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Natural solutions for disappearing islands

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Atoll islands are made from sediment produced by corals, clams, snails, and varieties of algae that secrete carbonate.  Under the right conditions, over time, fragments of coral skeletons, shells, and other sediments made by marine life are piled up by waves.  Eventually, islands are formed – some large and some small.  Atoll islands are home to a diversity of human cultures and are important refuges for a quarter of the world’s seabirds as well as numerous nesting sea turtles and tropical plants.

Rising sea levels – the rate of which has more than doubled over the past 30 years – are a mounting challenge for atoll islands.  And by the end of this century, sea level is projected to rise between 11 and 40 inches, depending on the world’s actions with regard to greenhouse gas emissions.

The ability of atoll islands to persist depends on the health of their ecosystems and the extent to which their natural processes have been disrupted by human activity.  To protect the most vulnerable islands, some researchers now propose using nature-based solutions – like restoring and protecting coral reefs and native forests.

Reclaiming seabird habitat can help reefs persist and restore the resilience of atoll islands.  Seabird guano washes off islands and into reefs, providing nutrients that boost coral growth and fish populations. 

Nature-based solutions cannot help the most urbanized atoll islands.  These islands have already irreversibly lost their natural adaptive capacity.  For those places, engineered approaches such as concrete seawalls are needed.

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How Natural Solutions Can Help Islands Survive Sea Level Rise

Photo, posted July 3, 2014, courtesy of Roderick Eime / MG Media via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Vegetation and climate change

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Temperatures have been steadily rising around the world as a result of the increased greenhouse gas emissions from human activities.  This warming trend has led to more frequent and intense heat waves, droughts, and other extreme weather events.  Rising temperatures are also impacting human health, leading to increased risks of heat-related illnesses and a higher number of fatalities during extreme heat events.

One simple but effective way to reduce the health risks from extreme heat is to increase urban vegetation.  According to new research led by scientists from Monash University in Australia, increasing urban vegetation by 30% could save more than one-third of all heat-related deaths.  The study, which was recently published in The Lancet Planetary Health, examined more than 11,000 urban areas and found that increasing greenery could have saved up to 1.16 million lives worldwide between 2000 and 2019.

The impact of increasing urban vegetation on heat-related deaths varies by climate, greenness, socioeconomic, and demographic factors, with the greatest benefits seen in Southern Asia, Eastern Europe, and Eastern Asia. 

Vegetation has a cooling effect on temperature.  Vegetation helps regulate the Earth’s climate by absorbing carbon dioxide during photosynthesis, which helps to reduce greenhouse gases in the atmosphere. Vegetation also cools the environment through shading, moisture release, and evapotranspiration, which reduces temperatures and mitigates heat-related health risks.

Incorporating more vegetation into urban areas is a powerful solution to mitigate the impacts of climate change and protect human health.

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Increasing urban vegetation could have saved over 1.1m lives in two decades

Photo, posted July 1, 2023, courtesy of Lauri via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tracking atmospheric mercury

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Atmospheric mercury is a toxic pollutant released into the air from natural sources—such as volcanoes and wildfires—and from human activities like coal burning and gold mining.  Once in the atmosphere, mercury can travel long distances before settling onto land or into water, transforming into toxic forms that threaten ecosystems and human health.

But tracking atmospheric mercury is a costly and challenging endeavor, requiring specialized equipment and trained personnel. Active monitors, which pump air to collect mercury, are expensive and need electricity, while passive samplers, using activated charcoal for remote areas, cost up to $100 each.

Researchers from Cornell University have found a cheap method for tracking toxic atmospheric mercury near gold mining sites throughout the Global South: wild fig trees.  In the study, which was conducted in the Peruvian Amazon and recently published in the journal Frontiers in Environmental Science, the research team found that the rings in wild fig trees can serve as natural archives of atmospheric mercury, capturing and preserving historical pollution levels over time.

The technique itself is not actually new.  Previous studies have used tree rings to track mercury pollution from coal combustion, particularly in Canada. But the research team wanted to test this method in regions of the Global South, where mercury emissions from gold mining are widespread.

According to the research team, wild fig trees might soon serve as an important biomonitoring tool, helping scientists better understand how mercury disperses across landscapes and through time.

