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Shrinking Ice In The Bering Sea | Earth Wise

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The Bering Sea forms the divide between the two largest landmasses on Earth:  Eurasia and the Americas.  Recent analysis of vegetation from a Bering Sea island has determined that the extent of sea ice in the region is the lowest it has been for over 5,000 years.

St. Matthew Island, a small island in the middle of the Bering Sea, has essentially been recording what is happening in the ocean and atmosphere around it, in the form of the composition of peat layers on the island.  By analyzing the chemical composition of peat core samples, scientists can estimate how sea ice in the region has changed over the course of time.

Changes in the relative amounts of two oxygen isotopes in the sediment and plant debris trapped in the peat on the island reflect the nature of precipitation during the period when the peat layers formed.  That ratio is correlated with the amount of sea ice in the region.  Satellite data acquired over the past 40 years confirms this correlation.

Analysis of the data shows that the current ice levels are unprecedented in the last 5,500 years.  These long-term findings affirm that reductions in Bering Sea ice are due to more than recent higher temperatures associated with global warming.  Atmospheric and ocean currents, which have also been altered by climate change, play a large role in the presence of sea ice.

Summertime sea ice in the Arctic was expected to reach its second-lowest extent in September in 40 years of observation.  Sea ice typically builds up again each winter, but the changes in ice extents actually lag behind changes in greenhouse gas level by decades.  Future ice loss is already built into the system.

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Bering Sea ice extent is at most reduced state in last 5,500 years

Photo, posted December 2, 2012, courtesy of Bering Land Bridge National Preserve via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon In The Ocean | Earth Wise

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New research from the University of Exeter in the UK reveals that the world’s oceans soak up more carbon than previously believed.  Previous estimates of the movement of carbon between the atmosphere and the oceans did not account for the temperature differences between the water’s surface and a few meters below.

The new model includes this factor and finds that there is a significantly higher flux of carbon into the oceans.

The study calculated carbon dioxide fluxes from 1992 to 2018 and found that at certain times and locations there was up to twice as much CO2 contained in the ocean as determined from previous models.

The temperature differences between the surface of the ocean and the water at a depth of a few meters is important because the amount of carbon dioxide that can be absorbed in water depends very strongly on the temperature of the water.   Anyone with a home soda maker knows this well as the devices always work much better with refrigerated water than room temperature water.

The difference in ocean carbon dioxide uptake measured from satellite data and calculated in the new modeling amounts to about 10% of global fossil fuel emissions, so it is a very significant revision.  The revised estimate for carbon dioxide uptake actually agrees much better with an independent method for calculating the amount of carbon dioxide in the oceans.  Those measurements came from a global ocean survey performed by research ships over decades.

Now that two so-called big data estimates of the ocean sink for CO2 agree pretty well, there is greater confidence that we understand this important aspect of the planet’s carbon cycle.

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Ocean carbon uptake widely underestimated

Photo, posted December 30, 2012, courtesy of Jerome Decq via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Giant Jellyfish | Earth Wise

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There have been recent news stories about giant jellyfish washing ashore from Maine to the south coast of Massachusetts.  These stories have claimed that some of these lion’s mane jellyfish have been the largest on record and even might be the largest animals in the ocean.

The truth of these accounts is rather suspect.  For one thing, it is rather difficult to measure the size of a jellyfish when it is out of the water.  Gravity compresses and spreads out the bell portion of the animal, and that makes up the bulk of its mass.  For example, a jellyfish bell that measures four feet across on the beach would appear to be much smaller if the animal was floating in the water.

Some claims that lion’s mane jellyfish are larger than blue whales date back a full century and are very much disputable.  The claimed size certainly included the animal’s long tentacles, and such things hardly compare with a blue whale.

In any event, the current spate of jellyfish sightings is not necessarily that unusual.  Many factors influence jellyfish populations, including water temperature and food supply.  It is possible that warming water temperatures may be influencing the jellyfish population this year, but there is not enough data to know for sure.

