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Wildfire Smoke And Global Weather | Earth Wise

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In 2019 and 2020, wildfires burned 72,000 square miles in Australia, roughly the same area as the entire country of Syria. During the nine months when the fires raged, persistent and widespread plumes of smoke filled the atmosphere.

These aerosols brightened a vast area of clouds above the subtropical Pacific Ocean.  Beneath these clouds, the surface of the ocean and the atmosphere cooled.  The effect of this was an unexpected and long-lasting cool phase of the Pacific’s La Niña-El Niño cycle.

A new modeling study by the National Center for Atmospheric Research in Boulder, Colorado quantified the extent to which aerosols from the Australian wildfires made clouds over the tropical Pacific reflect more sunlight back towards space.  The resultant cooling shifted the cloud and rain belt known as the Intertropical Convergence Zone northward.  These effects may have helped trigger the unusual three-year-long La Niña, which lasted from late 2019 through 2022.

The impacts of that La Niña included intensifying drought and famine in Eastern Africa and priming the Atlantic Ocean for hurricanes.  2020 was the most active tropical storm season on record, with 31 storm systems, including 11 that made landfall in the U.S.

The study highlights widespread multi-year climate impacts caused by an unprecedented wildfire season.  The wildfires set off a chain of events that influenced weather far from where the fires occurred.  In the future, climate experts will need to include the potential effects of wildfires in their forecasts.

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How Wildfire Smoke from Australia Affected Climate Events Around the World

Photo, posted December 19, 2019, courtesy of Simon Rumi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Seaweed On The Way | Earth Wise

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A type of seaweed called sargassum has long formed large blooms in the Atlantic Ocean.  It gets its name from the Sargasso Sea in the western Atlantic.  Since 2011, scientists have been tracking massive accumulations of the stuff each year that starts out off the coast of Africa and works its way across the Atlantic to end up in the Gulf of Mexico. 

The amount of sargassum present each year can shift depending on factors like changes in nutrients, rainfall, and wind conditions.  But since the 1980s, nitrogen content in the Atlantic has gone up by 45%.  This is likely due to human activities such as agriculture and fossil fuel production dumping materials into the rivers that feed into the ocean.

According to recent observations, the mass of seaweed now heading for Florida and other coastlines throughout the Gulf of Mexico may be the largest on record.  The giant blob of sargassum spans more than 5,000 miles in extent.  It is moving west and will pass through the Caribbean and up into the Gulf during the summer.  The seaweed is expected to become prevalent on beaches in Florida around July.

The seaweed provides food and protection for fishes, mammals, marine birds, crabs, sea turtles, and more.  But unfortunately, when sargassum hits the beaches, it piles up in mounds that can be difficult to walk through and eventually emits a gas that smells like rotten eggs.

Tourist destinations in the Caribbean region have their work cut out for them to remove seaweed that can pile up several feet deep.  For example, in Barbados, locals were using 1,600 dump trucks a day to clean their beaches.  Caribbean and Florida resorts spend millions of dollars each year to remove sargassum seaweed.

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A 5,000-mile-wide blob of seaweed is headed for Florida, threatening tourism across the Caribbean

Photo, posted February 24, 2020, courtesy of Bernard Dupont via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Trouble For The Outer Banks | Earth Wise

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The Outer Banks are a series of barrier islands off the coast of North Carolina that separate the Atlantic Ocean from the mainland.  They are a very popular tourist destination featuring open-sea beaches, state parks, shipwreck diving sites, and historic locations such as Roanoke Island, the site of England’s first settlement in the New World. There is also Kitty Hawk, the site of the Wright Brothers’ first flights.

The ribbon of islands is nearly 200 miles long.  Some of them are low and narrow and are only a few feet above sea level.  Many are especially vulnerable to Nor’easters in the winter and hurricanes in the summer.  The collision of warm Gulf Stream waters and the colder Labrador current helps to create dangerous shoals and some of the largest waves on the East Coast.

