Earth Wise

A look at our changing environment.

You are here: Home / Archives for humans

humans

Plastic Eating Fungus | Earth Wise

By Leave a Comment

More than five billion tons of plastic have accumulated on land and sea including the most remote regions of the planet as well as in the bodies of animals and humans.  There is a compelling need to recycle as much plastic as possible but doing so is a major challenge. Plastic comes in many varieties and breaking it down for reuse requires different methods for each.

Polypropylene is one of the biggest challenges for recycling.  It is a very common plastic used for all sorts of products including food containers, coat hangers, plastic wrap, toys, and much more. It accounts for roughly 28% of the world’s plastic waste, but only 1% of it is recycled.

Polypropylene is seldom recycled because it generally has a short life as a packaging material, and it often becomes contaminated by other materials and plastics.  Thus, it generally ends up in landfills.

Researchers at the University of Sydney in Australia have discovered that two common strains of fungi were able to successfully biodegrade polypropylene.  The fungi species – with unavoidable Latin names of Aspergillus terreus and Engyodontium album – are typically found in soil and plants.

The researchers found that the fungi were able to break down polypropylene after it had been pre-treated with either UV light or heat, by 21% over 30 days, and by 25-27% over 90 days.  This seems rather slow but compared with the nearly endless life of polypropylene in landfills, it is a major improvement.

The hope is that methods like this could ultimately reduce the amount of plastic polluting the environment by encouraging plastic to biodegrade naturally under the appropriate conditions.

**********

Web Links

Fungi makes meal of hard to recycle plastic

Photo, posted March 5, 2010, courtesy of Kevin Krejci via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Here Come The Lanternflies | Earth Wise

By Leave a Comment

The spotted lanternfly is an invasive pest from Asia that primarily feeds on tree of heaven, which is itself an invasive species that has become widespread.  The real problem is that the lanternfly can also feed on some 70 other plants such as grapevines, maples, fruit trees, and more.

The lanternfly was first discovered in the US in Pennsylvania in 2014 and has since spread to 14 states including New York, Massachusetts, Connecticut, and Rhode Island.  (It was first spotted in New York in Staten Island in 2020 and has continued to spread).

The insect poses a significant threat to New York’s agricultural and forest health. Both the adults and nymphs feed on the sap of plants which stresses them making them vulnerable to diseases and other insect attacks.  They also secrete a sticky substance that attracts molds and interferes with photosynthesis.

Lanternflies are not strong fliers.  They mostly spread through human activity by laying their eggs on vehicles, firewood, outdoor furniture, and other objects that people transport.

The bout of unusually warm weather that the Northeast experienced in early spring is likely to have jumpstarted the spotted lanternfly timeline and hatching could be bumped up to as early as May.

Agriculture officials are asking for people to look for spotted lanternfly egg masses and scrape them off with implements with a sharp edge.  Adult insects should be reported to local authorities and should be killed if at all possible.  There is lots of information online about how to recognize the egg masses and the insects.  Spotted lanternflies are not a direct threat to humans, but they have the potential to cause great harm to vineyards, orchards, and forests.

**********

Web Links

Spotted Lanternfly

Photo, posted September 12, 2018, courtesy of the U.S. Department of Agriculture via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plants Make Sounds | Earth Wise

By Leave a Comment

Some people talk to their plants.  It is highly unlikely that the plants are listening, but recent research has found that plants are doing quite a bit of talking of their own.

It turns out that plant emit a variety of click-like sounds, especially when they are stressed in some way, such as being dehydrated or injured.  The sounds are actually fairly loud – comparable to the volume of human speech – but occur at frequencies well above the range of human hearing.

The study at Tel Aviv University in Israel monitored plants in a greenhouse that were subjected to various stresses over time.  Unstressed plants emitted less than one sound per hour, on average, while stressed plants emitted dozens of sounds every hour.

Recordings of the plant sounds were analyzed by specially developed artificial intelligence algorithms.  The algorithms learned how to distinguish between different plants and different types of sounds.  Eventually, they could identify the plant and determine the type and level of stress from the recordings.  They could even do this in a greenhouse with a great deal of background noise.

