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Blue Carbon Credits | Earth Wise

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Carbon credits have been around since the late 1990s.  The idea is to offset carbon emissions from some carbon emitting activity – anything from a wedding in California to a factory operating in Minnesota – by buying carbon credits earned from a carbon-absorbing activity, such as planting trees in the Amazon.

Blue carbon credits are credits earned by increasing the carbon stored in coastal and marine ecosystems. Coastal ecosystems such as mangroves, tidal marshes, and seagrass meadows in fact sequester and store more carbon per unit area than terrestrial forests and are increasingly being recognized for their important role in mitigating climate change. 

Blue carbon credit awards have to date been relatively few and far between and have mostly been granted for mangrove restoration efforts.  But mangrove projects are now ramping up dramatically in scope.  Scientists are working hard to analyze the amount of carbon in other ecosystem types – seagrasses, salt marshes, seaweeds, and seafloor sediments – so that these systems can also enter the carbon credit market.

Over the past 20 years, conservation scientists have spread over 70 million seeds in the bays of Virginia to restore over 9,000 acres of seagrass meadows that were devastated by disease in the 1930s.  The restored meadows are absorbing nearly half a ton of CO2 per acre. 

The rules to allow for blue carbon credits are recent and evolving, which is a big deal. The market may currently be small, but it is growing exponentially.  But as important as carbon credits are, it is still paramount to decarbonize before turning to offsets for existing emissions.

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Why the Market for ‘Blue Carbon’ Credits May Be Poised to Take Off

Photo, posted July 2, 2009, courtesy of Nicolas Raymond via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Wood Into Plastic | Earth Wise

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Plastic pollution is particularly pernicious because plastics can take hundreds of years to degrade in the environment.  For this reason, researchers across the globe search for ways to shift from petrochemical plastics to ones that are biodegradable.

Producing biodegradable plastics is challenging both from the standpoint of the methods needed and from the results obtained.  Producing them often requires toxic chemicals and can be very expensive.  The materials that emerge often do not have the durability and strength of conventional plastics and can be unstable when exposed to moisture.

Researchers at the Yale School of the Environment have developed a process of decomposing the porous matrix of natural wood into a slurry that can be formed into a biodegradable plastic.  The material shows high mechanical strength, stability when holding liquids, and is resistant to the effects of ultraviolet light.  Along with all these favorable properties, the material can be recycled or safely biodegraded in the natural environment.

The slurry mixture is created by taking wood powder – a processing residue usually discarded in lumber mills – and deconstructing it with a biodegradable and recyclable solvent.  The resulting mixture has a high solid content and high viscosity and can be casted and rolled without breaking.

The researchers conducted a comprehensive life cycle assessment to test the environmental impacts of the bioplastic compared with conventional plastics.  Sheets of it were buried in soil and observed to fracture after two weeks and completely degrade after three months.  The material can also be broken back down into the slurry by mechanical stirring.

The remaining topic to investigate is the potential impact on forests if the manufacturing of this bioplastic is scaled up.

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Turning wood into plastic

Photo, posted October 12, 2016, courtesy of the US Forest Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Collapse of Northern California Kelp Forests | Earth Wise

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For thousands of years, thick canopies of kelp formed an underwater forest spanning the coast of Northern California.  Kelp is the cornerstone of a rich subtidal community, providing food and habitat for all sorts of marine creatures.  But in recent years, a shocking transformation has occurred.  Satellite imagery reveals that the area covered by kelp forests off the coast of Northern California has declined by more than 95%.  Only a few small, isolated patches remain.  

In a new study, researchers at the University of California Santa Cruz found that the kelp forest decline was an abrupt collapse as opposed to a gradual decline. 

According to the study, which was recently published in the journal Communications Biology, kelp forests north of San Francisco were resilient to warming events in the past, like El Niños and marine heatwaves. But the decline of a key sea urchin predator – the sunflower sea star – from sea star wasting disease caused the kelp forests’ resiliency to plummet.  Sea urchins are voracious consumers of kelp.     