Over the years, developers have added billions of dollars’ worth of real estate to the Outer Banks.  Rising sea levels and increasingly frequent storms threaten the barrier islands of the Outer Banks.  Beach-front cottages have tumbled into the ocean for as long as people have built them in the Outer Banks but now they are falling at a greater rate and more and more are in danger.

The Department of Transportation has spent nearly $100 million dollars to keep NC12, the highway connecting the string of islands, open to traffic.  Three new bridges built to traverse inlets opened by storms and bypassing rapidly eroding shorelines raised the cost by another half a billion dollars.

There are many other measures such as pumping sand into eroded areas going on in the Outer Banks, but ultimately, all of the measures may not be enough to deal with rising sea levels and more powerful storms.

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Shifting Sands: Carolina’s Outer Banks Face a Precarious Future

Photo, posted August 31, 2011, courtesy of NCDOT Communications via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Right Whales And The Warming Atlantic | Earth Wise

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The warming of the Atlantic Ocean has driven the critically endangered North Atlantic right whale population from its traditional and protected habitat.  This has exposed the whales to more lethal ship collisions, increased entanglements with commercial fishing gear, and greatly reduced calving rates.

Since 2010, the calving rate has declined, and the right whale population has dropped by an estimated 26%.  Ten years ago, there were about 500 North Atlantic right whales; now there are an estimated 356.

These are some of the best studied whales in the oceans; scientists basically recognize each individual whale and when they are the victims of ship collisions or fishing entanglements, it is easy to identify which animal was killed.

Because of the warming climate, the Atlantic Meridian Overturning Circulation – an important system of surface and deep currents – has slowed down, causing the Gulf Stream to move north.  This has injected warmer and saltier water into the Gulf of Maine.  The warming Gulf of Maine has reduced the abundance of copepods, tiny crustations that are the favorite snack of right whales.   This has reduced whale calving rates and forced the whales to move north to the cooler waters of the Gulf of St. Lawrence.

For the past 6 years, more and more right whales have been observed feeding in the Gulf of St. Lawrence, where there were no protections in place to prevent ship strikes and fishing gear entanglement.  In 2017 alone, 17 right whale deaths were confirmed.

According to a recent report from Cornell University and the University of South Carolina, unless its management is improved, right whale populations will decline and potentially become extinct in the coming decades.

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Warming Atlantic forces whales into new habitats, danger

Photo, posted December 8, 2016, courtesy of Sea to Shore Alliance/NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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

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

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

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

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

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

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Biden Administration Approves Nation’s First Major Offshore Wind Farm

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

Earth Wise is a production of WAMC Northeast Public Radio.

The Hot Year Continues | Earth Wise

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The National Oceanic and Atmospheric Administration’s monthly global climate report for October reports yet another month of high temperatures.  October 2020 was the fourth-hottest October on record, continuing the pace for the year to be the second hottest on record.

The 10 warmest Octobers have occurred since 2005 and the seven warmest have all occurred in the last seven years.  Europe had its warmest October ever, surpassing the previous record set in 2001.

For the year to date, the global temperature was a full degree Celsius (or 1.8 degrees Fahrenheit) above the 20th century average.  This was just 0.03 Celsius degrees lower than the record set in 2016.   Europe and Asia have had their warmest year-to-date period on record.

Other notable observations in the report included that Arctic sea ice coverage was almost 37% below the 1981-2010 average and was the smallest October coverage on record.  The previous record was set last year.

Heat records were set around the world including parts of the northern and western Pacific Ocean, southern North America, South America, eastern Europe, the northern Middle East, the eastern Mediterranean Sea, southern Asia, and in small areas across the Indian and Atlantic Oceans.

Despite the record global temperatures, the Northern Hemisphere’s snow coverage in October was the 10th largest over the past 53 years.  The snow coverage in North America was the largest on record for October.

