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A Miracle Tree | Earth Wise

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The world needs to be fed without destroying the environment.   We need to grow more trees to store more carbon on earth and reduce the amount in the atmosphere.  But meanwhile, we decimate rainforests to produce palm oil and grow soybeans.

A startup company in California called Terviva thinks they have a solution.  It’s called pongamia, which is an ordinary looking tropical tree.  It produces beans packed with protein and oil, much like soybeans.  However, it has the potential to produce much more nutrition per acre than soybeans and it is hardy enough to grow on pretty much any kind of land without the use of pesticides, fertilizers, or irrigation.  In short, it is a miracle crop for a hot and hungry planet that is running out of fertile farmland and fresh water.

Pongamia is not a new or rare tree.  It is common in India but grows all over the world.  It is often planted as an ornamental here in the U.S.

The initial idea for making use of the hardy tree was to use its oil as a biofuel.  The seeds of pongamia are known to have a bitter taste and disagreeable odor, which is why the seeds or oil were never used for human or animal feed.  However, Terviva has developed a way to de-bitter pongamia oil.  Once this is done, it becomes a golden-colored substitute for olive oil. It also has enormous potential as a protein for plant-based milks and meats, since it contains all nine essential amino acids.

Terviva has raised more than $100 million to further develop pongamia and is now partnering with Danone, a $25 billion multinational food company, to develop pongamia as a climate-friendly, climate-resilient, non-GMO alternative to soy and palm oil.

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This super-tree could help feed the world and fight climate change

Photo, posted December 15, 2015, courtesy of Lauren Gutierrez via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar-Powered Desalination | Earth Wise

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About two-thirds of humanity is affected by water shortages.  In the developing world, many areas with water shortages also lack dependable sources of electricity.  Given this situation, there is widespread research on using solar heat to desalinate seawater.  To date, many approaches to this face problems with fouling of equipment with salt buildup.  Tackling this issue has proven to add complexity and expense to solar desalination techniques.

A team of researchers from MIT and China has recently developed a solution to the problem of salt accumulation that is more efficient than previous methods and is less expensive as well.

Previous attempts at solar desalination have relied on some sort of wick to draw saline water through the device.  These wicks are vulnerable to salt accumulation and are difficult to clean.  The MIT-Chinese team has developed a wick-free system instead.  It is a layered system with dark material at the top to absorb the sun’s heat, and then a thin layer of water that sits above a perforated layer of plastic material.  That layer sits atop a deep reservoir of salty water such as a tank or pond.  The researchers determined the optimal size for the holes in the perforated plastic.

The 2.5 millimeter holes are large enough to allow for convective circulation between the warmer upper layer of water above the perforated layer and the colder reservoir below.  That circulation naturally draws the salt from the thin layer above down into the much larger body of water below.

The system utilizes low-cost, easy to use materials.  The next step is to scale up the devices into a size that has practical applications.  According to the team, just a one-square-meter system could provide a family’s daily needs for drinking water.

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Solar-powered system offers a route to inexpensive desalination

Photo, posted February 13, 2017, courtesy of Jacob Vanderheyden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lithium Mining And The Environment | Earth Wise

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The Salar de Atacama in Chile is a large, dry salt flat surrounded by mountain ranges and is one of the driest places on Earth. Parts of the Atacama Desert have gone without rain for as long as people have been keeping track. Water rich in dissolved salts lies beneath this flat surface and it is particularly rich in lithium salts.  Forty percent of the world’s known lithium deposits are the in the Salar.

Lithium is the key component of the batteries that power electric cars as well as cell phones and computers.  It is an essential part of the transition away from fossil fuels and towards green energy.  But it is important that this element is obtained responsibly with minimal damage to the environment.

Lithium, the lightest of the metals, tends to occur in layers of volcanic ash, but reacts quickly with water.  It leaches into groundwater and settles in flat basins where it remains in a briny solution.  This dense brine often ends up beneath pockets of fresh surface water, which are havens for fragile ecosystems.

A new study by the University of Massachusetts Amherst looked at the hydrological impact of lithium mining in the Salar.  The study found that the impact of lithium mining depends critically on how long surface water is in place.  Much of the fresh water there is at least 60 years old.  Both droughts and extreme rainfall can cause major changes to the surface water that ordinarily comes from mountain runoff.  Lithium mining itself only accounts for less than 10% of freshwater usage in the Salar. But the state of the surface water needs to be carefully monitored to protect the ecosystems as the climate continues to change.

