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Improving Solar Cells With Human Hair | Earth Wise

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Researchers at the Queensland University of Technology in Australia have been able to improve the performance of perovskite solar cells using material made from human hair.

Perovskite solar cells are an up-and-coming technology that offers the possibility of making solar cells less expensive, more efficient, and flexible so that there could be solar-powered clothing, backpacks, or even tents for camping.  While the technology has been shown to be as effective in converting sunlight to electricity as currently available silicon technology, it faces problems with stability and durability.

The Australian research centered on the use of carbon nanodots to improve perovskite solar cell performance.  The nanodots were created in a rather unique way.  The carbon came from hair scraps from a Brisbane barbershop that were first broken down and then burned at nearly 500 degrees Fahrenheit. 

By adding a solution of the carbon nanodots into the process of making the perovskites, the dots formed a wave-like layer in which the perovskite crystals in the cells are surrounded by the carbon dots.  It serves as a protective layer, essentially a kind of armor, for the active portions of the material.

The result was solar cells with a higher power conversion efficiency and greater stability.  The researchers did not explain why they chose human hair as the source of carbon, but it does make for an interesting sidelight to the promising research.

Perovskite solar cells could be very important for spacecraft applications where reducing weight is paramount.  But in order to be able to use them for this purpose, perovskite solar cells will need to be able to cope with the extreme radiation and temperature variations in space.

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Carbon dots from human hair boost solar cells

Photo, posted October 3, 2009, courtesy of Arktoi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Solar Power Boom In Texas | Earth Wise

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Texas has been a leader in wind energy for a number of years.  In 2020, wind made up 23% of the state’s generating capacity and provided 20% of in-state generation.  But although wind capacity in Texas has grown rapidly in recent years, solar power is expected to make up the largest share of the state’s capacity additions over the next two years.

Texas plans to add 4.6 gigawatts of utility-scale solar power this year and 5.4 gigawatts in 2022.  This will give the state a total capacity of 15 gigawatts, which will nearly catch up to California, the state with the most large-scale solar power.  California already has 16 gigawatts of installed solar capacity and plans to add about two more over the next two years.

The planned capacity for Texas will provide enough power for roughly 5 million homes, taking into account the intermittency of solar energy.  Much of the new solar capacity will be in the Permian Basin in West Texas, which is a particularly sunny place.  Because solar generation is greatest in the middle of the day, when wind generation is typically lower, the transmission line infrastructure already in place for the wind power will be adequate for the new solar installations.

The boom in solar power in Texas is driven in part by the federal solar Investment Tax Credit that is available to project developers as well as by the ever-lower cost of solar technology. 

One-third of the utility-scale solar capacity planned to come online in the U.S. in the next two years will be in Texas.  Currently, utility-scale solar only makes up 4% of electrical generating capacity in Texas, but that is clearly changing.

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Texas likely to add 10 GW of utility-scale solar capacity in the next two years

Photo, posted May 14, 2020, courtesy of Courtney Celley/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Post-COVID Emissions Rebound | Earth Wise

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The extensive shutdowns associated with the COVID-19 pandemic resulted in reduced activity across many sectors of the global economy.  As a result, global pollution and greenhouse gas emissions also saw lower levels.  As the COVID crisis lessens, an economic recovery is growing and as that occurs, emissions are on the rise.

The International Energy Agency forecasts that energy-related carbon dioxide emissions are projected to increase by 1.5 billion tons this year, the second-largest increase in history.

The emissions increase in 2021 is expected to be nearly 5%, reversing most of last year’s emissions decline caused by the pandemic. This would be the largest annual rise since the 2010 recovery from the global financial crisis.  In many places across the globe, people are making up for lost time and doing more of all the things that cause carbon emissions.

A key driver of the emissions increase is a rise in coal use.  The forecast is that coal-burning in 2021 would come close to the all-time peak of 2014.  Both natural gas and oil use are also expected to increase this year.  These increases are in spite of a predicted 17% increase in electricity generation from wind power and an 18% increase in solar-power generation. 

Atmospheric concentrations of CO2 are now at 417 parts per million and have increased by 3 PPM in the past year.  If human CO2 emissions are not reined in, atmospheric concentrations of planet-warming greenhouse gases could double those of pre-Industrial levels by mid-century, which would have disastrous impacts on the climate.