The study resolved a very old scientific controversy about whether plants emit sounds.  Not only do they, but the sounds contain useful information.  We don’t yet know what the mechanism is for plant sounds.  It is likely that in nature, the sounds are detected by various animals and perhaps even plants that can detect the high frequencies.  And perhaps they react to them as part of seeking food, shelter, or other services that plants provide.  Given the right tools, we humans may also be able to make use of the sounds being made by plants.

**********

Web Links

Plants Emit Sounds – Especially When Stressed

Photo, posted February 20, 2009, courtesy of ProBuild Garden Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Ocean-based Climate Intervention And Deep-sea Ecosystems | Earth Wise

By Leave a Comment

Deep-sea ecosystems cover more than 40% of the Earth.  These regions are some of the least well-known and understood areas of our planet but are home to numerous ecosystems.  The deep seas are already directly exposed to the effects of human-induced climate change but could potentially be greatly threatened by efforts to artificially counteract climate change.

A class of geoengineering solutions called ocean-based climate interventions are increasingly being claimed as promising ways to mitigate climate change.  Such interventions would remove carbon dioxide from the atmosphere and sequester it in the deep sea.  There is very little known about the impact of such efforts on ocean biogeochemistry and the biodiversity of ocean ecosystems.

One approach is direct CO2 injection into the deep ocean, which would sequester large amounts of it and reduce the concentration in the atmosphere.  However, too much carbon dioxide in the water is called hypercapnia, which can have serious consequences on marine life.

Other approaches include ocean fertilization – which is enhancing phytoplankton production at the surface, leading to their eventual deposition on the deep-sea floor – and crop waste deposition – which is deep-sea disposal of terrestrial crop waste. 

A multinational study led by the Scripps Institution of Oceanography warns that there needs to be much more research and governance before any such interventions ever take place.  The deep sea faces unprecedented threats from industrial fisheries, pollution, warming, deoxygenation, acidification, and other climate-related problems.  Ocean-based climate intervention represents yet another serious threat to the functioning of these essential ecosystems.

**********

Web Links

HKU Marine Scientist contributes to research assessing the potential risks of ocean-based climate intervention technologies on deep-sea ecosystems

Photo, posted January 6, 2010, courtesy of Emrys Roberts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Giant Farming Robots | Earth Wise

By Leave a Comment

Farmers are perpetually engaged in a battle against weeds, which can strangle crops and destroy their yields.  There are basically two ways to fight weeds:  spraying herbicides that are bad for the environment and human health or using human labor to pull the weeds by hand. 

Both choices are increasingly undesirable.  Herbicide resistance is a growing problem facing farms around the world and widespread labor shortages in the agricultural sector are making it increasingly difficult to use human resources to combat weeds.

A startup company called FarmWise founded by an MIT engineering alumnus is providing a third option for farmers.  The company has developed giant autonomous weeding robots that use artificial intelligence to cut out weeds without damaging crops.

The company’s first product is called the Titan.  It looks like a large tractor without a driver’s seat.  It uses machine vision to distinguish weeds from crop plants like leafy greens, cauliflower, artichokes, and tomatoes.  It snips off the weeds with sub-inch precision.

Fifteen titan robots have been roaming the fields of 30 large farms in California and Arizona for several years.  A newer robot, called the Vulcan, is more lightweight and is pulled by a tractor.  FarmWise continues to add new crops to its database so that the robots can be used to fight weeds in more and more kinds of farms.

Weed problems are especially acute for farmers of specialty crops, which grow on smaller farms than corn and soybeans, and have unique growing practices, which limit the effectiveness of chemical and technical solutions. 

The overall goal of FarmWise is to turn artificial intelligence into a tool that is as reliable and dependable as GPS is now in the farming industry.

**********

Web Links

Titanic robots make farming more sustainable

Photo, posted August 23, 2021, courtesy of Carol VanHook via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Antibiotics In Animal Agriculture | Earth Wise

By Leave a Comment

In animal agriculture, farmers use antibiotics to treat, prevent, and control animal diseases, and to increase the productivity of their operations.  According to the FDA, approximately 80% of all antibiotics sold in the U.S. are purchased for use in food-producing animals. 

The routine administration of antibiotics to farm animals for non-therapeutic purposes promotes the development of antibiotic-resistant bacteria, with repercussions for human and animal health.  As antibiotic-resistant bacteria spreads, medicines used to treat human diseases can become less effective. 

