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A Food For The Future | Earth Wise

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Researchers predict that climate change will negatively impact most staple food crops, including rice, corn, and soybeans.  Therefore, climate resilient food crops – those that are salt, drought, and heat resilient – will have an important role to play in global food security.  Examples of climate resilient crops include quinoa, kernza, amaranth, millet, and tepary beans.    

According to a new study by researchers from Northwestern University, breadfruit – a starchy tree fruit native to the Pacific Islands – will be relatively unaffected by climate change.  Because breadfruit is climate resilient and well-suited to grow in regions with high levels of food insecurity, the research team suggests breadfruit could be a part of the solution to global hunger.

While it has ”fruit” in its name, breadfruit is more like a potato.  It’s starchy and seedless, and is closely related to jackfruit.  Breadfruit is nutrient-rich, and high in fiber, vitamins, and minerals.  It can be steamed, roasted, fried, fermented, and even turned into flour.  People in tropical regions around the world have been eating breadfruit for thousands of years. 

In the study, which was recently published in the journal PLOS Climate, researchers determined the climate conditions necessary to cultivate breadfruit and then looked at how these conditions are predicted to change in the future.  They examined two future climate scenarios: one that reflects high greenhouse-gas emissions and another in which emissions stabilize.

In both scenarios, the regions suitable for breadfruit cultivation were mostly unaffected.  Additionally, the researchers identified new suitable land where breadfruit cultivation could expand.   

As the climate continues to change, breadfruit might soon be on a table near you.

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Climate-resilient breadfruit might be the food of the future

Photo, posted August 11, 2007, courtesy of Malcolm Manners 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.

Humans And Microplastics | Earth Wise

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While plastic comes in all different shapes and sizes, those that are less than five millimeters in length are called microplastics.  Primary sources of microplastics include microfibers from clothing, microbeads, and plastic pellets (known as nurdles).  Secondary sources of microplastics come from larger plastic debris, like bottles and bags, that degrades into smaller bits over time. 

Microplastic pollution can be found everywhere on earth, from the top of the tallest mountains to the bottom of the deepest oceans.  Microplastics are in the food we eat, the water we drink, and the air we breathe. 

According to research recently published in the journal Exposure & Health, humans ingest an average of five grams of plastic particles per week. This is roughly equivalent to the weight of a credit card.  The plastic particles are trafficked in via food, such as seafood and salt in particular, as well as water.  In fact, those who rely on plastic bottled water for their drinking needs ingest an additional 1,700 plastic particles each week.   

Microplastics have also been detected in human blood for the first time.  According to new research recently published in the journal Environment International, scientists detected microplastics in nearly 80% of the people they tested. 

Half of the blood samples contained PET plastic, which is commonly used for drinking bottles.  One third of the blood samples contained polystyrene plastic, which is often used for food packaging.  One quarter of the blood samples contained polyethylene plastic, which is used to make things like shopping bags and detergent bottles. 

With plastic production predicted to double by 2040, more research is urgently needed to understand how ingesting microplastics affects human health.

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Health risk due to micro- and nanoplastics in food

Microplastics found in human blood for first time

Discovery and quantification of plastic particle pollution in human blood

Photo, posted November 3, 2012, courtesy of Laura via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lake Tuz Is Disappearing | Earth Wise

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Lake Tuz is Turkey’s second-largest lake and one of the world’s largest hypersaline lakes.  Its high salt content makes it an ideal breeding ground for some migratory bird species, including flamingos, which are often present there in huge numbers in the spring and summer.

Now, Lake Tuz rarely spans an area much larger than a puddle. In some summers, it completely dries up.  It did so this past summer, which resulted in the deaths of thousands of flamingos.

According to experts, Lake Tuz is a victim of climate change-induced drought, which has hit the region hard, and decades of harmful agricultural policies that exhausted the underground water supply.

Water in this region has become increasingly scarce.  The Mediterranean Basin has already seen more frequent and intense droughts, and is considered a climate change hotspot. 