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Global CO2 Emissions Set to Surge in 2021 in Post-Covid Economic Rebound

Photo, posted October 22, 2020, courtesy of Hospital Clínic Barcelona via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Green Light For Commercial-Scale Offshore Wind | Earth Wise

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The Biden administration has given final approval to a project it hopes will usher in a new era of wind energy in the United States.  The greenlight was announced by the Department of the Interior on May 11.

The Vineyard Wind project intends to install up to 84 huge wind turbines about 12 nautical miles off the cost of Martha’s Vineyard, Massachusetts.  In total, Vineyard Wind could generate 800 megawatts of electricity, enough to power about 400,000 homes.  The construction project will create about 3,600 jobs.  The $2.8 billion project is a joint venture of the energy firms Avangrid Renewables and Copenhagen Infrastructure Partners.

The idea of a wind farm off the Massachusetts coast was conceived 20 years ago but ran into repeated setbacks, delays, and well-funded opposition from waterfront property owners concerned about what will ultimately be the barely discernable sight of tiny blips on the distant horizon.  The Trump administration moved to cancel the permitting process for Vineyard Wind, but the Biden administration revived the project in March as part of its greater efforts to tackle climate change.

Electricity generated by Vineyard Wind will travel via cables buried six feet below the ocean floor to Cape Cod, where they will connect to a substation and feed into the New England grid.  The project is expected to begin delivering wind-powered electricity in 2023.

The Biden administration says that it intends to fast-track permits for other wind projects off the Atlantic Coast and that it will offer $3 billion in federal loan guarantees for offshore wind projects and invest in upgrades to ports across the United States to support wind turbine construction.

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Biden Administration Approves Nation’s First Major Offshore Wind Farm

Photo, posted February 8, 2007, courtesy of mmatsuura via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Radar Satellites And Hazard Mitigation | Earth Wise

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Scientists have concluded that the changing climate is primarily the result of increased human-caused greenhouse gas emissions.  Some of the effects of global climate change include melting glaciers, warming oceans, intensifying storms, and rising seas.

Another consequence of global climate change is natural disasters like floods and wildfires.  Climate change is increasing the frequency and severity of wildfires and increasing the odds of record-breaking floods in many parts of the United States and all around the world.

As a result, scientists in Australia have turned to technology for better assistance in keeping tabs on these climate change-driven natural disasters.  Researchers from Curtin University in Perth, Australia have found that satellites can improve the ability to detect, monitor, prepare for, and withstand natural disasters, including floods, wildfires, and earthquakes.

The research team used Synthetic Aperture Radar (SAR) data, which was acquired by the European Space Agency Sentinel-1 satellite.  The researchers also used data acquired by other satellites to evaluate these Australia-specific case studies.

According to the researchers, SAR data provides remote monitoring capabilities of Earth’s surface around the clock and in all weather, which is something that traditional optical Earth Observation (EO) imagery cannot do. The ability to function through fog, clouds, rainfall, and smoke is what makes SAR so valuable.

The research team says that the data can be used to improve how people track and respond to natural disasters, by precisely mapping topography, tracking movements of the ground, and mapping damage to infrastructure. 

As the climate continues to change, the ability to mitigate hazards like floods and wildfires will be increasingly important. 

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Radar satellites can better protect against bushfires and floods

Photo, posted May 11, 2007, courtesy of Bert Knottenbeld via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Infinitely Recyclable Plastic | Earth Wise

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The glut of plastics is one of the world’s most challenging environmental problems.  The average American generates over 200 pounds of plastic waste each year and most of that ends up in landfills.  Researchers around the globe continue to work on potential solutions to the plastic waste problem.

Two years ago, scientists at Lawrence Berkeley National Laboratory announced the invention of a new plastic that could be an answer to the plastic waste problem.  The material is called polydiketoenamine or PDK and it differs from traditional plastics in a very important way:  it can be recycled indefinitely with no loss in quality because it can easily be broken down into its constituent component monomers and be used to make brand new plastic.

Only a small percentage of plastics are currently recycled.  When many plastics are melted down together, the polymers are mixed with a slew of incompatible additives, resulting in a new material with much lower quality than newly produced plastic.  As a result, less than 10% of plastic is recycled more than once.

Recently, the Berkeley Lab researchers released a study that shows what could be accomplished if manufacturers began using PDKs on a large scale.  They determined that PDK-based plastic could quickly become commercially competitive with conventional plastics and, furthermore, would get less expensive and more sustainable as time goes on.

