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A month of extra-hot days

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The past 12 months have been the hottest ever measured across the globe.  This may not be everyone’s experience in every location, but the average person on Earth experienced 26 more days of abnormally high temperatures than they would have in the absence of climate change.

Researchers considered a given day’s temperature to be abnormally high in a particular location if it exceeded 90% of the daily temperatures recorded there between 1991 and 2020.  Nearly 80% of the world’s population experienced at least 31 days of abnormal warmth since May of 2023.  Theoretically, the number of unusually warm days would have been far fewer in the absence of global warming.

In some countries, the extra-warm days added up to two or three weeks.  In others, such as Colombia, Indonesia, and Rwanda, there were up to 4 months of them. The average American experienced 39 days of extra-warm temperatures since last May.

Scientists also added up how many extreme heat waves the planet experienced since last May.  These are defined as episodes of unseasonable warmth across a large area, lasting three or more days, and causing significant loss of life or disruption to infrastructure or industry.  In total, the researchers identified 76 such episodes, affecting 90 countries, on every continent except Antarctica.

The world’s climate is now shifting toward the La Niña phase of the cyclical pattern called the El Niño-Southern Oscillation. This usually leads to cooler temperatures on average, but the recent heat could have lingering effects on weather and storms for months to come, including what is expected to be an extraordinarily active Atlantic hurricane season.

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Climate Change Added a Month’s Worth of Extra-Hot Days in Past Year

Photo, posted December 21, 2011, courtesy of Maggie Lin Photography via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fireflies are in decline

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If you are seeing fewer fireflies each year, you’re not alone.  Like many insects, firefly populations are in decline.  A new study by researchers from the University of Kentucky, Bucknell University, Penn State University, and the USDA has shed some light on the precarious situation facing firefly populations across North America. 

The research team used a mix of field surveys from citizen scientists and advanced machine learning techniques to analyze more than 24,000 surveys from the Firefly Watch citizen science initiative.  The study, which was recently published in the journal Science of the Total Environment, identified the factors likely responsible for the declines in firefly populations. 

The research team found that fireflies are sensitive to various environmental factors, from short-term weather conditions to longer climatic trends.  Fireflies thrive in temperate and tropical climates.  As global temperatures rise, these conditions become less predictable and less hospitable.

Light pollution is another threat to fireflies.  Artificial light at night – from things like street lights and billboards – is particularly disruptive to fireflies as it interferes with their bioluminescent communication essential for mating.

Urban growth, including buildings, roads, and sidewalks, poses another significant threat to fireflies by overtaking their natural habitats and decreasing available breeding areas. 

Additionally, certain agricultural practices seem to contribute to the decline of fireflies. 

According to the research team, reducing light pollution, preserving natural habitats, and implementing wildlife-friendly agricultural practices are conservation measures that could help mitigate the decline of fireflies. 

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Fading lights: Comprehensive study unveils multiple threats to North America’s firefly populations

Photo, posted July 12, 2021, courtesy of Bruce Hallman/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Penguin detectives

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Emperor penguins, the tallest and heaviest of all living penguins, are also the most famous, being the subject of a very popular documentary film.  The ongoing loss of sea ice in Antarctica has led to unprecedented breeding failures in emperor penguin colonies. 

Since 2016, Antarctica has seen the four years with the lowest sea ice extent on record.  Between 2018 and 2022, 30% of the 62 known emperor penguin colonies were affected by partial or total sea ice loss.  Current predictions suggest that the population of emperor penguins will fall by 99% by the end of the century.

To monitor remote emperor penguin colonies, researchers use satellite images in which the brown stains of the birds’ guano stand out against the white ice and snow.

Researchers at the British Antarctic Survey have launched the ‘Polar Observatory’ on the online citizen science website Zooniverse to recruit ‘penguin detectives’ to help validate the accuracy of satellite images in assessing penguin populations.

The online app contains drone photos taken over the Snow Hill penguin colony.  The images have been split into more than 300 10-meter squares.  Volunteers are asked to identify any adult and chick penguins in a given picture.  The results will be fed into machine learning algorithms to train the AI systems in automatically counting penguins in future surveys.

