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The U.S. Ratifies A Climate Treaty | Earth Wise

October 14, 2022 By EarthWise Leave a Comment

In a rare display of bipartisanship, the U.S. Senate voted 69-27 in favor of ratifying a key international climate agreement aimed at curbing global warming. The Kigali Amendment to the Montreal Protocol, which has been ratified by 137 other countries so far, ends the use of climate-warming hydrofluorocarbons that are 1,000 times more potent than carbon dioxide in warming the atmosphere. This is the first international climate treaty that the U.S. has joined in 30 years.

The Kigali Agreement was established in Kigali, Rwanda in 2016 to phase out HFCs, which have been the replacements for CFCs (chlorofluorocarbons) in air conditioners and refrigerators. CFCs were found to be depleting the ozone layers that protects the earth from harmful ultraviolet rays. HFCs do not deplete the ozone layer, but they have been a significant contributor to global warming.

The U.S. ratification of the treaty is largely symbolic. The American Innovation and Manufacturing Act, passed by Congress in 2020, gave the EPA authority to regulate HFCs and the agency has already been doing so. However, the Senate action shows that the U.S. is back on the international climate bandwagon.

Failure to ratify the Kigali Amendment would have closed segments of the chemical and manufacturing industries to U.S. producers after 2023 because the Montreal Protocol prohibits trade with countries not party to it or its amendments.

Environmental advocates are hopeful that the U.S. can move forward on other climate actions. A next step would be to focus on methane, the second leading driver of climate change after carbon dioxide.

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Senate Votes to Ratify the Kigali Amendment, Joining 137 Nations in an Effort to Curb Global Warming

Photo, posted June 13, 2017, courtesy of UNIDO via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electricity From Bacteria | Earth Wise

June 3, 2022 By EarthWise Leave a Comment

Microbiologists at Radboud University in the Netherlands have demonstrated in the laboratory that methane-consuming bacteria can generate electrical power. Their study was recently published in the journal Frontiers in Microbiology.

The bacteria studied is called Candidatus Methanoperedens and in the natural environment it consumes methane in water sources that are contaminated with nitrogen including places like water-filled ditches and some lakes. The bacteria in the study make use of the nitrates in the water to break down and digest the methane. Methanogens, which are bacteria that reduce carbon dioxide to form methane, are the source of the methane in these places.

The researchers exploited these complex interactions of bacteria to create a source of electrical power that is essentially a kind of battery with two terminals. One of the terminals is a chemical terminal and one is a biological terminal. They grew the bacteria on one of the electrodes where the bacteria donate electrons that result from its conversion of methane. (Other microbiologists at the same institution had previously demonstrated electrical generation from a similar battery containing anammox bacteria that use ammonium rather than methane in their metabolic processing).

In the study, the Radboud scientists managed to convert 31% of the methane in the water into electricity but they are aiming at higher efficiencies.

This approach represents a potential alternative to conventional biogas electricity generation. In those installations, methane is produced by microorganisms digesting plant materials and the methane is subsequently burned to drive a turbine to generate power. Those systems in fact have an efficiency of less than 50%. The researchers want to determine whether microorganisms can do a better job of generating electricity from biological sources than combustion and turbines can do.

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Bacteria generate electricity from methane

Photo, posted December 3, 2008, courtesy of Martin Sutherland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Pollution Into Cash | Earth Wise

April 22, 2022 By EarthWise Leave a Comment

Power plants and other industrial facilities are a major source of carbon emissions. There are a variety of techniques under development to prevent those emissions by capturing them rather than releasing them into the atmosphere. All of them add costs to the functioning of the facility. A good way to offset those costs is to convert the emissions into useful products, ideally making it profitable to capture emissions.

Engineers at the University of Cincinnati have developed an electrochemical system that converts carbon dioxide into ethylene, which is a chemical used in a wide range of manufacturing. Ethylene has sometimes been called “the world’s most important chemical”. It is used in many kinds of plastics, textiles, and the rubber found in tires and insulation. It is also used in heavy industry such as steel and cement plants as well as in the oil and gas industry.

The Cincinnati process is a two-stage cascade reaction that converts carbon dioxide to carbon monoxide and then into ethylene. It is based on the underlying principle of the plug-flow reactor that is used for variety of production applications. The study, published in the journal Nature Catalysis, demonstrates that the process has high ethylene selectivity – meaning that it effectively isolates the desired compound – as well as high productivity – meaning that it makes a lot of it. The system will take more time to become truly economical, but the researchers are continuing to make progress on that front with improved catalysts.