According to a new study led by researchers from the University of Washington, a California policy restricting the use of antibiotics in farm animals is associated with a reduction in one type of antibiotic-resistant infection in people in the state.  The findings, recently published in the journal Environmental Health Perspectives, suggest that regulations limiting the use of antibiotics in livestock can significantly impact human health. 

In 2018, California Senate Bill 27 banned routine preventive use of antibiotics in food-animal production and any antibiotic use without a veterinarian’s prescription.  Last year, the European Union passed a law restricting antibiotic use to only sick animals on farms.  And coming this June, most antibiotics – those that are medically important to humans and animals – will be by prescription only in the United States.  

Despite these changes, antibiotic resistance is projected to remain one of the biggest threats to human health over the next 50 years because resistance continues to grow and few new antibiotics are coming online. 

**********

Web Links

Restricting antibiotics for livestock could limit spread of antibiotic-resistant infections in people

Ranchers should prepare now for 2023 animal antibiotic guidelines

Photo, posted May 8, 2018, courtesy of Preston Keres / USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Humanity Weighs On The World | Earth Wise

By Leave a Comment

There are countless ways in which humankind has had disproportionate effects on our planet and most of those effects have been negative.  A recent study led by the Weizmann Institute of Science in Israel looked at the total combined weight of various groups of mammals on Earth.  The results are that human beings and our domesticated mammals are the overwhelming majority of the total mass of mammals.

We think of large land mammals – elephants, bears, bison, wildebeests, and so on – as adding up to a massive amount of animal matter.  The study determined that all wild land mammals put together add up to about 22 million metric tons. Wild marine mammals – such as dolphins and whales – add up to about 40 million tons in total.  These sound like pretty big numbers until we look at the human and human-created side of the equation.

The study found that humans weigh about 390 million metric tons, while domesticated mammals – like sheep, cows, and pigs as well as dogs and cats – weigh about 630 million metric tons combined.

All told, wild mammals account for only 6% of all mammals by weight.   People and their domesticated animals make up the other 94%.  This enormous imbalance is an indication of how profoundly humans have reshaped life on Earth.  House cats total twice the weight of African elephants and pigs add up to twice the weight of all wild land animals combined.

The conclusion to draw from the big picture here is that wild animals on Earth are not doing very well.  We already knew this from many other perspectives, but this census by weight presents a stark picture of the extent to which we have taken over the planet and its ecosystems.

**********

Web Links

Total Weight of Wild Land Mammals Less Than One-Tenth Weight of All Humans

Photo, posted December 27, 2006, courtesy of Nigel Hoult via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Dangers Of Melting Glaciers | Earth Wise

By Leave a Comment

Some of most dramatic evidence that the Earth’s climate is warming is the retreat and even disappearance of mountain glaciers around the world.  2022 was the 35th year in a row that glaciers tracked by the World Glacier Monitoring Service lost rather than gained ice.  Glaciers gain mass through snowfall and lose mass through melting and sublimation (water evaporating directly from solid ice.)  Some glaciers that terminate in lakes or the ocean lose mass through iceberg calving.

In the warming climate, glaciers retreat and meltwater collects at the front of the glacier forming a lake.  Such lakes can suddenly burst and create a fast-flowing Glacier Lake Outburst Flood that can spread over a large distance from the original site – in some cases over 70 miles.  These floods can damage property, infrastructure, and agricultural land and can also be deadly.

The number of glacial lakes has grown rapidly since 1990 as a result of climate change.  According to research by an international team of scientists led by Newcastle University in the UK, the number of people living in glacial lake catchments has increased significantly.

According to the study, 15 million people live within 30 miles of a glacial lake.  The highest danger is in High Mountain Asia – which encompasses the Tibetan Plateau.  That area, which spans from Kyrgyzstan to parts of China, has 9.3 million people potentially at risk.  India and Pakistan have around 5 million exposed people.

Detailed analysis shows that it is not the areas with the largest number or most rapidly growing lakes that are most dangerous.  It is the number of people in proximity to the lakes and their ability to cope with potential floods.

