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Research on solar geoengineering

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Ideas for potential technologies that could artificially cool the planet as a countermeasure against global warming have been considered radical and dangerous for a long time.  But as climate change continues to become increasingly apparent, ideas like solar geoengineering are gaining increasing attention.

Most environmental organizations are at best skeptical about such ideas and oppose them.  Their opposition is in part based on the assertion that there are no quick fixes for climate change and that not addressing its root causes is a dangerous path to take.  But an even greater concern is that intentionally manipulating global temperatures is likely to have a host of unintended consequences that could prove disastrous.

One of the world’s largest environmental organizations, the Environmental Defense Fund, has decided to fund research into solar geoengineering.  The EDF cautions that is in not in favor of deploying such technology.  Its position is that the discussion about ways to cool the planet is not going away and cannot be ignored.  The lack of proper research can promote unfounded optimism about such technology  So, they are going to fund research that can provide information based on solid, well-formulated science.

A major focus will be what other effects technologies like cloud brightening and injecting aerosols into the atmosphere might have apart from providing cooling. 

The EDF’s own position is that deliberate climate interventions present serious ecological, moral, and geopolitical concerns.  However, they believe that policymakers need to be informed by the most accurate information possible.

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Environmental Group to Study Effects of Artificially Cooling Earth

Photo, posted February 3, 2008, courtesy of Camilla Cannarsa via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Elephants have names

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Elephants are considered to be very smart creatures.  They have the largest brain of any land animal and have three times as many neurons as humans.  Of course, a lot of that brain hardware is needed to control those big elephant bodies, but elephants have also demonstrated impressive mental capabilities on many occasions.

A new study by an international team headed by researchers from Colorado State University has found that elephants call each other by name and respond when they hear others call their name.

The researchers analyzed hundreds of elephant calls recorded over more than a year in Kenya.  With machine learning techniques, they were able to identify specific sounds that elephants made when calling each other.  When the researchers played recordings of these sounds, the elephants responded to the sound of their own name by calling back or moving toward the loudspeaker.  Their response to other names was much less enthusiastic.

Very few animals use names at all, and, in most cases, it is more a matter of imitation.  For example, dolphins refer to other dolphins by mimicking their unique sounds.

These findings at least suggest that elephants may be capable of abstract thought and perhaps may have a vocabulary beyond names for each other.  The researchers are investigating whether elephants can identify food, water, or locations using their calls.  The great hope is that it might ultimately be possible to communicate with elephants directly.  It would be wonderful to be able to alert them to poachers or other threats.  The lead author of the study said that he would like to be able to tell elephants things like “Do not come here.  You’re going to be killed if you come here.”

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Elephants Have Names for Each Other, Study Finds

Photo, posted April 24, 2016, courtesy of Neil Ransom via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Seashells inspire better concrete

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Mother of pearl – also known as nacre – is a natural material found in certain seashells such as those of oysters and abalone.  On the microscopic level, it consists of hexagonal tablets of the hard mineral aragonite glued together by a soft biopolymer.  The aragonite gives nacre its strength, and the biopolymer adds flexibility and crack resistance. 

Scientists at Princeton University have developed innovative composite materials inspired by nacre by utilizing conventional construction materials like Portland cement paste combined with a limited amount of polymer.  The new material consists of alternating layers of cement paste sheets with the highly stretchable polymer polyvinyl siloxane.

The materials were subjected to bending tests to evaluate crack resistance or fracture toughness.  Three different versions of the material were tested that used different ways of interposing the polymer layers.  The new materials were compared with similar structures composed entirely of cement.

The concrete-only samples were brittle, breaking suddenly and completely upon reaching their failure point.  The samples with alternating cement and polymer layers demonstrated increased ductility and resistance to cracking. 

By fully mimicking the structure of nacre – using completely separated hexagonal cement tablets – the researchers demonstrated materials with 19 times the ductility and 17 times the fracture toughness of cement while retaining nearly the same strength as solid cement samples.

Engineered materials inspired by nature could eventually help increase the durability of a wide range of brittle ceramic materials, from concrete to porcelain.

