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The Cost Of Invasive Species | Earth Wise

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According to a new report published by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services for the United Nations, invasive species introduced to new ecosystems around the world are causing more than $423 billion in estimated losses to the global economy every year.  These economic costs are incurred by harming nature, damaging food systems, and threatening human health.

According to the report, these costs have at least quadrupled every decade since 1970 and the estimates are actually conservative because it’s difficult to account for all of the effects of invasive species.

The report estimates that humans have intentionally or unintentionally introduced more than 37,000 species to places outside their natural ranges.  More than 3,500 of them are considered invasive because they are harmful to their new ecosystems.  Invasive nonnative species were a major factor in 60% of known extinctions of plants and animals.

Some species are relocated deliberately by the wildlife trade and international shipping.  Other plants and animals end up hitching a ride with ordinary travelers as they move about by car, boat, plane, or train. 

Invasions can damage human health.  Mosquitos that transmit diseases like malaria, dengue fever, and the Zika virus have become invasive around the world. The wildfires in Hawaii this summer were fueled by invasive nonnative grasses in a warming climate. 

Nearly every country in the world has agreed to participate in a sweeping agreement to preserve biodiversity and reduce invasive species.  It is an essential global goal.

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Invasive Species Are Costing the Global Economy Billions, Study Finds

Photo, posted June 2, 2022, courtesy of Sam Stukel (USFWS) via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Greenhouse Gas Emissions Are Still Increasing | Earth Wise

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Recent research has found that the level of greenhouse gases emitted by human activity has reached an all-time high level of nearly 60 billion tons a year.  Despite increasing public attention, policy measures, and adoption of green technologies, the pace at which these changes have been taking place has simply not kept up with the ongoing burning of fossil fuels by increasingly industrialized societies.  The rate at which greenhouse gas emissions has increased over time has indeed slowed, but emissions need to start decreasing and as soon and as much as possible.

Human-induced warming has reached a ten-year average from 2013-2022 of 1.14 degrees Celsius above pre-industrial levels, up from a 1.07 degrees average between 2010-2019. 

Scientists have calculated a carbon budget that describes how much more carbon dioxide can be emitted before global warming exceeds the threshold of 1.5 degrees Celsius that is widely predicted to lead to potentially catastrophic changes to the climate.  In 2020, the Intergovernmental Panel on Climate Change calculated that the remaining carbon budget was about 500 billion tons of carbon dioxide.  Over the past three years, nearly half of that carbon budget has already been exhausted by the continuing onslaught of carbon emissions.

Researchers describe their study as a timely wake-up call that the pace and scale of climate action to date has been insufficient and that we need to change policy and approaches in light of the latest evidence about the state of the climate system.  Time is no longer on our side in trying to stave off the worst effects of climate change.

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Greenhouse gas emissions at ‘an all-time high’, warn scientists

Photo, posted September 18, 2015, courtesy of In Hiatus via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Large Lakes In Decline | Earth Wise

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Globally, freshwater lakes and reservoirs hold 87% of the planet’s liquid freshwater, making them a valuable resource for both people and wildlife.  Despite their value, the long-term trends and changes to water levels of lakes have been largely unknown – until now.

According to a new assessment recently published in the journal Science, more than half of the largest lakes around the world are losing water.  Using satellite observations and climate data, the research team created a technique to measure changes in water levels in nearly 2,000 of the world’s biggest lakes and reservoirs, representing 95% of the total lake water storage on Earth.

The results are staggering.  According to the findings, 53% of Earth’s largest lakes and reservoirs now store significantly less water than they did in 1992.  The total amount of water lost is estimated to be 144.5 cubic miles, which is equivalent to the volume of 17 Lake Meads (the largest reservoir in the U.S.). 

Unsurprisingly, climate warming and human consumption were the main drivers of water loss from lakes, whereas sedimentation — the buildup of debris — was the biggest driver of water loss in reservoirs.  Roughly one-quarter of the world’s population – two billion people – live in the basin of a drying lake, indicating the urgent need for sustainable water resources management.

But the news is not entirely bleak.  According to the research team, the new method of tracking lake water storage trends can give water managers and communities insight into how to better protect this critical resource. 

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Satellites reveal widespread decline in global lake water storage

Photo, posted February 10, 2010, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Pulling Carbon Dioxide Out Of Seawater | Earth Wise

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The world’s largest sink for carbon dioxide from the atmosphere is the ocean.  The world’s oceans soak up 30-40% of all the gas produced by human activities.  Dissolving carbon dioxide in water produces carbonic acid.   This is the reason that oceans are becoming increasingly acidic, which is causing serious damage to ocean ecosystems.

