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Triple La Niña | Earth Wise

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La Niña is an oceanic phenomenon consisting of cooler than normal sea-surface temperatures in the central and eastern tropic Pacific.  It is essentially the opposite of the better-known El Niño.   These sea-surface phenomena affect weather across the globe.  As one oceanographer put it:  when the Pacific speaks, the whole world listens.

There is currently a La Niña underway, and it is the third consecutive northern hemisphere winter that has had one.  This so-called triple-dip event is rather rare.  The only other times they have been recorded over the past 70 years were in 1954-56, 1973-76, and 1998-2001.

La Niñas appear when strong easterly trade winds increase the upwelling of cooler water from the depths of the eastern tropical Pacific Ocean near the equator.  This causes large-scale cooling of the ocean surface.  The cooler ocean surface modifies the moisture content of the atmosphere across the Pacific and can cause shifts in the path of jet streams that intensifies rainfall in some places and causes droughts in others.

These weather effects tend to include floods in northern Australia, Indonesia, and southeast Asia and, in contrast, drought in the American southwest.  In North America, cooler and stormier conditions often occur across the Pacific Northwest while the weather becomes warmer across the southern US and northern Mexico.

In the spring, the tropic Pacific essentially resets itself and starts building toward whatever condition will happen in the following winter, be it another La Niña or possibly an El Niño.   For the time being, forecasters expect the current La Niña to persist through February.

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La Niña Times Three

Photo, posted March 10, 2007, courtesy of Gail 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

North American Birds And Climate Change | Earth Wise

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Most plants and animals live in areas with specific climate conditions, such as rainfall patterns and temperature, that enable them to thrive. Any change in the climate of an area can affect the plants and animals living there, which in turn can impact the composition of the entire ecosystem.   

As such, the changing climate poses many challenges to plants and animals.  For example, appropriate climatic conditions for many species are changing.  As a result, some may even disappear altogether.  These problems can be compounded when the climate is changing in tandem with other human-caused stressors, such as land use change.

When there is increasing divergence between suitable climatic conditions for a particular species and its abundance and distribution through time, this is known as climate decoupling.

According to a new study recently published in the journal Nature Ecology & Evolution, some species of North American birds have not fully adjusted their distributions in response to climate change.  The areas where these birds live have become more decoupled from their optimal climate conditions.  Climate decoupling as a result of ongoing climate change could lead to additional stressors on many bird species and exacerbate bird population declines.

In the study, the research team analyzed data on bird population changes through time from the North American Bird Survey.  They found that at least 30 out of 114 species (or 26%) of North American birds have become less well adjusted to their climate over the last 30 years. This means that their distributions and abundances were increasingly decoupled from climate over time.

The researchers also found that the overall trend of climate decoupling shows no signs of slowing down. 

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North American birds not fully adjusting to changing climate

Photo, posted July 16, 2016, courtesy of Kelly Azar via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bumblebees And Climate Change | Earth Wise

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Pollinators, such as bees and bats, are vital for global food production.  They provide an ecological service that’s necessary for the reproduction of nearly 75% of the world’s flowering plants, including more than two-thirds of global food crops.

Bumblebees are among the most important plant pollinators.  They pollinate many food crops, including apples, tomatoes, blueberries and legumes, as well as countless types of trees, shrubs, and wildflowers.

According to a new study by researchers from Simon Fraser University in Canada, temperature changes have negatively impacted most bumblebee species during the past 120 years.  The research, which was recently published in the journal Biology Letters, found that these changes in temperature had more of a negative impact than other factors such as precipitation or floral resources. 

The research team analyzed existing data on 46 bumblebee species across North America between 1900 and 2020.  The researchers created two occupancy models – one that was focused on time and the other that focused on environmental factors – to see how climate change and land-use variables impacted species’ occupancy.  They found that six bumblebee species decreased through time, 22 increased, and 18 remained stable.

Temperature changes had primarily negative impacts on bumblebees.  In fact, 37 of the 46 species studied exhibited declines or less positive occupancy increases under observed changes in temperature when compared with temperatures remaining constant.  Approximately half of the bumblebee species were negatively impacted by changes in precipitation or floral resources while the other half were positively impacted.