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How environmentally responsible is lithium brine mining? It depends on how old the water is

Photo, posted February 21, 2016, courtesy of Jorge Pacheco via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Reshaping Our Planet | Earth Wise

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Human activity – especially agriculture – has altered 70% of the land on our planet.  According to a new report from the United Nations, damage to the Earth’s lands has put the planet on “crisis footing”.

Our health, our economy, and our well-being depend on land.  The food we eat, the water we drink, and the air we breathe all rely on status of the land to at least some extent.

According to the report, up to 40% of the planet’s land is already degraded, affecting half of the people alive today.  At current rates, an additional area nearly the size of South America will be degraded by 2050.

Degradation of land occurs in various ways, including deforestation, desertification, and the loss of wetlands or grasslands.  All of these things are caused by human activities.  As forests, savannas, wetlands, and mangrove swamps are converted to agriculture or are lost to urban expansion, greenhouse gas emissions rapidly increase, adding to the effects of climate change.  The climate crisis, biodiversity loss, and land degradation are integrally linked.

Much of the blame for degraded landscapes is on humanity’s ever-expanding need for food and the modern farming systems that produce it.  The global food system is responsible for 80% of the world’s deforestation, 70% of freshwater use, and is the greatest driver of land-based biodiversity loss.  Modern agriculture has altered the face of the planet more than any other human activity.

The report urges efforts at restoration of land.  Restoration can take multiple forms, including planting forests and shrubs or grazing livestock and growing crops between trees instead of clearing existing forests.

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UN Report Says Humanity Has Altered 70 Percent of the Earth’s Land, Putting the Planet on a ‘Crisis Footing’

Photo, posted June 20, 2010, courtesy of Nicholas A. Tonelli via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Scourge Of Salt | Earth Wise

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Rising seas are increasing saltwater intrusion on land and rising temperatures are causing greater evaporation.   The result is mounting levels of salt in waters and in soils.

Rising sea levels cause salty ocean water to push further into river deltas.  There is already a surge in saltiness across all inhabited continents.   Seawater works its way further upstream when dams hold back water.  Pumps that remove fresh water from underground sources for irrigation and drinking supplies add to the problem.  In dry regions, irrigation systems delivering water to crops increasingly bring salt onto fields.

People add to the problem by pouring saline drainage water from mines into rivers and by using salt to de-ice roads in the winter.

A modeling study pinpointed hotspots for climate change-induced salinization in numerous locations including the U.S. Southwest, wide areas of Australia, Mexico, South Africa, Brazil, central India, northern China, and more.

Some ecosystems are adapted to saline environments but major alterations in the balance between saline and fresh water is creating growing problems for ecosystems, lake fisheries, crop growing, and even human health.

The damage caused by salt is likely to be so severe that salinization will become a major cause of environmental refugees when the land they live on can no longer sustain them. 

Salt will be a growing threat to the world’s food supplies, especially where farmers depend on artificial irrigation.  About a third of the world’s food is grown in irrigated fields, and a fifth of those fields are deemed to already be salt-contaminated.  Ultimately, only a halt to climate change will be capable of combatting the scourge of salt.

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Salt Scourge: The Dual Threat of Warming and Rising Salinity

Photo, posted June 3, 2017, courtesy of Jason Jacobs via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change On Mount Everest | Earth Wise

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Climate change has shown up in the highest place on Earth.  The highest glacier on Mount Everest is rapidly retreating with rising temperatures.

New research by an international team led by the University of Maine and published in the journal Climate and Atmospheric Science has determined that the South Col Glacier atop Mount Everest has shrunk by half since the 1990s.   Its ice mass has thinned by an estimated 180 feet.

The glacier used to be covered by snow, which reflected the sun’s light and insulated the mass of ice under the snow.  But warmer temperatures, lower humidity, and more severe winds have eliminated the snow cover, fueling the decline of the glacier.

The study of the South Col Glacier highlights the critical balance created by snow-covered surfaces and exposes the potential for loss throughout high mountain glacier systems as snow cover is depleted by warming temperatures.  When even the highest glacier on Mount Everest is impacted, it is clear that no place is safe from the warming climate.

The human significance of this development is substantial.  More than 200 million people in Asia depend on meltwater from glaciers in the high mountains of the continent for their freshwater needs.  But now glaciers in the mountains are melting faster than they can be replenished by snowfall.