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From seashells to cement, nature inspires tougher building material

Photo, posted January 2, 2016, courtesy of Yantra via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The most endangered marine mammal

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For the better part of a decade, conservationists have been trying to eliminate the use of gill nets by fishermen in the Gulf of California.  Species such as the corvina fish have been decimated by the use of this fishing gear.  The nets also trap other marine creatures, include the rare and elusive vaquita porpoise.

The vaquita is the world’s smallest porpoise, measuring no more than five feet in length.  It is the most endangered marine mammal. They live only in the Gulf of California, which is the site of intense fishing activity. Some of that activity is directed towards a fish called the totoaba, which is an endangered species itself.  The totoaba’s swim bladder is highly prized for Chinese traditional medicine, so there is a booming illegal market for it.  The gill nets used to catch totoaba are especially lethal to vaquitas.

Every year, for a few weeks, an international team of scientists searches the Gulf for vaquitas.  Recent surveys estimated that there are around 10 individuals in the area where they are most likely to be living.  This year’s survey estimated that six to eight vaquitas are in the area.  The ones spotted appeared to be in good health and one yearling was seen.

Officially, fishing with gill nets is banned throughout much of the upper Gulf of California.  In practice, enforcement has been difficult to do.  However, the Mexican government has been making an effort to improve the situation.  The Mexican Navy dropped 193 concrete blocks with giant hooks designed to entangle gill nets to deter fishers and they plan to drop more.

The survival of the vaquita depends on whether the use of gill nets stops.

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The Most Endangered Marine Mammal Still Exists. Here’s the Latest Count.

Photo, posted July 12, 2011, courtesy of Semarnat via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Thawing permafrost:  Is it a ticking timebomb?

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Permafrost covers about a quarter of the landmass in the Northern Hemisphere.  It stores vast quantities of organic carbon in the form of dead plant matter.  As long as it stays frozen, it is no threat to the climate.  But as it thaws, microorganisms start breaking down that plant matter and large amounts of carbon are released into the atmosphere in the form of carbon dioxide and methane.

This process has often been described as a ticking timebomb for the climate.  The theory is that once global warming reaches a certain level, the process will become self-amplifying setting off a catastrophic amount of warming.  If that level was reached, it would be a tipping point in the changing climate.

An international research team from the Alfred Wegener Institute in Germany has extensively researched this hypothesis.  Their conclusion is that within the permafrost, there are multiple geological, hydrological, and physical processes that are self-amplifying and, in some cases, irreversible.  However, these processes act only locally or regionally.  There is no evidence that some particular threshold in global warming could affect all permafrost and accelerate its thawing on a global level.

This research does not mean that Arctic permafrost is nothing to worry about.  In fact, there are ways in which it is more worrisome.  Because the permafrost is very heterogenous – meaning it is very different in different places – there will be numerous small, local tipping points that will be exceeded at different times and at different levels of warming.  All of this will proceed in step with global warming, contributing to the overall worsening situation.  There is no warming level below which permafrost thawing is not a problem.

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Thawing permafrost: Not a climate tipping element, but nevertheless far-reaching impacts

Photo, posted January 24, 2014, courtesy of Brandt Meixell / USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Biofuel refineries and toxic pollution

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There have been decades of government support for renewable, crop-based fuels – primarily corn ethanol.  In fact, it is a required component of gasoline sold in this country.  The biofuels industry has long claimed ethanol to be a clean, greener alternative to petroleum. 

There have been arguments all along that the environmental benefits of corn ethanol are dubious at best because of the energy required to produce the stuff.  There are also issues related to burning a food crop instead of feeding it to people and that the conversion of grasslands and forests to produce it releases massive amounts of carbon.

Recently, another serious concern has emerged.  A new review of industry data has found that the country’s biofuel refineries, mostly located in the Midwest, produce large amounts of toxic air pollutants, in some cases ever more than from their petroleum counterparts.

Emissions data from the country’s 275 ethanol, biodiesel, and renewable diesel plants revealed that they release carcinogenic formaldehyde as well as other potentially dangerous substances including acetaldehyde, hexane, and acrolein.  In 2022, biofuel refineries released 12.9 million pounds of hazardous air pollutants, compared to 14.9 million pounds emitted by oil refineries, and the biofuel plants actually emitted more of the four chemicals just mentioned than petroleum refineries did.