But it was a series of events – not just the sea urchins – that combined to decimate the Northern California kelp forest.   A marine heatwave that became known as “the blob” developed in 2014 and moved down the West Coast in 2015.  Around the same time, a strong El Niño event developed and brought warmer water up the coast from the south.  The warming ocean waters combined with the ravenous sea urchin population resulted in the dramatic decline of kelp. 

According to researchers, the prospects for a Northern California kelp forest recovery remain poor unless sea urchin predators return to the ecosystem. 

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The collapse of Northern California kelp forests will be hard to reverse

Photo, posted August 13, 2019, courtesy of Sara Hamilton of OSU College of Science via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Not All Trees Cool The Planet | Earth Wise

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A new study from Clark University has found that deforestation does not always contribute to planetary warming, as is generally assumed.  The researchers have found that there can be places where removing trees actually cools the planet.

Forests soak up carbon dioxide from the air and store it in the trees themselves and in the soil.   This process is important for slowing the accumulation of greenhouse gases in the atmosphere.

The new research focuses on a different effect that forests have on climate.  They are darker than other surfaces, which causes them to absorb more sunlight and retain heat.  This is known as the albedo effect.

In most places, the absorption of carbon outweighs the albedo effect and forests help cool the planet.  But there are some locations, including the Intermountain and Rocky Mountain West, where more forest actually leads to a hotter planet when both processes are taken into account.  State-of-the-art satellite remote sensing allowed the researchers to quantify the effects of forest loss in the United States.

The upshot of this research is that large-scale tree-planting initiatives, such as Canada’s 2Billion Trees Initiative and the Nature Conservancy’s Plant a Billion Trees campaign need to make sure to put the right trees in the right places.

Every year, about a million acres of forest are being converted to non-forest across the lower 48 states as a result of suburban and exurban expansion and development.   It is important to take into account the albedo effect in trying to replace the climate-cooling capabilities of these disappearing forests by planting more trees.

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Clark geographer Christopher Williams: More trees do not always create a cooler planet

Photo, posted June 5, 2017, courtesy of Todd Petrie 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.

Tracking Endangered Species From Space | Earth Wise

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Scientists at the University of Bath and the University of Oxford in the UK have developed a technique for remotely surveying elephants and other wildlife using satellite images and deep learning.  The technique has the same accuracy as human counts done on the ground or from low-flying airplanes.

The new computer algorithm can analyze high-resolution satellite images and detect African elephants in both grasslands and forests.  Previous techniques for monitoring wildlife from space were limited to homogenous habitats, such as the case of tracking whales in the open ocean.

On-the-ground or airplane surveys to monitor animal numbers are expensive and time-consuming.  Satellites can collect nearly 2,000 square miles of imagery in a few minutes thereby eliminating the risk of double counting and reducing a process that previously took weeks to just a few days.  The use of satellites also eliminates the logistical problems of monitoring species populations that cross international borders.

Accurate monitoring is important for efforts to save endangered species.  There are only 40,000 – 50,000 African elephants left in the wild.  It is essential to know where the animals are and how many there are in various locations. The new method is able to count elephants in mixed ecosystems, such as savannah and forests, where tree cover would previously have made satellite tracking difficult.

With satellite imagery resolution increasing every few years, it should be possible to see ever-smaller things in greater detail.  The new algorithm works well for elephants; it may eventually become practical to track animals as small as an albatross from space.

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A New Way to Track Endangered Wildlife Populations from Space

Photo, posted March 15, 2008, courtesy of Michelle Gadd/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Global Warming Could Stabilize | Earth Wise

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The world has been heading toward climate disaster with the effects of greenhouse gas-induced warming looming larger and larger.  But recent analysis published in Nature Climate Change offers hope that rapidly eliminating emissions could stabilize global temperatures just within a couple of decades.