There are many efforts underway aimed at directly removing carbon dioxide from the air as a way to mitigate the effects of ongoing emissions.  But another possibility is to remove CO2 directly from ocean water.  Existing methods for doing it involve the use of expensive membranes and complex chemicals. The economics of such methods are quite unfavorable.

Recently, a team of researchers at MIT has identified what they claim is a truly efficient and inexpensive removal mechanism. It involves a reversible process based on membrane-free electrochemical cells.  Electrodes in the cells release protons that are introduced to seawater which drive the release of carbon dioxide dissolved in the water. The carbon dioxide can be collected and the processed water ends up being alkaline.

Running this process at a site that is already collecting seawater – such as at a desalination plant – would be an effective way to collect carbon dioxide as well as help mitigate ocean acidification.

Once the carbon dioxide is removed from the water, it still needs to be disposed of, just as is the case for other carbon removal processes.  It could be turned into useful chemicals or it could be stored in underground caverns.  But this approach is fairly unique in that the carbon dioxide has already been captured by the ocean.  The issue remains what to do with it.

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How to pull carbon dioxide out of seawater

Photo, posted January 19, 2016, courtesy of Judy Dean via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Growing Threat To Wheat | Earth Wise

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

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

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

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

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

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

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Harmful fungal toxins in wheat: a growing threat across Europe

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

Earth Wise is a production of WAMC Northeast Public Radio.

Electric Cars And Cleaner Air | Earth Wise

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Cities are awash in microscopic soot and other pollutants from the tailpipes of vehicles.  Apart from contributing substantially to the warming of the planet, these emissions have a significant impact on human health.  Research at Cornell University has determined that the continued growth of electric cars will lead to cleaner air and reduced human mortality in most if not all U.S. metropolitan areas.

The study, published in Renewable and Sustainable Energy Reviews, estimated the health impact and consequential economic impact of cleaner air in American cities as a result of the transition to electric vehicles.

For example, by 2050, Los Angeles will have 1,163 fewer premature deaths annually, corresponding to $12.6 billion in economic health benefits.  Greater New York City could see 574 fewer deaths a year leading to $6.24 billion in associated economic gains.

Global sales of electric cars have grown steadily.  In 2016, they accounted for less than 1% of the market.  That share grew to 2.2% in 2018, 4.1% in 2020, and 6.6% in 2021.

In the U.S., electric cars accounted for 4.5% of sales in 2021, but in many cities, the numbers were much higher. 

These trends are likely to accelerate as a combination of government policies and major decisions by automakers drive a rapid transition to electrification.  While mitigating the effects of climate change continues to be the main driving force for that transition, the human health benefits will be a very significant reward for doing the right thing for the planet.

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Electric car sales drive toward cleaner air, less mortality

Photo, posted May 11, 2021, courtesy of Chris Yarzab via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Miracle Tree | Earth Wise

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The world needs to be fed without destroying the environment.   We need to grow more trees to store more carbon on earth and reduce the amount in the atmosphere.  But meanwhile, we decimate rainforests to produce palm oil and grow soybeans.

A startup company in California called Terviva thinks they have a solution.  It’s called pongamia, which is an ordinary looking tropical tree.  It produces beans packed with protein and oil, much like soybeans.  However, it has the potential to produce much more nutrition per acre than soybeans and it is hardy enough to grow on pretty much any kind of land without the use of pesticides, fertilizers, or irrigation.  In short, it is a miracle crop for a hot and hungry planet that is running out of fertile farmland and fresh water.

Pongamia is not a new or rare tree.  It is common in India but grows all over the world.  It is often planted as an ornamental here in the U.S.

The initial idea for making use of the hardy tree was to use its oil as a biofuel.  The seeds of pongamia are known to have a bitter taste and disagreeable odor, which is why the seeds or oil were never used for human or animal feed.  However, Terviva has developed a way to de-bitter pongamia oil.  Once this is done, it becomes a golden-colored substitute for olive oil. It also has enormous potential as a protein for plant-based milks and meats, since it contains all nine essential amino acids.

Terviva has raised more than $100 million to further develop pongamia and is now partnering with Danone, a $25 billion multinational food company, to develop pongamia as a climate-friendly, climate-resilient, non-GMO alternative to soy and palm oil.