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Tree rings track atmospheric mercury cheaply

Photo, posted November 13, 2012, courtesy of Steve Kessler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The human impact on biodiversity

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Biodiversity is under threat.  More and more plant and animal species are disappearing and humans are to blame.  Humans cause biodiversity loss through habitat destruction, invasive species, pollution, direct exploitation, and climate change, all of which are significantly influenced by human activities.

But until now, drawing broad conclusions about human impacts on biodiversity has been difficult because a clear, global overview of how human activity affects nature across all species did not exist. Most studies have focused on specific places, impacts, or time periods.

To fill these research gaps, a research team from the University of Zurich in Switzerland and the Swiss Federal Institute of Aquatic Science and Technology conducted an unprecedented synthesis study.  The researchers compiled data from around 2,100 studies that compared biodiversity at almost 50,000 sites affected by humans with similar places that hadn’t been affected by humans. 

The synthesis study, which was recently published in the journal Nature, found humans are having a highly detrimental impact on biodiversity worldwide.  In fact, not only is the number of species declining, but the composition of species communities is also changing.  On average, the number of species at impacted sites was almost 20% lower than at unaffected sites.

The study, which is one of the largest ever conducted on this topic, highlights the widespread negative impact of human activities on nature, and emphasizes the need to consider all forms of life when assessing biodiversity loss. 

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The Devastating Human Impact on Biodiversity

Photo, posted November 19, 2014, courtesy of Green Mountain Girls Farm via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sharks and rays in a warming world

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Sharks and rays belong to a group of cartilaginous fish called elasmobranchs, which have been swimming in the world’s oceans for 450 million years. The resilient species have survived five mass extinction events, and are older than dinosaurs, trees, and Mount Everest. 

But despite their resilience, many species of sharks and rays today are threatened by human activities, including overfishing, habitat loss, and climate change.  In fact, according to a new study led by researchers from the University of Vienna in Austria, more than one third of the shark and ray species known today are severely under threat. 

The study, which was recently published in the journal Biology, found that higher carbon dioxide levels were having a negative effect on sharks and rays, ranging from impacts on the animals’ senses to changes in the skeleton during embryonic development.  An examination of fossil records found that higher CO2 levels had contributed to the extinction of individual shark and ray species in the past. 

But the study also found that global warming could be creating opportunities for sharks and rays.  Rising sea levels and higher temperatures have historically expanded shallow coastal habitats and warm waters, supporting species biodiversity.

But according to the research team, the rapid environmental changes, combined with the impacts from human activities, outpace the ability of sharks and rays to adapt, making it unlikely that they will benefit from global warming.

Protecting sharks and rays is crucial not only for their survival but also for maintaining entire ocean ecosystems. Without top predators, these ecosystems could collapse, impacting both marine life and the people and industries that depend on it.

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Sharks and rays benefit from global warming – but not from CO2 in the Oceans

Myths About Sharks and Rays

Photo, posted November 27, 2007, courtesy of Laszlo Ilyes via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Manatees are not Florida natives

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Florida is very proud of its manatees.  It has a county named after them and has pictures of them on license plates.  These gentle creatures are part of Florida culture.  But recent research indicates that manatees – also known as sea cows – might only be relatively recent residents of the Sunshine State.

Manatees have been spotted in Florida waters for several centuries but might have only been tourists visiting briefly before returning to their home waters in the Caribbean in places like Cuba.

The new research suggests that manatees might not have actually taken up residence in Florida until after Europeans colonized the area in the 1500s.  There is a rarity of manatee bones on archaeological sites that date back further.  It was particularly striking that Crystal River, which is an epicenter for modern manatee populations, had little evidence of their presence in earlier times.

Even into the early 1900s, Florida newspaper reports treated manatee sightings as a spectacle rather than a common occurrence.  In the 1920s and 1930s, there started to be more routine sightings in places like yacht basins and canal harbors.  In the 1950s, manatees became more plentiful in Tampa Bay and Crystal River. The warming waters and human activities creating shallow warm water refuges increased manatee populations, particularly near places like power plants.

The current Florida manatee population is between 8,000 and 12,000 and is classified as threatened under the Endangered Species Act, an improvement over its previous endangered status.  But pollution is killing a lot of the seagrass that they eat, and their safety is by no means assured.

