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Disappearing snow crabs

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Alaska snow crabs are a cold-water species found off the coast of Alaska in the Bering, Beaufort, and Chukchi Seas. They are one of ten commercially-fished species in Alaskan waters. The perils of crab fishing in this region have been well documented for many years in the reality TV series Deadliest Catch.

Last year, officials in Alaska canceled the winter snow crab season for the first time ever due to a sharp population decline. While the number of juvenile snow crabs was at record highs just a few years earlier, approximately 90% of snow crabs mysteriously disappeared ahead of the 2021 season. 

This year, officials in Alaska have once again canceled the snow crab harvest season for the second year in a row, citing the overwhelming numbers of crabs – in the billions – missing from Alaskan waters. 

Scientists have suspected that the warming ocean temperatures triggered this snow crab population collapse.  But did the crabs move someplace else or die off?  According to a new study recently published by scientists at the National Oceanic and Atmospheric Administration, warmer ocean temperatures likely caused the snow crabs to starve to death.  The research team found a significant link between recent marine heat waves in the eastern Bering Sea and the sudden disappearance of the snow crabs that began showing up in surveys in 2021.

According to the study, warmer ocean water dramatically increases snow crabs’ caloric needs. But with the warmer water also disrupting much of the region’s food web, snow crabs had a hard time foraging for food and weren’t able to keep up.

Researchers expect the population may eventually find refuge in colder waters further north.

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Climate Change And Crabs

Billions of crabs went missing around Alaska

Photo, posted August 28, 2013, courtesy of Boris Kasimov via Flickr.

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The end of a supergiant iceberg

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In 2017, a supergiant iceberg known as A-68 calved from the Larsen C ice shelf in Antarctica. In 2020, it drifted close to South Georgia, a British island in the South Atlantic Ocean, and then began to break up.  This iceberg was enormous – nearly the size of Delaware.  When it started to break up, it released huge quantities of fresh, cold meltwater in a relatively small region.

Scientists from the British Antarctic Survey and the University of Sheffield have studied how the melting iceberg has affected the temperature and the salinity of the ocean surface in the area.  They found that the water near the surface was 8 degrees Fahrenheit colder than normal and the water only had about two-thirds of its normal saltiness.

The effects from the melted iceberg eventually extended well beyond South Georgia as the colder, less-salty water was carried by ocean currents to form a long plume that stretched more than 600 miles across the South Atlantic.  It also took several months to disappear.

The calving of this massive iceberg provided a unique opportunity for scientists to study the impact of iceberg melting on surface ocean conditions.  A-68 was one of the largest and most studied of all icebergs.  The study has shown that each individual melting giant iceberg can have widespread and long-lasting impacts on ocean conditions, which has consequences for the plant and animal life that lives there.

Climate change is likely to lead to more giant iceberg calving in the future.  It is important to monitor these events to assess their future impacts on ocean circulation, biology, and even seafloor geology.

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Supergiant iceberg makes surrounding ocean surface colder and less salty

Photo, posted October 24, 2018, courtesy of Jefferson Beck / NASA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Powering Britain with sun and wind

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The United Kingdom is quite small in size compared with the US, but its population of 67 million makes it a fairly large country with substantial energy needs.  A recent study by Oxford University looked at the ability of wind and solar power to provide for those energy needs over the course of time.

According to the study, Britain’s energy needs could easily be met entirely by the two sources of clean power.  Wind and solar can provide significantly more energy than the highest energy demand forecasted for 2050 and nearly 10 times the current electricity demand. 

Britain currently requires 299 TWh per year.  The Oxford study found that wind and solar could generate as much as 2,896 TWh per year. Furthermore, the researchers stated that these estimates are intentionally conservative, taking into account concerns around land use and the visual impact of installations.

The analysis assumes that offshore wind would produce nearly three-quarters of the energy required.  Onshore wind would contribute about 7%, while taking up only 0.07% of the country’s land.  Utility-scale solar would add about 19% of the power.  The small remainder comes from rooftop solar.  The researchers do point out that the power grid would require significant upgrades to handle all this renewable energy and that there would need to be appropriate quantities of energy storage. 

According to the authors of the study, achieving these results is a question of ambition rather than technical feasibility.  So far, the UK government has not been aggressive in making the transition to renewable energy.