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This super-tree could help feed the world and fight climate change

Photo, posted December 15, 2015, courtesy of Lauren Gutierrez via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Space Tourism And The Climate | Earth Wise

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Space tourism is human space travel for recreational purposes.  A few well-known billionaires have taken rocket rides in recent years and at least a dozen companies are at the vanguard of what they are expecting to be a burgeoning industry.  If space tourism truly takes off – pun intended – it could be a serious threat to the climate and the environment.

Black carbon – essentially soot – is emitted when fossil fuels, including rocket fuels, are burned.  Black carbon absorbs light from the sun and releases thermal energy, making it a powerful climate warming agent.  At lower altitudes, black carbon quickly falls from the sky, remaining in the atmosphere for only a matter of days or weeks.

Rockets are another story entirely.  They dump black carbon into the stratosphere as they blast into space, and up there black carbon is 500 times worse for the climate and sticks around for several years.

A detailed study by researchers at University College London looked at the climate impact of present-day space launches compared with the potential massive expansion of launches from a large space tourism industry.

The overall result is that current space launches are not a significant source of emissions, but space launches would become incredibly significant if projections of tourist space flights proved to be true.  Currently, there are roughly 100 space launches a year world-wide.  If that number becomes thousands, the impact on the climate would be substantial.

The same researchers looked at the ozone impact of rocket launches and reached a similar conclusion.  The current impact of spaceflights is not very significant, but a massive increase in launches could have a major impact on atmospheric ozone concentrations.

Space tourism may be exciting, but it also could be very dangerous for the planet.

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Space Tourism Poses a Significant ‘Risk to the Climate’

Impact of Rocket Launch and Space Debris Air Pollutant Emissions on Stratospheric Ozone and Global Climate

Photo, posted May 30, 2020, courtesy of Daniel Oberhaus (2020) via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Air Pollution: The Greatest Danger | Earth Wise            

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The effort to reduce and ultimately eliminate the use of fossil fuels has largely been driven by the potentially catastrophic consequences of global climate change.  The need to stop dumping greenhouse gases into the atmosphere has become increasingly urgent.  But there is an equally compelling reason to stop burning fossil fuels.  According to a study published in the journal Lancet Planetary Health, outdoor air pollution is “the largest existential threat to human and planetary health.”

Pollution of various types was responsible for an estimated 9 million deaths around the world in 2019.  Half of those fatalities – 4.5 million deaths – were the result of outdoor air pollution coming from vehicles and industrial sources like power plants and factories.

The number of deaths attributed to air pollution has increased by 55% just since the year 2000.

The growth in air pollution deaths has offset a decline in deaths from other pollution sources that especially affect people living in extreme poverty, such as indoor air pollution and water pollution.  Overall, countries with lower collective incomes tend to bear a disproportionate share of pollution deaths.  Roughly 16% of deaths around the world are attributable to pollution, also resulting in more than $4 trillion in economic losses.

The peer-reviewed study was produced by the 2017 Lancet Commission on Pollution and Health.  The study notes that despite the enormous health, social, and economic impacts of pollution, preventing it is largely overlooked in the international development agenda.  The study calls upon governments, businesses, and other entities to abandon fossil fuels and adopt clean energy sources.

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Study Identifies Outdoor Air Pollution as the ‘Largest Existential Threat to Human and Planetary Health’

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

Earth Wise is a production of WAMC Northeast Public Radio.

Assessing Human-Caused Wildlife Mortality | Earth Wise

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Bycatch is the fishing industry term used to describe the deaths of non-target fish and ocean wildlife during the fishing process.  Some bycatch species are thrown away because regulations prohibit them from being kept.  Others are thrown out because they won’t fetch high enough prices.  According to some estimates, global bycatch amounts to about 10% of the world’s total catch. 

Approximately half of global bycatch is a result of trawling.  Trawling is a method of commercial fishing that involves pulling or dragging a fishing net – called a trawl – through the water or across the seabed in hopes of catching fish.  Commercial fishing companies favor towing trawl nets because large quantities of fish can be caught.  But the method is destructive to the seafloor and leads to the indiscriminate catch of all sorts of species, including whales, dolphins, porpoises, sharks, seals, rays, turtles, and seabirds. 