**********

Web Links

Glacial flooding threatens millions globally

Photo, posted February 12, 2022, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic From Sunlight | Earth Wise

By Leave a Comment

Photosynthesis is the process that plants use to turn water, carbon dioxide, and energy from sunlight into plant biomass.  It provides humans and much of animal life with food.  Photosynthesis is also nature’s way of reducing the amount of carbon dioxide in the atmosphere.  The CO2 is not directly stored in plants but rather is combined into organic compounds.

Researchers across the globe are trying to find effective ways to mimic photosynthesis.  One version of artificial photosynthesis seeks to take carbon dioxide and combine it into organic compounds that can be used as raw materials for various kinds of manufacturing. 

A research team in Japan has found a way to synthesize fumaric acid from carbon dioxide using sunlight to power the process.  Fumaric acid is a chemical typically synthesized from petroleum and is used as a raw material for making biodegradable plastics such as polybutylene succinate. 

Much of artificial photosynthesis research is aimed at using solar energy to convert carbon dioxide directly into a fuel rather than a raw material.  Such solar fuels can be produced by a variety of means including thermochemical (using the sun’s heat to drive chemical reactions), photochemical (using the sun’s light to drive chemical reactions), and electrochemical (using solar-generated electricity to drive chemical reactions.)   These approaches generally involve the use of specialized catalysts to drive the desired chemical reactions. 

One way or another, what techniques for artificial photosynthesis have in common is trying to imitate what plant life on Earth has been doing for millions of years. 

**********

Web Links

Artificial photosynthesis uses sunlight to make biodegradable plastic

Photo, posted June 14, 2017, courtesy of Alex Holyake via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Insects On The Menu | Earth Wise

By Leave a Comment

According to the World Food Programme, a record 349 million people across 79 countries are facing acute food insecurity.  This constitutes a staggering rise of 200 million people compared to pre-pandemic levels.  Nearly one million people globally are fighting to survive in famine-like conditions, which is ten times more people than just five years ago.  

As a result, many experts contend that alternative or so-called novel food sources – such as lab-grown meats, seaweed aquaculture, and insects – will be necessary to help fight global hunger and global food insecurity. 

Insects already form a significant part of diets in many cultures around the world.  Insects are great sources of nutrients, including protein, vitamins, and minerals.  But insects have yet to be embraced in any substantial way in western cultures… but that may be changing. 

In fact, the European Union has now certified four types of bugs as food fit for human consumption.  The larvae of lesser mealworms and house crickets recently became the third and fourth insects approved for sale as food in the EU, joining yellow mealworms and grasshoppers. Eight more applications are awaiting approval.

Insects are already a delicacy in many high-end restaurants around the world, and a normal and healthy part of diets in countries like Mexico and Thailand.  Embracing insects as a food of the future will not only help in the fight against global hunger, but will also help to reduce greenhouse gas emissions and to slow species extinction. 

In Western food markets, the so-called “yuck factor” remains the biggest hurdle to cross.  But as the world population grows, the need for sustainable solutions in the food industry grows with it. 

**********

Web Links

Insects on the menu as EU approves two for human consumption

World Hunger Surged in 2020, U.N. Says

A global food crisis

Photo, posted April, 2014, courtesy of Shankar S. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Reef Insurance | Earth Wise

By Leave a Comment

Coral reefs around the world face multiple dangers from warming waters, acidification, human activity, and more.  Powerful storms often cause tremendous damage to reefs.  When possible, snorkelers and divers are deployed to try to repair damage to reefs.  But philanthropy and government grants are basically the only resources available to fund such actions.

Three years ago, tourist businesses and the government in the Mexican state of Quintana Roo purchased an insurance policy to offset costs of protecting the local parts of the Mesoamerican Reef.  The environmental group the MAR Fund later took out an insurance policy on the rest of the reef in Mexico, Belize, Guatemala, and Honduras. 

With this precedent, the Nature Conservancy recently purchased an insurance policy on behalf of the state of Hawaii to help offset repair work on its coral reefs.  It is the first U.S. coral insurance contract.

Coral reefs are more than just hosts for marine life.  They provide barriers against ocean storm surges, which is a major financial incentive for protecting them and hence an incentive to invest in insurance.

The new Hawaiian insurance policy has a premium of $110,000 a year and will provide $2 million in protection.  Payouts occur when wind speeds go above 50 knots.  No further proof of damage is required.

