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A Vaccine For Bees | Earth Wise

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The US has seen annual reductions in honey bee colonies since 2006.  According to the USDA, there are many factors that have contributed to the decline.  These include parasites, pests, insecticides, disease, and a phenomenon called Colony Collapse Disorder in which worker bees abandon a hive and leave behind the queen.

One of major threats to bee colonies is American foulbrood disease, which is a bacterial condition that attacks bee larvae.  It is highly contagious and has no cure.  Until now, the only treatment method required burning the colony of infected bees along with the hives and equipment and treating nearby bee colonies with antibiotics.

Recently, the USDA has approved a conditional license for the world’s first vaccine for honey bees.  The vaccine contains inactive bacteria of the type that causes American foulbrood disease.

The vaccine is incorporated into the royal jelly fed by worker bees to the queen bee.  The queen ingests the feed and keeps some of vaccine in her ovaries.  This gives bee larvae immunity to the disease as they hatch and thereby reduces death from the illness.

According to the California State Beekeepers Association, the new vaccine could be a major breakthrough for protecting bees.  Preventing the infection in hives could avoid costly, destructive measures and allow the beekeepers to focus on other important elements of keeping bees healthy.

Bees as pollinators play a critical role in many ecosystems.  For humankind, pollinators such as bees, birds, and bats are responsible for about a third of the world’s crop production.

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US approves world’s first vaccine for declining honey bees

Photo, posted June 6, 2022, courtesy of Bernd Thaller via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Agriculture Turning Wild Plants Into Weeds | Earth Wise

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

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

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

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

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

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

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How intensive agriculture turned a wild plant into a pervasive weed

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

Earth Wise is a production of WAMC Northeast Public Radio

Energy From Rice Straw | Earth Wise

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Rice straw is produced as a byproduct of rice production.  Globally, as much as a billion tons of rice straw is produced each year, three-quarters of it in Asia.  Straw incorporation in soil for fertilization is not practical in most places because with multiple crops per year, there is not enough time for the material to decompose and become good fertilizer.  As a result, open-field straw burning is increasingly the standard practice.

Scientists at Aston University in Birmingham in the UK are embarking on a project to convert rice straw in Indonesia into low-cost energy on a commercial scale.

Indonesia produces 100 million tons of rice waste each year, of which 60% is burned in open fields, causing air pollution. 

The Aston researchers are developing a biomass conversion process based on pyrolysis.  This involves heating the rice straw to high temperatures over 900 degrees Fahrenheit to break it down, producing vapor and solid products.  Both of these things can be used to generate electricity.

A new combustion engine designed by a company called Carnot Limited is capable of converting 70% of the thermal energy extracted from the rice straw into electricity.

Energy extracted in this way could help low and middle-income countries to create their own locally generated energy, thereby reducing emissions, creating jobs, and improving human health.   The biomass electricity is predicted to be cheaper than solar, geothermal, wind, coal, or even subsidized gas-generated power.

The Aston University project will help develop a business model that could support companies and communities to produce local, cheap energy in Indonesia and other countries with biomass capacity. 

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Aston University to help power Indonesia with affordable energy made from rice straw

Photo, posted September 11, 2006, courtesy of Kristen McQuillin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Growing Threat To Wheat | Earth Wise

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Wheat is one of the most widely-grown crops in the world and plays a major role in human nutrition.  In fact, wheat contributes approximately 20% of the protein and 20% of the calories consumed by humans globally.  It is grown on every continent except Antarctica.  

But wheat is under growing attacks from harmful toxins.  According to a new study by researchers from the University of Bath and the University of Exeter in the U.K., almost half of wheat crops across Europe are impacted by the fungal infection that gives rise to mycotoxins.

Mycotoxins are naturally occurring toxins produced by the fungus that causes Fusarium Head Blight.  Fusarium Head Blight is a disease that affects wheat and other grains growing in the field. Eating products contaminated with mycotoxins can cause sickness in humans and livestock, including vomiting and other gastrointestinal problems.

In the study, the research team examined 10 years of government and agribusiness data, which tracked Fusarium mycotoxins in wheat entering the food and animal supply chains across Europe and the U.K.  Half of the wheat intended for human food in Europe contained the Fusarium mycotoxin.  In the UK, 70% of wheat was contaminated.