The researchers believe that this technique can reduce carbon emissions and make a profit doing it. Power plants and other facilities emit a lot of carbon dioxide. With this process, it may be possible to capture it and produce a valuable chemical.

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Conversion process turns pollution into cash

Photo, posted February 27, 2018, courtesy of Cyprien Hauser via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wastewater And Ammonia | Earth Wise

October 22, 2021 By EarthWise Leave a Comment

Ammonia is the second most produced chemical in the world. More than half of it is used in agriculture to produce various kinds of fertilizer, to produce cotton defoliants that make cotton easier to pick, and to make antifungal agents for fruits. Globally, ammonia represents more than a $50 billion a year market.

Current methods to make ammonia require enormous amounts of heat – generated by burning fossil fuels – to break apart nitrogen molecules so that they can bind to hydrogen to form the compound. Ammonia production accounts for about 2% of worldwide fossil energy use and generates over 400 million tons of CO2 annually.

Engineers at the University of Illinois Chicago have created a solar-powered electrochemical reaction that uses wastewater to make ammonia and does it with a solar-to-fuel efficiency that is 10 times better than previous comparable technologies.

The process uses nitrate – which is one of the most common groundwater contaminates – to supply nitrogen and uses sunlight to power the reaction. The system produces nearly 100% ammonia with almost no hydrogen side reactions. No fossil fuels are needed, and no carbon dioxide or other greenhouse gases are produced. The new method makes use of a cobalt catalyst that selectively converts nitrate molecules into ammonia.

Not only is the reaction itself carbon-neutral, which is good for the environment, but if it is scaled up for industrial use, it will consume wastewater, thereby actually being good for the environment. The new process is the subject of a patent filing and the researchers are already collaborating with municipal corporations, wastewater treatment centers, and others in industry to further develop the system.

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Combining sunlight and wastewater nitrate to make the world’s No. 2 chemical

Photo, posted August 29, 2018, courtesy of Montgomery County Planning Commission via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Sustainable Polymer From Wood | Earth Wise

February 24, 2021 By EarthWise Leave a Comment

Scientists from the University of Bath in the UK have developed a sustainable polymer using xylose, a sugar found in wood.

The new polymer is a member of the polyether family. It could be used in a variety of applications, including being a building block for polyurethane, used for example in mattresses and shoe soles. It could also be a bio-derived alternative to polyethylene glycol, a chemical widely used in biomedicine, or in polyethylene oxide, which is sometimes used as an electrolyte in batteries.

Xylose, also known as wood sugar, is one of the most abundant carbohydrates on earth, second only to glucose. Apart from comprising 5-20% of hardwoods, xylose is a major component of straw, corncobs, and many other plant materials.

The new polymer could reduce reliance on crude oil products and its properties can be easily controlled to make the material flexible or crystalline. Added functionality could be added to it by binding other chemical groups such as fluorescent probes or dyes to the sugar molecule for biological or chemical sensing applications.

Tweaking the physical and chemical properties of bio-derived polymers has previously been a very difficult thing to do. The Bath researchers discovered that combining two mirror-image chemical forms of xylose results in a stronger and more adaptable material. They have filed a patent for their technology and are seeking industrial collaborators for further development.

The reliance of plastics and polymers on fossil fuels is a major problem. Bio-derived polymers, such as this new one, are an important part of the effort to make plastics sustainable.

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Scientists make sustainable polymer from sugars in wood

Photo, posted January 25, 2017, courtesy of Keith Double via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

What’s Been Killing Salmon? | Earth Wise

January 5, 2021 By EarthWise Leave a Comment

For decades, there have been mysterious deaths of Coho salmon. The salmon return from the Pacific Ocean each year to spawn along the West Coast. They can be found from Alaska all the way down into California. After heavy rain events each fall, fish have been turning up dead in huge numbers before they spawn. Normally, less than 1% of adult Coho die before spawning. In these mass death events, anywhere from 40% to 90% of fish can perish in affected streams. The mysterious phenomenon has been the subject of intense research for years.

Recently, scientists announced that they may have solved the mystery. There is a chemical antioxidant known as 6PPD that is used in the manufacture of tires around the world to make them last longer. As tire treads break down over time, they leave behind bits of microplastics on roads. The 6PPD in the plastic bits reacts with ozone to become another chemical: a previously unreported substance called 6PPD-quinone.

That chemical turns out to be toxic to Coho salmon. Researchers have found the presence of 6PPD-quinone in roadway water runoff samples taken from across the West Coast. Based on these observations, they believe it is likely that exposure to this chemical is the main cause of the Coho salmon population decline.