People do need to be cautious around lion’s mane jellyfish.  They do sting and while their stings are not as bad as those of a number of other species, they can be a problem for people who have allergic reactions.  Furthermore, the stinging cells remain active in a jellyfish that has washed ashore.

Sightings of these animals are continuing, and reports of larger specimens continue as well, even if they don’t compare with blue whales.

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Jellyfish larger than blue whales?

Photo, posted September 13, 2015, courtesy Derek Keats via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A High-Tech Fire Alarm | Earth Wise

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In recent years, wildfires have been a global problem, notably in California, Brazil, and Australia.  It has become increasingly important to be able to respond to new fires as soon and as quickly as possible.  Such response can make the task of extinguishing them easier, thereby reducing the amount of damage and the loss of property and life.

Traditional methods for detecting forest fires include satellite monitoring, ground patrols, and watch towers, all of which have high labor and financial costs but suffer from low efficiency.  Remote sensing technologies are becoming increasingly common but rely on batteries for power, requiring servicing in remote locations to replace depleted batteries.  Solar cells represent an alternative to batteries, but it is challenging to use them in forests because of shading and foliage coverage.

A team of researchers at Michigan State University has developed a remote forest fire detection and alarm system powered by nothing more than the movement of tree limbs in the wind.  The device is known as an MC-TENG, which is an acronym for multilayered cylindrical triboelectric nanogenerator.  The triboelectric effect is a phenomenon where certain materials become electrically charged when they separate from a second material with which they were previously in contact.  In the new device, two cylindrical sleeves fit within one another – one anchored and the other free to slide.  The device is tied to a tree branch and when the branch sporadically moves in the wind, electricity is generated and stored in a carbon-nanotube-based micro supercapacitor.  This powers a sensing system that can continuously monitor environmental conditions without requiring any maintenance.

A combination of carbon monoxide and temperature sensors provides a high-tech fire alarm that can operate continuously in the most remote forest.

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Self-Powered Alarm Fights Forest Fires, Monitors Environment

Photo, posted August 3, 2012, courtesy of Lukas Schlagenhauf via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Making Use Of Invasive Seaweed | Earth Wise

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In recent years, millions of tons of brown Sargassum seaweed have formed gigantic blooms stretching all the way across the Atlantic Ocean from West Africa to the Gulf of Mexico.  The seaweed has become a problem for shorelines in the Caribbean, the Gulf of Mexico, and the east coast of Florida.  The massive increase in seaweed populations is related to changes in ocean chemistry resulting from nutrients from fertilizer use entering the water as well as from changes to the climate affecting ocean currents and temperatures.  The seaweed is harming the tourism industry as well as fisheries and ocean ecosystems.

Cleaning up the seaweed that washes ashore is labor-intensive and therefore expensive.  A research team led by two British universities has developed a cheap and simple way to pre-process seaweed to facilitate making it into bulk chemicals and biofuels.  With the new process, cleaning up the seaweed can be both economically and environmentally viable.

Previous techniques for processing seaweed generally required removing it from the saltwater, washing it in fresh water, and drying it – all of which add significant costs.  The new technique makes use of catalysts to release sugars from untreated seaweed that feed a yeast to produce a palm oil substitute.  At the same time, the process creates heat and pressure, turning the residual materials into a bio-oil that can be processed further into fuels, and a high-quality, low-cost fertilizer.

Apart from getting economic value out of the seaweed that is collected, any plastic collected alongside the seaweed can be converted to useful materials as well. 

It appears that the seaweed scourge is here to stay, so finding an economically viable way to deal with it is a welcome development.

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Solve invasive seaweed problem by turning it into biofuels and fertilisers

Photo, posted August 10, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Extreme Heat And Humidity | Earth Wise

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On hot, sticky summer days, one often hears the expression “it’s not the heat, it’s the humidity.” That isn’t just an old saw; it is a recognition of what might be the most underestimated direct, local danger of climate change.   Extreme humid heat events represent a major health risk.