According to new research, which was recently published in the journal Regional Environmental Change, Lake Tuz generally contained enough water in August for the lake to be considered permanent up until 2000.  But between 2001 and 2016, something shifted.  Water spanned less than 20% of the lake in every August except for one, and droughts became more frequent and intense. And in some years, the lake completely dried up.   

What caused this change?  According to the research team, Lake Tuz’s decline coincided with the excessive use of groundwater and surface water resources responsible for feeding the lake.  Some streams were rerouted for agricultural purposes, while others were dammed.  And when surface water sources dwindled, people turned to groundwater that historically fed the springs in Lake Tuz. 

Lake Tuz may be on the brink of extinction. 

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Impact of climate variability on the surface of Lake Tuz (Turkey), 1985–2016

Disappearing Lake Tuz

Photo, posted August 16, 2021, courtesy of Godot via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wind Farms Slowing Each Other Down | Earth Wise

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Offshore wind is booming in Europe.  The expansion of wind energy in the German Bight and Baltic Sea has been especially dramatic.  At this point, there are about 8 gigawatts of wind turbines in German waters, the equivalent of about 8 nuclear power plants.  But space in this region is limited so that wind farms are sometimes built very close to one another.

A team of researchers from the Helmholtz Center Hereon, a major German research institute, has found that wind speeds downstream from large windfarms are significantly slowed down.  In a study published in the journal Nature Scientific Reports, they found that this braking effect can result in astonishingly large-scale lowering of wind speeds.

On average, the regions of lowered wind can extend 20-30 miles and, under certain weather conditions, can even extend up to 60 miles.  As a result, the output of a neighboring wind farm located within this distance can be reduced by 20 to 25 percent.

These wake effects are weather dependent.  During stable weather conditions, which are typically the case in the spring in German waters, the effects can be especially large.  During stormy times, such as in November and December, the atmosphere is so mixed that the wind farm wake effects are relatively small.

Based on their modeling, it is clear that if wind farms are planned to be located close together, these wake effects need to be taken into account.  The researchers next want to investigate the effects that reduced wind speeds have on life in the sea.  Ocean winds affect salt and oxygen content, temperatures, and nutrients in the water.  It is important to find out how reduced winds might affect marine ecosystems.

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Are wind farms slowing each other down?

Photo, posted November 23, 2011, courtesy of David J Laporte 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.

Using CO2 To Convert Seawater Into Drinking Water | Earth Wise

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A chemist at the University of Copenhagen has invented a technology that uses carbon dioxide to convert seawater into drinking water within minutes.  This desalination technology has the potential to replace electricity with CO2 and be used in survival gear and in large-scale industrial plants in places where people don’t have clean drinking water.

Over 800 million people worldwide lack access to clean drinking water and that number is growing rapidly.  Seawater is a vital source of drinking water in many parts of the world, but desalination faces the major challenge of being highly energy intensive.  Desalination plants use huge amounts of fossil fuel-generated electricity and therefore contribute to climate change.

The Copenhagen technology is reminiscent of a SodaStream machine.  Carbon dioxide is added to water, initiating a chemical reaction.  But instead of using it for bubbly carbonation, it is used to separate salt from water.  It works by adding a chemical called CO2-responsive diamine to saltwater.  The diamine compound binds with the added CO2 and acts as a sponge to absorb the salt, which can then be separated.  The entire process takes one to ten minutes.  Once the CO2 is removed, the salt is released again, allowing the diamine to be reused for several more rounds of desalination.

In the laboratory, the method removed 99.6% of the salt in seawater.  The technology is still being developed to lower its price and optimize the recycling process.  It is also being tested on a small scale in the form of water bottles fitted with special filters that can be used in lifeboats or in other outdoor settings.  Ultimately, it could be used to greatly reduce the energy consumption of desalination plants.

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Chemist uses CO2 to convert seawater into drinking water

Photo, posted January 10, 2015, courtesy of Daniel Orth 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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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.