Governments set legal limits on mycotoxin contamination levels in wheat that is to be consumed by humans. But with the ubiquitous nature of these mycotoxins, the effect of constant, low-level exposure in the diet over the course of a lifetime is not known. 

With climate change and the war in Ukraine already impacting both wheat yield and price, preventing toxin contamination is critical to help maintain a stable crop price and to protect global good security. 

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Harmful fungal toxins in wheat: a growing threat across Europe

Photo, posted July 11, 2011, courtesy of Maria Keays via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Examining The Decline Of Honey Bees | Earth Wise

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For many years, scientists have been sounding the alarm on the global struggle of pollinators.  Many of the invertebrate pollinator species, such as bees and butterflies, are facing extinction. And since 75% of the world’s food crops depend on pollination to some extent, the decline of pollinators poses a major threat to global food security.

Honey bees are among the struggling pollinators.  Over the past 14 years, bee colonies have been disappearing at an alarming rate in what is known as the “colony collapse disorder.” 

In an effort to understand why, scientists have often focused their research on environmental stressors, such as parasites, pesticides, and disease.  But according to new research by entomologists from the University of Maryland, honey bee life spans are simply 50% shorter today than they were 50 years ago.  In the study, which was recently published in the journal Scientific Reports, the researchers found that honey bees kept in a controlled, laboratory environment lived half as long as honey bees did in the 1970s.  This is the first study to show that genetics – as opposed to environmental stressors – may be influencing the broader trends seen in the beekeeping industry.

When the researchers modeled the effect of their findings on a beekeeping operation, they found that the resulting loss rates were about 33%.  This is similar to the average overwinter and annual loss rates reported by beekeepers during the past 14 years.

The next step is for researchers to compare trends in honey bee life spans across the U.S. and in other countries to see if there are differences in bee longevity. 

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Honey Bee Lifespans are 50% Shorter Today Than They Were 50 Years Ago

Helping Agriculture’s Helpful Honey Bees

Photo, posted June 23, 2007, courtesy of Susan E. Ellis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Perennial Rice | Earth Wise

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People have been cultivating rice for more than 9,000 years.  Cultivated rice is an annual crop which is often extended to two crops a year by a process called ratooning, which is cutting back annual rice to obtain a second, weaker harvest.

An extensive project involving multiple institutions in China, the U.S., and Australia has been developing perennial rice.  The researchers developed it through hybridization, crossing a type of Asian domesticated annual rice with a wild perennial rice from Africa.  Using modern genetic tools to identify candidate plants, the team identified a promising hybrid in 2007, planted large-scale field experiments in 2016, and released the first commercial perennial rice variety, called PR23, in 2018.

The researchers spent five years studying the performance of the perennial rice alongside annual rice on farms in China’s Yunnan Province.  For the most part, the yield of the perennial rice was equivalent to that of annual rice over a period of four years. 

Because farmers don’t have to plant rice each season, growing perennial rice requires almost 60% less labor and saves nearly half the costs of seed, fertilizer, and other inputs.

Perennial rice is already changing the lives of more than 55,000 smallholder farmers in southern China and Uganda.  The economic benefits vary by location, but overall profit increases ranged from 17% to 161% over annual rice.

There are already three perennial rice varieties available to farmers, but researchers aren’t done refining the crop.  They plan to use their methodology to enhance traits such as aroma, disease resistance, and drought tolerance to newer versions.

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Farmers in China, Uganda move to high-yielding, cost-saving perennial rice

Photo, posted February 25, 2002, courtesy of Matthieu Lelievre via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fuel From Coffee Grounds | Earth Wise

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The world drinks a lot of coffee.  Americans alone consume 400 million cups a day.  Each cup of coffee results in about half an ounce of coffee grounds.  Adding that up, this country produces over 6,000 tons of coffee grounds each day.  While coffee grounds are not particularly harmful, that is an awful lot of waste that mostly ends up in landfills or is incinerated.

Researchers at Aston University in the UK have developed a method of producing high-quality biodiesel fuel from coffee grounds.  Their study was published in the journal Renewable and Sustainable Energy Reviews.

The technique consists of growing a particular species of microalgae (Chlorella vulgaris) directly on spent coffee grounds.  The coffee grounds provide both the nutrients for the microalgae and a structure upon which it can grow.   Exposing the algae to light for 20 hours a day and dark for just four hours a day produced the best quality biodiesel.