The broad use of crop ethanol is the result of intensive industry lobbying.  Ethanol plants are even exempt from some air pollution permitting requirements.  Perhaps the time has come to revisit its pervasive and mandated use.

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Biofuel Refineries Are Releasing Toxic Air Pollutants in Farm Communities Across the US

Photo, posted February 27, 2021, courtesy of Sue Thompson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Species and climate change

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Temperature extremes on Earth currently range from a low of -129°F to a high of 134°F.  But these climatic limits have changed throughout history.  In fact, during the last interglacial period 130,000 years ago, temperatures were warmer, resembling what we are projected to experience at the end of this century.

Species that evolved during such periods may possess pre-adaptations that could help them tolerate upcoming changes to the climate.  This factor is often overlooked by traditional statistical models predicting species’ responses to climate change.

But a new model, developed by researchers from Ifremer in France and Lausanne University in Switzerland, has taken this oversight into account, and reassessed the proportion of terrestrial and marine species threatened with extinction by climate change. 

In the study, which was recently published in the journal Nature Ecology and Evolution, the research team applied its model to nearly 25,000 terrestrial and marine species from around the world.  The researchers discovered that 49% of these species live in climate niches near the current climatic limits, and 86% could potentially extend beyond these limits. 

The most surprising result concerns tropical regions. While forecasts from traditional models estimate that the diversity of terrestrial species in tropical areas could decrease by 54% between now and 2041-2060, the new model predicts a more moderate decline of 39%.

The findings confirm the importance of taking urgent measures to mitigate climate change and its impact on biodiversity.

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Some species may better tolerate climate change than expected

Photo, posted October 23, 2015, courtesy of Anita Ritenour via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A brief bout of bad air in Scotland

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Scotland, and the UK in general, used to suffer from sulfur dioxide pollution.  Industrial and domestic emissions, especially from burning coal, contributed heavily to urban air leading to the London smog of the 1950s and the acid rain of the 1980s.  But national air pollution agreements and various international measures have been highly successful in reducing sulfur dioxide emissions.  Desulfurization of coal-fired powerplants and the introduction of ultralow sulfur fuels among other measures have decreased sulfur dioxide emission by 98% since 1970. 

As a result, it came as quite a surprise on May 31st when Edinburgh saw sulfur dioxide levels higher than had been observed in over 30 years.  The levels greatly exceeded air quality objectives for 10 hours with concentrations even creeping towards workplace exposure limits.

What happened?  For once, it was nothing that people did.  Two days earlier, a volcanic fissure eruption took place in the Reykjanes Peninsula in Iceland, some 850 miles from Edinburgh.  Because of an unusual meteorological configuration, the prevailing winds sent the plume of volcanic gases southward towards Scotland.  Had the eruption taken place 60 miles further north or happened a few hours later, the plume of gases would have missed the UK entirely and would have traveled north to the Arctic region.

Icelandic volcanic eruptions have impacted air travel in Europe on a number of occasions.  This non-explosive eruption had little impact outside of its local region, but it turned out to briefly wreak havoc in Scotland.  Fortunately, this pollution event was short-lived.

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Atmospheric sulphur dioxide levels reach historic high in Scotland following Icelandic volcano eruption

Photo, posted November 17, 2021, courtesy of Catherine Poh Huay Tan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Industrial heat and solar power

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Many industrial processes require extremely high temperatures, typically more than 1,800 degrees Fahrenheit.  This heat is generally produced by burning fossil fuels – either coal or natural gas – which emits large amounts of greenhouse gases. This level of heat cannot be economically produced using renewable electricity.  As a consequence, decarbonizing these industrial processes is very difficult.

Researchers at ETH Zurich in Switzerland have recently demonstrated a new method of obtaining high-temperature heat based on solar radiation.  They have engineered a device called a thermal trap.  It consists of a quartz rod coupled to a ceramic absorber that can efficiently absorb sunlight and convert it to heat.

In laboratory-scale experiments, they exposed a foot-long quartz rod to artificial light 135 times more intensive than sunlight and were able to produce temperatures as high as 1,900 degrees.  The artificial light source was needed to mimic the effects of concentrated solar energy plants that typically make use of large numbers of mirrors to direct intense solar energy onto a small area.