As for Mount Everest itself, future expeditions on the mountain will face new challenges as glacier melting causes more avalanches and climbers accustomed to digging into ice and snow will need to scale more exposed bedrock.  Climate predictions for the Himalaya in general all anticipate continued warming and continued loss of glacier mass.

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Climate Change Has Reached the Top of Mount Everest, Thinning Its Highest Glacier

Photo, posted October 27, 2011, courtesy of Goran Hogland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Drought And Desalination | Earth Wise

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The Western US is currently experiencing what might be the worst drought in over 1,000 years.   The region has seen many droughts in the past, but the changing climate is making dry years drier and wet years wetter.   Diminishing snow-packs mean that rivers, streams, reservoirs, and soil are not replenished enough in the spring and summer.

Meanwhile, the Southwest has seen a growth rate over the past 60 years that is twice that of the rest of the country.  More and more people are moving to areas expected to get even drier in the years to come.  There have been unprecedented water allocation cuts from the Colorado River – which provides water to seven states – and there have been shutdowns of hydroelectric power plants.

Only three percent of the planet’s water is fresh water and much of that is not available for our use.  Over 120 countries have turned to desalination for at least some of their drinking water.  In the US, the largest plant is in Carlsbad, California and a huge new plant is likely to be built in Huntington Beach, California.

Desalination has its drawbacks.  It is expensive, consumes large amounts of energy, and has detrimental environmental impacts.  Most of the world’s desal plants now use membrane filtration technology but there are still many that use the thermal distillation method.

There are efforts around the world aimed at improving desalination.  A giant project in Saudi Arabia is based on solar heating of sea water.  The U.S. Army and the University of Rochester are working on a different solar-based system.  European companies are developing a floating seawater desalination plant powered by wind energy. 

Droughts seem to be here to stay.  Finding better ways to get fresh water is essential.

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A 1,000 Year Drought is Hitting the West. Could Desalination Be a Solution?

Photo, posted May 31, 2021, courtesy of Frank Schulenburg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wastewater As A Freshwater Source | Earth Wise

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Water covers three-quarters of our planet, but freshwater – the water we drink, bathe in, and irrigate crops with – comprises only 3% of the world’s water and much of that is frozen in glaciers or otherwise unavailable.  Nearly 3 billion people suffer from water scarcity for at least some of the year.

Natural freshwater sources – lakes, rivers, and groundwater – are under stress from the effects of climate change and from the increasing demands of city populations.  The wastewater treatment plants in large cities represent a significant potential water source provided that sustainable and economical technologies to produce it can be developed.

Researchers at Lehigh University in Pennsylvania have patented an innovative ion exchange desalination process that is a legitimate candidate to transform wastewater into usable water.

Existing large-scale desalination systems make use of semipermeable reverse osmosis membranes that require an energy source to run the system.  The Lehigh process, which they call HIX-Desal, harnesses the unique chemistry of carbon dioxide to take the place of the energy used in reverse osmosis systems. 

Tests of the new system show that the salinity of treated wastewater can be reduced by more than 60% by the HIX-Desal process without requiring any reverse osmosis.  At an Allentown, Pennsylvania water treatment plant where the system was tested, the researchers estimated that using the system could save about a million kWh per day in electricity usage, enough energy to power 94 homes for a year.

With this system, waste carbon dioxide from landfills or turbine exhaust can be used to desalinate municipal wastewater.  It could be the basis of a circular economy.

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Desalination tech uses CO2 to tap into municipal wastewater as alternative freshwater source

Photo, posted November 28, 2020, courtesy of Richard Ricciardi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Surviving Climate Change | Earth Wise

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The sixth mass extinction of wildlife on Earth is happening now.  According to an analysis published last year in the journal Proceedings of the National Academy of Sciences, more than 500 species of land animals are on the brink of extinction and are likely to be lost within the next 20 years. Without the impact of humans, this quantity of extinctions would have taken thousands of years. 

Anthropogenic climate change continues to exacerbate problems that drive species to the brink.  Which species will be able to adapt and survive?

Using genome sequencing, a research team from McGill University in Montreal has found that some fish, like the threespine stickleback, can adapt very rapidly to extreme seasonal changes. Known for their different shapes, sizes, and behaviors, stickleback fish can live in both saltwater and freshwater, and can tolerate a wide range of temperatures.