Microalgae is well-known as a feedstock for biodiesel production.  Previously, it has been grown on materials like polyurethane foam or nylon which don’t provide any nutrients.   Using the coffee grounds as the substrate for growth means that no external nutrients are needed.

The resultant enhanced biodiesel produces minimal emissions and good engine performance and meets both US and European specifications.  This feedstock for producing biodiesel is ideal since it doesn’t require any competition with food crops and instead makes use of a widely available waste product.  The hope is that it may reduce the cutting down of palm trees to extract oil for biofuel.  In southeast Asia, this has been a major source of deforestation and increased greenhouse gas emissions.

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Aston University researchers ‘feed’ leftover coffee grounds to microalgae to produce low emission biodiesel

Photo, posted October 13, 2007, courtesy of David Joyce via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

El Paso’s Water Future | Earth Wise

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El Paso, Texas is part of the Paso del Norte region, which includes Ciudad Juarez in Mexico and Las Cruces, New Mexico.  The population on both sides of the border is booming, approaching 3 million people.  The region’s primary water source is the Rio Grande River.  But that river is declining.

Rising temperatures and decreasing rainfall have led to diminishing flow in the river.  Eighty percent of the river’s flow has historically been diverted to agriculture, but the reduced flow of the Rio Grande has forced many farmers to reduce planting or change to less water-hungry crops.  The river is expected to continue to decrease its flow as time goes by.

The city of El Paso gets 40% of its water supply directly from the Rio Grande.  Urban water authorities in the region are scrambling to find ways to provide cities with alternative supplies of water.

El Paso now gets some of its water from a desalination plant, which is the world’s largest inland municipal desalination plant.  The water comes from brackish groundwater rather than from the sea.  The briny waste from the plant is piped to an injection well many miles way and is permanently stored 4,000 feet underground.

El Paso continues to seek new water sources and reduce its water use.  It gets much of its water from wells drilled in nearby aquifers.  It is working to make this use of groundwater more sustainable.  The city recycles used residential water through its so-called purple pipe system, which cleans up waste water and delivers it for non-potable use on golf courses and park lawns. 

Like many places in the increasingly dry west, El Paso’s water future is uncertain. 

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As Rio Grande Shrinks, El Paso Plans for Uncertain Water Future

Photo, posted April 29, 2018, courtesy of R. Baire via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Agrivoltaics | Earth Wise

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According to a study last year at Oregon State University, co-developing land for both solar photovoltaic power and agriculture could provide 20% of total electricity generation in the United States with an investment of less than 1% of the annual U.S. budget.  Widespread installation of agrivoltaic systems could reduce carbon emissions by 330,000 tons annually and create more than 100,000 jobs in rural communities.

Agrivoltaics could provide the synergistic combination of more food, more energy, lower water demand, lower carbon emissions, and improved local prosperity.  The problem with agrivoltaics to date is that the existing implementations have used solar arrays designed strictly for electricity generation rather than to be used in combination with agriculture.  They are not that well suited to co-exist with growing crops or grazing animals.

A new project is underway at Oregon State that will help researchers to optimize agrivoltaic systems.  The five-acre Solar Harvest Project is being built at the university’s North Willamette Research and Extension Center in Aurora, Oregon in partnership with the Oregon Clean Power Cooperative. 

The solar array for the project is designed specifically for agrivoltaics research and uses panels that are more spread out and able to rotate to a near vertical position to allow farm equipment to pass through.  The project will allow researchers to study the impact of solar panels on soil health, water use, and plant physiology and yields.

Electricity generated from the 326-kW solar system will be available for purchase by Oregon State and community members. 

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Construction starts on Oregon State agrivoltaics farm that will merge agriculture and solar energy

Photo, posted April 5, 2020, courtesy of Sean Nealon / Oregon State University via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Onshore Algae Farms | Earth Wise

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According to some estimates, food production will need to increase by 50% by 2050 in order to feed a projected global population of 10 billion people.  How can this be achieved?  

One solution, according to researchers at Cornell University, could be to grow nutritious and protein-dense microalgae in seawater-fed onshore aquaculture systems.

According to the research, which was recently published in the journal Oceanography, growing algae onshore could close a projected gap in society’s future nutritional demands while also improving environmental sustainability.  