Researchers have developed a new method to assess the sustainable levels of human-caused wildlife mortality.  When this method is applied to a trawl fishery in Australia, it shows that the dolphin capture is not sustainable.  The study, led by scientists at the University of Bristol in the U.K. and United Arab Emirates University, modeled different levels of dolphin capture, including those reported in logbooks and those reported by independent observers.  According to the findings, which were recently published in the journal Conservation Biology, even the lowest recorded dolphin capture rates are not sustainable. 

The new approach is extremely adept at assessing human-caused mortality to wildlife, and can be applied to fisheries bycatch, hunting, lethal control measures, or even wind turbine collisions.

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Wasted Catch

Dolphin bycatch from fishing practices unsustainable, study finds

Photo, posted May 18, 2011, courtesy of Pete Markham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Unhealthy Air | Earth Wise

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According to the World Health Organization, almost the entire global population – 99% in fact – breathes air that exceeds WHO air quality limits and threatens their health.

Air quality is of great concern everywhere.  Over 6,000 cities in 117 countries monitor air quality, but the people living in those cities are still breathing unhealthy levels of fine particulate matter and nitrogen dioxide. The WHO is citing these findings as a compelling reason to curb fossil fuel use and to take other steps to reduce air pollution levels. 

There is growing number of studies of the damage air pollution does to the human body.  Even low levels of many air pollutants can cause significant harm.  Particulate matter – especially so-called PM2.5 – is capable of penetrating deep into the lungs and entering the bloodstream, contributing to cardiovascular, cerebrovascular, and respiratory problems. 

Nitrogen dioxide is associated with respiratory diseases – especially asthma – and leads to respiratory symptoms, hospital admissions, and visits to emergency rooms.

The WHO is calling to governments around the world to take additional steps to improve air quality including adopting stricter air quality standards, supporting the transition to clean household energy sources, implementing stricter vehicle emission standards, reducing the use of incineration, and many other actions.

According to the WHO, cities in high-income countries fare better in terms of air quality, but very few places avoid unhealthy air entirely.   Seven million deaths a year are linked to unhealthy air quality.  It is a global crisis that cannot be ignored.

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Billions of people still breathe unhealthy air: new WHO data

Photo, posted December 1, 2021, courtesy of Ron Reiring via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Conseguir un medicamento en las farmacias extranjeras no puede ser más difícil que la compra nocturna de alimentos. Si no se requiere una receta en línea para la compra de medicamentos, se puede comprar libremente, incluso no sólo en las farmacias, sino también en los supermercados, dijo un abogado y director general del grupo de consultoría vvCube Vadim Tkachenko.

Computing With Honey | Earth Wise           

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Researchers are always working to develop faster and more powerful computers.  Some of them believe that the future of computing lies with neuromorphic computers, which are systems designed to mimic the neurons and synapses found in the human brain.

The human brain has more than 100 billion neurons with more than 1 quadrillion synapses or connections among them.  These numbers far exceed anything people have built.  There have been some neuromorphic computer chips made that have the equivalent of more than 100 million neurons per chip, but this is still far less than the number in the brain.  Despite all its complexity, the brain uses vastly less power than a powerful computer.  Some supercomputers use tens of millions of watts to operate; the brain uses around 10 to 20 watts.

Many researchers are searching for biodegradable and renewable ways to make neuromorphic computing components.  Researchers at Washington State University have demonstrated a way to make them using, of all things, honey.  The honey is used to form a memristor, which is a component similar to a transistor that can both process and store data in memory.  The device uses honey processed into a solid form and sandwiched between two metal electrodes.  The organic device is very stable and reliable over a long time.

So far, these devices are on a micro scale – about the size of a human hair.  The researchers want to develop them on a nanoscale, which is about 1/1000 the width of a human hair, and then bundle many millions or even billions together to make a neuromorphic computing system.  Such a honey-based system would be renewable and biodegradable – which, pardon the pun, would be really sweet.

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Honey holds potential for making brain-like computer chips

Photo, posted January 28, 2008, courtesy of Dino Giordano via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change On Mount Everest | Earth Wise

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Climate change has shown up in the highest place on Earth.  The highest glacier on Mount Everest is rapidly retreating with rising temperatures.

New research by an international team led by the University of Maine and published in the journal Climate and Atmospheric Science has determined that the South Col Glacier atop Mount Everest has shrunk by half since the 1990s.   Its ice mass has thinned by an estimated 180 feet.

The glacier used to be covered by snow, which reflected the sun’s light and insulated the mass of ice under the snow.  But warmer temperatures, lower humidity, and more severe winds have eliminated the snow cover, fueling the decline of the glacier.