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Why manatees are likely not Florida natives

Photo, posted March 25, 2012, courtesy of David Hinkel / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Carbon levies for shipping

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The global shipping industry is responsible for 90 percent of world trade.  The ships crossing the world’s oceans emit nearly 3% of the global greenhouse gas emissions caused by human activity that are contributing to climate change.  Among the effects of climate change are sea level rise, which is threatening the very existence of small island nations.

One such nation is Tuvalu, which is a group of islands in the South Pacific.  Tuvalu has a total landmass of just 10 square miles, and sea level there is rising 1.5 times faster than the global average.  Predictions are that within 50 to 100 years, low-lying islands like those of Tuvalu could be fully submerged by the ocean.

Representatives from six Pacific Island states and a growing number of Caribbean nations known as the 6Pac+ Alliance are urgently calling upon the International Marine Organization to enact a mandatory universal levy of $150 per ton of shipping emissions from large commercial vessels. 

Most marine vessels typically run on highly polluting heavy fuel oil.  Burning really filthy fuel is the cheapest way to cross the oceans.  There are alternatives including entirely carbon-free technologies, but they will be expensive to implement and utilize.  The cost of shipping would undoubtedly go up and be especially felt by small island nations and in developing countries where most food is imported.

The idea behind putting a price on ships’ carbon emissions is to both provide a financial incentive for the shipping industry to reduce its emissions and provide revenue for countries that incur costs from dealing with rising seas.

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Pacific and Caribbean Island Nations Call for the First Universal Carbon Levy on International Shipping Emissions

Photo, posted November 23, 2006, courtesy of Stefan Lins via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rising methane emissions

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Methane is a colorless and odorless gas that occurs abundantly in nature and is also a product of certain human activities.  It’s a short-lived but highly potent greenhouse gas and, as a result, is a major driver of climate change.  In fact, methane heats the atmosphere nearly 90 times faster than carbon dioxide over a 20-year period. 

Despite a global pledge from more than 150 nations to reduce methane emissions by 30% this decade, methane emissions continue to rise.  In fact, according to a new paper led by researchers from Stanford University, total annual methane emissions have increased 20% over the past two decades. 

The paper, which was recently published in the journal Environmental Research Letters, found that atmospheric concentrations of methane today are more than 2.6 times higher than in pre-industrial times.  In fact, atmospheric methane concentrations are currently the highest they’ve been in at least 800,000 years.

Methane emissions from coal mining, oil and gas production and use, cattle and sheep ranching, and decomposing organic waste in landfills are responsible for driving the growth.  In 2020, the most recent year for which data was available, nearly 400 million tons – or about two-thirds – of global methane emissions came directly from human activities. 

Methane concentrations in Earth’s atmosphere have increased at record speed over the past five years.  According to the research team, only the European Union and possibly Australia seem to have decreased methane emissions from human activities over the past two decades.  This trend “cannot continue if we are to maintain a habitable climate.”

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Methane emissions are rising faster than ever

Photo, posted December 4, 2010, courtesy of Dani Mettler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The impact of climate change on agriculture

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Agriculture is a major part of the climate problem and remains one of the hardest human activities to decarbonize.  Agriculture is responsible for approximately 30% of global greenhouse gas emissions.

On farms around the world, excess fertilizer gets broken down by microbes in the soil, releasing nitrous oxide into the atmosphere.  Nitrous oxide is a greenhouse gas that is 300 times more potent than carbon dioxide.

According to a sweeping global research review recently published in the journal Science, greenhouse gas emissions from agriculture are now 18 times higher than they were in the 1960s. 

The research, which was co-written by professors at the University of Minnesota with more than 20 experts around the world, also reveals the likelihood of an emergent feedback loop between climate and agriculture.  As the changing climate puts more pressure on the global food supply, agriculture will, out of necessity, adopt practices that may exacerbate its environmental impact. Without changes in agriculture, this feedback loop could make it impossible to achieve the Paris Climate Agreement goal of limiting global warming to 1.5 degrees Celsius above pre-industrial levels. 

The research identifies several agricultural practices that could improve efficiency and stabilize our food supply in the decades to come, including precision farming, perennial crop integration, agrivoltaics, nitrogen fixation, and novel genome editing. 

Finding ways to reduce the warming impact of agriculture while maintaining high crop yields are essential to both mitigating climate change and protecting our food supply from its impacts.

