless Arctic waters before the 2050s.  In turn, conditions in the already fire-ravaged West are likely to be further exacerbated.  More than three million acres have burned across California alone during the 2021 wildfire season.

Climate conditions in one part of the world can, over time, influence climate outcomes thousands of miles away.  The research at Pacific Northwest Laboratory reveals how regional land and sea surface warming caused by Arctic ice melting can trigger hotter and drier conditions in the West later in the year.

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Fire and Ice: The Puzzling Link Between Western Wildfires and Arctic Sea Ice

Photo, posted July 28, 2018, courtesy of Bob Dass via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solid State Batteries For Cars | Earth Wise

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Today’s electric cars run on lithium-ion batteries, the same sort that power our phones, computers, and many other consumer electronic devices.  These batteries are far superior to the batteries of the past, offering long-life, high-energy density, and recyclable components.

Lithium-ion batteries do have their drawbacks.  They may be lighter than older battery technologies, but because the electrolytes in the batteries are liquid, they are still fairly heavy.  The huge number of them in an electric car adds up to a considerable amount of weight.  In addition, the flammability of the electrolytes can lead to explosions or fires if the batteries are damaged or exposed to extreme temperatures.

Solid-state batteries are an alternative technology that contain a solid electrolyte.  Such batteries are lighter, have higher energy density, offer more range, and recharge much more quickly than lithium-ion batteries. They have been used for years in some small devices like cardiac pacemakers, RFIDs, and some wearable devices.

For all these benefits, scaling up production to the level needed to be used in cars is an expensive and challenging endeavor.  The hope is that with sufficient effort, the result will be smaller, lighter battery packs for cars that can be charged in minutes and provide extended range.

Nissan Motor Company has recently announced that it is investing $17.6 billion over the next five years towards developing solid-state batteries for cars.  No doubt other companies will also be working on the technology.

Lithium-ion batteries have proven to be quite practical for powering vehicles.  But if solid-state batteries can meet the challenges of scaled up production, the lithium-ion era might end up being a relatively brief one.

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Nissan to Spend $18 Billion Developing a Cheaper, More Powerful EV Battery

Photo, posted November 13, 2018, courtesy of FirstEnergy Corp via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildfires And Giant Sequoias

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Two massive California wildfires that erupted during a lightning storm on September 9 have continued to threaten groves of giant sequoia trees in the southern Sierra Nevada mountains.  As of the beginning of October, flames from the KNP Complex fire had burned in or passed through 11 sequoia groves, including the famed Giant Forest in Sequoia National Park.

Hundreds of firefighters battled to protect some of the most renowned trees, including the 275-foot-tall General Sherman tree, widely considered to be the largest tree on earth by overall volume.  That tree and many near it are over 2,000 years old.

Firefighters wrapped the base of the General Sherman and several other trees with fire-resistant blankets to protect them from the intense heat of approaching fires.  Sequoias are actually well-adapted to fires because of their thick bark that protects them from heat.  But intense fires like the KNP Complex and Windy fires are more than the trees can handle.

As of the beginning of October, both fires continue to blaze, but thanks to the efforts of firefighters, most of the giant sequoias have survived.  One massive tree in the Giant Forest recently toppled over after burning for several days, but most are still standing and haven’t suffered serious damage.

As of early October, the two fires had blackened over 140,000 acres across national parks, national forests, the Tule River Indian Reservation, and local communities.  These two are among multiple wildfires burning in California this past summer.  The largest – the Dixie fire – has burned nearly a million acres as of early October.  In total, over 2.5 million acres have already burned in California this year.

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KNP Complex fire triggers flurry of new evacuations, as flames threaten more giant sequoia trees

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Hundreds of California firefighters battle to protect ancient sequoia groves from raging wildfires – with world’s largest tree General Sherman wrapped in aluminum foil blanket

Photo, posted November 5, 2017, courtesy of Ken Lund via Flickr.

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Wildfires And The Climate | Earth Wise

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Scientists from the National Center for Atmospheric Research recently published a study analyzing the events that influenced the world’s climate in 2020.  Among these were the pandemic-related lockdowns that reduced emissions and resulted in clearer air in many of the world’s cities.

While this was a significant event, the study found that something entirely different had a more immediate effect on global climate:  the enormous bushfires that burned in Australia from late 2019 to 2020, producing plumes of smoke that reached the stratosphere and circled much of the southern hemisphere.

Those fires sprung up in September 2019 and lasted until March 2020.  The fires burned more than 46 million acres (about 72,000 square miles), which is roughly the same area as the entire country of Syria.  Thousands of homes and other buildings were lost.

Major fires inject so many sulfates and other particles into the atmosphere that they can disrupt the climate system, push tropical thunderstorms northward from the equator, and potentially influence the periodic warming and cooling of tropical Pacific Ocean waters known as El Nino and La Nina.