For quite some time, it has been assumed that further global warming would be locked in for generations regardless of the extent of emissions reductions going forward.  This conclusion was based on having a certain carbon dioxide concentration in the atmosphere which would linger for hundreds of years even if emissions were reduced.

Recent analysis takes into account the dynamism of the Earth’s natural systems which could actually reduce atmospheric CO2 content because of the huge carbon absorption capacity of oceans, wetlands, and forests.  The key requirement is to drastically reduce emissions so that these natural systems can take over.

More than 100 countries have pledged to get to net zero emissions by 2050.  That means they will emit no more carbon dioxide than is removed from the atmosphere by such actions as restoring forests.   The UK, Japan, and the European Union are among the countries that have set this zero target, and the United States is joining the club.

Climate models show that a global temperature rise of 2 degrees Celsius over that of the pre-industrial period would lead to global calamities that include punishing heatwaves, flooding, and mass displacement of people.  The world has already heated up by 1.1 degrees and governments have committed to restrain the rise to less than 1.5 degrees under the Paris Climate Agreement.

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Global Warming Could Stabilize Faster than Originally Thought If Nations Achieve Net Zero

Photo, posted September 10, 2017, courtesy of Ron Cogswell via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The First Earth Fund Awards | Earth Wise

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Last February, Amazon CEO Jeff Bezos announced that he was launching the Bezos Earth Fund that would grant money to scientists, activists, NGOs and others making an effort to help preserve and protect the natural world.  The fund would start out with $10 billion and would begin issuing grants later in the year.

In November, the first Earth Fund award recipients were announced.  In total, 16 organizations will be receiving nearly $800 million in funding.

The largest awards include the following:  the Environmental Defense Fund received $100 million to build and launch MethaneSAT, a satellite that will locate and measure sources of methane pollution around the world and provide public access to data that assures accountability.

The Natural Resources Defense Council was awarded $100 million to advance climate solutions and legislation at the state level, promote policies and programs focused on reducing oil and gas production, protect and restore ecosystems that store carbon, and accelerate sustainable and regenerative agriculture practices.

The Nature Conservancy also received $100 million and plans to use the money to help protect the Emerald Edge forest.  (That is the largest intact coastal rainforest on Earth, spanning 100 million acres through Washington, British Columbia and Alaska).

The World Resources Institute will receive $100 million, doled out over five years, to be used to develop a satellite-based monitoring system to advance natural climate solutions around the world.

An additional $100 million award went to the World Wildlife Fund to help protect and restore mangroves, develop new markets for seaweed as an alternative to fossil fuel-based products, and to protect forests and other ecosystems around the world.

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The organizations that will benefit from Bezos’ $791M and what will they do with the money

Photo, posted March 4, 2015, courtesy of Kevin Gill via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Palm Oil Replacement | Earth Wise

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In the 1990s, cardiovascular health issues associated with partially hydrogenated oils containing harmful trans fats became a focus of great concern.  As a result, food companies looked for substitutes and the alternative they identified was palm oil.  Its ability to remain solid at room temperature made it well suited for many food applications.  Unfortunately, that property stems from its high saturated fat content, which means it also increases the risk of coronary heart disease.

The widespread use of palm oil has also caused significant environmental problems.  Palm oil plantations have replaced millions of acres of tropical forests, destroying the habitat for numerous species and threatening biodiversity.

Other potential replacements for partially hydrogenated oils such as coconut oil tend to be more costly, limited in supply, and also high in saturated fats.

Food scientists at the University of Guelph in Ontario, Canada, recently demonstrated the use of enzymatic glycerolysis (EG) to turn liquid vegetable oils into solid fats.  Their process is able to produce solid fats with the textural and structural properties desired by consumers.

The process is fairly simple, relatively easy to scale up, and is amenable to smaller food production or even local production.  Using it would enable food producers to use all sorts of readily available vegetable oils that can be produced in parts of the world that are not necessarily tropical regions.

Palm oil use is not going to go away, but this work may point a way to help slow down the destruction of ecosystems and animal habitats as well lead to more sustainable and healthy food sources.