Climate change, environmental degradation, limited arable land, and lack of freshwater will all constrain the amount of food that can be grown in the coming decades.  Wild fish stocks are already heavily exploited, and there are limits to how much finfish, shellfish, and seaweed aquaculture can be produced in the coastal ocean. 

As a result, the researchers argue for expanding algae production in onshore aquaculture facilities.  The research team’s models found that the best locations for onshore algae farming facilities are along the coasts of the Global South, including desert environments. 

Algae can grow as much as ten times faster than traditional crops.  Algae can also be produced in a manner that is more efficient than agriculture in its use of nutrients.  In addition to its high protein content, algae also provides nutrients lacking in vegetarian diets, such as essential amino acids, minerals, and omega-3 fatty acids.

Algae could become the breadbasket of the Global South.

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Onshore algae farms could feed the world sustainably

Photo, posted June 17, 2011, courtesy of NOAA Great Lakes Environmental Research Laboratory via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Bad Year For California Rice | Earth Wise

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Rice production is the third largest cereal crop in the United States after corn and wheat.  Four regions in the country produce almost the entire U.S. rice crop:  the Arkansas Grand Prairie, the Mississippi Delta, the Gulf Coast, and the Sacramento Valley in California.  Arkansas is the largest producer of rice in the country by far, but California ranks second.

A combination of drought and water shortages in the Sacramento Valley has taken a major toll on the California rice crop.  This year, rice growers have only planted half as much grain as usual.  The changes in rice plantings in California are so substantial that they are easily visible from space.

In Colusa and Glenn counties, rice acreage this year dropped by 84 and 75 percent respectively, compared to 2021.  Farther to the east, in Butte Country, rice acreage was down by 17%.  The change was smaller there because farmers in that county had more groundwater to tap into.

According to the USDA, the California rice crop will be reduced by 38% this year, making it the smallest rice crop in the state since 1977.  California mostly grows short- and medium-grained rice, which is used in dishes like sushi, paella, and risotto.  Arkansas and other states produce most of the long-grain rice such as basmati and jasmine rice.

In late September, there was a burst of rain, which offered some short-term relief for farmers.  However, it will take much more wet weather to ease the ongoing drought conditions.  As of the end of September, over 40% of California remained in extreme drought and 17% was in exceptional drought.

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A Rough Year for Rice in California

Photo, posted March 21, 2020, courtesy of Ajay Suresh via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

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

Tepary Beans | Earth Wise

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Tepary beans are an ancient crop native to the northern part of Mexico and the southwestern part of the U.S..  They have been grown in those places by native peoples since pre-Columbian times.  They are still grown in Native American reservations in Arizona’s Sonoran Desert.  One can purchase them from some small farms in that region. 

What sets tepary beans apart from other beans is that they are among the most drought- and heat-tolerant legume crops in the world.  They can be grown without irrigation under conditions that are not viable for other crops.  They can be consumed by people like many other kinds of beans, and they can also provide forage for livestock with better nutrition content than many other plants.  They seem to be a very attractive option for a crop in the changing climate.  What is lacking, at present, is large supplies of tepary seeds to be planted.

Researchers at Texas A&M have been funded to bring tepary beans into modern cropping systems and diets.  The goal is to develop tepary bean cultivars with high biomass and yield that are still well-suited to drought and heat conditions.  Getting the beans to the point of widespread commercialization will take several years.  The end result should be of interest to pulse growers, seed industries, and food companies across the U.S.

Tepary beans are higher in fiber and protein than most other beans.  They come in several different colors, each of which has unique flavor and texture characteristics.  The white ones have a naturally sweet flavor.   The brown beans are slightly nutty in flavor and are similar to pinto beans.  If the Texas program is successful, we may all be eating tepary beans some day.

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Tepary Beans Offer Producers A Low-Input, Climate-Resilient Legume Alternative

Photo, posted August 25, 2017, courtesy of Katja Schulz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Progress On Artificial Photosynthesis | Earth Wise

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Photosynthesis is the process by which plants use the energy from sunlight to turn water and carbon dioxide into biomass and ultimately the foods we and other organisms eat.  Scientists at the University of California Riverside and the University of Delaware have found a way to create food from water and carbon dioxide without using biological photosynthesis and without needing sunlight.