There are already concentrated solar power plants that operate at temperatures as high as 1,100 degrees and use the heat to operate turbines to generate electricity.  These plants lose efficiency at higher temperatures because of radiative heat losses.  The Zurich thermal trap minimizes these losses and permits higher temperature operation.

The hope is that at a large scale, the new approach may make it possible to use solar energy to decarbonize energy-intensive industrial processes.

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Using solar energy to generate heat at high temperatures

Photo courtesy of ETH Zurich / Emiliano Casati.

Earth Wise is a production of WAMC Northeast Public Radio

Benefits of electric school buses

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There are about half a million school buses in use in the U.S.  A large number of them are older, highly polluting diesel buses.  There are well-established health and climate benefits of switching from diesel vehicles to electric vehicles but making the switch is expensive.  Diesel buses generally cost between $65,000 to $120,000, depending on the type and configuration.  Electric buses cost about $250,000 each.

The substantial cost makes it a difficult decision for local, state, and federal officials, particularly since the actual magnitude of the benefits is not well known.

A new study by researchers at Harvard’s T.H. Chan School of Public Health has quantified these benefits.  According to the study, replacing each bus may yield up to $247,600 in climate and health benefits. These benefits derive from fewer greenhouse gas emissions and from reduced rates of adult mortality and childhood asthma. 

The study compared the amounts of carbon dioxide emitted from diesel bus tailpipes to the emissions associated with generating electricity for the buses and producing their batteries.  It also compared how these respective emissions contribute to fine particulate air pollution, which is linked to adult mortality and the onset of childhood asthma.  The study concluded that particularly in dense urban settings, the savings incurred from electrifying older school buses easily outweigh the costs of replacing them.

An important question not tackled in the study is how electric school buses impact children’s exposure to in-cabin air pollution while riding the bus.  This issue could further inform policy decisions.

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Electric school buses may yield significant health and climate benefits, cost savings

Photo, posted May 9, 2008, courtesy of Christine H. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Declining pollinator populations

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Scientists have been sounding the alarm on the global struggle of pollinators for decades.  Many recent studies have highlighted alarming declines in pollinator populations, sparking concern about the potential negative impacts on ecosystems and agriculture.  Habitat loss, invasive species, and climate change are some of the factors linked to the population declines. But most pollinator research has focused on well-studied species in easily-accessible regions.

In a new study recently published in the journal PLOS One, a research team led by Northern Arizona University compiled data on four major families of bees and butterflies to create species distribution models, allowing them to assess changes over time and space across North America.

The researchers confirmed that bee and butterfly populations are declining in major regions of North America due to ongoing environmental changes, and found that significant gaps in pollinator research limit the ability to protect these species. 

The highest species richness was found along North America’s West Coast –  especially in California. But the models showed a decline in species richness over the past century in western North America.  In contrast, the research team found disproportionate increases in eastern North America.

Comparisons with climate data indicate that the pollinator population changes are at least partly due to the impacts of climate change, including prolonged drought and habitat degradation. 

The study identifies regions of declining populations where officials can prioritize conservation efforts, and highlights how improved monitoring methods could address the knowledge gaps on pollinator populations.

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Bee and butterfly records indicate diversity losses in western and southern North America, but extensive knowledge gaps remain

Bees and butterflies on the decline in western and southern North America

Photo, posted April 3, 2017, courtesy of Tracie Hall via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Minerals from seawater

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There are about 18,000 desalination plants around the world that take in 23 trillion gallons of water each year.  The plants produce more than 37 billion gallons of brine – enough to fill 50,000 Olympic-size swimming pools – every day.  Disposing of this brine is an ongoing challenge.  Dumping it into the ocean can damage marine ecosystems.  Inland desalination plants either bury this waste or inject it into wells, adding further cost and complexity to the already expensive process of desalination.

According to researchers at Oregon State University, this waste brine contains large amounts of copper, zinc, magnesium, lithium, and other valuable metals.  A company in Oakland, California called Magrathea Metals has started producing modest amounts of magnesium from waste brine in its pilot projects.  With support from the U.S. Defense Department, it is building a larger-scale facility to produce hundreds of tons of the metal over two to four years. 

Most of the world’s magnesium supply comes from China, where producing it requires burning lots of coal and utilizing lots of labor.  Magrathea’s brine mining makes use of off-peak wind and solar energy and is much less labor intensive.