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U of G Food Scientists Find Palm Oil Alternative That’s Good for Human, Planet Health

Photo, posted February 21, 2010, courtesy of Craig Morey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Do Forests Grow Better With Our Help? | Earth Wise

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Tree planting has become a worldwide cause.  International calls to plant a trillion trees to combat climate change have led to multiple initiatives by countries around the world.  Even the current U.S. administration, with support from businesses and nonprofits has promised to plant over 800 million trees across an estimated 2.8 million acres.  Planting trees is widely seen to be a vital nature-based solution to climate change; a way of moderating its effects as the world works to reduce carbon emissions.  However, recent studies have created some pushback from that view.

The new studies are not opposed to trees.  What they have revealed is that allowing forests to grow back naturally is a better strategy than planting trees.  The new data has shown that, among other things, estimates of the rate of carbon accumulation by natural forest regrowth have on average been 32% too low and, for tropical forests, have been 53% too low.

A new study published in Nature identified 1.67 billion acres that could be set aside to allow trees to regrow.  It excludes land under cultivation or built on, along with various existing valuable ecosystems. 

Natural regrowth allows nature to select which tree species take hold and turns out to happen quite rapidly and in a widespread manner.  The great thing about natural restoration of forests is that it often requires nothing more than human inaction.  Because it requires no policy initiatives, investments, or oversight, data on its extent is rather scarce.  But the data we have reveals that wherever forests have been allowed to recover on their own, it appears to happen rapidly and with great success.

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Natural Debate: Do Forests Grow Better With Our Help or Without?

Photo, posted September 5, 2015, courtesy of Nicholas A. Tonelli via Flickr.

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.

Earth Wise is a production of WAMC Northeast Public Radio.

The Dangers Of Negative Emissions Technologies | Earth Wise

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Reducing carbon emissions is not easy and there are plenty of people who don’t even want to try for various reasons, generally related to their perceived economic interests and convenience.  As a result, there is a great deal of interest in so-called negative emissions technologies or NETs.   These are methods for removing carbon dioxide from the atmosphere.  Even the UN Intergovernmental Panel on Climate Change assumes that NETs will play a role in mitigating the effects of climate change and meeting international goals.

The most widely studied approaches to negative emissions technology are bioenergy with carbon capture and storage – which entails growing crops for fuel, and then capturing and burying the CO2 produced from burning the fuel; planting more forests; and direct air capture, which involves actually pulling CO2 out of the air and storing it – probably underground. 

A new study published in Nature Climate Change points out that none of these technologies has even been tried at the demonstration scale, much less at the massive levels required to make a dent in current CO2 emissions. 

Their analysis of the biofuel and reforestation strategies show that each would take up vast land and water resources already needed for agriculture and nature.  Air capture uses less water than the other two approaches, but still uses quite a bit and even more energy, which if supplied by fossil fuels, would offset the benefits of carbon capture.

Negative emissions technologies may well play an important role in combating climate change, but it is essential that we understand what the consequences will be from implementing them.  We need to know the pitfalls that could arise.  It would be a major mistake to simply count on NETs to be some kind of silver bullet.

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Remove CO2 from the air? Don’t bet on it before examining costs, researchers say

Photo, posted January 11, 2008, courtesy of Al Pavangkanan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Restoring Tropical Forests | Earth Wise

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Tropical forests store more than half of the world’s above-ground carbon.  For this reason, deforestation is one of the greatest threats to global climate regulation.   Once forests are degraded through partial clearing and agricultural conversion, they are often perceived as no longer having much ecological value even though degraded forests still provide important ecosystem services despite no longer storing as much carbon.

As a result, once forests have been degraded, they tend to be seen as prime candidates for full conversion to agricultural plantations.   But this is not actually the case.

An international team of scientists, including researchers from Arizona State University’s Center for Global Discovery and Conservation Science, has provided the first long-term comparison of above-ground carbon recovery rates between naturally regenerating and actively restored forests in Southeast Asia.