Stickleback fish, which can be found in different estuaries along coastal California, provided researchers with an opportunity to study natural selection in real-time.  The researchers analyzed six populations of threespine stickleback fish before and after seasonal changes to their environment.   The research team discovered evidence of genetic changes driven by the seasonal shifts in habitat that mirrored the differences found between long-established freshwater and saltwater populations.  Since these genetic changes occurred in independent populations over a single season, the study highlights just how quickly the effects of natural selection can be detected. 

These findings suggest that scientists may be able to use the genetic differences that evolved in the past as a way to predict how species may adapt to climate change in the future.

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Which animals will survive climate change?

Sixth Mass Extinction of Wildlife Accelerating- Study

Photo, posted August 3, 2015, courtesy of Jason Ching/University of Washington via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rising Seas In The Maldives | Earth Wise

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The Republic of Maldives is an archipelago in the Indian Ocean, southwest of Sri Lanka and India and about 400 miles from the Asian mainland.  It is one of the world’s most geographically dispersed sovereign states, the smallest Asian country by land area, and, with a little over 500,000 inhabitants, the second least populous country in Asia.  With its spectacular scenic beauty, it is also a premier tourist attraction.

With more than 80% of its 1,190 coral islands standing less than 1 meter above sea level, the Maldives has the lowest terrain of any country in the world.  As a result, the Maldives is particularly vulnerable to the sea level rise associated with climate change.

Some studies predict a grim future for the Maldives as well as other low-lying islands.  One study concluded that the islands could become uninhabitable by 2050 as wave-driven flooding becomes more common and freshwater becomes limited.

The Maldives government has explored plans to purchase land on higher ground in other countries.  Planners are also working to enhance the resilience of the country’s current islands.   An example is Hulhumalé, a newly constructed artificial island northeast of the country’s capital, Malé.

Construction of Hulhumalé began in 1997 and it now covers 1.5 square miles, making it the fourth largest island in the Maldives.  Its population is now more than 50,000, with more than 200,000 expected to eventually move there.  The new island, built by pumping sand from the seafloor onto a coral platform, rises about 2 meters above sea level.  The extra height could make the new island a refuge for Maldivians driven off lower-lying islands by the rising seas.

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Preparing for Rising Seas in the Maldives

Photo, posted June 15, 2009, courtesy of Elena N via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Harvesting Water From Air | Earth Wise

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Developing new technologies that harvest water from the air is a growing field of research driven by the fact that more and more people live in areas where fresh water is in short supply.  Estimates are that roughly half the world’s population lives in regions with severe freshwater shortages for at least one month each year.

We have previously discussed some of the novel approaches that researchers are taking to enhance water harvesting.  The work at UC Berkeley using metalorganic frameworks is a notable example.

One of the key problems in harvesting water from air is that many droplets that condense from water vapor in the air are too small to be collected and when they cover a surface, they can actually impede further condensation.

University of Texas at Dallas researchers have developed a novel surface that encourages tiny water droplets to move spontaneously into larger droplets.  The droplets actually self-climb along an oil, ramp-shaped meniscus.  The meniscus acts like a bridge along which microdroplets spontaneously climb upward and coalesce with larger water droplets.  They call this the coarsening droplet phenomenon.  It is enabled by a liquid lubricant with a unique hydrophilic nature.  They actually discovered the lubricant’s special properties by accident when in a lubricant test they observed smaller water droplets propel themselves into larger droplets.

Based on experimental data, the coarsening surface enhances the water harvesting rate 200% higher than other techniques.  The team continues to work on ways to use the new lubricant to make sustainable water harvesting systems that are mobile, smaller in size, lower in weight, and less expensive.  If they are successful, they will essentially be able to harvest water anywhere that has air.

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New Physical Phenomenon Aids Harvest of Water from Air

Photo, posted April 26, 2014, courtesy of Toukou Sousui via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Can We Tow Icebergs To Use Their Water? | Earth Wise

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At any given time, there are thousands of icebergs adrift in Antarctica that are hundreds or even thousands of feet across.  For at least fifty years, there has been speculation about whether such icebergs could be towed from the Antarctic to places experiencing freshwater shortages.  The feasibility of such a scheme is still the subject of studies that nowadays include sophisticated computer modeling.

Places like the Persian Gulf, Cape Town, South Africa, and Perth, Australia all experience water shortages and could benefit tremendously from having a large iceberg towed to their waters.