PDK is starting to draw interest from companies needing to source plastic.  The best initial application for PDKs are markets where manufacturers have the most access to products at the end of their lifespans such as in the automobile industry and consumer electronics.  Making plastics part of a circular economy is a challenging task.

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The Future Looks Bright for Infinitely Recyclable Plastic

Photo, posted April 19, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rising Seas In The Maldives | Earth Wise

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

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

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

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

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

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Preparing for Rising Seas in the Maldives

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

Earth Wise is a production of WAMC Northeast Public Radio.

A Better Solar Evaporator | Earth Wise

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Water security is a serious global problem.  Nearly 1.5 billion people – including almost half a billion children – live in areas of high or extremely high water vulnerability.  Less than 3% of the world’s water is fresh and demand for it is rising with increasing population growth, urbanization, and growing water needs from a range of sectors.

Researchers at the University of South Australia have developed a promising new technique that could help reduce or eliminate water stress for millions of people.  The technique uses highly efficient solar evaporation to obtain fresh water from seawater, brackish water, or even contaminated water.   According to the researchers, their technique can deliver enough daily fresh drinking water for a family of four from just one square meter of source water.

Solar evaporation has been the focus of a great deal of effort in recent years, but it has generally been found to be too inefficient to be practically useful.  The new technique overcomes those inefficiencies and can deliver fresh water at a fraction of the cost of existing technologies like reverse osmosis.

The system utilizes a highly efficient photothermal structure that sits on the surface of a water source and converts sunlight to heat, focusing energy precisely on the surface to rapidly evaporate the uppermost portion of the liquid.  The technique prevents any loss of solar energy and even draws additional energy from the bulk water and surrounding environment.

The system is built entirely from simple, everyday materials that are low cost, sustainable, and easily obtainable.

The technology has the potential to provide a long-term clean water solution to people who can’t afford other systems, and these are the places where such solutions are most needed.

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Sunlight to solve the world’s clean water crisis

Photo, posted November 13, 2016, courtesy of Steve Austin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Global Assessment Of Groundwater Wells | Earth Wise

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Water is a fundamental need for every human being on the planet.  Each person requires more than five gallons of clean and safe water a day for drinking, cooking, and keeping clean.

Groundwater wells remain one of the primary sources of drinking water.  In fact, more than half of the world’s population gets its drinking water from groundwater wells.  Groundwater wells also sustain more than 40% of irrigated agriculture.

Researchers from UC Santa Barbara have recently compiled the most comprehensive assessment of groundwater wells to date.  Their research, which was recently published in the journal Science, spanned 40 countries, which collectively account for more than 50% of all groundwater pumping. 

According to the survey’s findings, many wells are at risk of running dry – up to one in five wells, to be exact.  The researchers compared the depths of water tables against well depths. They found that 6% to 20% of the wells in the study were at risk of running dry if water levels continue to decline by just a few meters.

In many areas where groundwater levels are declining, the research team found that new wells are not being drilled deeper to keep pace with the falling water table. As a result, newer wells are just as vulnerable as older wells should groundwater levels continue to decline.  

The researchers hope to expand on this study to include data from China, Iran, and Pakistan, three major users of groundwater from which the researchers could not obtain records.  The researchers also plan to investigate how quickly water tables are dropping and where the trend is accelerating.   

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The largest assessment of global groundwater wells finds many are at risk of drying up

Photo, posted January 20, 2018, courtesy of François Molle via Water Alternatives Photos on Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Sunscreen And Coral Reefs | Earth Wise

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The dangers of overexposure to UV solar radiation have led to the extensive production and use of sunscreen products.  It is generally understood that many of the chemical compounds used in sunscreen products have toxic effects on marine organisms, but research in this area is relatively limited.

There are estimates that as many as 82,000 kinds of chemicals from personal care products have made their way into the world’s oceans.  In 2015, it was estimated that around 14,000 tons of sunscreen are ending up in the world’s coral reefs per year and causing irreparable damage.

Eighty-five percent of the Caribbean’s coral reefs died before the turn of the century, not as a result of global warming, but because of pollution.  Oxybenzone and octinoxate are two of the common sunscreen ingredients that are most toxic to corals.  Preservatives like parabens are also toxic.

There are much safer sunscreens such as those based on zinc oxide or titanium oxide.  In some places, such eco-friendly sunscreens are mandatory.  Sunscreens with SPF values above 30 contain a higher percentage of chemicals and have been shown to not really provide any more protection than SPF 30 products.