First of all, the research shows that allowing forests to regenerate naturally results in significant amounts of restored above-ground carbon storage.  It is definitely worthwhile to allow forests to recover rather than giving up on them and putting the land to other uses.

But more importantly, the researchers found that forest areas that undergo active restoration recover their carbon-storing ability 50% faster than naturally recovering forests.

Restoration methods include planting native tree species and thinning vegetation around saplings to improve their chances of survival.   

These findings suggest that restoring tropical forests is a viable and highly scalable solution to regaining lost carbon stocks on land.  What is needed is sufficient incentive to engage in active forest restoration.  The current price of carbon is not sufficient to pay for restoration, but as the climate crisis intensifies, this is likely to change.

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Tempe to Hawaii: ASU professors teach Hawaiian youth about coral reef conservation

Photo, posted May 22, 2008, courtesy of Eric Chan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tree-Planting Is Not Necessarily A Good Thing | Earth Wise

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There is no question that forests have a major role in efforts to combat climate change as well as to slow biodiversity loss.   As a result, tree-planting on a massive scale has gained traction as a strategy and there have been major commitments made to plant billions of trees around the world.

A new study at Stanford University has rigorously analyzed the potential effects of these efforts and has found some significant problems.  For example, the Bonn Challenge, which seeks to restore an area of forest more than eight times the size of California over the next 10 years, has 80% of its commitments in the form of  planting monoculture tree plantations or a limited mix of trees that produce fruit and rubber, rather than restoring natural forests.   The problem is that plantations have significantly less potential for carbon sequestration, habitat creation, and erosion control than natural forests.  The potential benefits of the planting dwindle further if planted trees replace natural flora – forests, grasslands, or savannahs – which are ecosystems that have evolved to support local biodiversity.

The study looked at previous policies that created subsidies for planting trees.  Chile’s Decree Law, in effect from 1974 to 2012, has served as a model for similar policies in a number of countries.  Those subsidies further reduced native forest cover by encouraging the establishment of plantations in places where forests might have naturally regenerated.  The subsidies expanded the area covered by trees, but decreased the area of native forests.

The study recommends that nations should design and enforce their forest subsidy policies to avoid undesirable ecological impacts and actually promote the recovery of carbon- and biodiversity-rich ecosystems.

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Poorly designed tree-planting campaigns could do more harm than good, according to Stanford researcher and others

Photo, posted April 28, 2016, courtesy of the U.S. Department of State via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A High-Tech Fire Alarm | Earth Wise

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In recent years, wildfires have been a global problem, notably in California, Brazil, and Australia.  It has become increasingly important to be able to respond to new fires as soon and as quickly as possible.  Such response can make the task of extinguishing them easier, thereby reducing the amount of damage and the loss of property and life.

Traditional methods for detecting forest fires include satellite monitoring, ground patrols, and watch towers, all of which have high labor and financial costs but suffer from low efficiency.  Remote sensing technologies are becoming increasingly common but rely on batteries for power, requiring servicing in remote locations to replace depleted batteries.  Solar cells represent an alternative to batteries, but it is challenging to use them in forests because of shading and foliage coverage.

A team of researchers at Michigan State University has developed a remote forest fire detection and alarm system powered by nothing more than the movement of tree limbs in the wind.  The device is known as an MC-TENG, which is an acronym for multilayered cylindrical triboelectric nanogenerator.  The triboelectric effect is a phenomenon where certain materials become electrically charged when they separate from a second material with which they were previously in contact.  In the new device, two cylindrical sleeves fit within one another – one anchored and the other free to slide.  The device is tied to a tree branch and when the branch sporadically moves in the wind, electricity is generated and stored in a carbon-nanotube-based micro supercapacitor.  This powers a sensing system that can continuously monitor environmental conditions without requiring any maintenance.

A combination of carbon monoxide and temperature sensors provides a high-tech fire alarm that can operate continuously in the most remote forest.