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Wind and solar power could significantly exceed Britain’s energy needs

Photo, posted November 4, 2021, courtesy of Steve Knight via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Record low Antarctic sea ice

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Antarctica’s winter came to a close in September and during that month, the continent reaches its maximum amount of sea ice that grows during the darkest and coldest months.  This year, that maximum occurred on September 10th and turned out to be the lowest on record.

The sea ice around Antarctica reached a maximum extent of 6.5 million square miles according to NASA researchers.  That was nearly 400,000 square miles below the previous record low set in 1986. 

There are several possible causes for the meager growth of Antarctic sea ice this year.  It may be a combination of several factors including El Niño, wind patterns, and warming ocean temperatures.  Recent research indicates that ocean heat is most likely playing an important role in slowing ice growth in the cold season and enhancing ice melting in the warm season.

The record-low ice extent so far this year is a continuation of a downward trend in Antarctic sea ice that has gone on since the ice reached a record high in 2014.  Prior to that year, the ice surrounding the southern continent was actually increasing slightly by about 1% every decade.

Meanwhile, Arctic sea ice reached its minimum extent in September and it was the sixth-lowest level in the satellite record.  Scientists track the seasonal and annual fluctuations of polar sea ice because they shape polar ecosystems and play a significant role in global climate.  Sea ice melting at both poles reinforces global warming because bright sea ice reflects most of the Sun’s energy back to space while open ocean water absorbs 90% of it.

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Antarctic Sea Ice Sees Record Low Growth  

Photo, posted June 30, 2023, courtesy of Pedro Szekely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Floating Sea Farms | Earth Wise

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Researchers at the University of South Australia have designed a self-sustaining solar-driven system that turns seawater into fresh water and grows crops without any involvement.  In theory, such a system could help address the growing problems of freshwater shortages and inadequate food supplies as the world’s population continues to increase.

The system can be described as a vertical floating sea farm.  It is made up of two chambers:  an upper layer similar to a greenhouse and a lower chamber for water harvesting.

Clean water is supplied by an array of solar evaporators that soak up seawater, trap the salts in the evaporator body and, heated by the sun, release clean water vapor into the air which is then condensed on belts that transfer the water into the upper plant growth chamber.

The researchers tested the system by growing broccoli, lettuce and bok choi on seawater surfaces without maintenance or additional clean water irrigation.  The system was powered entirely by solar light.

The design is only a proof-of-concept at this point.   The next step is to scale it up using an array of individual devices to increase plant production. 

The futuristic potential for such technology would be huge farm biodomes floating on the ocean.  The UN estimates that by 2050, nearly 2.5 billion people are likely to experience water shortages while the global supply of water for irrigation is expected to decline by 19%.  Nearly 98% of the world’s water is in the oceans.  Harnessing the sea and the sun to address growing global shortages could be the way to go.

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Floating sea farms: a solution to feed the world and ensure freshwater by 2050

Photo, posted February 11, 2015, courtesy of Ed Dunens via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cryopreserving Corals | Earth Wise

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Recent climate models estimate that if the effects of climate change are not mitigated soon enough, 95% of the world’s corals could die by the mid 2030s.  Given the current rate of greenhouse gas emissions, this is an increasingly likely outcome.  Coral reefs are estimated to have a $10 trillion economic value apart from their essential role in marine ecosystems.

Researchers at the University of Hawaii at Manoa have demonstrated a successful technique for cryopreserving entire coral fragments; in other words, preserving coral using cold temperatures and successfully reviving them.

Existing coral cryopreservation techniques rely on freezing sperm and larvae, which can only be collected during spawning events, which occur only a few days each year for coral species.  This makes it logistically very challenging for researchers and conservationists.

The Hawaiian researchers focused on a process called isochoric vitrification, which is a method of freezing with liquid nitrogen that prevents the formation of ice crystals.  They tested the technique with thumbnail-sized fragments of coral, freezing them in small aluminum chambers which restrict the growth of ice crystals that would otherwise damage delicate polyp tissues.  Once the chambers were warmed, the fragments were transferred to seawater and allowed to recover.  They found that the revived corals behaved the same as those that were never cooled.