How big an iceberg would it take to quench the thirst of a city like Cape Town?  Computer models show that an iceberg 2,000 feet long and 650 feet thick could produce enough water to supply the city for more than a year.  However, with water temperatures in the 60s in the area, even such a large iceberg would melt away within weeks.  So, to get enough water for a year, it would require a much larger iceberg – one at least a couple of miles long.

Daunting problems include figuring out how many and what sort of ships would be required.  An alternative to such giant icebergs would be finding a way to insulate the icebergs so they don’t melt as quickly, thereby allowing much smaller and more towable icebergs to be harvested.

Beyond these issues, there are the ecological issues of the effects of huge amounts of very cold fresh water affecting local marine ecosystems. 

Despite a wide range of challenges, there is continued interest in the idea of using icebergs as a source of very pure fresh water.  In an increasingly thirsty world, it might someday actually happen.

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Can icebergs be towed to water-starved cities?

Photo, posted November 1, 2007, courtesy of M A Felton via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Understanding How To Enhance Desalination | Earth Wise

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Desalination is the process of removing mineral components – notably salt – from saline water, generally seawater.  Over 16,000 desalination plants operate across 177 countries, generating 25 billion gallons of fresh water each year.  Currently, desalination accounts for about 1% of the world’s drinking water.

The leading process for desalination in terms of installed capacity as well as new installations is reverse osmosis that makes use of a thin-film composite membrane based on ultra-thin polyamide.

Despite the fact that these membranes are widely used for desalination, they are actually rather poorly understood.  It has not been known exactly how water moves through them.  As a result, much of the progress made on the technology over the decades has been essentially based on guesswork.

A team of researchers at the University of Texas, Austin has used advanced microscopy techniques to solve some of the mysteries of reverse osmosis membranes.  By mapping membranes at very high resolution – less than half the diameter of a DNA strand – they gained a much better understanding of what makes a membrane better at reverse osmosis.

They found that desalination membranes are inconsistent in mass distribution and density and that these inconsistencies can impair membrane performance.  It turns out that inconsistencies and dead zones in membranes play a bigger role than membrane thickness.  By making the membranes more uniform in density at the nanoscale, they were able to increase desalination efficiency 30 to 40 percent, therefore cleaning more water with less energy and at lower cost.

Producing fresh water is not just essential for public health, it is also crucial for use in agriculture and energy production.

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Nanoscale control of internal inhomogeneity enhances water transport in desalination membranes

Photo, posted February 13, 2017, courtesy of Jacob Vanderheyden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A New Fishway Technology | Earth Wise

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Freshwater fish populations have declined by more than 80% over the past forty years across the globe.  This is in part due to hundreds of thousands of dams, weirs, and barriers stopping their movements.  These river barriers have disrupted fish reproduction cycles the world over by preventing river fish from migrating to spawn.

Fishways or fish ladders are waterways constructed on or around obstructions in order to provide passageways for fish and other aquatic species.  Often, they consist of a series of small overflow weirs and pools constructed in the form of steps.  Fish need to jump from one pool to another to migrate to the upstream.  Such fish ladders require a large space to construct.  These and several other types of fishways tend to be expensive to install and maintain and are not always successful in allowing fish to get to where they need to go.

Researchers at the University of New South Wales in Australia have come up with an ingenious new type of fishway.  Called a “tube fishway”, it is a low-cost and low-energy installation that works by pumping fish at high velocity – protected by a cushion of bubbly water – through a tube running over the obstructing barrier to deliver them safely into the water on the other side.

They successfully demonstrated a prototype system on a rugged slope behind a campus building that transported fish from one tank to another about 25 feet up the slope.

Fish are attracted into the chamber by suitable geometry and the system uses the energy available from the upper reservoir to lift the fish.  Modeling shows that the system will work for pipes as large as three feet in diameter and could lift fish more than 300 feet vertically. 

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New fishway technology to get fish up and over those dam walls

Photo, posted October 19, 2019, courtesy of Andrew Harvey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Global Decline In Wildlife | Earth Wise

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According to a new report released by the World Wildlife Fund, global populations of mammals, birds, amphibians, reptiles, and fish have declined by 68% in less than half a century. 

The report presents a comprehensive overview of the state of the natural world based on the tracking of almost 21,000 populations of more than 4,000 vertebrate species between 1970 and 2016. 

The report shows that the main cause of the dramatic decline in species populations on land is habitat loss and degradation, which includes deforestation driven by food production.  Additional factors include land-use change and the use and trade of wildlife.