The research, recently published in the journal Nature Food, uses a two-step electrocatalytic process to convert carbon dioxide, electricity, and water into acetate, which is the primary component of vinegar.   Food-producing microorganisms then consume the acetate in order to grow.   Solar panels are used to generate the electricity to power the electrocatalysis.  The result is a hybrid organic-inorganic system that is far more efficient in converting sunlight into food than biological photosynthesis.

The research showed that a wide range of food-producing organisms can be grown in the dark directly on the acetate output of the electrolyzer.  These include green algae, yeast, and the fungal mycelium that produce mushrooms.   Producing algae with this technology is about 4 times more energy efficient than growing it with photosynthesis.  Yeast production is about 18 times more energy efficient than the typical method of cultivating it using sugar extracted from corn.

Artificial photosynthesis has the potential to liberate agriculture from its complete dependence on the sun, opening the door to a wide range of possibilities for growing food under the increasingly difficult conditions imposed by the changing climate.

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Artificial photosynthesis can produce food without sunshine

Photo, posted September 7, 2016, courtesy of Kevin Doncaster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bumblebees And Climate Change | Earth Wise

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Pollinators, such as bees and bats, are vital for global food production.  They provide an ecological service that’s necessary for the reproduction of nearly 75% of the world’s flowering plants, including more than two-thirds of global food crops.

Bumblebees are among the most important plant pollinators.  They pollinate many food crops, including apples, tomatoes, blueberries and legumes, as well as countless types of trees, shrubs, and wildflowers.

According to a new study by researchers from Simon Fraser University in Canada, temperature changes have negatively impacted most bumblebee species during the past 120 years.  The research, which was recently published in the journal Biology Letters, found that these changes in temperature had more of a negative impact than other factors such as precipitation or floral resources. 

The research team analyzed existing data on 46 bumblebee species across North America between 1900 and 2020.  The researchers created two occupancy models – one that was focused on time and the other that focused on environmental factors – to see how climate change and land-use variables impacted species’ occupancy.  They found that six bumblebee species decreased through time, 22 increased, and 18 remained stable.

Temperature changes had primarily negative impacts on bumblebees.  In fact, 37 of the 46 species studied exhibited declines or less positive occupancy increases under observed changes in temperature when compared with temperatures remaining constant.  Approximately half of the bumblebee species were negatively impacted by changes in precipitation or floral resources while the other half were positively impacted.

Bumblebee populations are changing as a consequence of climate change. 

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The American Bumblebee

Climate change negatively impacting bumble bees: Study

Photo, posted July 14, 2019, courtesy of Dmitry Grigoriev via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Declining Flying Insects | Earth Wise

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In recent years, there has been increasing awareness of the global decline in insect abundance.  A recently published survey of the abundance of flying insects in the UK has revealed very troubling results.

The Kent Wildlife Trust and Buglife – two UK-based conservation groups – compared the number of dead insects on vehicles in 2004 and 2021.  In this Bugs Matter Citizen Science Survey, the data was collected by roughly 20,000 ordinary citizens using a smartphone app.

The results were that the number of flying insects in Britain dropped nearly 60% over that time period.  The insects declined most in England and Wales, with drops of 65% and 55%, respectively. 

It is possible that 2004 was a particularly good year for British insects and 2021 an especially bad one, but the findings of this study are consistent with other research around the world showing an alarming decline in insects.  A series of studies in 2019 found that the global mass of insects is shrinking by 2.5% a year and that insects are going extinct eight times faster than reptiles, birds, or mammals.

Insects face multiple overlapping threats including the destruction of wild habitats for farming, urbanization, pesticides, and light pollution.  On top of these things is climate change which is disrupting ecosystems in multiple ways.

Insects play a vital role in pollinating crops, consuming organic waste, killing pests, and as essential parts of multiple ecosystems.  Severe insect declines can potentially have dire global ecological and economic consequences.

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Flying Insects Have Declined by 60 Percent in the U.K., Survey Finds

Insect decline in the Anthropocene: Death by a thousand cuts

Photo, posted May 6, 2007, courtesy of Richard Giddins 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.

The Atmosphere Is Thirstier | Earth Wise      

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The American West is in the throes of a two-decade-long drought.  The climate there is getting warmer and drier, which has led to increasing demand for water resources from both humans and ecosystems.  According to a new study by the Desert Research Institute and collaborators, the atmosphere across much of the U.S. is also demanding a greater share of water than it used to.