The Nature Conservancy has created teams called ‘Reef Brigades’ composed of snorkelers and divers who recover reef fragments, store them in ocean or shore-based nurseries, and then re-attach them when conditions are safe.  It can be very expensive to do this sort of work, particularly when new corals grown in a nursery are required.

**********

Web Links

Analysis: First U.S. coral insurance marks the rise of the reef brigades

Photo, posted September 14, 2011, courtesy of Greg McFall/NOAA Office of National Marine Sanctuaries via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tick-Borne Pathogens In Canada | Earth Wise

By Leave a Comment

Measuring only three to five millimeters in size, tiny ticks are a big problem.  They are widely distributed in many parts of the world, especially in warm and humid climates.  Ticks are arachnids – not insects – meaning they’re more closely related to spiders than to flies or mosquitos.  They are external parasites that feast on the blood of birds, reptiles, amphibians, and mammals – including humans.

In the United States, ticks are responsible for spreading potentially life-threatening infectious diseases.  According to estimates from the Centers for Disease Control and Prevention, ticks infect more than 300,000 people with Lyme disease in the U.S. every year, and the numbers continue to rise.  Other common tick-borne diseases include anaplasmosis, babesiosis, Rocky Mountain Spotted Fever, and powassan encephalitis.

Ticks are becoming a problem in Canada as well.  According to a new study by researchers from McGill University and the University of Ottawa, tick-borne pathogens are on the rise in Central Canada – a region where ticks were never previously detected. 

In the study, the researchers collected ticks across Ontario and Quebec.  They found that five emerging pathogens were present across their study sites, including the pathogens that cause Lyme disease and babesiosis.  The researchers also found that pathogens can transmit in different ways.  Typically, pathogens are transmitted to a tick after feeding from the blood of an infected host, like a small mammal.  But the research team found evidence of pathogens that could be directly transmitted from adult female ticks to larval ticks.

According to the researchers, more comprehensive testing and tracking is needed to detect the spread and risks of tick-borne pathogens to humans and wildlife in Canada.

**********

Web Links

Tick-borne pathogens increasingly widespread in Central Canada

Photo, posted May 4, 2009, courtesy of Jerry Kirkhart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

It Really Is Greenhouse Gases | Earth Wise

By Leave a Comment

The scientific consensus that human-generated carbon dioxide is changing the climate began to form in the 1980s. 

For a long time, the changes to the climate were simply denied.  After a while, as those changes became increasingly hard to ignore, the argument shifted to the changes being real but not caused by anything people are doing.  The multi-trillion-dollar fossil fuel industry was strongly motivated to focus attention away from the association between carbon dioxide and climate change.

The greenhouse gas effect has been known since the 19th century.  It isn’t just real; it is essential to life on earth.  Without sufficient levels of carbon dioxide in the atmosphere to trap some of the sun’s heat, the earth would be an ice planet incapable of supporting much in the way of life.  But there can be too much of a good thing.

Naysayers continue to grasp at alternative explanations for the warming planet rather than the inconvenient truth.  Some people try to claim that it is the release of heat from all our energy-generating activities -power plants, heaters and air conditioners, vehicles, and so on – that is warming the planet.

That issue has been studied in detail.  Human activity does generate a lot of heat and, technically speaking, that heat does help warm the planet.  However, the sun dumps 10,000 times more heat on the earth than all of human energy production added together.  Just the normal fluctuations in solar energy are 10 times larger than everything we do put together.

What is increasingly warming the planet is not the continuing energy striking the earth; it is primarily the fact that growing levels of greenhouse gases in the atmosphere are trapping more and more of that heat and preventing it from escaping into space.

***********

Web Links

Integrating anthropogenic heat flux with global climate models

Photo, posted August 25, 2009, courtesy of Gerald Simmons via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Renewable Energy Booming in India | Earth Wise

By Leave a Comment

India is the country with the second largest population in the world – over 1.4 billion people – second only to China – and will undoubtedly pass China soon based on population trends in the two countries.   India is the third largest emitter of carbon dioxide, after China and the U.S.  With its rapidly growing population and an economy heavily dependent on coal and oil, emissions in India are on a steep upward trajectory.  Currently, fossil fuels account for about 60% of India’s installed energy capacity.  It is essential that actions are taken to curb its rapid increase in greenhouse gas emissions.