Coho salmon are a favorite of sport fishermen and have great cultural significance to many Native American tribes on the West Coast. The central California Coho population is classified as endangered and three other Coho populations are listed as threatened.

Tire industry representatives call the study results “preliminary” but say the industry is deeply committed to protecting the environment. A safe chemical substitute for 6PPD is clearly needed.

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Salmon have been dying mysteriously on the West Coast for years. Scientists think a chemical in tires may be responsible

Photo, posted November 17, 2011, courtesy of Lynn Ketchum/Oregon State University via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carnivores Eating Human Food | Earth Wise

December 1, 2020 By EarthWise Leave a Comment

A recent study by ecologists at the University of Wisconsin-Madison has found that carnivores living near people often get more than half of their diets from human food sources rather than from their traditional prey. This represents a major lifestyle disruption that puts North America’s carnivore-dominated ecosystems at risk.

The researchers studied the diets of seven predator species across the Great Lakes region using bone and fur samples taken from animals from areas as remote as national parks to metropolitan areas including Albany, New York. What they found – unsurprisingly – is that the closer carnivores lived to cities and farms, the more human food they ate. Dietary contributions of human food varied with species, but on average was more than 25% in most human-altered habitats.

The researchers studied the diets of carnivores like bobcats, coyotes, red and gray foxes, fishers, and American martens by chemical analysis of samples from Minnesota, Wisconsin, upstate New York, and the Upper Peninsula of Michigan. The diets of the animals could be analyzed on the basis of the carbon content of bone and fur samples. Human food, heavy in corn and sugar, lends these samples a distinctive carbon isotope signature. In contrast, prey species confer their own carbon signatures. The ratio of these isotope fingerprints provides information on the proportion of an animal’s diet that came from human sources.

Relying upon human food increases how much carnivores overlap one another in their competition for food. Compared to when these predators vie for distinct prey, there can be more conflicts between animals. Changing how a species gets their food can have far-ranging effects on ecosystems.

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Carnivores living near people feast on human food, threatening ecosystems

Photo, posted August 18, 2007, courtesy of Jitze Couperus via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fuel From Lignin | Earth Wise

November 26, 2020 By EarthWise Leave a Comment

Lignin is an organic polymer that provides the rigid structure of plants and is what gives wood and bark their characteristic properties. Lignin typically comprises between 20 and 35% of the mass of wood. The two major substances extracted from trees, grasses, and other biomass materials are cellulose and lignin. Cellulose is used to make paper, bioethanol, and other products, but lignin is largely unused because it is difficult to break down into useful substances such as feedstocks for fuels. As a result, lignin is largely wasted. Worldwide, some 50 million tons of lignin are produced from paper and bioethanol manufacturing each year and almost all of that is simply burned to generate heat.

Lignin can be broken down using pyrolysis techniques at high temperatures to create bio-oils, but those oils lack sufficient hydrogen and contain too much oxygen to be useful as fuels. There is a process called hydrodeoxygenation that adds hydrogen and removes oxygen, but it requires high temperatures and very high pressures as well as producing char and tar that reduces the efficiency of the process.

Researchers at Georgia Tech recently published work describing a new process for turning lignin into useful products. They developed a dual catalyst system of super-acid and platinum particles that adds hydrogen and removes oxygen from lignin bio-oil and makes it useful as a fuel and source of chemical feedstocks.

The new process could help meet the growing demand for bio-based oils as well as helping the forest product, paper, and bioethanol industries by providing an additional revenue stream from what previously was a waste product.

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New Process Boosts Lignin Bio-oil as a Next-Generation Fuel

Photo, posted August 16, 2017, courtesy of evcabartakova via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hacking Photosynthesis | Earth Wise

September 14, 2020 By EarthWise Leave a Comment

A team led by the University of Illinois has been pursuing a project called Realizing Increased Photosynthetic Efficiency or RIPE, which has the aim of improving photosynthesis in order to provide farmers with higher-yielding crops in an increasingly challenging climate. Photosynthesis is the natural, sunlight-powered process that plants use to convert carbon dioxide into sugars that fuel growth, development, and for us, crop yield.

If we think of photosynthesis as a factory line composed of multiple machines, the growth of plants is limited by the slowest machines in the line. The RIPE project has identified some steps in photosynthesis that are slower than others and are attempting to enable plants to build more machines to speed up those slower steps.