The study of the South Col Glacier highlights the critical balance created by snow-covered surfaces and exposes the potential for loss throughout high mountain glacier systems as snow cover is depleted by warming temperatures.  When even the highest glacier on Mount Everest is impacted, it is clear that no place is safe from the warming climate.

The human significance of this development is substantial.  More than 200 million people in Asia depend on meltwater from glaciers in the high mountains of the continent for their freshwater needs.  But now glaciers in the mountains are melting faster than they can be replenished by snowfall.

As for Mount Everest itself, future expeditions on the mountain will face new challenges as glacier melting causes more avalanches and climbers accustomed to digging into ice and snow will need to scale more exposed bedrock.  Climate predictions for the Himalaya in general all anticipate continued warming and continued loss of glacier mass.

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Climate Change Has Reached the Top of Mount Everest, Thinning Its Highest Glacier

Photo, posted October 27, 2011, courtesy of Goran Hogland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Oil Drilling In Los Angeles | Earth Wise      

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Movies were not the first industry to boom in Los Angeles.  Oil was.  There was a lot of it, and it flowed close to the surface triggering rampant drilling all over the area.  By the 1920s, Los Angeles was one of the largest oil-exporting regions in the world.

A century later, there are over 20,000 active, idle, or abandoned wells spread across LA county, home to 10 million people.  Some are hidden behind facades; others are plainly visible, pumping away day and night.  About a third of Angelenos live less than a mile from an active well site.  In the last 20 years, improved oil extraction technology has actually led to a resurgence of oil drilling in Los Angeles.

Studies of the health impact of LA’s oil wells found that asthma is significantly more common among people living near oil wells than elsewhere in the county.  Surveys of residents’ lung functions revealed lower function on average when people live near wells.   Measurements of toxins in the air – such as benzene, toluene, and n-hexane – showed that levels of these substances were significantly reduced when oil production at a site stopped.

This issue has finally come to the forefront after a nearly a decade of community organizing and studies of adverse health effects.  In a unanimous vote on January 26, the Los Angeles City Council took the first step toward phasing out all oil and gas extraction in the city by declaring oil extraction a nonconforming land use.  The LA County Board of Supervisors voted unanimously to phase out oil extraction in unincorporated county areas.  Los Angeles’ long, troubled history with urban oil drilling appears to be nearing an end.

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Los Angeles’ long, troubled history with urban oil drilling is nearing an end after years of health concerns

Photo, posted March 26, 2016, courtesy of Giuseppe Milo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Heat-Related Deaths | Earth Wise

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According to a new study recently published in the journal Nature Climate Change, more than one-third of the world’s heat-related deaths each year are attributable to human-induced climate change. 

Researchers from the London School of Hygiene and Tropical Medicine in the UK  and the University of Bern in Switzerland analyzed data from 732 locations in 43 countries.  They took observed temperatures and compared them with 10 computer models simulating a world without climate change.  By applying this technique to their data, the researchers were able to calculate for the first time the actual contribution of anthropogenic climate change in increasing mortality risks due to heat.

The research team found that 37% of all heat-related deaths between 1991 and 2018 were attributable to the warming of the planet due to human activities.  This percentage was highest in South America, Central America, and South-East Asia. 

In the United States, 35% of heat deaths were found to be a result of climate change.  New York had the most heat-related deaths at 141, and Honolulu had the highest percentage of heat deaths attributable to climate change at 82%.

But scientists caution that this is only a small portion of the climate’s overall impact. Many more people die from other extreme weather amplified by climate change, including severe storms, floods, and droughts.  Heat-related death figures will grow exponentially as temperatures rise.

According to the research team, the study’s findings highlight the need to adopt stronger climate change mitigation strategies, and to implement interventions to protect people from the adverse consequences of heat exposure.    

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Global warming already responsible for one in three heat-related deaths

Photo, posted April 14, 2017, courtesy of Karim Bench via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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.

The Pandemic And Global Temperatures | Earth Wise

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The early months of the Covid-19 pandemic last year saw dramatic reductions in travel and many forms of commerce.  With much of human activity greatly curtailed, greenhouse gas emissions were greatly reduced.   And yet, all of that did not slow down global warming: 2020 ended up tied with 2016 as the warmest year on record and atmospheric greenhouse gas levels reached a new high.