Wildlife populations found in freshwater habitats have suffered a decline of 84%, which is the steepest decline in any biome.

Insect populations have declined rapidly in many places, but most of the information about insects comes from a small number of countries in the northern hemisphere.  There is very little information from large parts of the world, such as Africa, South America, and Asia, where land-use change and agricultural expansion are happening fast.  What happens to insects matters a lot to humanity.  Insects play central roles in the world’s ecosystems as waste processors, pollinators, predators, and prey. 

The report is clear evidence of the damage human activity is doing to the natural world.  Threats to the integrity of ecosystems endanger humans and all of nature.  This is especially apparent in the midst of a global pandemic.  It is now more important than ever to take coordinated global action to halt and reverse the loss of biodiversity and wildlife populations across the globe.

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Living Planet Report reveals 68% decline in global wildlife populations since 1970

Photo, posted May 7, 2020, courtesy of Bernard Spragg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Foods of the Future? | Earth Wise

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In a world where many go hungry in the context of rapidly changing environments, many experts contend that alternative food sources will be necessary to solve global food security problems.  So-called novel food sources are central to this conversation, defined as foods with no history of consumption in a region – or perhaps anywhere.

Three popular examples are lab-grown meat, insect farming, and seaweed aquaculture.  Each of these offer opportunities as well as challenges.

Lab-grown meat can refer to actual animal tissues raised in vats as well as the increasingly common cultured plant products made to resemble meat.  Lab-grown meat faces push back from the livestock industry that contends it should not be labeled as any kind of meat. While results to date are positive, barriers still remain including concerns over product taste, healthiness, and cost.  And while less land- and water-intensive than conventional livestock, cultured meat production is still energy intensive.

Insects do form a significant part of diets across the globe but have yet to be embraced in any substantial way in western cultures.  Nutritionally, numerous species of insects are rich in key proteins, micronutrients, and minerals.  But the “yuck factor” is a big barrier to cross.

Seaweed is a long-established part of many East Asian diets and has many potential dietary uses.  Several selectively bred varieties of seaweed supply a range of valuable nutrients.  Growing seaweed does not tax freshwater and terrestrial resources.  But intensively cultivated seaweeds would have potential negative effects on local marine ecosystems.

There is no single solution to complex issues like food security.  Novel foods may very well form part of the solution to a growing food crisis.

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Insects, seaweed and lab-grown meat could be the foods of the future

Photo, posted March 12, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Blue Acceleration | Earth Wise

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The oil and gas sector is the largest ocean industry.  It’s responsible for about one third of the value of the ocean economy.  Sand and gravel, destined for the construction industry, are the most mined minerals in the ocean.  And during the past 50 years, approximately 16,000 desalination plants have popped up around the world to help supply people with an increasingly scarce commodity: freshwater. 

As a result of these and other human pressures, the world’s oceans have suffered a lot over time.  But according to a comprehensive new analysis on the state of the ocean, human pressure on the world’s oceans, driven by a combination of technological progress and declining land-based resources, sharply accelerated at the start of the 21st century.  Scientists have dubbed this dramatic increase, which shows no signs of slowing down, the “Blue Acceleration.”

A  research team from Stockholm University analyzed 50 years of data from aquaculture, bioprospecting, shipping, drilling, deep-sea mining, and more.  Their findings were recently published in the journal One Earth.

While claiming ocean resources and space is not new, lead author Jean-Baptiste Jouffray from the Stockholm Resilience Centre says “the extent, intensity, and diversity of today’s aspirations are unprecedented.”

The researchers also highlight how not all human impacts on the ocean are negative.  For example, offshore wind farm technology has reached commercial viability allowing the world to reduce reliance on fossil fuels.

But how can the Blue Acceleration be slowed?  Since only a handful of multinational companies dominate sectors like the seafood industry, oil and gas exploitation, and bioprospecting, one idea is to have banks and other investors adopt more stringent sustainability criteria for making ocean investments. 

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Human pressure on world’s ocean shows no sign of slowing

Photo, posted October 29, 2008, courtesy of Silke Baron via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Harvesting Blue Energy | Earth Wise

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There are various ways to generate renewable energy from the world’s oceans, most obviously from the power of tides and waves.  But there is also an oceanic energy source called osmotic or “blue” energy.  Osmotic energy uses the differences in pressure and salinity between freshwater and saltwater to generate electricity. 