The researchers modeled a total of 170 steps in the process of photosynthesis to identify how plants could manufacture sugars more efficiently. In the study, the team increased crop growth by 27% by resolving two constraints: one in the first part of photosynthesis where plants turn light energy into chemical energy and one in the second part when carbon dioxide is turned into sugars.

The researchers effectively hacked photosynthesis by adding a more efficient transport protein from algae to enhance the energy conversion process.

In the greenhouse, these changes improved crop productivity by 52%, but in field trials, which are a more important test, these photosynthetic hacks boosted crop production by 27%.

Ultimately, the team hopes to translate these discoveries to a series of staple food crops, such as cassava, cowpea, corn, soybean and rice, which are needed to feed the world’s growing population this century.

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Photosynthetic hacks can boost crop yield, conserve water

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

Earth Wise is a production of WAMC Northeast Public Radio.

Concrete Production And Diminishing Coal Burning | Earth Wise

June 5, 2020 By EarthWise Leave a Comment

Coal burning is still one of the primary means of generating electricity in the United States, but its use is diminishing and doing so fairly rapidly. The coal burning process produces residual, incombustible materials. One of them is fly ash, which is composed of fine, glassy, rounded particles rich in silicon, aluminum, calcium, and iron oxides. Fly ash is captured from coal plant flue gas by precipitators and bag filters. It turns out that two-thirds of this fly ash is not dumped into landfills or impoundments, but rather is put to use.

Because of its chemical and physical characteristics, fly ash can substitute for a portion of portland cement in concrete. Using this byproduct material in making cement actually reduces its cost. Beyond cost, the addition of fly ash as a so-called supplementary cementitious material or SCM improves concrete’s long-term strength and reduces porosity and permeability. It reduces the risk of thermal cracking and provides good long-term mechanical properties.

The amount of fly ash used in concrete products increased by 5% between 2011 and 2017 while the amount produced dropped by 36%. Concrete production continues to increase steadily while fly ash production is steadily dropping.

Therefore, the concrete industry is looking for alternative sources of SCM. The most obvious is the approximately 1/3 of fly ash that hasn’t been used to make concrete. Much of that is landfilled or ponded onsite at power plants. So, opportunities exist for excavating or dredging and recovering these materials.

As coal burning goes away, concrete manufacturing needs to make some changes.

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What Does the Changing Face of Electricity Production Mean for Concrete?

Photo, posted February 16, 2017, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A New Membrane For Converting Carbon Dioxide | Earth Wise

March 24, 2020 By EarthWise Leave a Comment

Methanol is a valuable chemical used as fuel in the production of countless products. Carbon dioxide is a greenhouse gas that is produced by countless industrial processes. Carbon dioxide can be converted into methanol, which is one way all that CO2 can be put to good use instead of causing harm.

In research recently published in Science, chemical engineers from Rensselaer Polytechnic Institute have developed a process that converts CO2 to methanol in a more efficient way by using a highly effective separation membrane they produced.

The chemical reaction responsible for the transformation of CO2 into methanol also produces water, which severely restricts the continued reaction. The Rensselaer team has found a way to filter out the water as the reaction is happening, without losing other essential gas molecules.

They produced a membrane made up of sodium ions and zeolite crystals that was able to carefully and quickly permeate water through small pores — known as water-conduction nanochannels — without losing gas molecules. The sodium ions effectively only allow water to go through. When water was effectively removed from the process, the team found that the chemical reaction was able to happen very quickly. By removing the water, the equilibrium shifts, which means more CO2 will be converted and more methanol will be produced.

The team is now working to develop a scalable process and a startup company that would allow this membrane to be used commercially to produce high purity methanol. This membrane could also be used to improve a number of other reactions.

In industry there are many reactions limited by water and this RPI membrane could be an important enhancement for many of them.

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Water-Conducting Membrane Allows Carbon Dioxide To Transform into Fuel More Efficiently

Photo courtesy of RPI.

Earth Wise is a production of WAMC Northeast Public Radio.

Converting A Toxin Into An Industrial Chemical | Earth Wise

January 16, 2020 By EarthWise Leave a Comment

Nitrogen dioxide is a prominent air pollutant produced by internal combustion engines burning fossil fuels as well as by a variety of industrial processes. It is a toxic material associated with a number of respiratory illnesses.

Researchers at the University of Manchester in the UK along with an international team of scientists have developed a new advanced material that can convert nitrogen dioxide from an exhaust gas stream into useful industrial chemical using only water and air.