The process holds great promise to conserve the biodiversity and genetic diversity of coral.  If the process can be scaled up, it may be possible to preserve as many species of coral as possible by 2030, when it may no longer be viable for them to survive in the warming and acidifying oceans.

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Cryopreservation breakthrough could save coral reefs

Photo, posted June 2, 2023, courtesy of USFWS – Pacific Region via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

More Offshore Wind Proposed For New Jersey | Earth Wise

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There have been three offshore wind projects previously approved by utility regulators in New Jersey.  New Jersey is vying to become an East Coast leader in the fast-growing offshore wind industry and now developers have proposed four new projects off the New Jersey Shore.

Two of the projects would be located far out to sea where they would not be visible at all from the shore.  One of them, called Community Offshore Wind, would be built 37 miles offshore from Long Beach Island.  It aims to generate enough electricity to power 500,000 homes.

A second project, called Leading Light Wind, would be located 40 miles off Long Beach Island and would consist of up to 100 turbines that would generate enough electricity to power 1 million homes.

The two companies that are building the already-approved Atlantic Shores Wind Farm have submitted a bid for a new project located 10 to 20 miles offshore.  In addition, a fourth application to the New Jersey Board of Public Utilities has also been submitted, but there is yet no public information about it.

Existing offshore projects have drawn intense opposition from homeowners in part because they are close enough to the Atlantic City and Ocean City shorelines to be seen by beachgoers, albeit as tiny objects on the horizon.  The new proposed projects located far offshore would not have this problem.

The new projects can take advantage of existing federal tax credits, but the bidders say they will not seek the tax breaks from New Jersey that the earlier project received as they have also been the subject of legal challenges by opponents of offshore wind.

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4 new offshore wind power projects proposed for New Jersey Shore; 2 would be far out to sea

Photo, posted March 25, 2016, courtesy of TEIA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Biosurfactants And Oil Spills | Earth Wise

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About 400 million gallons of oil leaks into the ocean every year.  This is a major source of environmental pollution.  Oil contains many hazardous compounds that are toxic or mutagenic for marine organisms. 

When oil spill incidents occur, large quantities of chemical dispersants, sometimes as much as millions of gallons, are applied to dissolve oil slicks, prevent oil from reaching coastlines, and enhance the dispersion of the oil in the water.  The hope for doing this is that microbial oil degradation will be enhanced as a result.  Certain microorganisms present in the water can feed on crude oil components and break them down into harmless substances.

A study at the University of Stuttgart in Germany in 2015 showed that chemical dispersants in fact can slow down microbial oil degradation and therefore inhibit water purification.  The oil components need to be broken down sufficiently for them to be bioavailable to microorganisms.  The study found that dispersants were not accomplishing this.

A new study by the same group along with researchers from the University of Tubingen in Germany and the University of Georgia has found that using biosurfactants rather than chemical dispersants stimulates different microbial oil degraders with respect to their growth and activity and can enhance our ability to deal with oil spills.   Treating the water with the biosurfactant rhamnolipid rather than any of the generally-used dispersants provided much higher rates of microbial breakdown of oil components.

The hope is that this work can lead to the development of effective and environmentally friendly approaches to combatting oil spills.

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Biosurfactants might offer an environmentally friendly solution for tackling oil spills

Photo, posted June 11, 2010, courtesy of Deepwater Horizon Response via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Marine Heat Waves | Earth Wise

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In late July, the ocean temperature measured in Florida Bay, between the southern end of the Florida mainland and the Florida Keys, was 101.1 degrees Fahrenheit, a possible world record for sea surface temperature.  There is no official record keeping for ocean temperatures, but the highest previous reading ever reported was 99.7 degrees in the middle of Kuwait Bay in 2020. 

What is going on is a marine heat wave and marine heat waves can last for weeks, months, or even years.  The current Gulf of Mexico marine heat wave has been present for several months, beginning in February or March.  Experimental forecasts by the National Oceanic and Atmospheric Administration say the extreme ocean temperatures in the area may persist through at least October.

The ocean absorbs 90% of the excess heat associated with global warming.  Therefore, marine heat waves all over the planet are becoming warmer over time.  The current marine heat wave would likely have occurred even without climate change, but because of it, the event is extraordinarily warm.