Apart from the choice of sunscreen product, if one really wants to reduce the negative impact sunscreen has on reefs and marine life, wearing sun-protective clothing such as rash-guards will allow the use of much less sunscreen and therefore result in less of it entering the ocean.

Products that can help protect against the harmful effects of UV radiation on human health are extremely important, but it is also important to identify and quantify the risks associated with these products to reef ecosystems.

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How to Know If Your Sunscreen Is Killing Coral Reefs — and the Brands to Try Instead

Impacts of sunscreen on coral reefs needs urgent attention, say scientists

Photo, posted January 11, 2015, courtesy of Elch Korallen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Harvesting Water From Air | Earth Wise

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

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

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

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

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

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New Physical Phenomenon Aids Harvest of Water from Air

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

Earth Wise is a production of WAMC Northeast Public Radio.

Ever Cheaper Solar Power | Earth Wise

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The price of electricity from solar panels has been dropping dramatically over the last decade.  The average cost of utility-scale solar power has gone down more than 80% since 1980, making it the least expensive power source in many places.  The plunging price of solar power is one of the driving forces behind the transition to clean energy. 

The 2020 average cost of solar power was 4.6 cents per kilowatt-hour.  The Department of Energy has recently set a target of reducing the cost of solar power by more than half again by 2030, to an unsubsidized average of 2 cents per kilowatt-hour.  The 2-cent goal is not just the ordinary cost of electricity; it is the levelized cost of energy which is based on a formula that includes the cost of construction and operation of a power plant.

If the least expensive power source becomes that much cheaper, it will really shake the foundation of many energy debates.  One of these debates is how to meet the need for more interstate power lines to transport renewable energy from rural areas to population centers.   If large amounts of additional renewable energy sources are added, policymakers will need to work harder to reform the regulatory system to make sure that new interstate power lines get built.

If the average cost of solar power reaches 2 cents a kilowatt-hour, the actual price will be lower in sunnier regions and higher in those that get less sun.  However, the continuing decrease in solar electricity costs will actually have the greatest impact in the northern, less sunny regions, because solar power may not currently be the least expensive option there but it will become the cheapest alternative over time.

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Inside Clean Energy: What Happens When Solar Power Gets Much, Much Cheaper?

Photo, posted May 14, 2020, courtesy of Courtney Celley/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Seagrasses And Ocean Acidification | Earth Wise

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Seagrasses are the basis of important marine ecosystems.   Sea turtles, bat rays, leopard sharks, fish, and harbor seals are just some of the marine creatures that visit seagrass ecosystems for the food and habitat they provide.  They are nursery grounds for many aquatic animals and many birds visit seagrass meadows to dine on what lives within them.  They may seem like slimy grasses that we walk through along some shorelines, but they are important.

These marine forests are valuable for many different reasons including climate mitigation and erosion control.  A third of the carbon dioxide emitted across the globe is absorbed by the ocean and seagrass meadows are an important carbon sink.

A new study, recently published in the journal Global Change Biology, investigated how seagrasses can buffer ocean acidification.  The six-year-long study found that these ecosystems can alleviate low ocean pH – that is, more acidic – conditions for extended periods of time, even at night in the absence of photosynthesis. 

In some places, the pH buffering from the seagrasses brings the local environments back to preindustrial pH conditions, like what the ocean might have experienced around the year 1750.

Seagrasses naturally absorb carbon as they photosynthesize when the sun is out, which drives the buffering ability.  The study found the surprising result that the effects of pH buffering even persisted during the night, when there is no photosynthesis.

The study has implications for aquaculture management as well as climate change mitigation, and conservation and restoration efforts.  Globally, seagrass ecosystems are in decline.  These results show how important it is to help them survive and prosper.

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Seagrasses Turn Back the Clock on Ocean Acidification

Photo, posted October 13, 2010, courtesy of Claire Fackler, CINMS, NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cleaner Water Using Corn | Earth Wise

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Corn is the largest agricultural crop in the U.S., and it is also one of the most wasteful.  About half of the harvest ends up as stover – corn stalks, leaves, husks, and cobs – once the kernels are used for food.

Corn stover has relatively few commercial or industrial uses.  It can be used to produce biofuel, but that is not very energy efficient.  It is sometimes used as a low-quality livestock feed as well.  Mostly, it is just burned if it is used at all.