The project is a fun opportunity for aspiring conservationists and penguin lovers in general to help learn more about the future of the species.  Interested people can learn more on the Zooniverse website.

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‘Penguin detectives’ required for new counting app

Polar Observatory

Photo, posted October 7, 2017, courtesy of Christopher Michel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Good owls and bad owls

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In the forests of the Pacific Northwest, spotted owls have been the subject of environmental concern for more than 30 years.  Over the past 20 years, northern spotted owl populations have declined by up to 80% as the birds have faced marginalized territories and increasing numbers of wildfires.  Only about 3,000 of them remain on federal lands.  Spotted owls are picky eaters and are not very adaptable.

The barred owl, a larger and more ornery species, has been moving in on spotted owl turf for 50 years, competing for food and space, and out-reproducing them and chasing them out of their nesting spots.

A last-ditch effort to rescue the northern spotted owl from possible extinction has been proposed by the U.S. Fish and Wildlife Service.  The plan would be to eradicate up to half a million barred owls over the next 30 years in Washington, Oregon, and Northern California.  The owls would be dispatched using cheap and efficient methods, such as shotguns.

The concept of killing off vast numbers of barred owls is awful, and nobody likes the idea.  However, other strategies have failed, and time is running out.  The only way to preserve the northern spotted owl is to protect and increase its habitat and have fewer barred owls.

To say that the proposed plan is controversial is a massive understatement.  A coalition of 75 wildlife and animal welfare organizations described it as a “colossally reckless action.”

A central issue in the debate is whether humans are responsible for this situation and should try to rectify it or, despite our desire to protect the spotted owl, we should just let nature take its course.

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They Shoot Owls in California, Don’t They?

Photo, posted April 4, 2022, courtesy of Kyle Sullivan / BLM via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Global coral bleaching

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The world’s coral reefs are in the midst of a global bleaching event being driven by extraordinarily high ocean temperatures.  This is the fourth such global event on record and is predicted to be the largest one ever.  Coral bleaching occurs when corals are stressed by heat and eject the symbiotic algae within them that they need to survive.  Bleached corals can recover if water temperatures cool soon enough.  Otherwise, they die.

Each of the three previous coral bleaching events has been worse than the last.  The first, in 1998, affected 20% of the world’s reefs.  The second, in 2010, affected 35%.  The third, from 2014 to 2017, affected 56% of reefs.

The current bleaching event was confirmed by satellite observations early in April and was already seen to be affecting more than half of the world’s coral areas across the Pacific, Indian, and Atlantic Oceans.  The ongoing event is expected to be the worst bleaching ever experienced by Australia’s Great Barrier Reef.  A small saving grace is that the current bleaching event is not expected to be of extremely long duration because the El Niño in the Pacific has abated.

Coral bleaching events are becoming more severe and frequent due to increased marine heat waves driven by climate change.  Last year was particularly difficult for corals as global sea temperatures reached record high levels for several months.

Widespread coral bleaching impacts economies, livelihoods, food security, and more.  Coral reefs provide ecosystem services essential to marine life and human populations as well.  Global action will be needed for coral interventions and restorations.

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Satellites watch as 4th global coral bleaching event unfolds

Photo, posted March 23, 2012, courtesy of Oregon State University via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Oases and desertification

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Oases are important sources of water for people, plants, and animals in the world’s desert areas.  In fact, oases sustain 10% of the world’s population despite taking up only about 1.5% of land area.  They form when groundwater flows and settles into low-lying areas or when surface meltwater flows down from nearby mountains and pools.

New research from the Chinese Academy of Sciences has found that oases added 85,000 square miles of new area from 1995 to 2020, mostly from artificial expansion projects, but over the same period lost 52,000 square miles from desertification and water scarcity.  The net gain of 33,000 square miles is not considered to be sustainable given that it was mostly due to artificial causes.  The oasis expansion projects were in Asia but losses due to desertification were also mostly in Asia.

Today, oases are found in 37 countries.  Increases in oases mostly come from people intentionally converting desert land into oases using runoff water and groundwater pumping, creating grasslands and croplands. This mostly has taken place in China.