In order to understand how this came about, it is necessary to understand the complex climate influences of different types of emissions from power plants, motor vehicles, industrial facilities, and other sources.  The fact is that some types of pollution actually have a cooling effect rather than contributing to global warming.

Tiny industrial pollution particles called aerosols actually make clouds brighter, causing them to reflect away more solar heat from the surface of the planet.   During the drastic shutdown last year, the biggest emissions decline was from the most polluting industries.  The reduction of aerosols had immediate, short-term effects on temperatures.  These types of pollutants are very bad for human health, but when they are present, they do have the effect of reducing temperatures.

It is important to keep in mind that carbon dioxide spreads through the Earth’s atmosphere and stays there for a century or more, trapping heat on a global scale.  Industrial aerosols stay relatively concentrated in the region where they are emitted and are often removed by rain and winds within a few weeks.  So, their cooling effect doesn’t spread very far or last very long.

Overall, the initial pandemic slowdown probably didn’t have any real long-term impact on the climate but over the short term, the effects were not as simple as one might expect.

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Covid-19 Cut Gases That Warm the Globe But a Drop in Other Pollution Boosted Regional Temperatures

Photo, posted July 7, 2020, courtesy of Joey Zanotti via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hudson River Tidal Marshes And Sea Level Rise | Earth Wise

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A new study at the University of Massachusetts Amherst looked at the resilience of Hudson River Estuary marshes to rising sea levels.  They observed that these marshes are growing upward at a rate two or three times faster than sea level rise, suggesting that they should be resilient to accelerated sea level rise in the future.

The study documented the fact that more than half of Hudson River tidal marshes actually formed since 1850.  In that year, the river channel was straightened, and a riverside railroad, berms, jetties and human-made islands of dredged soil were built.  All of these human-made features trapped sediment and created backwaters that often turned into marshes.

The research centered on seven sites spanning more than 100 miles of the Hudson Estuary from Wall Street up to Albany.  Although these marshes were an unintended result of early industrial development, they serve to protect the shoreline and provide rich ecosystems in terms of direct ecological and human benefits.  Marshes are a first line of defense against coastal flooding, provide an essential habitat for juvenile commercial fish species, store huge amounts of carbon that mitigates climate change, provide habitat for migratory birds, and filter nutrients coming off the land.

The study determined that such marches form relatively quickly.  When sediment is readily available, freshwater tidal wetlands can develop rapidly in sheltered settings.   There is concern that marshes globally will be drowned by rising sea levels, but this Hudson River case study shows how marshes may be able to resist the rising seas.  The research will help guide future land acquisition and land conservation strategies for areas adjacent to the river.

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New Study Finds More than Half of Hudson River Tidal Marshes were Created Accidentally by Humans; Resilient Against Sea Level Rise

Photo, posted December 4, 2008, courtesy of Daina Dajevskis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carnivores Eating Human Food | Earth Wise

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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.

Pandemic Lockdowns And Carbon Emissions | Earth Wise

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The early months of the COVID-19 pandemic saw many human activities reduced to a fraction of what they were previously.  Notably, air pollution in major cities was dramatically lower than it had been in decades.  Now, a new study has looked at the effect of the pandemic shutdowns on carbon dioxide emissions.

An international team of climate scientists has published an assessment of carbon dioxide emissions by industry, transportation, and other sectors from January through June.  According to their measurements, this year’s pandemic lockdowns resulted in a 9% decline in emissions from 2019 levels.

An earlier study reported a 17% drop in CO2 emissions, but the new study was more comprehensive and detailed.

The new data includes estimates of day-by-day, sector-specific and country-level differences in CO2 emissions derived from frequently updated data sources, some of which are nearly in real-time.  It tracks the effects of COVID-19-related disruptions of human activities in China starting in February and in the United States and Europe in March through May.

The data revealed the resumption of emissions in many regions, such as in China, where they are now back to pre-pandemic levels.  Emissions in the Americas and Europe have been slower to recover, especially in the US, where COVID-19 hotspots are continuing to emerge. 

The reduction in carbon emissions has been due mostly to transportation with fewer people driving to work and traveling by air.  Even by June, when lockdowns were easing, global emissions were still significantly reduced.  In any case, a pandemic is a highly undesirable and unwelcome way to reduce carbon emissions, but the data from this year does show that it is effective.

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Pandemic lockdowns caused steep and lasting carbon dioxide decline

Photo, posted August 7, 2020, courtesy of Michael Mueller 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...)