Marine heat waves cause stress to corals and other marine ecosystems.  Exposure to extreme temperatures for long periods of time causes corals to eject the algae that live inside of them, resulting in white or pale coral.  This coral bleaching leaves the coral without food and will ultimately kill it.

In general, extreme heat can be destructive and deadly for marine ecosystems.  A massive marine heat wave known as “the Blob” took hold in 2013-2016 in the northeastern Pacific Ocean and led to an ecological cascade of fishery collapses, toxic algal blooms, and record numbers of humpback whale entanglements.

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The ongoing marine heat waves in U.S. waters, explained

Photo, posted December 25, 2016, courtesy of Paul Asman and Jill Lenoble via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Value Of Seagrass | Earth Wise

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Seagrasses are found in shallow salty and brackish waters in many places around the world, from the tropics to the Arctic Circle.  They get their name from their long green, grass-like leaves.  They are not seaweeds at all but are more closely related to flowering plants on land. 

We hear a lot about threatened ocean ecosystems and most of the attention is on coral reefs and coastal mangrove forests.  Seagrass meadows get much less press, but they in fact provide wide-ranging services to society and store a great deal of carbon.

A new study by the University of Michigan demonstrates that seagrass ecosystems should be high up on the global conservation agenda.  The study puts a dollar value on the many services – which include storm protection, fish habitat, and carbon storage – provided by seagrasses in the Caribbean.  The numbers are enormous.

The researchers estimate that the Caribbean holds up to half of the world’s seagrass meadows by surface area, and it contains about a third of the global carbon storage by seagrasses.  They calculated that the Caribbean seagrasses provide about $255 billion in services to society each year, which includes $88 billion in carbon storage.

In the Bahamas alone, ecosystems services provided by seagrasses are valued at more than 15 times the country’s 2020 gross domestic product.

Blue carbon is the name used to describe carbon stored in coastal and open-ocean ecosystems.  The idea of selling blue carbon offset credits, which monetize the carbon stored in this way, is gaining traction.  For many Caribbean nations, this is likely to provide impetus for protecting seagrass ecosystems from human impacts, including nutrient pollution and overfishing.

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Caribbean seagrasses provide services worth $255B annually, including vast carbon storage, study shows

Photo, posted June 27, 2023, courtesy of Daniel Eidsmoe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Shrinking Glaciers And Methane | Earth Wise

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The Arctic region is warming much faster than the rest of the planet.  In fact, according to a study published last year in the journal Nature, the Arctic has been warming nearly four times faster than the rest of the globe during the last 43 years.  This rapid warming is leading to substantial reductions in sea ice, thawing of permafrost, shifts in wildlife populations, and changes in ocean circulation patterns, among other changes. 

According to new research recently published in the journal Nature Geoscience, shrinking glaciers in the warming Arctic are exposing bubbling groundwater springs, which could provide an underestimated source of methane, a potent greenhouse gas.  Methane is more than 25 times as potent as carbon dioxide at trapping heat in the atmosphere.

The study, which was led by researchers from the University of Cambridge and the University Centre in Svalbard, Norway, found large sources of methane gas leaking from groundwater springs unveiled by melting glaciers. 

As glaciers retreat in the Norwegian archipelago of Svalbard and leave behind newly exposed land, groundwater beneath the Earth seeps upward and forms springs. In 122 out of the 123 springs studied, the research team found that the water was highly concentrated with dissolved methane.  When the spring water reaches the surface, the excess methane can escape to the atmosphere. 

Researchers are concerned that additional methane emissions released by the Arctic thaw could dramatically increase human-induced global warming.  If this phenomenon in the Svalbard archipelago is found to be more widespread across the Arctic — where temperatures are quickly rising and glaciers melting — the methane emissions could have global implications. 

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The Arctic has warmed nearly four times faster than the globe since 1979

Shrinking Arctic glaciers are unearthing a new source of methane

Photo, posted October 22, 2022, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Orcas Versus Boats | Earth Wise

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Over the past three years, orcas (also known as killer whales) have been attacking boats off the coasts of Portugal and Spain.  The subpopulation of orcas in this region has been harassing boats, most often by biting at their rudders.