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Impact of Climate Change on Agriculture Suggests Even Greater Challenges to the Environment, Global Food Supply and Public Health

Photo, posted October 16, 2010, courtesy of Timlewisnm via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Slow-moving landslides

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Landslides are mass movements of rock, earth, or debris down a slope.  They can be initiated by rainfall, snowmelt, changes in water level, erosion by streams, earthquakes, volcanic activity, or by various human activities.  Most landslides we hear about are sudden events that can cause all sorts of calamities.  But not all landslides are rapid occurrences.  There are also slow-moving landslides.

A new study by the University of Potsdam in Germany has found that as urban centers in mountainous regions grow, more people are building homes on steeper slopes prone to slow-moving landslides.  Slow-moving landslides can move as little as one millimeter a year and up to as much as three meters per year.  Locations with slow-moving landslides can seem safe to settle on; in some cases, the movement itself can be inconspicuous or even completely undetected.

Slow slides can gradually produce damage in houses and other infrastructure and there can also be sudden acceleration from heavy rain or other influences.

The study compiled a new database of nearly 8,000 slow-moving landslides with areas of at least 25 acres located in regions classified as “mountain risk.”  Of the landslides documented, 563 are inhabited by hundreds of thousands of people.  The densest settlements on slow-moving landslides are in northwestern South America and southeastern Africa. 

In all regions of the study, urban center expansion was associated with an increase in exposure to slow-moving landslides.  As cities expand in mountainous areas, people are moving into unsafe areas, but poorer populations may have few other options.

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Slow-moving landslides a growing, but ignored, threat to mountain communities

Photo, posted March 4, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rivers And Climate Change | Earth Wise

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Our planet is heating up.  Scientists have concluded that the changing climate is primarily the result of increased greenhouse gas emissions from human activities.  Some of the effects of global climate change include thawing permafrost, rising seas, intensifying storms and wildfires, and warming oceans.   

According to a new study led by researchers from Penn State University, rivers are warming and losing oxygen even faster than oceans.  The study, which was recently published in the journal Nature Climate Change, found that warming occurred in 87% and oxygen loss occurred in 70% of the nearly 800 rivers studied.

The research team projects that within the next 70 years some river systems, especially those in the American South, will experience such low oxygen levels that the rivers could “induce acute death” for some fish species and threaten the aquatic diversity of river ecosystems. 

The research team used artificial intelligence and deep learning to analyze water quality data from nearly 800 rivers across the U.S. and central Europe.  The researchers found that rivers are warming up and deoxygenating faster than oceans, which could have serious implications for both aquatic life and humans.

While climate change has led to warming and oxygen loss in oceans and lakes around the world, the researchers did not expect to find warming and deoxygenation in shallower, flowing rivers.  Since life in water depends on temperature and dissolved oxygen, the researchers hope this study serves as a wake up call.  Warming and deoxygenating rivers have significant implications for water quality and the health of aquatic ecosystems worldwide.

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Rivers are rapidly warming, losing oxygen; aquatic life at risk

Photo, posted June 2, 2017, courtesy of Francisco Anzola via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

 Restoring Biocrusts | Earth Wise

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Biocrusts are complex ecosystems that form a thin layer on the surface of soils in arid and semiarid environments.  They are composed of variety of microbes including cyanobacteria, green algae, fungi, lichens, and mosses.  Biocrusts play a crucial role in maintaining soil health and ecosystem sustainability.

Biocrusts are under assault from human activities including agriculture, urbanization, and off-road vehicle use. Climate change is also placing stress on biocrusts, which are struggling to adapt to increasing temperatures.

Researchers at Arizona State University have proposed a novel approach to restoring healthy biocrusts.  Their idea is to make use of solar energy farms as nurseries for generating fresh biocrust.  The arrays of solar panels serve as shields from excessive heat and allow biocrusts to flourish and develop.  The newly generated biocrusts can then be used to replenish arid lands where the existing biocrusts have been damaged or destroyed.

When such biocrusts are harvested, the natural recovery process is rather slow, taking around six or eight years to fully recuperate.  But the researchers found that when harvested areas are reinoculated with the microbes, the biocrust cover can reach near-original levels within a year.