Adding in the extremely active hurricane season, with 12 hurricanes and 29 tropical depressions, weather around the world continues to be anything but typical.

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Remarkably warm October fuels march toward 2nd-hottest year

Photo, posted February 8, 2016, courtesy of Jasmin Toubi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Dust From The Sahara | Earth Wise

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A vast cloud of dust from the Sahara Desert blanketed the Caribbean in late June before drifting across the southeastern U.S.  The phenomenon is nothing new; only the magnitude of the occurrence this time around was unusual.  According to experts, this is the most significant Sahara dust event in 50 years.

The Sahara Desert is the major source on Earth of mineral dust, with some 60-200 million tons of it per year being lifted into the atmosphere.  Convection currents over hot desert areas lift the dust to very high altitudes.  From there, it can be transported worldwide by winds.   The dust, combined with the extremely hot, dry air of the Sahara Desert often forms an atmospheric layer called the Saharan Air Layer, which can have significant effects on tropical weather by interfering with the development of hurricanes.  The Saharan Air Layer typically moves across the North Atlantic every three to five days from late spring to early fall, peaking in the middle of the summer.  It can occupy a layer as much as two miles thick in the atmosphere.

The dust plume this summer was highly visible from space, covering thousands of miles of the Atlantic Ocean and the Caribbean Sea.

A common effect of Sahara dust is that normally blue skies can acquire a milky haze, but beyond that can lead to spectacular sunsets.  But apart from the visual spectacle, the dust can aggravate the conditions of people with asthma, respiratory illnesses, and allergies. On the positive side, as long as the dust is around, it is much less likely that tropical storms and hurricanes will form.

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Sahara dust blankets Caribbean, air quality hazardous

Photo, posted June 22, 2020, courtesy of Sagar Rana 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.

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.

A Giant Seaweed Bloom

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Scientists using data from NASA satellites have discovered and documented the largest bloom of seaweed in the world, stretching all the way from West Africa to the Gulf of Mexico.  The gigantic macroalgae bloom has been dubbed the Great Atlantic Sargassum Belt. 

The brown seaweed floats in surface water and in recent years has become a problem to shorelines lining the tropical Atlantic, Caribbean Sea, Gulf of Mexico, and east coast of Florida.  The stuff carpets popular beach destinations and crowded coastal waters. In 2018, more than 20 million tons of it floated on the ocean surface.

Scientists have been studying the Sargassum algae using satellites since 2006, but the major blooms have only started appearing since 2011.  They have occurred every year between 2011 and 2018 except for 2013.  Before 2011, most of the free-floating Sargassum in the ocean was primarily found in patches around the Gulf of Mexico and the Sargasso Sea located on the western edge of the central Atlantic Ocean.

Sargassum provides habitat for turtles, crabs, fish and birds, and produces oxygen via photosynthesis.  However, too much of it can crowd out many marine species.

According to researchers, the ocean’s chemistry must have changed in order for the bloom to get so out of hand.  The factors involved include a large seed population left over from a previous bloom, nutrient input from West Africa, and nutrient input from the Amazon River.  The increase in nutrients may be a result of deforestation and fertilizer use.

Climate-change effects on precipitation and ocean currents ultimately do play a role in this, but increased ocean temperatures do not.  Unfortunately, these giant seaweed blooms are probably here to stay.

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NASA Satellites Find Biggest Seaweed Bloom in the World

Photo courtesy of NASA.

Earth Wise is a production of WAMC Northeast Public Radio.

Alien Waters Invade The Arctic

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The Arctic is heating up faster than any other region of the planet.  As a result, once-distinct boundaries between the frigid polar ocean and the warmer, neighboring Atlantic and Pacific Oceans are blurring, opening the way for the southern waters to enter the polar regions.  The volume of Pacific Ocean water flowing into the Arctic Ocean through the Bering Strait has increased by 70% over the past decade.  The Arctic Ocean’s cold layering system that blocks Atlantic inflows is breaking down.

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