According to the study, the COVID-19 lockdowns actually had a slight warming influence on global climate, as a result of clearer skies enabling more heat to reach the earth’s surface.  In contrast, the Australian bushfires cooled the Southern Hemisphere because the atmospheric particles reflected some of the incoming solar radiation back to space.

This summer, there have been raging wildfires in the western US and Canada, which have affected air quality in many parts of the nation and have been a serious health hazard.  Undoubtedly, these fires are influencing the climate system as well in ways that we are still trying to understand.

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Bushfires, not pandemic lockdowns, had biggest impact on global climate in 2020

Photo, posted January 18, 2020, courtesy of BLM-Idaho via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wine And Wildfire Smoke | Earth Wise

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Rising global temperatures have made droughts and heatwaves more common and intense, leading to larger and more destructive wildfires.   In 2020, wildfires in California blackened more than 4 million acres, the largest wildfire season on record.   With its continuing drought, California has already had 1.5 million acres burned by wildfires this year, and the fires continue.

Wildfires can cause extensive damage throughout the agricultural industry by destroying crops and killing livestock.  But the fires can have a unique effect on the wine industry:  wine grapes can be affected by smoke taint.

Vineyards have demonstrated themselves to be good fire breaks.  They definitely help prevent the movement of wildfires.  But there is no way to stop smoke from the fires from drifting into vineyards.  By far, the damage caused by smoke far outweighs direct losses from fires in vineyards.

Winemakers sometimes add subtle smoky notes to their vintages by aging them in toasted oak barrels.   But wildfire smoke permeating vineyards – even from distant blazes – can end up making wines undrinkable.  Smoke-tainted wines end up having unpleasant aromas that people describe as being like disinfectants or burnt rubber. 

With wildfires an increasingly persistent presence in California, the state’s $43 billion wine industry is facing a major challenge.  An estimated 165,000 to 325,000 tons of California wine grapes went unharvested last year, adding up to more than $600 million in losses from fire and smoke.  The industry will need to figure out ways to detect and manage smoke taint as the problem isn’t going to go away.

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Wildfire Smoke: An Emerging Threat to West Coast Wines

Photo, posted July 25, 2021, courtesy of Felton Davis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Overwintering Fires | Earth Wise

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Fires that go on for long periods of time, surviving the snow and rain of winter to reemerge in the spring, are becoming more common in high northern latitudes as the climate warms.  Such fires are called holdover fires, hibernating fires, overwintering fires, or even zombie fires.  Whatever people choose to call them, this type of wildfire is occurring more often.

These smoldering fires start out as flaming fires but then enter an energy-saver mode.  They start above ground but then smolder in the soil or under tree roots through the winter.  They barely survive based on the oxygen and fuel resources that they have but can transition back into flaming fires once conditions are more favorable.

Dutch researchers used ground-based data with fire detection data from NASA’s Moderate Resolution Imaging Spectroradiometer instruments on the Terra and Aqua satellites to study fires in the boreal forests of Alaska and Canada’s Northwest Territories.  They found a way to identify overwintering fires based on their unique characteristics.  

Their data indicates that overwintering fires tend to be linked to high summer temperatures and large fire seasons.  Between 2002 and 2018, overwintering fires generally accounted for a small amount of the total burned area in the region but in individual years with hot and severe fire seasons, the number can escalate.  In 2008 in Alaska, for example, overwintering fires accounted for nearly 40% of the burned area.

Early detection of these overwintering fires could help with fire management and reduce the amount of carbon – which is stored in large amounts in the region’s organic soils – that gets released to the atmosphere during fires.

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Overwintering Fires on the Rise

Photo, posted September 14, 2017, courtesy of Andrew R. Mitchell/USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Dangerous Fire Season | Earth Wise

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The western United States is entering the fire season under much worse drought conditions than last year.  Last year, 15,800 square miles burned in the U.S., mostly in the West.

The western U.S. is in the midst of a 20-year mega-drought.  Rainfall in the Rocky Mountains and farther west was the second lowest on record this April.  The soil in the western half of the country is the driest it has been since 1895.

The situation is particularly bad in California and the Southwest.  In March, less than a third of California was experiencing extreme or exceptional drought.  Now, 73% of the state is.  A year ago, a record-breaking fire season burned 4% of the state and, at that time, only 3% of California was in a state of extreme drought.

A year ago, no parts of Arizona, Nevada, or Utah were in extreme or exceptional drought.  Now, more than 90% of Utah, 86% of Arizona, and 75% of Nevada face severe drought conditions.  At this time last year, only 4% of New Mexico faced extreme drought but 77% does now.

These extreme drought conditions, which are believed to be linked to climate change, are causing increased tree mortality among many species, ranging from junipers in the Southwest even to drought-tolerant blue oaks in the San Francisco Bay Area.

Conditions are extremely ripe for a lot of forest fire this year.  Last year was a terrible year for wildfires in the West and we are heading into a fire season with much drier fuels than there were last year.  The risks of great damage from wildfires are higher than ever.