There have been over 500 reported instances of orcas reacting to boats.  Sometimes they simply approach the vessels, but some of the time they actually attack.  Almost 20% of the attacks have caused enough damage to disable the vessels.  In three cases, including one in May in the Strait of Gibraltar, the animals damaged a boat so badly that it sank.  To date, no one has been injured during these attacks.

Orca researchers have observed several different killer whales during these attacks.  They seem to come from two separate groups: a trio of juveniles occasionally joined by a fourth, as well as a mixed-age group consisting of an adult female, two of her offspring, and two of her sisters.  The attacks typically last less than 30 minutes but can go on for up to 2 hours.

Researchers don’t really know why orcas are going after watercraft.  This behavior has not been observed anywhere else in the world.  One theory is that the orcas have invented a new fad.  That’s actually something that they are known to do.  Much as with people, orca fads are often spearheaded by juveniles.  An alternative theory is that the attacks may be a response to a bad past experience involving a boat.  The fact that nobody has been injured in any of these attacks, even when the boats sank, suggests that only the boats themselves are the target of the attacks and not the people on them.

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Why Has a Group of Orcas Suddenly Started Attacking Boats?

Photo, posted May 24, 2023, courtesy of Pedro Szekely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Ocean Oxygen Levels And The Future Of Fish | Earth Wise

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Climate change is creating a cascade of effects in the world’s oceans.  Not only are ocean temperatures on the rise, but oceans are becoming more acidic, and oxygen deprived.  The warming temperatures and acidification have grabbed headlines and prompted academic research. Declining oxygen levels have not garnered as much attention.  But they spell bad news for fish.

Oxygen levels in the world’s oceans have dropped over 2% between 1960 and 2010 and are expected to decline up to 7% over the next century.  There are places in the northeast Pacific that have lost more than 15% of their oxygen.  There are a growing number of “oxygen minimum zones” where big fish cannot survive but jellyfish can.

Oceans are losing oxygen for several reasons.  First, warmer water can hold less dissolved gas than colder water.  (This is why warm soda is flatter than cold soda.)  Deeper in the ocean, oxygen levels are governed by currents that mix oxygen-rich surface water from above.  Melting ice in the warming polar regions add fresh, less-dense water that resists downward mixing in key regions.  Finally, increasing amounts of ocean bacteria in warming waters gobble up oxygen creating dead zones in the ocean.

In many places, fish species that cannot cope with lower oxygen levels are migrating from their usual homes, resulting in a decline in species diversity.  Our future oceans – warmer and oxygen-deprived – will not only hold fewer kinds of fish, but also smaller fish and even more greenhouse-gas producing bacteria.   

Climate change is bad news for fish and for the more than 3 billion people in the world who depend on seafood as a significant source of protein.

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As Ocean Oxygen Levels Dip, Fish Face an Uncertain Future

Photo, posted January 10, 2022, courtesy of Willy Goldsmith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

El Niño Will Likely Return | Earth Wise

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El Niño, a weather phenomenon triggered by warm waters in the eastern Pacific, is likely to return this year, according to the World Meteorological Organization.  The Pacific has been in the cooler La Niña phase for the past 3 years, which is unusual, but that appears to be coming to a close.  According to the WMO, there is an 80% chance that the Pacific will shift to the El Niño phase before fall.

Record hot years typically coincide with El Niño, which adds to the ongoing warming trend in the climate.   There is not yet a clear picture of how strong the forthcoming El Niño event will be or how long it might last, but even a mild El Niño could affect precipitation and temperature patterns around the world.

The hottest year on record, 2016, occurred during a particularly strong El Niño.  Experts expect that 2024 is likely to see soaring temperatures again.  El Niño generally leads to drier conditions in Australia, Indonesia, and southern Asia, but greater amounts of rainfall in South America, the U.S., and parts of Africa.  Despite the presence of a cooling La Niña for the past three years, the last eight years have been the hottest on record.

El Niño and La Niña form an intermittent cycle known as the El Niño Southern Oscillation, or ENSO, that is highly influential in shaping the year-to-year variations in weather conditions around the world.  ENSO is a natural phenomenon and scientists are still trying to understand how human-caused climate change might be impacting the behavior and dynamics of the cycle.