Human over-exploitation of dwindling groundwater can limit the sustainability of oases as can the long-term loss of glaciers.

The study highlighted ways to sustain healthy oases, including suggestions for improving water resource management, promoting sustainable land use and management, and encouraging water conservation and efficient water use.  As the climate continues to change, these efforts will be increasingly important for a significant portion of the world’s population.

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World’s Oases Threatened By Desertification, Even As Humans Expand Them

Photo, posted August 3, 2008, courtesy of Paul Williams via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rising fossil fuel emissions

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Almost every nation in the world has pledged to reduce carbon dioxide emissions.  There is expanding use of renewable energy sources and growing numbers of electric cars.  But despite all this, carbon dioxide emissions from fossil fuels rose again in 2023, reaching record levels.

The world’s population continues to grow and nations with large, rapidly growing populations are becoming increasingly industrialized and are embracing more and more of the trappings of modern life.  As a result, the global burning of oil, coal, and natural gas is increasing.

Analysis of 2023 date shows that emissions from fossil fuels rose 1.1 percent compared to 2022 levels.  The total fossil fuel emissions in 2023 was 40 billion tons of carbon dioxide. 

Clearly, the world continues to head in the wrong direction in order to limit global warming.  The concentration of carbon dioxide in the atmosphere has increased from about 278 parts per million in 1750 – considered to be the start of the industrial era – to 420 parts per million in 2023.

The rise in heat-trapping carbon dioxide along with other greenhouse gases such as methane is the primary reason that the planet’s temperature is continuing to rise.  The average global surface temperature in 2023 was 1.2 degrees Celsius – or 2.1 degrees Fahrenheit – higher than it was in the NASA baseline period of 1951-1980.  Last year was the hottest year on record.  Unfortunately, the rise in global ocean temperature was even larger, compounding the effects of global warming.

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Emissions from Fossil Fuels Continue to Rise

Photo, posted June 22, 2020, courtesy of John Morton via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The world’s largest energy plant

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The largest energy plant in the world is being built in India.  In an area of barren desert in western India near the Pakistani border, Adani Green Energy Limited (or AGEL) is building a sprawling solar and wind power plant that will cover more than 200 square miles.  It will be five times the size of Paris and will produce enough electricity to power 16 million homes.

The Khavda Renewable Energy Park will cost about $20 billion to build and will take about five years to complete.

The success of the plant is critical to India’s efforts to reduce pollution and meet its climate goals.  India is the world’s third-largest energy consuming country.  Even though its energy use and emissions per person are less than half the global average, its enormous population offsets that advantage and its expanding economy and ongoing modernization are driving rapid growth of energy demand.  Energy demand has doubled since 2000 and 80% is still being met by coal, oil, and solid biomass.  India uses massive amounts of coal, and, in fact, the Adani Group of companies is India’s biggest coal importer and a leading miner of the fossil fuel.   Adani represents two sides of the coin.

More than 600 million people in India will be coming into middle and upper income over the next 10 to 15 years and they will have increasing energy needs.  India is in a race to develop clean energy capacity.  If it simply follows the torturous path that China, Europe, and US all have done, the prospects for the global climate are bleak.

Building the world’s largest clean energy plant is just a first small step in the necessary direction.

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A coal billionaire is building the world’s biggest clean energy plant and it’s five times the size of Paris

Photo, posted February 25, 2010, courtesy of Bhavin Toprani via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Iceland power

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Iceland burns very little fossil fuel to power its economy and heat its homes.  About 85% of its energy comes from geothermal power and hydropower.  Its unique geology provides it with the highest percentage of renewable energy in the world.  The fossil fuel that Iceland does burn is primarily used to power cars and trucks as well as boats in its fishing fleet.  And Iceland is rapidly embracing the use of electric vehicles.

Iceland can make far more electricity than its 373,000 people can use.  The majority of its electricity is essentially exported as bars of aluminum.  Iceland is one of the world’s largest refiners of aluminum.  The aluminum ore comes from other countries but gets shipped to Iceland where electricity is cheap.  Refining aluminum is so energy-intensive that some say that aluminum is basically just pure electricity in solid metal form.