To that end, India’s renewables sector is booming.  The country is projected to add 35 to 40 gigawatts of renewable energy each year until 2030.  That’s enough energy to power up 30 million more homes each year.  The country has established a target of producing 50% of its electricity from non-fossil fuel sources by the end of this decade.

 India is expected to reach over 400 gigawatts of renewable energy capacity by 2030

according to the Institute for Energy Economics and Financial Analysis and Climate Energy Finance.  The Indian government’s own projections estimate that the country will reach 500 gigawatts of renewable capacity in that timeframe.

As is the case with China, a country with an enormous population undergoing major economic growth and modernization has vast energy needs.  While it is imperative for the entire world that India puts a cap on its growing greenhouse gas emissions, it is a difficult challenge for an energy-hungry country.

**********

Web Links

Renewable energy booms in India

Photo, posted November 14, 2011, courtesy of Amaury Laporte via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Moving Endangered Species | Earth Wise

By Leave a Comment

People have intentionally or accidentally introduced numerous invasive species to habitats around the world.  At the same time, the planet’s wildlife is in a steep decline.  A recent study estimated that the populations of over 5,000 vertebrate species have declined by an average of nearly 70% since 1970.  A United Nations report warns that human activity has threatened as many as a million species with extinction.

With all of this as a background, there is climate change that is altering the habitats of the world’s species – warming lakes and oceans, turning forests into grasslands, tundra into woodland, and melting glaciers.  In response to these changes, living things are rearranging themselves, migrating to more hospitable locations.  But many species are just not capable of finding more suitable habitats on their own.

Conservationists are now increasingly considering the use of assisted migration. In some cases, when a species’ critical habitat has been irreversibly altered or destroyed, agencies are establishing experimental populations outside of the species’ historical range.  Such actions are often deemed extreme but may be increasingly necessary.

However, clear-cut cases are relatively rare.  More likely, it is a more difficult judgement call as to whether assisted migration is a good idea or is possibly a threat to the ecosystem of the species’ new location.  The relative dearth of assisted migration experiments is less likely a result of legal barriers than it is a lack of scientific and societal consensus on the practice. Scientists are now trying to develop risk-analysis frameworks that various agencies can use in considering potential assisted migration experiments. 

**********

Web Links

Last Resort: Moving Endangered Species in Order to Save Them

Photo, posted March 18, 2010, courtesy of Jean via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Mosquito Magnets | Earth Wise

By Leave a Comment

We’ve all probably had the experience of being in the great outdoors with other people and having some of them being nearly devoured by mosquitoes while others didn’t get bitten at all.  It seemed like some people are mosquito magnets while others just aren’t the insects’ cup of tea, so to speak.

There have been various theories proposed over the years including such things as it being a question of blood type, or it having to do with how close one’s blood vessels are to their skin surface.

A new study by the Howard Hughes Medical Institute and the Rockefeller University has uncovered what appears to be the real explanation.  According to the paper published in the journal Cell, certain body odors are the deciding factor.  Every person has a unique scent profile associated with different chemicals present on their skin.  The researchers found that people whose skin produces high levels of carboxylic acids are the most attractive to mosquitos.

The researchers collected scent samples from participants by having them wear silk stockings on their arms for six hours.  The nylons were then cut into pieces and the pieces exposed to mosquitos.  After several months of head-to-head battles between various nylon samples, the study clearly demonstrated that the samples from subjects with higher levels of carboxylic acids in the skin were far more attractive to mosquitos.

Humans produce the substance at much higher levels than other animals.  There is little one can do about their own levels.  Changing one’s diet or what soap they use doesn’t seem to make a difference. 

Perhaps researchers can come up with some method of breaking down carboxylic acids in the skin in the future.  Until such time, there are really people who are mosquito magnets.

**********

Web Links

Some People Really Are Mosquito Magnets, and They’re Stuck That Way

Photo, posted September 4, 2014, courtesy of James Gathany / Centers for Disease Control via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Food Waste And The Environment | Earth Wise

By Leave a Comment

It is tragic that 31% of the world’s food production goes uneaten.  About 14% isn’t distributed after it is harvested.  Another 17% ends up wasted in retail or by consumers.  Worldwide, the amount of food that is wasted is enough to feed more than a billion people while at least 828 million people continue to be affected by hunger.  To make matters worse, food waste accounts for 8 to 10% of global greenhouse gas emissions, which is at least double that of aviation.  Food waste, rotting away in landfills, produces methane gas, a major source of global warming.