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Self-Powered Alarm Fights Forest Fires, Monitors Environment

Photo, posted August 3, 2012, courtesy of Lukas Schlagenhauf via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Planting Trees and Climate Change | Earth Wise

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Forests are among the most important natural carbon sinks.  Trees remove carbon from the air and store it in their trunks, branches, and leaves, and transfer part of it into the soil.  But in some regions, these natural carbon sinks are starting to weaken due to deforestation, forest degradation, and the impacts of climate change.  This problem has led some climate mitigation projects to focus on increasing the overall number of trees on the planet. 

But, according to a paper recently published in the journal Science, “we can’t plant our way out of climate change.”  That’s the simple message from Restoration Ecologist Karen Holl and University of São Paulo Professor Pedro Brancalion to anyone who thinks planting one trillion trees will reverse the effects of climate change.  They say planting more trees is only one piece of the puzzle.  Any initiatives like 1t.org or the Trillion Tree Campaign must be done carefully and be accompanied by commitments to long-term management.

Tree plantings can provide many environmental benefits, including improving water quality, biodiversity, and increasing shade.  But trees can sometimes have undesirable impacts, such as harming native species and ecosystems or reducing water availability, depending on where and how the trees are planted.

The authors suggest four principles that should guide forest enhancement initiatives: reduce forest clearing and degradation, balance ecological and social goals, view tree plantings as one part of a multifaceted solution, and plan, coordinate and monitor the work. 

While tree plantings can clearly be part of the solution, slowing the pace of climate change requires a comprehensive approach that must start with burning less fossil fuels.

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Challenges in tree-planting programs

Planting trees is no panacea for climate change

Photo, posted December 1, 2019, courtesy of Akuppa John Wigham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Natural Habitats And Strawberry Farms | Earth Wise

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According to a new study led by researchers from the University of California – Davis, conserving natural habitat around strawberry fields can protect farmers’ yields, their bottom line, and the environment.  The study also suggests that conserving natural habitat in this way has no detectable threat to food safety. 

In this study, which was recently published in the journal Ecological Applications, the research team conducted surveys and experiments at 20 strawberry farms along California’s Central Coast.  This region is responsible for 43% of the nation’s strawberry production. 

The researchers found that strawberry farmers were better off with natural habitat, like forests, grasslands, wetlands, and shrubs, around their farms than without it.  According to the study’s models, adding natural habitat can reduce crop damage costs by 23%.  Removing natural habitat can increase costs by as much as 76%. 

Importantly, the strawberry farms with natural habitat surrounding them showed no signs of increased fecal contamination.  While bird feces were regularly encountered on the ground, only 2 of 10,000 strawberries examined show signs of direct fecal contamination.  Those contaminated berries would be discarded during the hand-harvesting process.   

These findings run contradictory to current best practice recommendations that support natural habitat removal around strawberry farms in order to decrease bird fecal contamination and crop damage.  These food safety requirements were a consequence of the deadly outbreak of E. coli in 2006, which was traced back to spinach grown in this region.   

It seems like our agricultural landscapes can both support and benefit from biodiversity. 

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Natural habitat around farms a win for strawberry growers, birds and consumers

Photo, posted June 16, 2011, courtesy of the USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Rising Threat Of Rising Seas | Earth Wise

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Global sea level rose by about 6 inches during the 20th century.  It is currently rising more than twice as fast and accelerating.  The rate of rise was 2.5 times faster from 2006 to 2016 than it was for nearly all of the 20th century.

Sea level rise occurs when glaciers and ice sheets lose mass.  Much of that meltwater comes from Greenland and Antarctica.  But levels also rise because, as water warms, it expands.  Added to that are the effects of human activities such as groundwater depletion and a geological phenomenon called isostatic adjustment that is going on in parts of the East Coast where the land is actually sinking.

In Atlantic Canada, sea level rise is outpacing the global average and has already led to boardwalks swamped by swelling tides, drowned forests, submerged wharfs, and threatened historic shoreline buildings.