There is an index called “wet-bulb temperature” that is calculated from a combination of temperature and humidity data.  The reading, which is taken from a thermometer covered in a wet cloth, is related to how muggy it feels and indicates how effectively a person sheds heat by sweating.  When the wet-bulb temperature surpasses 95o Fahrenheit, evaporation of sweat is no longer enough for our bodies to regulate their internal temperature.  When people are exposed to these conditions for multiple hours, organ failure and death can result. 

Climate models project that combinations of heat and humidity could reach deadly thresholds for anyone spending several hours outdoors by the end of this century. 

Dangerous extremes only a few degrees below the human tolerance limits – including in parts of the southwestern and southeastern US – have more than doubled in frequency since 1979.  Since then, there have been more than 7,000 occurrences of wet-bulb temperatures above 88o, 250 above 91o, and multiple reading above 95o.  Even at lower wet-bulb temperatures around 80o, people with pre-existing health conditions, the elderly, as well as those performing strenuous outdoor labor and athletic activities, are at high risk.

More research is needed on the factors that generate extreme wet-bulb temperatures as well as the potential impacts on energy, food systems, and human security.

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Dangerous Humid Heat Extremes Occurring Decades Before Expected

Photo, posted April 16, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Microplastic Hotspots In The Ocean | Earth Wise

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Many of us are aware of the infamous ocean “garbage patches” of floating plastic.  The Great Pacific Garbage Patch is roughly the size of Texas.  But over 10 million tons of plastic waste enter the oceans each year and the floating patches only account for 1% of that total.  The remaining 99% of the plastic ends up in the deep ocean, generally in the form of microplastics – tiny fragments of large plastic debris that have broken down as well as manufactured polyethylene beads used in various products.

According to a new study published in the journal Science, there are actually microplastic hotspots on the ocean floor, formed by deep-sea currents that act as conveyer belts moving the tiny plastic fragments around.  One of these hotspots – in the Tyrrhenian Sea off the west coast of Italy – contained 1.9 million microplastic pieces in just one square meter of seafloor.  This is the highest reported value for any place in the world.

Because of their small size, microplastics can be ingested by organisms across all levels of the marine food chain and eventually find their way into human diets. 

The spatial distribution and ultimate fate of ocean microplastics are strongly controlled by near-bed thermohaline currents.  These are deep-ocean currents driven by differences in water density, which is controlled by temperature and salinity.  Thermohaline currents are known to supply oxygen and nutrients to the flora and fauna found at the ocean bottom.  As a result, deep sea biodiversity hotspots are likely to be in same places where there are microplastic hotspots.

The discovery of these deep- sea hotspots is just another reason why we need behavior and policy interventions to limit the flow of plastics into natural environments.

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Seafloor microplastic hotspots controlled by deep-sea circulation

Photo, posted September 6, 2012, courtesy of Oregon State University via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Why The Arctic Is Warming So Fast | Earth Wise

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The Arctic has been warming at the fastest rate of any place on Earth.  There have long been observations of amplification of Arctic warming, meaning that its temperature increases have been well above what would be expected from the global temperature rise.

Many climate models have attributed this warming to the melting of sea ice.  As the bright white ice disappears for longer periods of the year, the dark surface waters that are exposed absorb sunlight rather than reflecting it back into space the way the ice does.  This is known as the ice-albedo feedback.  But it does not entirely explain the amount of warming in the Arctic.

Researchers at the Scripps Institution of Oceanography have developed a new theory that helps to explain what is going on.

In the areas of the Arctic Ocean where there is sea ice, the water is actually warmer at depth and colder near the surface.  The deeper waters are fed by the relatively warm Pacific and Atlantic Oceans while the surface water is cooled by the ice.  The increasing temperature difference between surface and deeper water causes a greater upward flow of heat.  This was first observed in research cruises that revealed evidence that the Arctic Ocean water was becoming more turbulent over time.