When freshwater and saltwater are mixed together, large amounts of energy are released. If the freshwater and seawater are then separated via a semi-permeable membrane, the freshwater will pass through the membrane and dilute the saltwater due to the chemical potential difference. This process is called osmosis. If the salt ions are captured completely by the membrane, the passing of water through the membrane will create a pressure known as osmotic pressure. This pressure can be used to generate electricity by using it to drive a turbine.  This has been demonstrated to work as far back as the 1970s, but the materials we have to use are not adequate to withstand ocean conditions over the long term and tend to break down quickly in the water.

New research, published in the journal Joule, looked to living organisms for inspiration to develop an improved osmotic energy system.  Scientists from the U.S. and Australia combined multiple materials to mimic the kind of high-performance membranes that are found in living organisms.  They created a hybrid membrane made from aramid microfibers (like those used in Kevlar) and boron nitride.  The new material provides both the flexibility of cartilage and the strength and stability of bone.

The researchers believe that the low cost and high stability of the new hybrid membrane will allow it to succeed in volatile marine environments.  They also expect the technology will be both efficient and scalable. 

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Inspired by the Tissues of Living Organisms, Researchers Take One Step Closer to Harvesting “Blue Energy”

Photo, posted February 14, 2017, courtesy of Marian May via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Forest Regrowth In The Amazon | Earth Wise

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The Amazon is the largest tropical rainforest in the world.  It covers an area approximately equal in size to the lower 48 states, and is home to an estimated 10% of the world’s biodiversity and 15% of its freshwater.  These so-called “lungs of the planet” provide many important global ecological services, including carbon storage, and regulating air quality and climate.

Deforestation in the Amazon exploded in the 1970s and remains one of its biggest threats today.  Since the 1970s, more than 20% of the Amazon rainforest has been cleared.  Cattle ranching, soy and palm plantations, logging, and climate change are some of the biggest drivers of deforestation.  

Now, according to a new study recently published in the journal Ecology, the regrowth of Amazonian forests following deforestation may happen more slowly than previously thought.  These findings could have significant impacts on climate change predictions as the ability of forest regrowth in the Amazon – so-called secondary forests – may have been overestimated.  The research, which was conducted in Bragança, Brazil and includes two decades of forest monitoring, reveals that climate change and the wider loss of forests could be hampering regrowth.    

After 60 years of regrowth, the research team found that secondary forests only held 40% of the carbon when compared with forests undisturbed by humans.  Secondary forests also take less carbon from the atmosphere during periods of drought, and climate change is increasing the number of drought-years in the Amazon.  (During their 20 years of monitoring, the researchers also found biodiversity levels in secondary forests were only 56% of those seen in undisturbed forests). 

More long-term studies are needed to better understand the impacts of reforestation efforts.  

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Web Links

Amazon forest regrowth much slower than previously thought

Photo, posted September 6, 2009, courtesy of Nao Lizuka via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lake George Health Report

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The Offshore Chemistry Program, run by the Darrin Fresh Water Institute at RPI, has been monitoring the deep waters of Lake George in New York for 40 years.  Lake George, nicknamed the Queen of American Lakes, is famed for the transparency of its water and a new report on the health of the lake reveals that it is doing rather well.

According to the report, although concentrations of chemicals and pollutants like salt and nutrients have increased in the deep waters of Lake George, they are still too low to harm the ecosystem at those depths.

The Offshore Chemistry Program studies the lake as part of a collaboration between RPI, IBM Research, and the FUND for Lake George that is called the Jefferson Project.  This long-term commitment provides a wealth of information over time matched by few lake studies in the world.

The recent results show that levels of salt, the nutrient orthophosphate, and chlorophyll have increased substantially over time, but none are yet at a level that will cause harm.

Orthophosphate occurs naturally, but most likely the higher levels are due to improperly functioning septic systems, failing wastewater treatment systems, and stormwater runoff.  The orthophosphate most likely triggered the increase in chlorophyll, which probably is associated with increased density of chlorophyll in individual algal cells, rather than an increase in total algal mass in the lake.

Overall, the results demonstrate the continuing resilience of Lake George to a growing array of stressors.  In nearly 40 years of human activities, the lake has changed in a number of ways, but the changes have so far been relatively small.  With such careful monitoring, we can hope to keep them that way.

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Web Links

Four Decades of Data Sounds Early Warning on Lake George

Photo, posted September 24, 2009, courtesy of GPA Photo Archive via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

WAMC Northeast Public Radio

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