Electricity-rich Iceland is finding other ways to make use of its resources.  There is a proposed project called Icelink, which is an electricity interconnector between Iceland and Great Britain.  The high-voltage direct current link would run between 620 and 750 miles and would be the longest sub-sea power interconnector in the world.  It is controversial in Iceland and it may or may not happen.

Another technology that is establishing an early foothold in Iceland is carbon capture.  An Icelandic company called Carbix is doing leading work on taking captured carbon dioxide and sequestering it underground.  Capturing and storing carbon dioxide is energy-intensive and the promise of cheap, clean geothermal power makes Iceland an attractive place to do it.

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Iceland Is Living in our Future

Photo, posted July 2, 2012, courtesy of  Emily Qualey / PopTech via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Record renewable energy in Scotland

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The Scottish government recently announced that in 2022, renewable technologies in that country produced the equivalent of 113% of Scotland’s electricity consumption.

Fossil fuels still supplied electricity in Scotland, helping to fill in gaps in renewable power, but the government figures showed that the growing amount of Scottish renewable generation can easily generate more power than the country uses.  Scotland has seen significant growth in wind power as well as a small drop in overall electricity consumption.

Scotland, with a population of only 5.5 million, aims to produce enough renewable power to both meet its own demand and export clean electricity to other countries.  The U.K. is the obvious potential customer, but it will need to upgrade its national power grid and develop enough capacity to store up surplus wind and solar power.

The U.K. itself is drawing less power from natural gas and coal than it has at any point in the last 66 years.  Fossil fuels supplied only 33% of British electricity in 2023 while renewables supplied 43%. 

Fossil power use in Britain peaked in 2008.  Since then, power from natural gas has fallen nearly in half while coal power has dropped by 97%.  The U.K. has aggressive decarbonization goals in place, but the current Conservative government under Prime Minister Sunak has recently set about weakening British climate policy.

Meanwhile, the Scottish government is talking about becoming a global renewables powerhouse and is making investments aimed at achieving it.

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Record renewable energy output

Photo, posted July 21, 2010, courtesy of Martin Abegglen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Satellites discovering penguins

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The loss of sea ice in Antarctica has forced emperor penguins to seek out new breeding grounds.  Some colonies have traveled more than 20 miles in search of stable ice.  Emperor females lay a single egg on a stretch of sea ice at the start of winter and males keep the eggs warm while the females go hunting for up to two months to bring back food for their hatchlings.

Emperor penguins are the tallest and heaviest of all living penguin species.  The loss of sea ice has led to unprecedented breeding failure in some emperor penguin colonies.  Emperor penguins are not threatened by hunting, habitat loss, or other human-caused problems, but the changing climate could be their undoing.

Emperor colonies are easy to spot from above.  The penguins are up to four feet tall and the droppings from large colonies stand out vividly against white snow.  A careful study of satellite imagery has revealed four previously unknown colonies of emperor penguins along the edges of Antarctica.  This is the first bit of good news about the penguins in quite a while.  The new discoveries, reported in the journal Antarctic Science, brings the total number of known colonies to 66.

The new discoveries are encouraging, but emperor penguins remain at risk from the warming climate.  Three of the four new colonies are small, with fewer than 1,000 birds.  So, the discovery does not have a big impact on the overall emperor penguin population.  The addition of the new colonies is overshadowed by the recently reported colony breeding failures resulting from early and rapid ice losses.

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Thousands of Emperor Penguins Discovered by Satellite

Photo, posted January 19, 2014, courtesy of Christopher Michel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Elephants and protected areas

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Standing up to 13 feet tall and weighing up to 7 tons, African savanna elephants are the largest species of elephant and the biggest terrestrial animal on Earth.  According to the World Wildlife Fund, African savanna elephants can be found in 23 countries and live in a variety of habitats, including savannas, forests, and deserts.  The largest populations are in Southern and Eastern African countries.

According to assessments from the International Union for Conservation of Nature, the population of African savanna elephants has decreased by at least 60% over the last 50 years.  Poaching and habitat loss are the two main drivers of the population decline.  In 2021, the status of the African savanna elephant was changed from vulnerable to endangered on the IUCN’s Red List of Threatened Species. 