According to computer modeling, this phenomenon is responsible for about 20% of the amplification of global warming that occurs in the Arctic.

There are multiple ongoing studies looking at the Arctic warming trend.  Other factors that have contributed over time are the presence of chlorfluorocarbons in the atmosphere.   That contribution is waning since the use of CFCs has been phasing out over time.

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Researchers Find New Reason Why Arctic is Warming So Fast

Photo, posted April 19, 2017, courtesy of Markus Trienke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Record Antarctic Temperature | Earth Wise

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It is still early in the year, but extreme weather events are already piling up.  January was the warmest month on record globally and there have been many records shattered in Europe and Asia.  A number of places in Eastern Europe, including parts of Russia, have seen temperatures 12 to 13 degrees above average.

While the warming of the Arctic has been in the news with increasing frequency, the Antarctic is also seeing rising temperatures and is one of the fastest-warming regions in the world. 

On February 6th, Esperanza Base along Antarctica’s Trinity Peninsula measured a temperature of 65 degrees Fahrenheit, which is the highest temperature ever recorded on that continent.   This rather balmy temperature narrowly beat out the previous record of 63.5 degrees, which occurred in March of 2015.

This one-time reading is certainly anomalous, and scientists say it is associated with a ridge of high pressure that was lingering over the region for several days.  Local wind conditions led to additional warming.

However, the conditions leading to record-breaking high temperatures are not one-time anomalous events. Over the past 50 years, temperatures in the Antarctic have surged by an extraordinary 5 degrees in response to the Earth’s rapidly warming climate.  A rise of five degrees in day-to-day weather is no big deal. A five-degree rise in a region’s average temperature is enormous.

About 87% of the glaciers along the west coast of Antarctica’s Trinity Peninsula have retreated over that 50-year period, most of which doing so during just the past 12 years.

Some researchers claim that the new temperature record is an extreme event that doesn’t tell us anything about the changing climate.  Many others are convinced that there will be many more high temperature records to follow.

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Antarctica just hit 65 degrees, its warmest temperature ever recorded

Photo, posted February 24, 2019, courtesy of Mike via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Melting Permafrost | Earth Wise

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The Arctic is warming faster than any region on Earth and mostly we’ve been hearing about the rapid disappearance of Arctic sea ice.  But the land in the Arctic is also undergoing major changes, especially to the permafrost that has been there for millennia.

Permafrost occurs in areas where the temperature of the ground remains below freezing for two years or more.  About a quarter of the Northern Hemisphere’s landscape meets this criterion.  Most of the world’s permafrost is found in northern Russia, Canada, Alaska, Iceland, and Scandinavia.

Permafrost regions previously carpeted in cranberries, blueberries, shrubs, sedges, and lichen are now being transformed into nothing but mud, silt, and peat.  So-called regressive thaw slumps – essentially landslides – are creating large craters in the landscape.  (The Batagaika Crater in the Yana River Basin of Siberia is a kilometer long and 100 meters deep).

Apart from the violence being done to the Arctic landscape, the greatest concern is that the permafrost has locked in huge stores of greenhouse gases, including methane, carbon dioxide, and nitrous oxide.  It is estimated that the permafrost contains twice as much carbon as is currently contained in the atmosphere.  As the permafrost thaws, these gases will be released.  With them will be pathogens from bygone millennia whose impact cannot be predicted.  Climatologists estimate that 40% of the permafrost could be gone by the end of the century.

As the permafrost thaws, the region’s ecosystems are changing, making it increasingly difficult for subsistence indigenous people and Arctic animals to find food.  Landslides are causing stream flows to change, lakes to suddenly drain, seashores to collapse, and water chemistry to be altered.

The warming Arctic is about much more than disappearing sea ice.