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US West Enters Fire Season Facing Extremely Dry Conditions

Photo, posted September 18, 2020, courtesy of USFS/National Interagency Fire Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving The Giant Sequoia | Earth Wise

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Giant sequoia trees are some of the most remarkable living things on earth.  They can live up to 3,000 years.  The tallest specimens tower over 300 feet, but it is their girth that really sets them apart.  They are usually 20 feet in diameter, and some are up to 35 feet across at the widest.  The largest tree in the world by volume is the General Sherman tree, which has a volume of 52,508 cubic feet. At 2,100 years old, it weighs 2.7 million pounds and is not only the largest living tree, but also the largest living organism by volume on the planet.

Giant sequoias are incredibly hardy.  To have survived thousands of years, the oldest of these trees have endured hungry animals, diseases, fires, snowstorms, El Niño events, years-long droughts, and the efforts of loggers during the 19th and 20th centuries.

In February, unusually high winds knocked down 15 giant sequoias in Yosemite National Park.  While sequoias are amazingly adapted to their narrow range in California’s Western Sierras, it appears as though climate change is altering their habitat faster than the species can migrate or adapt.  Shorter cold seasons have meant more rain instead of snow, leading to floods and mudslides in the winter.  Fires are more likely with less snowpack.  Hotter, drier summers put sequoias under greater stress.

Forest managers work to preserve existing groves through fire mitigation, supplementary water, and careful stewardship of young trees in existing groves.  If these efforts are successful through the ensuing decades, climate change may be just one more thing the sequoias outlasted.  But at least some conservationists are now considering planting a new generation of sequoias in colder, nearby habitats. 

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To Save Giant Sequoia Trees, Maybe It’s Time to Plant Backups

Photo, posted June 8, 2008, courtesy of Joi Ito via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Air Pollution Reduction And Global Warming | Earth Wise

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The world is dealing with two serious problems affecting the atmosphere:  the growing levels of carbon dioxide leading to a warming climate and the effects of air pollution on human health.  It turns out that these two things are connected in complicated ways.

Countries around the world are racing to mitigate global warming by limiting carbon dioxide emissions.   The combustion of fossil fuels as well as wood and other biomass produces sulfate aerosols, which are associated with acid rain as well as many human health problems.   Air pollution causes an estimated seven million premature deaths per year worldwide, so reducing it is imperative.

The complication is that sulfate aerosols in the upper atmosphere actually have a cooling effect on surface air temperatures.  Aerosols create bigger clouds and increase light scattering, both of which result in less sunlight reaching the surface.  Large natural sources of sulfate aerosols – such as volcanic eruptions – can temporarily cool the earth until they settle out of the atmosphere.

There are many kinds and sizes of atmospheric aerosols, making predicting their effects and behavior difficult.  For example, black carbon aerosols from forest fires tend to suppress cloud formation by warming the air and making tiny water droplets evaporate.  However, sulfate aerosols from burning fossil fuels make clouds grow larger.

Analysis has shown that air pollution has actually reduced the amount of warming that has taken place to date.  A new study by Kyushu University in Japan looked at the long-term climate effects of reductions in sulfate aerosols.  The loss of cooling effect from light-scattering aerosols as emissions are reduced is a factor that cannot be ignored. 

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Air pollutant reductions could enhance global warming without greenhouse gas cuts

Photo, posted January 23, 2021, courtesy of Wutthichai Charoenburi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Disappearing Rainforests | Earth Wise

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Forest loss is a major contributor to climate change, and it is continuing at a rapid pace.  The tropics lost about 30 million acres of tree cover in 2019, a third of which was within humid tropical primary forests, which are especially important for biodiversity and carbon storage.  To put that loss in a human-scale perspective, it is the equivalent of losing a football field of primary forest every six seconds for the entire year.

The losses last year were 2.8% higher than in the previous year, and these losses have continued over the past 20 years despite worldwide efforts to halt deforestation.  

Brazil single-handedly accounted for over a third of all global loss of humid tropical primary forests. Bolivia experienced record-breaking tree cover loss due to fires.  The losses in its forests were 80% greater than in any previous year.  The fires were often started by people who were trying to clear land for agriculture but had the fires go out of control. Several countries in Africa’s Congo Basin also experienced sustained or worsening forest loss. 

Indonesia, often the focus of the world’s attention for its deforestation activities, actually saw a 5% reduction in primary forest loss in 2019.  It was the third year in a row for lower losses.  The now-permanent moratorium on clearing forests for oil palm plantations and logging seems to be working.

Going forward, the coronavirus pandemic poses additional threats to the world’s forests in the near future.  There may be a tendency to sacrifice forests in pursuit of economic recovery, which will only lead to future complications for the health and livelihoods of millions of people around the world.

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We Lost a Football Pitch of Primary Rainforest Every 6 Seconds in 2019

Photo, posted February 7, 2011, courtesy of Chad Skeers via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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WAMC Northeast Public Radio

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