No large-scale brine mining operations currently exist and when there are some, they might end up having negative environmental impacts.  But in principle, the process should produce valuable metals without the massive land disturbance, acid-mine drainage, and other pollution associated with traditional mining.  Brine mining could turn a growing waste problem into a valuable resource.

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In Seawater, Researchers See an Untapped Bounty of Critical Metals

Photo, posted February 18, 2017, courtesy of Jacob Vanderheyden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Car tires in your salad

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There seems to be no end to the types of pollution we have introduced into the environment.  One that has only recently started to gain attention is pollution caused by vehicle tires. 

Through normal wear and tear, as vehicles drive along roadways, their tires cast off countless bits of rubber.  These particles can linger in the atmosphere or can be washed down sewage drains and into waterways.  In the water, these particles leach compounds that are toxic to wildlife.

Tires contain various chemical additives that prevent them from cracking and degrading along with various metals and other materials added to rubber and artificial rubber.  Some of these additives are acutely toxic or even carcinogenic.

A recent study by researchers at the University of Vienna tested leafy vegetables that were grown in Switzerland, Spain, and Italy, and were sold in Swiss supermarkets.  The study also tested vegetables harvested directly from Israeli farmlands.

Tire ingredients were found in 11 out of 15 samples gathered from Swiss supermarkets and 9 out of 13 samples collected from Israeli fields.  Among these are 6PPD, a tire additive that has been identified as the cause of the extensive deaths of coho salmon on the US West Coast.

The researchers say that farmers may be introducing tire additives by irrigating crops with treated wastewater or by using sewage sludge as fertilizer.  Airborne tire particles may also be settling on farm soil.

The concentration of tire particles found in the leafy vegetables are relatively low, but it is troubling that we are eating dangerous chemicals used to improve the quality of tires.

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Leafy Vegetables Found to Contain Tire Additives

Photo, posted October 14, 2014, courtesy of Green Mountain Girls Farm via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Record carbon dioxide levels

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Despite the increasing concern about the warming climate, the period between March of last year and March of this year has set a new record for the largest 12-month gain in atmospheric CO2 concentration ever observed.  The new level, measured at Hawaii’s Mauna Loa Observatory was nearly 5 parts per million higher than last year’s level reaching more than 426 parts per million.

CO2 levels averaged 280 ppm for the past 800,000 years until the Industrial Revolution began and people started burning fossil fuels.  Levels started being measured at Mauna Loa in 1958, when they were 315 ppm.  Between 1958 and 2005, the CO2 level rose to 380 ppm.  Over the past 19 years, the amount of CO2 has continued to rise rapidly and with it, global temperatures.

The record increase in carbon dioxide over this past year is probably associated with the end of an El Niño event.  The previous record increase in 2015-2016 was also associated with El Niño.

But the overall trend is clear and discouraging.  Over the past 66 years, the amount of carbon dioxide in the atmosphere has increased by 35%.  This increase is a result of the burning of coal, oil, and natural gas, as well as the effects of deforestation and livestock agriculture.

Carbon dioxide absorbs heat radiating from the Earth’s surface and re-releases it in all directions, including back toward Earth’s surface.  Without this greenhouse effect, the Earth would actually be frozen.  But people are supercharging the natural greenhouse effect and causing the global temperature to rise.  Global energy demand continues to grow and if we continue to meet that demand mostly with fossil fuels, temperatures will continue to rise.

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Scripps Institution of Oceanography: CO2 levels have largest 12-month gain

Photo, posted March 3, 2014, courtesy of Jon Roig via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Glaciers in Venezuela

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There are nearly 200,000 glaciers in the world.  About 91% of them are in Antarctica and 8% in Greenland.  The rest are scattered across nearly 50 countries.  The non-polar country with the most glaciers is actually Pakistan, which has over 7,200 of them.  But as the world continues to warm, glaciers are shrinking back, and many are disappearing altogether.

Venezuela, once home to six glaciers, has become the first country in the Americas to lose all of its glaciers.  Slovenia is considered to be the first country to lose its glaciers in modern times, perhaps as long as 30 years ago.  Glacial thawing has been worsening over the past decade throughout the Andes, which cover parts of Colombia, Venezuela, Bolivia, Ecuador, Peru, Chile, and Argentina.