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How Thawing Permafrost Is Beginning to Transform the Arctic

Photo, posted February 9, 2017, courtesy of the U.S. Geological Survey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Record Low Ice In The Bering Sea | Earth Wise

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The Bering Sea is the area of the far northern Pacific Ocean that separates Alaska from Russia.  Sea ice in the Bering Sea shrank to its lowest levels in recorded history in 2018, an event with profound effects on northwest Alaska residents who depend on marine resources for food, cash, and culture.

The loss of ice is indicative of very rapid change in the entire northern Bering Sea ecosystem with ramifications for everyone in the region.  A new peer-reviewed study published in the Bulletin of the American Meteorological Society examined the details and consequences of the drastic changes in the Bering Sea.

The study found that the maximum daily Bering Sea ice was the lowest on record, and the widespread impacts of that fact include unprecedented weather effects, marine wildlife die-offs, and sightings of animals outside of their normal range.  Ecological changes included the first documented mass strandings of ice-associated seals, a redistribution of thermally sensitive fish, and a multispecies die-off of seabirds due to starvation.

Persistent and anomalous warm winter weather contributed to poor ice conditions that resulted in a fatal accident on an ice road and retreating and fractured sea ice led to ice-laden flooding that caused power outages and infrastructure damage.  In addition, there have been more than 50 reports of unusual events related to weather and marine wildlife.

The record-low sea ice is a consequence of the warming climate resulting in a warmer ocean, later arrival of sea ice, and more frequent storms than in the pre-industrial era.  These conditions are continuing to increase in occurrence.

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Record low level of Bering Sea ice causes profound, widespread impacts

Photo, posted April 7, 2014, courtesy of Allen Smith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cooling The Earth With A Warmer Arctic | Climate Change | Earth Wise

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Researchers are considering a wide range of approaches to mitigate the effects of global climate change.  Among these are various strategies of geoengineering, which must be viewed with enormous caution, given the high likelihood of unintended consequences from almost anything we might do.

Researchers at the International Institute for Applied Systems Analysis have investigated potential strategies for cooling the planet in the absence of Arctic sea ice.

The Arctic region is heating up faster than any other place on earth and its sea ice is rapidly disappearing.  Estimates are that summer sea ice in the Arctic Ocean will be largely gone within a generation.  Arctic ice and snow reflect the sun’s energy into space, which helps to keep the planet cool.  What happens if that ice is gone?

The researchers explored the fact that the Arctic Ocean ice actually insulates the Arctic atmosphere from the warmer water under the ice.  Without the ice layer, the surface water would actually increase air temperatures by 20 degrees C during the winter.  That in turn would increase the heat irradiated into space and thereby cool down the planet.

The Arctic sea ice is in part maintained because the upper regions of the Arctic Ocean have lower salinity than the Atlantic Ocean.  This stops Atlantic water from flowing above the cold Arctic waters.  So, if we were to somehow deliberately increase the salinity of the Arctic Ocean surface water, warmer, less salty Atlantic Ocean water would flow in, increase the temperature of the Arctic atmosphere, and release heat trapped in the ocean into space.

It all sounds pretty crazy, but the researchers say that given the seriousness of climate change, all options should be considered when dealing with it.

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Could we cool the Earth with an ice-free Arctic?

Photo, posted August 19, 2016, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bird Migration And Climate Change | Earth Wise

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A new study of bird migration shows the migration patterns are shifting as a result of climate change.   Researchers at Colorado State University, the University of Massachusetts, and the Cornell Lab of Ornithology, looked at the impacts of climate change on a continental scale.

The team looked at the nocturnal migratory behaviors of hundreds of species representing billions of birds using radar and other data.  They found that spring migrants are likely to pass certain stops earlier now than they would have 20 years ago.  Temperature and migration timing are closely aligned and the greatest changes in migration timing are occurring in regions warming most rapidly.  During the fall, shifts in migration were less apparent.