Bumblebee populations are changing as a consequence of climate change. 

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The American Bumblebee

Climate change negatively impacting bumble bees: Study

Photo, posted July 14, 2019, courtesy of Dmitry Grigoriev via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildfires And Cancer Risk | Earth Wise

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Hotter and drier conditions are leading to an increasing number of wildfires in North America and elsewhere around the globe.  Scientists have linked the severe heat and drought that fuel these wildfires to climate change. As the climate continues to change, wildfires are projected to become more prevalent, more severe, and longer in duration. 

According to a United Nations report released earlier this year, the Western U.S., northern Siberia, central India, and eastern Australia have already seen an uptick in wildfires.  The likelihood of catastrophic wildfires globally could increase by a third by 2050 and more than 50% by the turn of the century. 

According to a new study by researchers from McGill University, living near regions prone to wildfires may boost the risk of developing serious health issues.  The study, which tracked more than two million Canadians over a period of 20 years, found a higher incidence of lung cancer and brain tumors in people exposed to wildfires.  People living within 50 kilometers of wildfires during the past 10 years had a 10% higher incidence of brain tumors and a 4.9% higher incidence of lung cancer when compared to people living further away. 

This study, which was recently published in The Lancet Planetary Health, is the first to examine how proximity to forest fires may influence cancer risk.

In addition to the impacts on air quality, wildfires also pollute aquatic, soil, and indoor environments.  While some pollutants return to normal levels shortly after the fire, many others persist in the environment for long periods of time. 

The research team notes that additional work is needed to develop more long-term estimates of the chronic health effects of wildfires.

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Exposure to wildfires increases risk of cancer

Climate change is causing more wildfires and governments are unprepared, says U.N.

Photo, posted August 17, 2020, courtesy of USFS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recycling Shingles | Earth Wise

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Every year in the US, about 13 million tons of asphalt material is removed from old roofs to be replaced with new shingles.  Only about 10% of that is recycled for use in paving and various roadway projects.  The other 12 million tons of asphalt ends up in landfills where it takes a very long time to break down.

GAF, the largest roofing manufacturer in North America, has developed a shingle recycling process for which it has received three patents.  The process involves grinding torn-off shingles into a refined material which can then be introduced into the shingle manufacturing process.  The material – referred to as RAS for recycled asphalt shingles – has the potential to significantly reduce the amount of virgin asphalt needed to make new shingles.

Tests by GAF reclaimed upwards of 90% of the waste shingle material and produced new shingles containing up to 15% recycled content.  Underwriters Laboratories certified the shingles containing RAS material with regard to their safety and effectiveness.  The GAF process opens to door to creating a circular, sustainable economy for asphalt used for roofing shingles.

Roofs play an important role in the transition to a green economy.  Apart from recycling asphalt shingles, there are increasing options for solar shingles, which take the place of both traditional asphalt shingles and ordinary solar panels by integrating them into a single roofing product.  There are also so-called green roofs, which replace conventional roofing materials with a contained green space atop a building. Such roofs provide stormwater management, cooling, and an interesting aesthetic.

All aspects of buildings play important roles in our environment – even their roofs.

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5 Ways Roofers Can Celebrate Earth Day, Everyday

Photo, posted April 15, 2012, courtesy of Robert Taylor via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Hot Year With Record GHG Levels | Earth Wise

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Last year was a year that saw rising temperatures and rising levels of greenhouse gases.  2021 was the fifth-hottest year on record.  The average global temperature was nearly 1.2 degrees Celsius or 2.1 Fahrenheit degrees higher than the preindustrial average.  The past seven years were the hottest ever by a significant margin.

The concentration of carbon dioxide in the atmosphere reached 414 parts per million, compared with preindustrial levels of 280 parts per million.  Concentrations of methane reached 1876 parts per billion, the highest levels ever recorded. 

Apart from these global measurements, local and regional weather saw the effects of the heating planet.  Extreme temperatures were common with the hottest summer in Europe, heatwaves in the Mediterranean, and unprecedented high temperatures in North America.