Researchers at the University of California Riverside have developed an energy-efficient way to make good use of stover by transforming it into activated carbon for use in water treatment.

Activated carbon – often called activated charcoal – is an organic material that is specially treated to contain millions of microscopic pores that make it highly absorbent.  It has many industrial uses, the most common of which is for filtering pollutants out of drinking water.  Most household water filters such as Brita filters as well as the ones built into refrigerators make use of activated carbon.

The Riverside researchers explored methods for producing activated carbon from charred corn stover and found that processing the material with hot compressed water – a process known as hydrothermal carbonization – produced highly absorbent activated carbon with superior properties compared to material produced by slow pyrolysis, where corn stover is charred at increasing temperatures over a long period of time.

According to the researchers, it is important to create approaches that convert waste into high-value materials, fuels, and chemicals in order to create new value streams and eliminate the environmental harm that comes from a so-called “take-make-dispose” economic model.

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Cleaner Water Through Corn

Photo, posted September 15, 2010, courtesy of the United Soybean Board / the Soybean Checkoff via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Plunging Cost Of Lithium-Ion Batteries | Earth Wise

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Lithium-ion batteries are the power source for phones, laptops, and electric cars.  These rechargeable batteries were first commercially introduced in 1991.  Since then, their performance has improved, and their cost has dropped tremendously.

There have been dramatic cost declines in many advanced technologies.   The price of big-screen televisions is a prime example.  Most people think of solar photovoltaic panels as the most exceptional case.  In the 1970s, solar panels cost over $100 per watt. Today, they are 20 cents a watt.

How much lithium-ion batteries have dropped in price has been somewhat unclear.  This is because much of the information about battery costs is in the form of closely held corporate data.  Most lithium-ion batteries are not sold directly to consumers but rather are built into consumer electronics and cars.  Large companies like Apple and Tesla buy batteries by the millions or manufacture them themselves, and the true costs are not publicly disclosed.

Recently, MIT researchers have carried out an extensive analysis of lithium-ion battery costs over the past three decades.  The researchers found that the cost of these batteries has dropped by 97% over that period.

It is clear that the decline in battery costs has been an enabler of the recent growth in sales of electric vehicles.  It is also clear that further declines in lithium-ion battery costs are likely to increase the batteries’ usage in stationary applications such as storing energy from intermittent green power sources like solar and wind.

The batteries have ever-improving energy density (energy stored within a given volume) and specific energy (energy stored within a given mass.)  As lithium-ion batteries continue to get better and cheaper, their role in the world continues to grow.

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Study reveals plunge in lithium-ion battery costs

Photo, posted October 26, 2020, courtesy of Ajay Suresh via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Should We Block The Sun? | Earth Wise

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There is growing concern that greenhouse gas emissions are not falling quickly enough to avoid dangerous levels of global warming.  As a result, there is the impetus to examine other options.  Among these are geoengineering, which is one of the most contentious issues in climate policy.  Geoengineering embodies many risks that make even seriously considering it seem risky in itself.

Despite this, the National Academies of Science, Engineering, and Medicine has issued a report saying that governments urgently need to know whether solar geoengineering could work and what its side effects might be.

Solar geoengineering is also called solar radiation modification, which entails reflecting more of the sun’s energy back into space.  This would likely be accomplished by injecting aerosols into the atmosphere, much like what happens after large volcanic eruptions.

Schemes for solar geoengineering raise numerous issues.  Although solar geoengineering might cool the earth’s surface to a global temperature target, the cooling may not be evenly distributed, affecting many ecosystem functions and biodiversity.   It would likely upset regional weather patterns in potentially devastating ways, for example by changing the behavior of the monsoon in South Asia.  It might dangerously relax public commitments to reduce greenhouse emissions. 

Despite these concerns, or perhaps because of them, the committee that produced the report believes that technology to reflect sunlight deserves substantial funding and should be researched as rapidly and effectively as possible.  Once any geoengineering projects get into the hands of policymakers, they may gather momentum that bypasses the advice of scientists.  So, it important to make progress on the science while geoengineering is still only theoretical.

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Should We Block the Sun? Scientists Say the Time Has Come to Study It.