Evaporative demand, which is also called atmospheric thirst, is a measure of the potential loss of water from the earth’s surface up to the atmosphere.  It is a function of temperature, humidity, wind speed, and solar radiation.  The study, published in the Journal of Hydrometeorology, assessed trends in evaporative demand during a 40-year period from 1980-2020.

The study’s findings showed substantial increases in atmospheric thirst across much of the Western U.S. over that period, with the largest increases centered around the Rio Grande and Lower Colorado rivers.  This is important because atmospheric thirst is a persistent force in pushing Western landscapes and water supplies toward drought.

The study found that, on average, increases in temperature were responsible for 57% of the changes observed in atmospheric thirst, humidity 26%, and the other factors playing lesser roles.

For farmers and other water users, increases in atmospheric thirst mean that, in the future, more water will be required to meet existing water needs.  Crops already require more water than they did in the past and can be expected to require more water in the future.  Over time, for every drop of precipitation that falls, less and less water is likely to drain into streams, wetlands, aquifers, or other water bodies.

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New study shows robust increases in atmospheric thirst across much of U.S. during past 40 years

Photo, posted August 9, 2007, courtesy of William Clifford via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Birds Bees And Coffee | Earth Wise

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A new study by the University of Vermont in collaboration with researchers from three Latin American countries looked at the effects of birds and bees on coffee crops.  They found that coffee beans are bigger and more plentiful when birds and bees team up to protect and pollinate coffee plants.

The real-world study manipulated coffee plants across 30 farms by excluding birds and bees with a combination of large nets and small lace bags.  They looked at four scenarios:  bird activity alone (pest control), bee activity alone (pollination), no bird and bee activity at all, and a natural environment where birds and bees were free to pollinate and eat insects that otherwise damage coffee plants.

The study looked at fruit set, fruit weight, and fruit uniformity – important factors that determine the quality and price of the coffee crop.  The results were that the combined positive effects of birds and bees were greater than their individual effects.   Without birds and bees, the average coffee yield on the farms declined nearly 25%.  That is important information for the $26 billion coffee industry.

A surprising result of the study is that many birds providing pest control to coffee plants in Costa Rica had migrated thousands of miles from Canada and the U.S.

Previous studies looked at the benefits of natural factors separately and then added them up.  But the new study demonstrates that nature is an interacting system with both synergies and trade-offs.  Past assessments of individual ecological services may have underestimated the benefits biodiversity provides to agriculture and human wellbeing.  Ecosystems services are more valuable together than separately.

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The Secret to Better Coffee? The Birds and the Bees

Photo, posted March 2, 2012, courtesy of Caroline Gluck/Oxfam via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Historic Western Drought | Earth Wise

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The American Southwest has suffered from drought conditions since the year 2000.  The drought has reduced water supplies, devastated farmers and ranchers, and it has helped to fuel numerous wildfires across the region.  It has generally been considered to be worst in 500 years.

According to a recent analysis, the drought has become so severe that it has actually led to the driest two decades in at least 1,200 years and the changing climate is largely responsible.  The summer of 2021 was especially dry; about 2/3 of the West was in severe drought conditions.

Scientists at UCLA used tree ring data to gauge drought.  Based on that analysis, 2000-2021 is the driest 22-year period since 800 A.D. which is as far back as the data goes.

The study confirmed the role of temperature, more than precipitation, in driving exceptional droughts.  Precipitation levels can go up and down over time and can vary in different regions.  But the ongoing emissions of greenhouse gases into the atmosphere are causing temperatures to generally rise over time.  Warmer temperatures make the air more capable of pulling water out of the soil, out of vegetation, out of crops, and out of forests.  All of that makes drought conditions more severe.

A megadrought is generally considered to be one that is both severe and long.  But even during one, there can be wet years.  2005 was a notable one.  But there must be enough consecutive wet years to actually end a drought.

Several previous megadroughts over the past 1,200 years lasted as long as 30 years.  So, the current drought is in full swing and may go on for a long time to come.

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Web Links

How Bad Is the Western Drought? Worst in 12 Centuries, Study Finds.

Photo, posted September 25, 2021, courtesy of David Sierralupe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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