The West Coast of the US, northeast Canada, Greenland, and parts of north Africa and the Middle East all experienced the highest above-average temperatures.  However, some places, including Australia, Antarctica, Siberia, and much of the Pacific Ocean often saw below-average temperatures, even though the same places occasionally experienced record high temperatures.

The Covid-19 pandemic and its economic disruptions continued to lead to some reductions in greenhouse gas emissions, but in the US, emissions from energy use and industry nonetheless grew 6.2% in 2021 after falling more than 10% in 2020.

Carbon dioxide and methane concentrations are continuing to increase each year and don’t appear to be slowing down.  As long as this situation persists, global temperatures will continue to rise, and extreme and erratic weather will be more and more commonplace.

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2021 Rated One of the Hottest Years Ever as CO2 Levels Hit Record High

Photo, posted November 11, 2011, courtesy of NASA Goddard Space Flight Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Could Lyme Disease Be Eradicated? | Earth Wise

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Tiny ticks are a big problem.  Measuring only three to five millimeters in size, ticks are widely distributed around the world.  They are external parasites, feasting on the blood of birds, reptiles, amphibians, and mammals – including humans.

According to estimates from the Centers for Disease Control and Prevention, ticks infect an estimated 476,000 people with Lyme disease in the United States every year.  Lyme disease is caused by a bacterium called Borrelia burgdorferi that lurks in wild mice. Ticks that feed on the mice become infected and can then in turn infect people and animals.   

The disease is not only a problem in the United States, but in other parts of North America, Europe and Asia as well.  It often causes a characteristic “bullseye” rash and flu-like symptoms. If left untreated, it can lead to serious long-term health problems.

Currently, lyme disease is treated using antibiotics.  But antibiotics kill a wide range of bacteria – including healthy gut bacteria – which can lead to additional health issues and more antibiotic resistance.

A recent discovery by researchers from Northeastern University in Boston could allow Lyme disease to be eradicated in the wild.  The researchers found that a compound called hygromycin A is deadly to the bacterium that causes Lyme disease but harmless to animals and has little effect on most other bacteria. 

The little-known antibiotic cleared Lyme disease infection in mice, both when administered via injection and when ingested using bait.  As a result, dropping feeding baits could eradicate Lyme disease from whole areas or even entire countries.  The first field trial will be next summer.

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Drug treatment for Lyme disease could lead to its eradication

Photo, posted June 21, 2017, courtesy of NIAID via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Earth Is Dimming | Earth Wise

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According to a new study published in the journal Geophysical Research Letters, warming ocean waters have caused a drop in the brightness of the earth.

Researchers measure the earth’s albedo by observing the light reflected from earth that illuminates the surface of the moon as well as with satellite measurements. The earth reflects about 30% of the sunlight that shines on it.  The data shows that the earth now reflects about half a percent less light than it did 20 years ago, with most of the drop occurring in the last three years.  That number had been fairly constant for most of the past 20 years.

According to the researchers at the New Jersey Institute of Technology, New York University, and a Spanish astrophysical agency, the apparent cause of the albedo drop has been a reduction of bright, reflective low-lying clouds over the eastern Pacific Ocean in most recent years.  That is the same area off the west coasts of North and South America where increases in sea surface temperature have been observed because of the reversal of a climate condition called the Pacific Decadal Oscillation, which is likely a result of global climate change.

The dimming of the earth implies that more solar energy is being absorbed rather than reflected, which may contribute further to global warming.

These results are somewhat surprising.  Scientists had postulated that the warming of the earth could lead to more clouds and therefore a higher albedo – more reflection of the sun’s light.  If that were the case, it would help to moderate warming and balance the climate system.  These new results indicate that the opposite is true.

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The Earth Is Dimming Due To Climate Change

Photo, posted August 18, 2021, courtesy of Arek Socha/GPA Photo Archive via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Global Light Pollution

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Light pollution is excessive or obtrusive artificial light. It’s a consequence of industrial civilization.  Too much artificial light can cause a host of problems, including disrupting ecosystems, causing adverse health effects, and wasting energy. 