However, according to a new study recently published in the journal Science Advances, conservation measures have successfully stopped African savanna elephant population declines across southern Africa.  The international team of researchers found that the pattern varies regionally, with some elephant populations soaring while others are still facing large declines.

Overall, the study found that there are the same number of elephants now as there were 25 years ago. According to researchers, the key to long-term elephant population growth and sustainability isn’t where a protected area is, but rather how connected it is to other protected or neutral areas around it. 

This isn’t a new concept; in fact, many parks have been connected to one another.  But this study helps prove that the method is effective for elephant conservation.  

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Protected Areas for Elephants Work Best if They Are Connected

African elephant species now Endangered and Critically Endangered – IUCN Red List

African savanna elephant

Photo, posted October 20, 2018, courtesy of Ray via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Farming the frozen north

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Agriculture is the primary cause of land-based biodiversity loss.  As the global population grows, agricultural production needs to keep pace.  Estimates are that production needs to double by 2050.  How this can be accomplished without doing further harm to the environment and biodiversity is extremely challenging.

Climate change adds further complications to the challenge.  As the climate warms in the middle latitudes, agricultural zones may need to shift northward to regions which have evolved to have more suitable climates.  This represents a very real threat to the wilderness areas of Canada, Russia, and Scandinavia.  These places represent a significant fraction of the world’s wilderness areas outside of Antarctica.

According to researchers at the University of Exeter in the UK, if the forces driving climate change are not diminished, over the next 40 years warming temperatures are expected to make more than 1 million square miles newly suitable for growing crops.  As cropland goes barren in areas that have warmed too much, northern wilderness could be turned over to farming.  The vital integrity of these valuable areas could be irreversibly lost.

The study, published in the journal Current Biology, also says that climate change will shrink the variety of crops that can be grown on 72% of the land that is currently farmed worldwide.  Given this situation along with the rising global population, it is essential that land be used more efficiently.  We can feed a larger population from the farmland we already have, but people need to reduce meat consumption, cut food waste, and grow crops suited to their local climate.

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Warming Could Make Northern Wilderness Ripe for Farming, Study Finds

Photo, posted September 7, 2016, courtesy of Scott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Disappearing snow crabs

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Alaska snow crabs are a cold-water species found off the coast of Alaska in the Bering, Beaufort, and Chukchi Seas. They are one of ten commercially-fished species in Alaskan waters. The perils of crab fishing in this region have been well documented for many years in the reality TV series Deadliest Catch.

Last year, officials in Alaska canceled the winter snow crab season for the first time ever due to a sharp population decline. While the number of juvenile snow crabs was at record highs just a few years earlier, approximately 90% of snow crabs mysteriously disappeared ahead of the 2021 season. 

This year, officials in Alaska have once again canceled the snow crab harvest season for the second year in a row, citing the overwhelming numbers of crabs – in the billions – missing from Alaskan waters. 

Scientists have suspected that the warming ocean temperatures triggered this snow crab population collapse.  But did the crabs move someplace else or die off?  According to a new study recently published by scientists at the National Oceanic and Atmospheric Administration, warmer ocean temperatures likely caused the snow crabs to starve to death.  The research team found a significant link between recent marine heat waves in the eastern Bering Sea and the sudden disappearance of the snow crabs that began showing up in surveys in 2021.

According to the study, warmer ocean water dramatically increases snow crabs’ caloric needs. But with the warmer water also disrupting much of the region’s food web, snow crabs had a hard time foraging for food and weren’t able to keep up.

Researchers expect the population may eventually find refuge in colder waters further north.

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Climate Change And Crabs

Billions of crabs went missing around Alaska

Photo, posted August 28, 2013, courtesy of Boris Kasimov via Flickr.

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Floating Sea Farms | Earth Wise

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Researchers at the University of South Australia have designed a self-sustaining solar-driven system that turns seawater into fresh water and grows crops without any involvement.  In theory, such a system could help address the growing problems of freshwater shortages and inadequate food supplies as the world’s population continues to increase.