Five of Venezuela’s glaciers had largely melted away by 2011.  The Humboldt glacier, which is on the highest peak in the Cordillera de Mérida mountain range in Venezuela, has now been declared as too small to be classified as a glacier.  It once covered over a thousand acres; it now has less than 5 acres of ice.  The US Geological Survey defines glaciers as ice bodies extending 25 acres or more.

The loss of glaciers in the Andes has serious consequences for communities that live on their slopes and depend upon glacial melt for water and for energy and food production. 

At least 80% of glaciers worldwide are on track to mostly disappear by the year 2100 because of global warming.  Given that previous forecasts estimated that the Humboldt glacier might last another decade, the prospects for the world’s remaining glaciers are not good.

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Venezuela becomes first nation in the Americas to lose all glaciers

Photo, posted November 11, 2012, courtesy of Tim Snell via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Recycling cement

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Concrete is the second-most-used material on the planet.  Only water is used more.  Producing concrete is responsible for 7.5% of human-produced carbon dioxide emissions.  So, finding a cost-effective way to reduce these emissions is a major challenge in the face of ever-growing global demand for concrete.

Researchers at Cambridge University have found that used cement is an effective substitute for lime flux, which is an essential material used in steel recycling that results in a waste product called slag.  When lime is replaced with used cement, the end product instead is recycled cement that can be used to make new concrete.

The process does not add any significant costs to concrete or steel production and significantly reduces the emissions associated with both.

Concrete is made from sand, gravel, water, and cement.  Cement is made by a process called clinkering, in which limestone and other materials are heated to 2,600 degrees Fahrenheit.  The process converts the materials into cement but releases large amounts of CO2 as limestone decarbonates into lime. 

Cambridge researchers found that using cement clinker and iron oxide instead of lime works well in steel recycling.  Crushing old concrete and taking out the sand and stone results in a cement that is reactivated by the recycling furnace to produce a material with excellent properties. 

Recent tests by the Materials Processing Institute showed that recycled cement can be produced at scale in an electric arc furnace.  Ultimately, this method could produce zero emission cement if the electricity for the furnace comes from renewable sources.

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Cement recycling method could help solve one of the world’s biggest climate challenges

Photo, posted July 18, 2011, courtesy of Kenta Mabuchi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Beware of the blob

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For the past 10 years, there have been several occurrences of a vast expanse of ocean stretching from Alaska to California in which water temperatures are as much as 7 degrees Fahrenheit warmer than normal.  Known jocularly as “the Blob,” the phenomenon can last for several years and decimates fish stocks, starves seabirds, creates blooms of toxic algae, prevents salmon from returning to rivers, and displaces sea lions and whales.

Until recently, there was no accepted explanation for this abrupt ocean heating.  Climate change, even combined with natural cycles like El Niños, is not enough to account for it.

In depth analysis by an international team of researchers has found that the extraordinary heating is the result of a dramatic cleanup of Chinese air pollution.  The decline of smog particles, which to some extent shield the planet from the sun’s rays, has accelerated warming and set off a chain of atmospheric events across the Pacific, essentially cooking the ocean.

This is an example of what can be called the pollution paradox in which global warming is actually increased when air pollution is reduced.  Reduced air pollution on the US West Coast has even been identified as a factor contributing to increased wildfires.  However, air pollution causes more than 4 million premature deaths from cancers and respiratory and cardiovascular diseases each year. 

Nobody thinks that we should stop cleaning up the air to slow down global warming.  The only viable solution is to reduce greenhouse gas emissions as rapidly as possible.

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Pollution Paradox: How Cleaning Up Smog Drives Ocean Warming

Photo, posted December 18, 2017, courtesy of SGUP via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A month of extra-hot days

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The past 12 months have been the hottest ever measured across the globe.  This may not be everyone’s experience in every location, but the average person on Earth experienced 26 more days of abnormally high temperatures than they would have in the absence of climate change.

Researchers considered a given day’s temperature to be abnormally high in a particular location if it exceeded 90% of the daily temperatures recorded there between 1991 and 2020.  Nearly 80% of the world’s population experienced at least 31 days of abnormal warmth since May of 2023.  Theoretically, the number of unusually warm days would have been far fewer in the absence of global warming.