According to a new study led by researchers from the University of Exeter in the U.K., global light pollution has increased by at least 49% over 25 years.  But this figure only includes light visible via satellites.  Scientists estimate that the true increase may be significantly higher – up to 270% more globally. 

That’s because there is a hidden impact of LED technology that isn’t accounted for in the satellite data. LEDs emit more blue light than previous lighting technologies, but satellite sensors fail to pick up this blue light.   This leads to a large underestimate of global light pollution.

The researchers examined light pollution from 1992 to 2017.  They found persistently increasing light pollution in Asia, South America, Oceania and Africa.  In Europe, detected light increased until around 2010, after which it leveled off.  In North America, artificial light appears to be on the decline.  However, the researchers point out that the satellites inability to detect blue light of LEDs means that light pollution has likely actually increased in most locations.

Light pollution has widespread impacts on both animals and plants.  For example, light pollution can confuse the migratory patterns of animals and change predator-prey relationships.   It’s also been shown to cause trees to bud earlier in spring.      

While there’s no off switch for the planet, there are ways that we could reduce the amount of light drastically with little impact on our lives. 

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Rapid increase in global light pollution

Photo, posted November 2, 2008, courtesy of Timothy Tsui via Flickr.

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Record Heat Across the Globe | Earth Wise

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While the Pacific Northwest was setting new records for high temperatures in June, many other places across the globe also experienced unprecedented heat.  Places in Russia and Scandinavia, including locations above the Arctic Circle, set new records for temperature.

The heatwave in Europe was the result of a persistent northward bulge in the polar jet stream.  This blocking pattern in the jet stream has been prevalent over Scandinavia this year and has contributed to unusually warm conditions there.  Further east, similar conditions have created unusual warm temperatures in Siberia.

On June 23, Moscow reached a high of 94.6 degrees, the hottest June temperature on record.  Helsinki, Finland set a record at 89.1 degrees, and both Belarus at 96.3 degrees and Estonia at 94.3 degrees set new records.  The town of Saskylah, north of the Arctic Circle in Siberia, measured almost 90 degrees on June 20. 

High temperature records have been broken in many places.  The all-time record high for June for all of Mexico fell at Mexicali in Baja California on June 17 when the temperature reached 125 degrees.  Palm Springs, California, while known for its desert heat, nonetheless set a new all-time high temperature of 123 degrees and also set a new record for the warmest overnight low temperature for a June night anywhere in North America at an unbelievable 105 degrees.

Stories like this have become all-too common in recent years and are undoubtedly going to occur with greater frequency as the world’s climate continues to react to the growing buildup of greenhouse gases in the atmosphere.

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A Scorcher in Siberia and Europe

Photo, posted June 8, 2007, courtesy of Niko Pettersen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Allergies | Earth Wise

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According to a new study published in the Proceedings of the National Academy of Sciences, an addition to the many hardships that climate change is causing around the world is the fact that it is making allergy season worse.

Researchers have found that there is a strong link between planetary warming and pollen seasons.  The combination of warming air and higher levels of carbon dioxide in the atmosphere has caused North American pollen seasons since 1990 to start some 20 days earlier, on average, and to have 21% more pollen.

The most pronounced effects were seen in Texas, the Midwest, and the Southeast.  The effects were less obvious in the northern United States, including New England and the Great Lakes states.  The greatest pollen increases came from trees, as opposed to grasses and weeds.

Allergies do not just trigger sniffles and sneezes; they have serious effects on public health in the form of asthma and other respiratory conditions.  Studies have shown that students do less well in school during peak pollen season.  Of special concern at the moment is that high-pollen periods have been associated with greater susceptibility to respiratory viruses.  The U.S. has nearly 25 million people with asthma and 19 million adults reported hay fever in the past 12 months.  Research suggests that the early onset of pollen season correlates with a higher risk of hospitalization for asthma.

There are far fewer pollen monitoring stations than those measuring particle pollutants and air quality.  As the climate warms, we need to pay more attention to pollen as an airborne pollutant.