Recent research suggests that globally, land now occupied by 300 million people could be affected by floods at least once a year by 2050 unless carbon emissions are significantly reduced, and coastal defenses strengthened.  (This new figure is more than three times higher than earlier estimates).

Researchers at Dalhousie University in Nova Scotia are studying nature-based strategies for mitigating the effects of the rising seas.  These include conserving or restoring coastal ecosystems like dunes, wetlands, and reefs which could provide protection at a lower cost than building seawalls and other man-made obstacles.  Wetlands, for example, can reduce the force of waves and act as obstacles to storm surges, while also trapping sediment and stemming erosion.  Wetlands also serve as important carbon stores, but it is estimated that roughly half of the world’s coastal wetlands have been lost over the past 100 years to human activity and extreme weather events.

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The Looming Threat of Rising Sea Levels – And What We Can Do About it

Photo, posted February 14, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bioacoustics

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Researchers are increasingly placing microphones in forests and other ecosystems to monitor birds, insects, frogs, and other animals.  Advances in technology are enabling the wide-spread use of bioacoustics as an important research tool.

Studying animals in their natural habitat Is often a difficult task.  For one thing, many animals are difficult to find, and the presence of humans disrupts their behavior or even drives them off.  Remote cameras are useful, but cameras can only see what is in front of them and aren’t much use for detecting small animals, hidden animals, or ones high up in trees.

Biologists have long recognized the value of recording sound to identify animals and learn about their havior.  Animal sounds can be as definitive a means of identification as visual images and microphones can pick up the sounds from animals located anywhere within their detection range.

The two advances in technology that are turning bioacoustics into a widely used tool are a steep drop in the price of recording equipment and the rapidly expanding capabilities of user-friendly artificial intelligence algorithms.

Autonomous environmental audio recorders tended to cost between $500 and $1000 until quite recently.  Now, such equipment can be had for as little as $70.

The other big challenge is analyzing audio data.  Finding specific animal sounds among hundreds of hours of recordings is an untenably tedious task.  Identifying the characteristic sounds of specific species in crowded environments is a tricky business.  But neural network-based artificial intelligence technology is making such big data analysis quite practical and, remarkably, it is becoming quite user-friendly.

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Listening to Nature: The Emerging Field of Bioacoustics

Photo, posted January 28, 2013, courtesy of Felix Uribe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Out-Migration And Reforestation

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A challenging global trend is that of deforestation in developing countries.  But there are places where the opposite trend is happening.  Nepal is one such place.

According to satellite imaging, in 1992 forest covered 26% of Nepal.  As of 2016, that number was 45%. 

To some extent, the forest regrowth was a result of policy changes from about three decades ago, when the government began removing management authority from bureaucrats and shifting it to local communities across the country.  This local management helped to reduce illegal logging and many local villages undertook tree-planting campaigns.

But perhaps a bigger factor at play is human migration.  In recent decades, millions of Nepalis have left the country to work in the Persian Gulf, Southeast Asia, and elsewhere.  The out-migrants wire money home and meanwhile, families left behind rely less on forest products or abandon farmland, aiding reforestation.  A 2018 study showed that the areas with the highest out-migration experience, on average, had the most forest recovery.

Globally, migration has important impacts on forests, but not always positive ones.  In many countries, forests seem to recover as people leave rural areas to work elsewhere.  El Salvador, for example, has seen a rebound of its forests as many of its rural residents move to cities or even to the United States. But in Guatemala and Nicaragua, the return of migrants bringing money they have earned overseas has led to an expansion of cattle ranching that has harmed forests.

The global relationship between migration and forests is a complicated one that depends on whether the migration is one-way or “circular” (meaning that the migrants eventually return) and how returning migrants make use of their earnings from abroad.

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In Nepal, Out-Migration Is Helping Fuel a Forest Resurgence

Photo, posted September 30, 2018, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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