The ASU researchers demonstrated the viability of the approach in a three-year study at a solar farm in Arizona’s lower Sonoran Desert.  Based on their results, they conclude that the use of large solar farms for this purpose could provide a low-cost, low-impact, and high-capacity method to regenerate biocrusts and enable soil restoration on a regional scale.  They have dubbed their new approach as “crustivoltaics.”

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Using solar farms to generate fresh desert soil crust

Photo, posted March 12, 2023, courtesy of Eric Peterson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Seaweed On The Way | Earth Wise

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A type of seaweed called sargassum has long formed large blooms in the Atlantic Ocean.  It gets its name from the Sargasso Sea in the western Atlantic.  Since 2011, scientists have been tracking massive accumulations of the stuff each year that starts out off the coast of Africa and works its way across the Atlantic to end up in the Gulf of Mexico. 

The amount of sargassum present each year can shift depending on factors like changes in nutrients, rainfall, and wind conditions.  But since the 1980s, nitrogen content in the Atlantic has gone up by 45%.  This is likely due to human activities such as agriculture and fossil fuel production dumping materials into the rivers that feed into the ocean.

According to recent observations, the mass of seaweed now heading for Florida and other coastlines throughout the Gulf of Mexico may be the largest on record.  The giant blob of sargassum spans more than 5,000 miles in extent.  It is moving west and will pass through the Caribbean and up into the Gulf during the summer.  The seaweed is expected to become prevalent on beaches in Florida around July.

The seaweed provides food and protection for fishes, mammals, marine birds, crabs, sea turtles, and more.  But unfortunately, when sargassum hits the beaches, it piles up in mounds that can be difficult to walk through and eventually emits a gas that smells like rotten eggs.

Tourist destinations in the Caribbean region have their work cut out for them to remove seaweed that can pile up several feet deep.  For example, in Barbados, locals were using 1,600 dump trucks a day to clean their beaches.  Caribbean and Florida resorts spend millions of dollars each year to remove sargassum seaweed.

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A 5,000-mile-wide blob of seaweed is headed for Florida, threatening tourism across the Caribbean

Photo, posted February 24, 2020, courtesy of Bernard Dupont via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Protecting Wetlands | Earth Wise

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Wetlands are distinct ecosystems that are flooded or saturated by water, either permanently or seasonally.  They include mangroves, marshes, swamps, forested wetlands, bogs, wet prairies, and vernal pools.   The feature that most wetlands share is soil or substrate that is at least periodically saturated with or covered by water.

Wetlands are some of the most threatened ecosystems in the world.  While wetlands can be affected by a variety of natural stressors, including erosion, droughts, and storms, human activities have been the major driver of wetland decline. 

But according to a new study by researchers from McGill University in Canada, the global loss of wetland areas since 1700 has likely been overestimated.  The research team calculated that the area of wetland ecosystems around the world has declined 21-35% since 1700 as a result of human activities – far less than the 50-87% decline estimated in other studies.  The study’s focus beyond regions with historically high wetland losses and its avoidance of possibly misleading extrapolations likely resulted in the lower estimate.      

According to the study, which was published in the journal Nature, more than 2.1 million square miles of wetlands have been lost during the past 300 years – an area roughly the size of India.  The five countries with the highest wetland losses are the United States, China, India, Russia and Indonesia. 

But discovering that fewer wetlands have been historically lost than previously thought gives researchers a second chance to protect wetlands.  The findings of the study will help researchers prioritize global conservation and restoration actions.

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A second chance to protect wetlands

Photo, posted February 2, 2005, courtesy of Jan Tik via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Agriculture Turning Wild Plants Into Weeds | Earth Wise

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We often hear about the importance of native plants in the environment and how invasive species can wreak havoc with ecosystems.   But it turns out that human activities can change the characteristics of native species and create unexpected new problems.

Common waterhemp is plant native to North America that typically grows near lakes and streams.  It never used to be any kind of problem, but in recent times it has become nearly impossible to eradicate from farms as a result of genetic adaptations triggered by modern agriculture.

A study led by researchers at the University of British Columbia looked at waterhemp samples from modern farms and neighboring wetlands and compared them with historical samples dating back as far as 1820 stored in various museums.