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Achoo! Climate Change Lengthening Pollen Season in U.S., Study Shows

Photo, posted May 18, 2012, courtesy of Forest Wander via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Even The Common House Sparrow Is Declining | Earth Wise

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According to the first-ever comprehensive assessment of net bird populations published in 2019, nearly three billion birds have disappeared in the United States and Canada since 1970.  The study, by researchers from the Cornell University Lab of Ornithology, found that North American bird populations have lost 2.9 billion breeding adults during that timespan.  Forests lost one billion birds, and grassland birds declined 53%. 

According to a newer study from Cornell University, it appears that even the common house sparrow is declining.  In parts of its native range in Europe, house sparrow numbers are down nearly 60%.  Researchers from the Cornell Lab of Ornithology sought to clarify the status of the species in the U.S. and Canada by using 21 years of citizen science data collected through its Project Feederwatch program. 

Project FeederWatch is a winter-long survey of birds that visit feeders at backyards, nature centers, community areas, and other locales. For the study, which was recently published in the Wilson Journal of Ornithology, the research team reviewed recorded observations of house sparrows during their non-breeding season.  These sightings from nearly 12,500 sites were used and cross-referenced with the National Land Cover database to determine whether the U.S. sightings came from rural or urban locations.  

From 1995 to 2016, researchers found that Feederwatch sites reporting house sparrows declined 7.5%, and the mean flock sizes declined 22%.  House sparrow populations declined in urban areas, but actually remained stable in rural areas. 

The researchers say a lack of green space and nesting sites in urban areas are likely factors in the population declines. 

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Study finds even the common house sparrow is declining

Nearly 3 Billion Birds Gone

Photo, posted May 14, 2014, courtesy of Jacob Spinks via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Not Enough Buzz For Bees | Earth Wise

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The dramatic worldwide decline in bees and other pollinating insects represents a serious threat to the global food supply, but it isn’t really getting much attention in the mainstream news.  Close to 75% of the world’s crops for human consumption depend, at least in part, on pollinators for sustained production, yield, and quality.

A new study by researchers at the University of Illinois Urbana-Champaign looked at nearly 25 million news items from six prominent sources, including The New York Times, The Washington Post, the Associated Press, as well as three overseas English-language news services.  The study found “vanishingly low levels of attention to pollinator population topics”, even compared with what many people consider to be the limited coverage of climate change.

The study made use of the Global News Index, which is a unique database of millions of news items from thousands of global sources published over decades.  It may be the largest academic study of the evolving nature of news coverage ever performed.

Even though the entomological community is highly focused on the impending pollinator crisis, the public is not paying much attention.  It is not even indifference; it is just that people don’t even know about it.

The majority of studies on pollinator decline have been done in Europe and North America, which means we don’t even know how serious the problem is given that most insect biodiversity is in the tropics.

Public awareness is important because individuals can make a difference by their decisions about what flowers to plant in their gardens, which weeds to tolerate in their yards, and how to manage insect pests.

The loss of pollinators is a very serious problem, and it is not likely to get enough attention if people don’t know about it.

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Pollinators not getting the ‘buzz’ they need in news coverage

Photo, posted December 28, 2006, courtesy of Alpha via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Reduced Air Travel And Weather Forecasts | Earth Wise

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There have been countless stories about the major and minor changes in the world caused by the Covid-19 pandemic.  A few of those changes, such as reductions in pollution and traffic, have been positive.  Most have been decidedly negative.

One of the stranger things that has happened is that the pandemic has affected the quality of weather forecasting by sharply reducing the amount of atmospheric data routinely collected by commercial airliners.

It turns out that atmospheric observations from passenger and cargo flights are among the most important data used in weather forecasting models.  These observations are made by instruments aboard thousands of airliners, mostly based in North America and Europe.  The observation program has been in place for decades.  The data is transmitted in real time to forecasting organizations around the world, including the National Weather Service.  About 40 airlines participate in the program, which has equipment aboard about 3,500 aircraft.  Here in the US, Delta, United, American, and Southwest Airlines participate, as do UPS and FedEx.

During the first few months of the pandemic, air traffic declined by 75% or more worldwide.  As a result, atmospheric observations dropped by the same percentage.  A government research study showed that when weather forecasting models receive less data on temperature, wind, and humidity from aircraft, the accuracy of forecasts was reduced.