Around the world, there are efforts being launched to try to improve the situation.  California now has a law that requires grocery stores to donate edible food that would otherwise be disposed of or they face fines.  The state’s cities and counties are required to reduce the amount of organic waste going into landfills by 75% by 2025 and compost it instead.

In London, grocers no longer put date labels on fruits and vegetables because the labels were leading people to trash perfectly good food.  France now requires supermarkets and large caterers to donate food that is still safe to eat.

South Korea has little space for landfills.  So, the country has been campaigning against throwing away food for 20 years.  Nearly all organic waste in the country is turned into animal feed, compost, or biogas.  Koreans even have to pay for throwing out food waste.  There are now trash bins equipped with electronic sensors that weigh food waste.

All of these things can help.  There is no single magic bullet for reducing food waste, but it is essential to do for so many reasons.

**********

Web Links

Inside the Global Effort to Keep Perfectly Good Food Out of the Dump

Photo, posted November 30, 2020, courtesy of Marco Verch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Better Way To Recycle Plastics | Earth Wise

By Leave a Comment

The global accumulation of plastic waste is an ever-growing problem.  At least five billion tons of the stuff has accumulated on land and sea and is even showing up in the bodies of animals and humans.  Recycling plastic instead of making even more of it seems like an essential thing to do but it has proven to be extremely challenging.

The main problem is that plastics come in many different varieties and the ways of breaking them down into a form that can be reused are very specific to each type of plastic.  Sorting plastic waste by plastic type is extremely impractical at large scale.  Certainly, most consumers can’t do it themselves.  As a result, most plastic gathered in recycling programs ends up in landfills.

New research at MIT has developed a chemical process using a catalyst based on cobalt that is very effective at breaking down a variety of plastics, including polyethylene and polypropylene, which are the two most widely produced plastics.   The MIT process breaks plastics down into propane.  Propane can be used as a fuel or as a feedstock for making many different products, including new plastics.

Plastics are hard to recycle because their long-chain molecules are very stable and difficult to break apart.  Most chemical methods for breaking their chemical bonds produce a random mix of different molecules which would somehow have to be sorted out in order to be useful for anything.

The new process uses a catalyst called a zeolite that contains cobalt nanoparticles.  The catalyst selectively breaks down various plastic polymer molecules and turns more than 80% of them into propane.

The researchers are still studying the economics and logistics of the method, but it looks quite promising.

**********

Web Links

New process could enable more efficient plastics recycling

Photo, posted April 25, 2016, courtesy of NOAA Coral Reef Ecosystem Program via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tepary Beans | Earth Wise

By Leave a Comment

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.

**********

Web Links

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.

What Is Healthy Soil? | Earth Wise

By Leave a Comment

Soil supports life by providing many critical ecosystem services.  For example, soil acts as a water filter, a growing medium, and provides habitat for billions of organisms.  Soil is also the foundation of our cities and towns, and the basis of global agroecosystems, which provide humans with feed, fiber, food, and fuel.

For all of these reasons and many more, having healthy soil is vital.  But what does soil health mean? And how should it be measured?

According to new analysis by researchers from Cranfield University and Nottingham University in the U.K., how we think about, measure, and study soil must change in order to better understand how to manage this resource effectively. 

While the term ‘soil health’ is widely used, it means different things to different people.  There is no single agreed upon way to gauge the overall health of soil. 

Current approaches to assess soil health measure individual soil properties and use findings  to assign a single number giving an overall score.  But according to the research team, this does not reflect the wider system perspective that’s needed to fully evaluate the health of soil over time.

Instead, the researchers propose a new system to assess soil health based on a hierarchical framework that takes in several measures, including signs of life, signs of function, signs of complexity, and signs of emergence, which is the extent to which soils recover from multiple stressors. 

This new approach, which can be applied to all soils, moves us closer to an interdisciplinary understanding of the whole picture of soil health.  After all, healthy soil is fundamental to our survival.

**********

Web Links

We need to change how we think about soil

Photo, posted April 8, 2008, courtesy of Brian Boucheron 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...)