Migratory birds play an important role in ecosystems.  They consume insects, disperse seeds, and perform various other significant functions. Birds serve as critical metrics of the health of ecosystems.

Bird migration is a global phenomenon that can provide unique visibility into changes in the climate.  The ability to look at it on a global scale has only recently become practical as a result of big data technology and cloud computing.  The team was able to crunch the numbers for the study in 48 hours, a task that previously would have taken over a year of continuous computing.

The findings have implications for understanding future patterns of bird migration because birds depend on food and other resources as they travel.  As the climate changes, the timing of blooming vegetation or the emergence of insects may end up out of sync with the passage of migratory birds.  This could have negative consequences for the health of migratory birds.

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Bird migration timing skewed by climate, new research finds

Photo, posted November 5, 2019, courtesy of Jerry Kirkhart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Scandinavian Wine

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The warming climate is creating some unexpected entrepreneurial opportunities.  Many places that have traditionally dominated the wine industry are starting to be worried that the local climates that made them ideal for vineyards are changing and becoming much less ideal.  On the other hand, places where wine-making was regarded as a losing proposition are becoming much more hospitable.  A prime example is Scandinavia.

Nordic vintners are increasingly convinced that they can develop thriving commercial operations in what used to be places that are too cold for successful wine-making.

Denmark now has 90 commercial vineyards, up from just two 15 years ago.  Forty vineyards have sprung up in Sweden.  About a dozen vineyards are now operating as far north as Norway.

Many of these Nordic vineyards are in the startup stage and are tiny compared with the established wineries of Europe.  Europe has 10 million acres of vineyards, which is enough to cover almost the entire country of Denmark.  At the moment, there are only about 1,000 acres of vineyards in Denmark and Sweden.

But, looking forward, Scandinavia’s climate is forecast to be more like northern France, as regional temperatures climb as much as 10 degrees Fahrenheit.  Over the past decade, warming has produced milder winters, a longer growing season, and even a small but rising number of award-winning Scandinavian wines.

Meanwhile, traditional wine-growing regions are also dealing with climate change.  Winemakers in France, for example, are experimenting with grapes from warmer countries like Tunisia to see if they can retain the tastes and yields that are the basis of a multibillion-dollar wine industry.  Spanish and Italian winemakers are planting grapes higher up on mountainsides or on shaded north-facing slopes to preserve the quality of their wine.

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Scandinavian Wine? A Warming Climate Tempts Entrepreneurs

Photo, posted August 24, 2019, courtesy of Ron Reiring via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And El Niño

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The term El Niño refers to a large-scale ocean-atmosphere climate interaction linked to a periodic warming in sea surface temperature across the central and east-central equatorial Pacific Ocean.  Amazingly, the phenomenon was originally recognized by fishermen off the coast of South America in the 1600s, with the appearance of unusually warm water in the Pacific Ocean.

According to a new study published in the Proceedings of the National Academy of Sciences, climate change is increasing the frequency of extreme El Niño events, leading to intensifying droughts, worsening floods, and shifting hurricane patterns.

The study, led by scientists in China and the US, looked at data from 33 El Niños dating back to 1901.  Since the 1970s, El Niños have been forming farther to the west in the Pacific Ocean, where temperatures are warmer.  Strong El Niños can cause severe drought in dry climates such as Australia and India, intense flooding in wetter climates such as the US Pacific Northwest and Peru, and more hurricanes to form in the Pacific and fewer in the Atlantic.

Before 1978, 12 out of 14 El Niños formed east of the International Dateline.  Since 1978, all 11 have formed in the central or western Pacific Ocean a shift of hundreds of miles.  There have been three so-called super El Niños since the shift – in 1982, 1997, and 2015.  These have set new average temperature records and triggered catastrophic natural disasters.

With rising global temperatures, El Niños are likely to continue to intensify, with major impacts on human societies around the world.