The amount of data from aircraft has increased in recent months as air travel has picked up to roughly 50% of pre-pandemic levels.  So, the observation program is on the mend.  Nonetheless, impaired weather forecasting is just another unexpected result of the global pandemic.

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Slump in Air Travel Hindered Weather Forecasting, Study Shows

Photo, posted July 15, 2017, courtesy of Daria Nepriakhina via Flickr. Photo by Photo by Daria / epicantus.

Earth Wise is a production of WAMC Northeast Public Radio.

The Hot Year Continues | Earth Wise

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The National Oceanic and Atmospheric Administration’s monthly global climate report for October reports yet another month of high temperatures.  October 2020 was the fourth-hottest October on record, continuing the pace for the year to be the second hottest on record.

The 10 warmest Octobers have occurred since 2005 and the seven warmest have all occurred in the last seven years.  Europe had its warmest October ever, surpassing the previous record set in 2001.

For the year to date, the global temperature was a full degree Celsius (or 1.8 degrees Fahrenheit) above the 20th century average.  This was just 0.03 Celsius degrees lower than the record set in 2016.   Europe and Asia have had their warmest year-to-date period on record.

Other notable observations in the report included that Arctic sea ice coverage was almost 37% below the 1981-2010 average and was the smallest October coverage on record.  The previous record was set last year.

Heat records were set around the world including parts of the northern and western Pacific Ocean, southern North America, South America, eastern Europe, the northern Middle East, the eastern Mediterranean Sea, southern Asia, and in small areas across the Indian and Atlantic Oceans.

Despite the record global temperatures, the Northern Hemisphere’s snow coverage in October was the 10th largest over the past 53 years.  The snow coverage in North America was the largest on record for October.

Adding in the extremely active hurricane season, with 12 hurricanes and 29 tropical depressions, weather around the world continues to be anything but typical.

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Remarkably warm October fuels march toward 2nd-hottest year

Photo, posted February 8, 2016, courtesy of Jasmin Toubi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carnivores Eating Human Food | Earth Wise

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A recent study by ecologists at the University of Wisconsin-Madison has found that carnivores living near people often get more than half of their diets from human food sources rather than from their traditional prey.  This represents a major lifestyle disruption that puts North America’s carnivore-dominated ecosystems at risk.

The researchers studied the diets of seven predator species across the Great Lakes region using bone and fur samples taken from animals from areas as remote as national parks to metropolitan areas including Albany, New York.  What they found – unsurprisingly – is that the closer carnivores lived to cities and farms, the more human food they ate.  Dietary contributions of human food varied with species, but on average was more than 25% in most human-altered habitats.

The researchers studied the diets of carnivores like bobcats, coyotes, red and gray foxes, fishers, and American martens by chemical analysis of samples from Minnesota, Wisconsin, upstate New York, and the Upper Peninsula of Michigan.  The diets of the animals could be analyzed on the basis of the carbon content of bone and fur samples.  Human food, heavy in corn and sugar, lends these samples a distinctive carbon isotope signature.  In contrast, prey species confer their own carbon signatures.  The ratio of these isotope fingerprints provides information on the proportion of an animal’s diet that came from human sources.

Relying upon human food increases how much carnivores overlap one another in their competition for food.  Compared to when these predators vie for distinct prey, there can be more conflicts between animals.  Changing how a species gets their food can have far-ranging effects on ecosystems.

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Carnivores living near people feast on human food, threatening ecosystems

Photo, posted August 18, 2007, courtesy of Jitze Couperus via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Arctic Northeast Passage May Open | Earth Wise

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The Northwest Passage is the sea route between the Atlantic and Pacific oceans through the Arctic Ocean.  It goes along the northern coast of North America, traveling though the Canadian Arctic Archipelago.  In the past, it was the domain of intrepid explorers like Roald Amundsen.  Because of the receding ice in the Arctic, in recent years it has become possible to travel the Northwest Passage by cruise ship.

The Northeast Passage connects the same two oceans along the Arctic coasts of Norway and Siberia.  The sustained loss of sea ice is now leading to accessibility of Arctic sea passages through this route.