The system can be described as a vertical floating sea farm.  It is made up of two chambers:  an upper layer similar to a greenhouse and a lower chamber for water harvesting.

Clean water is supplied by an array of solar evaporators that soak up seawater, trap the salts in the evaporator body and, heated by the sun, release clean water vapor into the air which is then condensed on belts that transfer the water into the upper plant growth chamber.

The researchers tested the system by growing broccoli, lettuce and bok choi on seawater surfaces without maintenance or additional clean water irrigation.  The system was powered entirely by solar light.

The design is only a proof-of-concept at this point.   The next step is to scale it up using an array of individual devices to increase plant production. 

The futuristic potential for such technology would be huge farm biodomes floating on the ocean.  The UN estimates that by 2050, nearly 2.5 billion people are likely to experience water shortages while the global supply of water for irrigation is expected to decline by 19%.  Nearly 98% of the world’s water is in the oceans.  Harnessing the sea and the sun to address growing global shortages could be the way to go.

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Floating sea farms: a solution to feed the world and ensure freshwater by 2050

Photo, posted February 11, 2015, courtesy of Ed Dunens via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Too Many Bison | Earth Wise

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In the northern part of Yellowstone National Park, an historically large bison herd is hampering the comeback of quaking aspen trees, whose numbers were greatly diminished by decades of over-browsing by elk.  Restoring the balance of ecosystems at Yellowstone is proving to be a complicated matter.

Long ago, the bison population in the Great Plains was as much as 30 million.  The population sharply decreased in the 1800s.  By the 1830s, there were no bison east of the Mississippi River.  Fifty years later, the Plains bison was nearly extinct.  Several small herds lived near Yellowstone Park when it was established in 1872, but poachers killed off nearly of them by the turn of the century.  Protective measures were taken and by 1925, Yellowstone’s Lamar Valley herd had grown to more than 750.  After that, occasional culling took place for over 40 years. 

When gray wolves and cougars were removed from the park, elk populations boomed, and the elk gradually decimated the growth of quaking aspen, cottonwood, willow, and berry-producing shrubs.  Both elk and bison were regularly culled until 1968 when public and congressional outcry intervened.

The return of wolves and cougars to the park made some progress in restoring ecosystem balance, particularly with respect to the elk population which has dropped from 20,000 to 5,000.  But bison numbers have grown to over 4,000 over past 20 years and the damage once caused by elk is now continuing from bison.

Park administrators are faced with complex management decisions about how to best preserve the ecosystems at Yellowstone National Park.

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Bison in northern Yellowstone proving to be too much of a good thing

Photo, posted October 6, 2016, courtesy of Christian Collins via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Aphids And Monarchs | Earth Wise

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Last year, the monarch butterfly was officially designated as endangered by the International Union for Conservation of Nature.  Estimates are that the overall population of the species has dropped between 20% and 90% over the past several decades. 

The migratory western population of monarchs is at the greatest risk of extinction, having declined by as much as 99.9% between the 1980s and 2021.  Legal and illegal logging and deforestation to make space for agriculture and urban development has destroyed much of the butterflies’ winter shelter in Mexico and California and pesticides and herbicides throughout the butterflies’ range kills both the butterflies and the milkweed that their larvae feed on.

A new study by the University of Florida has found that aphids feeding on the milkweed that grows across the southern portions of the US causes the butterflies to lay fewer eggs on the plants and the caterpillars developing on those plants were slower to mature.  The study showed that monarch laid three times as many eggs on aphid-free plants as they did on aphid-infested plants.

For years, there have been efforts to plant milkweed in urban areas to support monarch populations.  However, aphids and other insect pests often reach high densities on plants in urban settings. 

The researchers are advising home gardeners in the southern U.S. who want to conserve monarch butterflies to make use of safe techniques to limit aphid populations such as insecticidal soap.  This may not always be an option and the researchers are investigating other options to keep aphids at low levels that aren’t harmful to monarchs.