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Climate Change is Making El Niños More Intense, Study Finds

Photo, posted January 20, 2016, courtesy of Los Angeles District via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Roofs Going Green

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Green roofs are roofs on buildings that are partially or completely covered with vegetation and a growing medium, generally planted over a waterproofing membrane.  The modern version of these roofs began in Germany in the 1960s and spread to many other European countries over time.  With concerns about climate change and shrinking natural resources rising, green roofs are becoming increasingly popular across North America.  The Toronto-based organization Green Roofs for Healthy Cities estimates that the number in North America has increased by about 15% since 2013.

Replacing black asphalt and shingles with plants can lower the surrounding air temperature, filter dirty storm water, and reduce building energy use.  The National Research Council of Canada estimates that a green roof can reduce air conditioning use in a building by as much as 75%.  The roofs also help to reduce air pollution and greenhouse gas emissions according to the EPA.

As the benefits of green roofs become more widely known, cities around the world are passing green roof legislation.  Copenhagen passed a law in 2010 requiring all new commercial buildings to have green roofs if their roofs are not sloped too much.  Toronto was the first city in North America to pass a green roof law in 2009.  Over 640 green roofs covering more than five million square feet have since been constructed in Toronto.

Apart from the environmental benefits, green roofs are providing pleasant spaces in the urban environment that may include flower beds, trees, herb gardens, gazebos and picnic tables.  As for the economics, studies show that over the course of a roof’s lifetime, green roofs are actually considerably cheaper than conventional roofs taking into account energy savings.

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The Green Revolution Spreading Across Our Rooftops

Photo, posted July 15, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A New Kind Of Coral Nursery

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Coral reefs around the world are struggling from warming waters and increasing ocean acidification driven by excess carbon dioxide.  Many of the world’s greatest reefs – such as Australia’s Great Barrier Reef – have seen steep declines over the past decade.

But apart from the global environmental threat, reefs also are often damaged by various marine accidents such as ships grounding on them.   Such events can severely damage a reef and scatter countless small coral fragments onto the seafloor.  These small pieces of coral are not actually dead; they can continue on with their lives if they are relocated to a suitable environment such as a coral nursery.

Coral nurseries are generally small installations that allow coral fragments – typically pieces about 4 inches in length – to recover from their reef breaking up and to grow until they are large enough for conservation managers to replant them into reefs that need them.  This strategy works well in places where corals grow relatively quickly – such as Florida and the Caribbean – but not as well in places where coral grows more slowly, such as Hawaii.

Recently, coral experts at the National Oceanic and Atmospheric Administration working with mechanical engineering students at the University of Hawaii have developed a new type of coral nursery that can save fully formed coral colonies as opposed to small coral fragments.

The nurseries are large, carefully designed structures that can be loaded up with corals that have become detached from their reefs.  Some of these new structures were installed in the waters of Oahu in the summer of 2018 and were populated with corals.  The relocated corals, which would have otherwise died, are now recovering nicely in their new coral daycare centers and will soon be replanted back into the reef.

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NOAA Develops A New Type of Coral Nursery

Photo, posted July 29, 2010, courtesy of Kyle Taylor via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Other Ways To Cut Vehicle Emissions

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It is pretty clear that the way to drastically reduce vehicle greenhouse gas emissions is to switch as many vehicles as possible to electric power.  As a result, more and more localities are putting in place policies that encourage electrification.

While there is no doubt that electrification is the long-term solution to vehicle emissions, a recent study by MIT and the Ford Motor Company found that, in the short term, there are some places in the US where electric cars are not the best way to reduce emissions.

The study looked at a variety of factors that affect the relative performance of vehicles.  These include the role of low temperatures in reducing battery performance, regional differences in the average number of miles driven annually, and significant differences in the way electricity is generated in different parts of the US.