Another Problem For Coral Reefs

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Coral reefs around the world have been suffering in recent years from warming ocean temperatures as well as from increasing ocean acidification.  Corals are very sensitive organisms that can only tolerate relatively slight changes in their environment.  Thus, the majority of reef-building corals are found in tropical and subtropical waters with favorable conditions.

New research has confirmed that drastic changes in ocean salinity from, for example, severe freshwater flooding, provoke similar stress responses in corals as the heating that has resulted in freshwater bleaching and, eventually, coral death.

The coast of northeast Queensland in Australia has experienced abnormal monsoon-related freshwater flooding that caused extreme and sudden changes in the ocean salt concentration.  In places, nearshore reefs were exposed to water with only half the normal ocean salinity.  The result has been a shock response in corals that prevents normal cell function.  Unlike their response to heat stress, corals exposed to reduced salinity experience a complete collapse of their internal cellular protein balance.

The central Great Barrier Reef has actually been relatively free from mass thermal bleaching events this Australian summer, but many coastal reefs instead have been battling dramatic changes in water conditions as a result of massive plumes of floodwater.

The wild weather in Australia is undoubtedly associated with the changing climate and this new research shows that it is leading to yet another threat to the world’s coral reefs.  With the frequency and severity of heavy rainfall and runoff events predicted to continue to increase over the next few decades, proactive measures to increase the resiliency of coral reefs are needed more than ever.

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Reduced salinity of seawater wreaks havoc on coral chemistry

Photo, posted December 12, 2010, courtesy of Gareth Williams via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Power From The Sun’s Heat

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When we think of solar power, we usually are talking about the panels that generate electricity using the photovoltaic effect.  These panels are on millions of rooftops around the world and in utility-scale solar farms.   There are also solar water heating systems that use the sun’s heat to provide hot water for homes and businesses.

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A Better Filter For Saltwater

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Turning seawater into drinkable water is a highly desirable capability given that fresh water is generally in short supply and seawater is endlessly abundant.  Desalination plants typically strain salt out of seawater by pumping it through films made of polyamide.  Polyamide filters are riddled with tiny pores that allow water molecules to squeeze through, but not sodium ions.

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Salt Cocktails Compromise Freshwater

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Human activities are exposing US rivers and streams to a cocktail of salts, with consequences for infrastructure and drinking water supplies. Road salt, fertilizers, and mining waste – as well as natural weathering of concrete, rocks, and soils – all contribute to increased salt in waterways. When these different salt compounds combine, their harmful effects can amplify.

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Saving The Sea From Salt

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The Persian Gulf along with the Red and Mediterranean seas are getting saltier all the time because of the waste products of desalination.   The United Arab Emirates, Saudi Arabia, Kuwait, Qatar, Bahrain and Oman account for 45% of the world’s desalination capacity.  And the byproduct of desalination is brine, which is twice as salty as seawater.   Even advanced desalination plants produce two cubic meters of waste brine for every one cubic meter of clean water.

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De-Icing Roadways

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We have been using salt to keep winter roads free of ice and snow since the late 1930s.  In the United States alone, some 20 million tons of salt are applied to roadways each year.  And while its use has real benefits in terms of safety and navigation, there have been cumulative costs to the environment, including degrading freshwater resources and contaminating groundwater. 

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Road Salt

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Snow season is here.  The chances are good you’ll find yourself behind a truck spreading salt on the roads in an attempt to deice them. You may even try a little salt on your own front porch. Annually we spread about 20 million tons of road salt in the U.S., and we’ve been doing it since the late 1930s.

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Microplastics And Salt

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Today, thousands of personal care products – such as facial scrubs, body washes, and toothpastes – are known to contain minuscule balls of plastic called microbeads.  When we shower or brush our teeth, these microbeads are washed down the drain and travel undetected through wastewater treatment plants.  When they reach their final destination — our lakes, rivers and oceans — they mix with other sources of microplastics, including industrial waste and degraded plastic litter.    

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