In recent times, mutations in genes related to drought tolerance, rapid growth, and resistance to herbicides have resulted in waterhemp that has become a pervasive weed on farms.  These genetic shifts, scarcely ever seen in historical samples, have made the plant thrive among human agricultural activities and enable it to outcompete crops.

Genetic analysis of the plants showed that herbicide-resistant mutations that were mostly absent from historical samples stand out as factors that allow waterhemp to prosper in agricultural settings. There are some plants in natural habitats that have herbicide-resistant mutations, but in many cases, these mutations are actually harmful to the plants in the wild.

Understanding how plant adaptations occur on relatively short timescales is increasingly important as farming and climate  change continue to drive rapid plant evolution.

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How intensive agriculture turned a wild plant into a pervasive weed

Photo, posted February 16, 2016, courtesy of Aqua Mechanical via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cloud Seeding And The Western Drought | Earth Wise

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The massive megadrought affecting the American West is now considered to be the driest two-decade period in the past 1,200 years.  The lengthy drought has led to increased wildfires, reduced agricultural productivity, and reduced electricity generation by hydropower plants.  The historically low water levels in the largest two reservoirs in the U.S. – Lake Mead and Lake Powell – has triggered reductions in water allocations to Arizona, Nevada, and Mexico.

Several western states have expanded cloud seeding programs in an attempt to increase precipitation.  During the past two years, Idaho, Utah, Colorado, Wyoming, and California have all stepped up their cloud seeding efforts.  Outside of the US, the United Arab Emirates and China both have implemented massive cloud seeding programs.

A study by researchers at the University of Colorado and the National Center for Atmospheric Research looked at the ability of cloud seeding to increase snowfall.  The study unambiguously demonstrated that cloud seeding can increase snowfall.  Just how effective it is in terms of how much additional snow seeding produces is less clear.

Given the dire need for water and the fact that cloud seeding is not especially expensive, governments and other users are not hesitating to make use of it.

Unfortunately, the study shed no light on the efficacy of warm weather seeding to produce rain.  There is in fact little evidence that seeding clouds to produce rain accomplishes very much.  Once again, the prevailing view is that it is worth trying.  There do not appear to be environmental downsides to seeding.

The hope is that cloud seeding may at least restore clouds to the state they had been in before industrial pollution and other human activities affected them.

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Can Cloud Seeding Help Quench the Thirst of the U.S. West?

Photo, posted November 21, 2013, courtesy of Sharon Tate Soberon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Capturing Methane To Feed Fish | Earth Wise

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Methane in the atmosphere is an extremely potent greenhouse gas.  Its warming potential is about 85 times that of carbon dioxide over a 20-year period.  It also worsens air quality by increasing atmospheric ozone.  Many human activities add methane to the atmosphere, notably emissions from landfills and oil and gas facilities.

Capturing methane from these sources for subsequent use is currently uneconomical but new research from Stanford University analyzes the market for using the methane to feed bacteria to produce fishmeal.

Methane-consuming bacteria called methanotrophs can be grown in chilled, water-filled bioreactors containing pressurized methane, oxygen, and nutrients.  The bacteria produce a protein-rich biomass that can be used as fishmeal in aquaculture.  This could offset demand for fishmeal made from small fish or plant-based feeds that require land, water, and fertilizer.

Some companies already do this using natural gas provided by utility pipelines, but it would be far better for the environment to use methane emitted at large landfills, wastewater treatment plants, and oil and gas facilities.

Consumption of seafood has more than quadrupled since 1960, depleting wild fish stocks.  Farmed fish now provide half of all the animal-sourced seafood we eat.

The Stanford research analyzed the cost of methanotrophic fishmeal production under various scenarios and found it to be very competitive with and in some cases considerably cheaper than current market prices for fishmeal. 

According to the study, this process could profitably supply total global demand for fishmeal with methane captured in the U.S. alone.

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Stanford researchers reveal how to turn a global warming liability into a profitable food security solution

Photo, posted April 30, 2017, courtesy of Artur Rydzewski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Food And Greenhouse Gas Emissions | Earth Wise

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According to a study published in the journal Nature Food, the world’s food systems are responsible for more than one third of global greenhouse gas emissions caused by human activities. 

‘Eat Local’ is often recommended as a way to minimize the carbon footprint of our diet.  But from a climate impact perspective, eating local only has a significant impact if transportation is responsible for a large portion of a food’s final carbon footprint.  And in many cases, greenhouse gas emissions related to transportation make up only a small portion of the emissions from food and what we eat is far more important. 