The material is a metal-organic framework (or MOF) that provides a selective, fully reversible, and repeatable capability to capture nitrogen dioxide. MOFs are tiny three-dimensional structures that are porous and can trap gases inside as though there were tiny cages. MOFs have enormous amounts of surface area for their size. One gram of material can have a surface area as large as a football field.

The material, named MOF-520, can capture nitrogen dioxide at ambient temperatures and pressures and even at low concentration and during flow in the presence of moisture, sulfur dioxide, and carbon dioxide. Such conditions are typical of the exhaust of internal combustion engines. In fact, the process works best at the typical temperature of automobile exhausts.

Once the nitrogen oxide is absorbed, treating the material with water in air converts it into nitric acid and restores the MOF for additional use. Nitric acid is the basis of a multi-billion dollar industry with uses including agricultural fertilizers, rocket propellant, and nylon. Thus, there is great potential for recouping the costs of using the MOF technology and even profiting from it.

It would be great to convert a toxic pollutant into valuable industrial chemicals.

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Clean air research converts toxic air pollutant into industrial chemical

Photo courtesy of the University of Manchester.

Earth Wise is a production of WAMC Northeast Public Radio.

Keeping Plants Plump

December 3, 2019 By EarthWise Leave a Comment

The leading cause of crop failures worldwide is drought. Ironically, the very close runner-up is flooding. Facing a changing and increasingly erratic climate, farmers need all the help they can get in protecting their crops.

Researchers at the University of California, Riverside, have created a chemical to help plants hold onto water, which could stem the tide of massive annual crop losses from drought. Details of the team’s work is described in a paper published in Science.

The chemical is called Opabactin, but is also known as “OP.” OP is gamer slang for overpowered, referring to the best character or weapon in a game.

OP mimics abscisic acid, or ABA, which is the natural hormone produced by plants in response to drought stress. ABA slows a plant’s growth, so it doesn’t consume more water than is available and doesn’t wilt. OP is 10-times stronger than ABA, which makes it a super hormone. It works fast. Within hours, there is a measurable improvement in the amount of water plants release. Because it works so quickly, OP could give farmers more flexibility in how they deal with drought. Plants can’t predict the future, but if, for example, farmers think there is a reasonable chance of drought, they could make decisions such as to apply OP to improve crop yields.

The research team is now trying to find a second chemical tool. Whereas OP slows down plant growth, the team wants to find a molecule that will accelerate it. Such a molecule could be useful in controlled environments such as indoor greenhouses. There are times when you want to speed up growth and times when you want to slow it down.

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Game changer: New chemical keeps plants plump

Photo, posted June 7, 2013, courtesy of Bayer CropScience UK via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Safe And Simple Hydrogen Peroxide

November 29, 2019 By EarthWise Leave a Comment

We don’t think about hydrogen peroxide very often. Perhaps we have a bottle of it under our bathroom sink that we haven’t touched in a few years. But it is an important product manufactured in the millions of tons each year and the basis of a $6 billion global business.

Hydrogen peroxide is widely used as an antiseptic, a detergent, in cosmetics, as a bleaching agent, in water purification, and in many other applications. It is produced in industrial concentrations of up to 60% in solution with water in order to maximize the economics of transportation. This makes transportation hazardous and costly because the concentrated form is unstable. Most applications use a far more diluted form.

Researchers at Rice University have developed a new method for producing hydrogen peroxide that is much simpler and safer than the current technology, which actually dates back to the 1930s. The Rice technique requires only air, water and electricity to produce the chemical. The electrosynthesis process, which is detailed in the journal Science, uses an oxidized carbon nanoparticle-based catalyst.

The process could enable point-of-use production of pure hydrogen peroxide solutions, which would eliminate the need to transport the hazardous concentrated chemical. The use of a solid electrolyte instead of the traditional liquid electrolyte eliminates the need for product separation or purification that is part of the current technology.

In the future, instead of storing containers of hydrogen peroxide, hospitals that use it as a disinfectant could turn on a spigot and get, for example a 3% solution on demand. Instead of storing chemicals to disinfect swimming pool water, future homeowners could flick a switch and turn on their peroxide reactor to clean their pools.

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Water + air + electricity = hydrogen peroxide

Photo, posted April 19, 2009, courtesy of Robert Taylor via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Ocean Acidification And Mass Extinction

November 26, 2019 By EarthWise Leave a Comment

Since the industrial revolution, the concentration of carbon dioxide in the atmosphere has increased due to the burning of fossil fuels and land use changes. The ocean absorbs about 30% of the CO2 that is released in the atmosphere. As the levels of atmospheric CO2 increase, so do the levels in the ocean.