To intervene or not to intervene? That is the future climate question

Photo, posted August 3, 2018, courtesy of Tomasz Baranowski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Deep Learning And Dirty Air | Earth Wise

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Poor air quality is a major global problem.  According to the World Health Organization, exposure to air pollution is linked to the premature deaths of an estimated seven million people every year.  In fact, 9 out of 10 people breathe air that contains more pollutants than what the WHO considers safe.  Air pollution is the fourth largest threat to human health, trailing only high blood pressure, dietary risks, and smoking.

But predicting pollution levels at a given place and time remains challenging.  According to a new study recently published in the journal Science of the Total Environment, scientists are turning to deep learning to improve air quality estimates. 

According to researchers, satellite observations and ground observations both measure air pollution, but both have major limitations.  For example, satellites may collect data at the same time and at the same location each day, but they miss how emissions may vary throughout the day.  Ground-based observations from weather stations do continuously collect data, but they only do so in a limited number of locations.    

As a result, scientists have turned to deep learning – a type of machine learning – to analyze the relationship between satellite and ground-based observations of nitrogen dioxide around Los Angeles.  Nitrogen dioxide is associated with emissions from traffic and power plants.  The researchers were able to rely on the learned relationship to take daily satellite observations and create hourly estimates of atmospheric nitrogen dioxide levels in approximately three mile grids.     

According to the research team, this study could be repeated for other greenhouse gases, and applied to different cities and regions – or even whole continents. 

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Scientists turn to deep learning to improve air quality forecasts

Air Pollution

Photo, posted November 4, 2019, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Increasing Palm Oil Production Without Harming The Environment | Earth Wise

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Palm oil is the most important source of vegetable oil in the world.  The oil itself and ingredients based on it are found in approximately 50% of the products on supermarket shelves, including both food and non-food items.  Many of the mysterious chemicals that show up on ingredient lists such as sodium lauryl sulfate are actually derived from palm oil.

Dozens of countries produce palm oil, but about 2/3 of the world’s supply comes from Indonesia and the demand for its oil keeps growing.  To keep up with that demand, Indonesia continues to convert valuable ecosystems that contribute greatly to biodiversity to palm production.

A four-year research project at the University of Nebraska- Lincoln has found that keeping up with palm oil demand may not necessarily mean converting valuable, fragile ecosystems into agricultural land.  According to the study published in Nature Sustainability, palm oil yields on existing farms and plantations could be greatly increased with improved management practices.

The researchers identified key practices that could lead to larger yield.  These include improved harvest methods, better weed control, improved pruning, and better plant nutrition.  With such practices, Indonesia could produce 68% more palm oil on existing plantation areas.

The results were surprising to the researchers and are significant from both environmental and economic standpoints.  In particular, it could have a great impact on the millions of individual farmers who draw their livelihood from small palm farms often containing just a few acres.  In Indonesia, about 42% of land used for palm oil production is owned by smallholder farms.

The researchers are now working with various stakeholders in Indonesia to put these management techniques into practice.

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Husker research shows palm oil production can grow while protecting ecosystems

Photo, posted August 15, 2006, courtesy of Lian Pin Koh via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Wood Into Plastic | Earth Wise

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

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

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

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

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

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

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Turning wood into plastic

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

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Farming Productivity | Earth Wise

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The future potential impacts of anthropogenic climate change on global agricultural systems has been well studied, but how human-caused climate change has already affected the agricultural sector is not as well understood.  But a new study led by researchers at Cornell University and supported by the USDA National Institute of Food and Agriculture and the National Science Foundation examined this issue. 

Despite important agricultural breakthroughs in technology, fertilizer use and global trade during the past 60 years, it turns out that the climate crisis is already eroding farm productivity.  According to the study, which was recently published in the journal Nature Climate Change, global farming productivity is 21% lower than it could have been without climate change.  This is the equivalent of losing approximately seven years of farm productivity increases since the 1960s. 

The researchers developed a model linking annual changes in weather and productivity with output from the latest climate models over six decades to quantify the effect of anthropogenic climate change on what economists call “total factor productivity.” This measure captures the overall productivity of the agricultural sector. 

The research team reviewed 200 variations of the model, but the results remained largely consistent:  anthropogenic climate change is already slowing down global food production.  The researchers say the historical impacts of climate change have been larger in naturally warmer climates, like in parts of Africa, Asia, and Latin America.   

Climate change is not some distant problem to solve in the future.  It is already having an impact on the planet and it needs to be addressed now.

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Climate change cut global farming productivity 21% since 1960s

Photo, posted October 2, 2013, courtesy of the United Soybean Board 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...)