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Aphids make tropical milkweed less inviting to monarch butterflies, study finds

Photo, posted October 12, 2018, courtesy of Renee Grayson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Lakes Are Shrinking | Earth Wise

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A study by the University of Colorado Boulder has found that more than half of the world’s largest lakes have shrunk over the last three decades.  This is a very big problem because about one-quarter of the Earth’s population lives in the basin of a drying lake.  People depend on lakes for drinking water and irrigation and lakes are central to the survival of local ecosystems as well as migrating birds.  Lakes cover only about 3% of the planet, but they hold nearly 90% of the liquid surface freshwater.

The study used satellite observations from 1992 to 2020 to estimate the area and water levels of nearly 2,000 freshwater bodies.  These account for 96% of Earth’s total natural lake storage and 83% of that in man-made reservoirs.  About 53% of the world’s lakes have clearly shrunk, while only 22% have gained water.  The study estimates that about 160 trillion gallons of water has been lost over the 28-year period.  That’s about 17 times the maximum capacity of Lake Mead, the largest reservoir in the United States.

Many of the world’s most significant lakes have been shrinking. The dramatic declines in Lake Mead have been headline news for years.  The Caspian Sea, which is the world’s largest inland body of water – has long been declining.

The main causes of the decline in natural lakes are climate change and human consumption.  Reservoirs face an additional major problem of sediment buildup which reduces their storage capacity and diminishes their benefits of water supply, flood control, and hydropower.

Lake loss is a big problem.

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More than half of the world’s largest lakes are drying up

Photo, posted April 10, 2018, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cryo Conservation | Earth Wise

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Recent studies have shown that there has been a 69% decline in global animal populations since 1970.  There is a biodiversity crisis in the world.  In the face of this situation, there is a growing interest in using cold storage to preserve genetic samples taken from animals threatened with extinction.

Just as egg-freezing is used to preserve human fertility for a later date, the cryogenic freezing of genetic material from animals could be important in reducing species extinctions.  Living cell banks – also known as cryobanks – could preserve genetic materials from animals that include skin cells, embryos, semen, and live tissues.  These materials could be cultured and used for various applications including DNA extraction, assisted reproduction, ensuring genetic diversity in animal populations, and potentially reintroducing species back into their natural habitats.

There is a facility called the Frozen Zoo at the San Diego Wildlife Alliance which has genetic material from 965 different species, including 5% of the vertebrates currently listed as threatened on the IUCN Red List.  Further sampling from zoos and aquariums could increase that representation to almost 17%.

Genetic samples of 50% of the species currently listed as extinct in the wild are already represented in the Frozen Zoo.  Further sampling from the zoological community could increase this number to 91%.  This could provide a critical lifeline for these species that are on the brink of extinction.  As wildlife populations continue to decline around the world, it is more critical than ever to collect and preserve genetic samples from threatened species.

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Cryo conservation – a cool solution to saving species from extinction

Photo, posted September 30, 2018, courtesy of Andy Morffew via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Large Lakes In Decline | Earth Wise

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Globally, freshwater lakes and reservoirs hold 87% of the planet’s liquid freshwater, making them a valuable resource for both people and wildlife.  Despite their value, the long-term trends and changes to water levels of lakes have been largely unknown – until now.

According to a new assessment recently published in the journal Science, more than half of the largest lakes around the world are losing water.  Using satellite observations and climate data, the research team created a technique to measure changes in water levels in nearly 2,000 of the world’s biggest lakes and reservoirs, representing 95% of the total lake water storage on Earth.

The results are staggering.  According to the findings, 53% of Earth’s largest lakes and reservoirs now store significantly less water than they did in 1992.  The total amount of water lost is estimated to be 144.5 cubic miles, which is equivalent to the volume of 17 Lake Meads (the largest reservoir in the U.S.). 

Unsurprisingly, climate warming and human consumption were the main drivers of water loss from lakes, whereas sedimentation — the buildup of debris — was the biggest driver of water loss in reservoirs.  Roughly one-quarter of the world’s population – two billion people – live in the basin of a drying lake, indicating the urgent need for sustainable water resources management.

But the news is not entirely bleak.  According to the research team, the new method of tracking lake water storage trends can give water managers and communities insight into how to better protect this critical resource. 

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Satellites reveal widespread decline in global lake water storage

Photo, posted February 10, 2010, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

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