When CO2 is absorbed by the ocean, a series of chemical reactions occur, resulting in seawater becoming more acidic. Ocean acidification threatens calcifying organisms, such as clams and corals, as well as other marine animals, like fish. When these organisms are at risk, the entire marine ecosystem may also be at risk.

In fact, according to research recently published in the journal Proceedings of the National Academy of Sciences, fossil evidence from 66 million years ago has revealed that ocean acidification can cause the mass extinction of marine life. Researchers analyzed seashells in sediment laid down shortly after a giant meteorite hit earth. This strike wiped out the dinosaurs and 75% of marine species. Chemical analysis of the shells revealed a sharp drop in the PH of the ocean over hundreds of years after the meteorite strike. The meteorite impact vaporized rocks, causing carbonic acid and sulphuric acid to rain down, acidifying the ocean. The strike also resulted in mass die-off of plants on land, increasing atmospheric CO2.

Researchers found that the pH dropped by 0.25 pH units in the 100 to 1,000 years after the meteorite strike. Alarmingly, scientists expect the pH of the ocean to drop by 0.4 pH units by 2100 if our carbon emissions continue as projected.

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Ocean acidification can cause mass extinctions, fossils reveal

Photo, posted March 16, 2017, courtesy of Zachary Martin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Contrails And Climate Change

September 6, 2019 By EarthWise Leave a Comment

The white wispy trails of condensation produced by the exhaust from aircraft engines have been the subject of a popular conspiracy theory for quite a while. The story goes that the long-lasting condensation trails are actually “chemtrails” composed of chemical or biological agents left in the sky by aircraft and are intentionally sprayed for a variety of nefarious purposes undisclosed to the general public. This story, of course, is nonsense.

But while contrails are not deliberate efforts to modify weather, control population, manipulate psychology, or any of the other bizarre things attributed to them, it turns out that they are having unfortunate effects on the climate.

It turns out that contrails are creating an often-invisible thermal blanket of cloud across the planet that has a significant effect on atmospheric temperatures. Contrails are essentially human-made clouds that form above 25,000 feet where the air is moist and colder than -40 degrees Celsius. At times, contrails stick around in the sky, either as tight, white lines like chalk marks, or by spreading to create thin layers of ice clouds. At any one time, contrail-created clouds cover more than half a percent of global skies.

Research has shown that when contrails are around, nighttime temperatures can go up appreciably. After 9/11, when all U.S. flights were grounded for three days, the difference between daytime and nighttime temperatures actually increased by about 3 degrees Fahrenheit because nights were cooler.

The effects of aviation on climate, both from the CO2 emissions from aircraft engines and from these contrail effects are becoming an increasingly important issue. To complicate matters further, as aircraft engines become more efficient, they will create more, whiter, and longer-lasting contrails.

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How Airplane Contrails Are Helping Make the Planet Warmer

Photo, posted May 15, 2012, courtesy of Mike Lewinski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Return Of An Old Threat

July 3, 2019 By EarthWise Leave a Comment

The 1987 signing of the Montreal Protocol was one of the biggest victories for global environmental stewardship. The 197 signatory nations banded together to address a planetary emergency: the depletion of the ozone layer in the upper atmosphere resulting from the use of chlorofluorocarbons or CFCs.

Over the years, there were celebratory headlines like “The Earth’s Ozone Hole is Shrinking” and “Without the Ozone Treaty, You’d Get Sunburned in 5 Minutes”. And indeed, the hole in the ozone layer has shrunk over time.

However, the presence of CFCs in the atmosphere is continually monitored and studies in recent years reported new emissions of about 13,000 tons of CFC-11 a year from somewhere in eastern Asia starting in 2012. That was two years after the 2010 date for ending all CFC production under the terms of the Montreal Protocol.

A new study published in Nature has pinned down the source of more than half of the new CFC emissions to the provinces of Shandong and Hebei on the northeastern coast of China. The bulk of these emissions are believed to come from small factories using the chemical to manufacture foam insulation used in refrigerators and buildings.

The Chinese government has already shut down two manufacturing locations, but undercover agents have found that 18 out of 21 manufacturers in the region are using the banned substance. They appear to be quite adept at circumventing enforcement.

The new emissions aren’t large enough so far to be catastrophic, but the Chinese government needs to crack down on this illegal activity. It is difficult to stop because these are small companies operating in meth lab-like facilities. Saving the earth’s atmosphere from ourselves is a tricky business.

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