The results showed that electric vehicles definitely provide the greatest impact in reducing greenhouse gas emissions for most of the country – and particularly on both coasts and in the south – but that there are some places in the upper Midwest where the greatest reduction would be achieved by the use of lightweight gasoline-powered vehicles.

In places like parts of Wisconsin and Michigan, it is mostly rural, there are cold winters, and electricity is predominantly generated by coal-powered plants.  In these places, if gas-powered lightweight cars were to be used, the overall benefit would be greater than that of electric cars.  Unfortunately, there are no high-volume lightweight gasoline-powered mid-sized cars on the market in the US.  Ironically, the only cars of that class using lightweight aluminum construction are Teslas.

While electric cars are truly the long-term solution, the study does demonstrate the benefits of reducing the weight of vehicles.

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What’s the best way to cut vehicle greenhouse-gas emissions?

Photo, posted February 9, 2018, courtesy of Dave Field via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Hottest Month Ever

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European climate researchers announced that July was the hottest July ever recorded and since July is generally the hottest month of the year, it was indeed the hottest month ever recorded.  It just barely beat out the previous record set in July 2016.  There are multiple agencies that track temperatures around the world, and it is possible that some of them may report slightly different results. 

But whatever July’s ultimate ranking is, it is part of a long-term trend.  The past five years have been the hottest on record.   The 10 hottest years ever recorded have all occurred during the past twenty years.

This June was also the warmest on record, and the previous five months were all among the four warmest for their respective months.  All of that puts this year on track to be in the top five warmest years, or perhaps the hottest ever.

The highest above-average conditions were recorded across Alaska, Greenland, and large areas of Siberia.   Large parts of Africa and Australia were warmer than normal, as was much of central Asia.  New temperature records were set in Belgium, the Netherlands, and Germany with temperatures over 104 degrees Fahrenheit.  Great Britain saw an all-time record of 101.7 degrees and Anchorage, Alaska stayed above 79 degrees for a record six days in a row.

Wildfires have raged across the Russian Arctic, India has suffered heatwaves and severe water shortages, and Japan saw more than 5,000 people seek hospital treatment during a heatwave.

While scientists cannot directly link any particular heatwave to climate change, the trend for new heat records is likely to continue and accelerate unless we do something about curbing greenhouse gas emissions.

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How Hot Was July? Hotter Than Ever, Global Data Shows

Photo, posted May 25, 2019, courtesy of Jakob Montrasio via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Record European Heatwave

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Sahara Desert winds blasted Europe in June, especially during a five-day heatwave that set many records.  Between that and weather elsewhere, June was not only one of the hottest ever for that continent, but also for the world as a whole.

In Europe, the average temperature was about 5 degrees Fahrenheit above the June average of a century ago.  The global temperature was nearly 2 degrees Fahrenheit higher.

The European heatwave broke temperature records in France, Switzerland, Austria, Germany, and Spain.  A temperature above 114 degrees was recorded near the French city of Nîmes.

The intense heat lead to wildfires in Spain and Germany, and widespread disruption across Europe.  Undoubtedly, the heatwave has caused many premature deaths, but it will take some time to compile those statistics.  The European heatwave of 2003 caused more than 70,000 premature deaths.


According to calculations by climate scientists, the record-breaking heatwave in June was made at least 5 and as much as 100 times more likely by climate change.  Global heating caused by the carbon emissions from burning fossil fuels and other human activities means that heatwaves are becoming more probable and severe.  So-called attribution studies estimate how much more likely and severe such events are.

The researchers used temperature records stretching back to 1901 to assess the probability of a heatwave last month and in the past.  They also examined climate change models to assess the impact of global heating.  More than 230 attribution studies to date around the world have found that 95% of heatwaves were made more likely or worse by climate change.

It was the hottest June on record in Europe by a country mile and there are likely to be more months like it in the future.

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Climate Change Made Last Month’s European Heatwave At Least Five Times More Likely

Photo, posted February 13, 2018, courtesy of Guilhem Vellut 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...)