There are massive differences in the greenhouse gas emissions of various foods. 

For example, producing one pound of beef generates 60 pounds of greenhouse gas emissions.  This is more than double the next closest food (lamb), and more than 60 times greater than some plant crops like corn and cassava. 

For most foods – especially the largest emitters – greenhouse gas emissions from land use change combined with the emissions from processes at the farm stage account for more than 80% of the environmental footprint.  Meanwhile, transportation accounts for less than 10%, and its contribution for the largest emitters is even smaller.  For example, transportation accounts for 0.5% of emissions from beef production.

Eating beef or lamb has many times the carbon footprint of most other foods.  It matters very little in terms of emissions whether it was grown locally or shipped from another part of the world.  It’s not the location that makes the carbon footprint of our dinner large.  It’s what is on our plate that matters.

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Food systems account for over one-third of global greenhouse gas emissions

You want to reduce the carbon footprint of your food?

Photo, posted November 7, 2018, courtesy of Preston Keres / USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Arctic Communities And Permafrost Thaw | Earth Wise

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Permafrost is frozen soil, rock or sediment that can be as much as a few thousand feet thick.  To qualify as permafrost , the material has to have been at or below the freezing point of water for two or more years.  Most of it is located in high latitudes in the Arctic and Antarctic regions.   Permafrost covers nearly a quarter of the exposed land in the Northern Hemisphere.

Permafrost contains enormous amounts of carbon in the form of frozen soil that includes remnants of plants and animals, in some cases that have been there for more than 20,000 years.

The Arctic region has been warming faster than any place else on earth and thawing permafrost is already unleashing methane and carbon dioxide to the atmosphere, adding to the global temperature rise.

Apart from the impact on the global climate, thawing permafrost is making the ground unstable and is causing serious problems for local communities.

Recent research using satellite observations provides an overview of the Arctic to identify communities and infrastructure that will be at risk over the next 30 years.

Using high-resolution data from the Copernicus Sentinel satellite missions along with ground-based data going back to 1997, researchers modeled the permafrost ground temperature trends and extrapolated them out to 2050.  The results were that 55% of the infrastructure currently located on permafrost and within 60 miles of the Arctic coastline – infrastructure on which many communities rely – is likely to be affected.

Most human activity in the Arctic takes place along permafrost coasts.  Permafrost thaw is exposing these coasts to rapid change that threatens biodiversity and puts pressure on communities.

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Satellites pinpoint communities at risk of permafrost thaw

Photo, posted January 24, 2014, courtesy of Brandt Meixell / USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Peatlands And Greenhouse Gas Emissions | Earth Wise

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As the world seeks to reduce the greenhouse gas emissions that have been warming the climate, most of the focus has been on the primary contributors to the problem, such as the burning of fossil fuels.  But there are many smaller contributors to greenhouse gas emissions that individually play only a minor role but collectively add up to significant amounts.  One of these is the emissions from peatlands.

Peatlands are a type of wetland that occur in almost every country on Earth, covering 3% of the global land surface.  They are terrestrial ecosystems in which waterlogged conditions prevent plant material from fully decomposing.  As a result, the production of organic matter exceeds its decomposition, which results in a net accumulation of peat.  Peatlands are, in fact, the largest natural terrestrial carbon store, storing more over 700 billion tons of carbon, more than all other types of vegetation combined.

Human activity, such as creating drainage in peatlands for agriculture and forest plantation, results in the release of over 1.6 billion tons of CO2 into the atmosphere each year. This constitutes 3% of all global greenhouse gas emissions caused by human activities.

Large numbers of people rely on peatlands for their livelihoods, so it is not reasonable for these emission-generating activities to be greatly curtailed.  But researchers at the University of Leicester in the UK analyzed the potential effects of cutting the current drainage depths in croplands and grasslands on peat in half and showed that this could reduce CO2 emissions by more than 500 million tons a year. This equates to one percent of all greenhouse gas emissions caused by human activities.

There are numerous opportunities to reduce emissions a little bit at a time.

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Better peatland management could cut half a billion tonnes of carbon

Photo, posted August 17, 2013, courtesy of Joshua Mayer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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