In some countries, the extra-warm days added up to two or three weeks.  In others, such as Colombia, Indonesia, and Rwanda, there were up to 4 months of them. The average American experienced 39 days of extra-warm temperatures since last May.

Scientists also added up how many extreme heat waves the planet experienced since last May.  These are defined as episodes of unseasonable warmth across a large area, lasting three or more days, and causing significant loss of life or disruption to infrastructure or industry.  In total, the researchers identified 76 such episodes, affecting 90 countries, on every continent except Antarctica.

The world’s climate is now shifting toward the La Niña phase of the cyclical pattern called the El Niño-Southern Oscillation. This usually leads to cooler temperatures on average, but the recent heat could have lingering effects on weather and storms for months to come, including what is expected to be an extraordinarily active Atlantic hurricane season.

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Climate Change Added a Month’s Worth of Extra-Hot Days in Past Year

Photo, posted December 21, 2011, courtesy of Maggie Lin Photography via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Olive oil and climate change

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Olive oil is a liquid fat obtained by mashing whole olives and extracting the oil.  A superfood staple of the Mediterranean diet, olive oil is used in kitchens around the world for frying, sauteing, baking, and as a condiment.  It can also be widely found in cosmetics, soaps, and pharmaceutical products. 

Globally, 2.6 million tons of olive oil were consumed last year.  Spain is currently the world’s largest producer of this “liquid gold,” accounting for 44% of global production.  The second largest producer of olive oil is Italy, followed by Greece, Tunisia, Turkey, and Morocco.   

But recently, the price of olive oil has been rocketing up.  Droughts, wildfires, floods, and heat waves, combined with pests, have punished olive-producing regions around the world.  The climate-fueled extreme weather has significantly impacted olive oil production in southern Europe.  Olive trees are exceedingly vulnerable to climate change. 

Spain, for example, typically produces somewhere between 1.3 to 1.5 million metric tons of olive oil each harvest.  However, officials expect a production range of only 830,000 to 850,000 metric tons this season. 

This shortage has sent prices soaring.  According to the International Monetary Fund, the average price of olive oil has doubled over the past two years.  In fact, the price is currently hovering at or around $10,000 per metric ton.  And there doesn’t seem to be much relief in sight.  

The record-breaking price has also unsurprisingly fueled a surge in crime, with criminals targeting supermarkets, oil mills, and olive groves. 

The changing climate continues to threaten food security around the world. 

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‘Liquid gold’: An olive oil shortage is fueling record prices and food insecurity fears

Extra virgin olive oil prices tipped to top £16 a litre next month

Photo, posted October 29, 2015, courtesy of the U.S. Department of Agriculture via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cloud brightening

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Solar geoengineering is a type of climate intervention:  deliberate actions designed to affect the climate.  There are several ways to try to reduce the amount of sunlight reaching the surface of the earth and all of them are controversial.  Perhaps the least controversial approach is cloud brightening.

The idea is based on something called the Twomey effect, which is that large numbers of small droplets in the atmosphere reflect more sunlight than small numbers of large droplets.  Spraying vast quantities of minuscule aerosols into the sky, thereby forming many small droplets, could change the reflective properties of clouds.  If clouds are more reflective, then less sunlight reaches the surface, and the temperature goes down.

This form of geoengineering is thought to be less risky because it can be performed on a localized basis and can use relatively benign materials such as sea salt. 

In early April, scientists from the University of Washington started testing a device that sprays tiny sea-salt particles into the air from the deck of a decommissioned aircraft carrier in Alameda, California.  The test was simply to see whether the machine propelled a mist of suitable size.

Within two weeks, Alameda officials ordered a stop to the experiment, citing potential health and environmental risks.  After a month-long investigation, Alameda ruled that the experiment does not generate a measurable risk to health, wildlife, or the environment.

But before more ambitious experiments take place, there are potential side effects of cloud brightening that need to be studied.  It may turn out to be a useful tool in fighting global warming, but in any case, such technology should not be viewed as a substitute for moving away from fossil fuels.

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A Test of Cloud-Brightening Machines Poses No Health Risk, Officials Say

Photo, posted September 8, 2011, courtesy of Justin Ladia via Flickr.

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