Compared with the customary route through the Strait of Malacca in Malaysia and the Suez Canal, using the Northeast Passage could reduce the travel distance between Europe and northwest Asia by one-third.  This would reduce the expense of transportation and lower environmental pollution.  Many Asian countries have a strong strategic and economic interest in Arctic shipping.  Russia would gain strong competitive advantages for its liquified natural gas industry.

According to a recent study at the Northwest Institute of Eco-Environment and Resources of the Chinese Academy of Sciences, the continuing warming of the Arctic seas is likely to result in the Northeast Passage being navigable for open water ships by next year and will continue to be increasingly hospitable to marine traffic.

The economic and strategic benefits to the opening of the Northeast Passage are quite clear.  What is also clear is that the underlying cause of the opening of the passage – the dramatic loss of Arctic sea ice – is not beneficial to the world at all and is a harbinger of troubling things in our future.

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Arctic Northeast Passage may be Navigable in Near Future

Photo, posted September 24, 2005, courtesy of Paul Downey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Alien Species On The Rise | Earth Wise

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Alien species are species that are introduced, accidentally or intentionally, outside of their natural geographic range as a result of human activities.  More than 35,000 alien species have been recorded through 2005, which is the most recent year for which researchers have comprehensive global data. 

Some of the alien species go on to become invasive alien species, which can have damaging impacts on both ecosystems and economies.  In fact, alien species are one of the main drivers of plant and animal extinctions around the globe.  

According to a new study by an international research team involving University College London, the number of alien species, particularly insects, arthropods and birds, is expected to increase globally by 36% by 2050 when compared to 2005 levels.  The research was recently published in the journal Global Change Biology.

Using a mathematical model developed for the study, the researchers identified high levels of variations between regions.  For example, the largest increase in alien species by the middle of the century is expected in Europe, where numbers are predicted to jump by 64%.  The temperate regions of Asia, North America, and South America are also predicted to be hotspots of alien species.  The lowest relative increase in alien species is expected in Australia.

The researchers do not expect a reversal or slowdown in the spread of alien species.  In fact, with global transportation and trade forecasted to increase in the coming decades, they anticipate many new species will infiltrate non-native habitats by hitching rides as stowaways.   

According to the research team, it would take a concerted global effort with stricter regulations and more rigorous enforcement to slow the flow of new species. 

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Alien species to increase by 36% worldwide by 2050

Photo, posted October 3, 2016, courtesy of the Asian Carp Regional Coordinating Committee via Flickr. Photo credit: Ryan Hagerty/USFWS.

Earth Wise is a production of WAMC Northeast Public Radio.

Danger For North American Biomes | Earth Wise

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Biomes are large, naturally occurring communities of flora and fauna that occupy a major habitat.  Examples include several different kinds of forests, grasslands, deserts, and tundra.  According to a new study published in the journal Global Change Biology, the resilience of North America’s plant biomes is declining, which means that they are in danger of succumbing to a major extinction event.

The research analyzed over 14,000 fossil pollen samples from 358 sites across North America for the purpose of reconstructing their “landscape resilience”, meaning the ability of the habitats to persist or quickly rebound in response to disturbances.

Some 13,000 years ago, North American ecosystems were destabilized by the one-two punch of the retreat of glaciers at the end of the last ice age along with the arrival of humans.  That combination resulted in the extinction of large terrestrial mammals on the continent. 

Today, there is a comparable one-two punch created by the rapidly changing climate combined with the dramatic expansion of the footprint of human civilization.   The result could again be the demise of some of North America’s biomes.  In past eras, forests persisted longer than grasslands, but also took longer to reestablish after disruptions.  Overall, only 64% of historic biomes regained their original ecosystem type.

The scientists said that strategic conservation effects could help counteract or slow down the impacts of climate change in the coming decades.  In particular, efforts focusing on improving landscape and ecosystem resilience by increasing local connectivity and concentrating on regions with high richness and diversity could have the greatest positive effect.

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North American Biomes Are Losing Their Resilience, With Risks for Mass Extinctions

Photo, posted January 9, 2020, courtesy of Tony Webster via Flickr.

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