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‘A New Spike’ in Global Temperatures in the Forecast

Photo, posted October 11, 2015, courtesy of Harshil Shah via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Offshore Wind In Maine | Earth Wise

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There are currently only two small offshore wind farms operating in the United States, but there are now several more under construction or in the permitting process.  Substantial wind farms are expected to come online over the next five years off the coasts of Virginia, New Jersey, Massachusetts. North Carolina, Delaware, Rhode Island, and New York.   There has been a recent auction for offshore wind sites off the California coast as well.

In April, the Bureau of Ocean Energy Management issued its Gulf of Maine Call for Information and Nominations, inviting public comment and assessing the interest in areas offshore of Maine, New Hampshire, and Massachusetts.  This is the first official step in the lengthy process that leads to offshore wind development in new areas.  Last year, the Department of the Interior defined an area of about 13.7 million acres in the Gulf of Maine that could end up providing energy leases for windfarm development.

The Biden administration has set a goal of deploying 30 gigawatts of offshore wind electricity generation by 2030, which is enough to power more than 10 million homes. It would also create thousands of jobs across manufacturing, shipbuilding, port operations, construction, and other industrial sectors.  Existing offshore wind projects have been structured to develop American-based supply chains for the offshore wind industry.

The European Union currently has over 15 gigawatts of installed offshore wind, has a target of 60 gigawatts by 2030, and 300 gigawatts by 2050.  The EU has five substantial sea basins which have tremendous potential for wind energy generation.  As a result, offshore wind is the centerpiece of the ambitious European Green Deal.

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U.S. moves to develop offshore wind in the Gulf of Maine

Photo, posted August 31, 2022, courtesy of Nina Ali via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Record Polar Ice Melting | Earth Wise

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Sea levels are rising and ocean warming is responsible for the bulk of that rise.  As water heats up, it expands, which drives up sea levels.  But on top of that, global warming is melting the polar ice sheets, and that is leading to about a quarter of the world’s sea level rise. So far, polar melting has fueled about an inch of sea level rise, two-thirds from Greenland and one third from Antarctica.   According to scientists, by the end of this century, melting polar ice caps could raise sea levels between 6 and 10 inches.

The seven worst years for polar ice sheet melting have occurred during the past decade.  The worst year on record was 2019.  The loss in 2019 was driven by an Arctic summer heatwave, which resulted in record melting from Greenland, amounting to nearly 500 billion tons melted that year.  Antarctica lost 180 billion tons of ice that year, mostly due to melting glaciers and record melting from the Antarctic Peninsula.

Ice losses from Greenland and Antarctica can now be reliably measured by satellites in space.  A team of researchers led by Northumbria University in the UK has combined 50 satellite surveys taken between 1992 and 2020.

They have found that the Earth’s polar ice sheets have lost over 8,000 billion tons of ice over that time period.  That much ice corresponds to an ice cube roughly 12 miles high.

The satellite technology is now at the stage where the ice sheet status can be continuously updated.  Such monitoring is critical to predict the future behavior of the ice sheets and provide risk warnings of the dangers that coastal communities around the world will face.

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Polar ice sheet melting records have toppled during the past decade

Photo, posted December 19, 2017, courtesy of Jasmine Nears via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Storing Carbon Dioxide In The Ocean | Earth Wise

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Reducing the amount of carbon dioxide entering the atmosphere means either shutting down emission sources (primarily curbing the use of fossil fuels) or capturing the CO2 as it is emitted.  Capturing carbon dioxide from smokestacks and other point sources with high concentrations is relatively efficient and can make economic sense.  Removing it from the air, which even at today’s dangerously high levels contains only 400 parts per million, is difficult and energy intensive.  And even when it is removed, it then must be stored somewhere.

Researchers at Lehigh University have developed a novel way to capture carbon dioxide from the air and store it in what is effectively the infinite sink of the ocean.  The approach uses an innovative copper-containing filter that essentially converts CO2 into sodium bicarbonate (better known as baking soda.)  The bicarbonate can be released harmlessly into the ocean.

This technique has produced a 300 percent increase in the amount of carbon dioxide captured compared with existing direct air capture methods.   It does not require any specific level of carbon dioxide to work.  The filter becomes saturated with the gas molecules as air is blown through it.  Once this occurs, seawater is passed through the filter and the CO2 is converted to dissolved bicarbonate.  Dumping it into the ocean has no adverse effect on the ocean.  It doesn’t change the salinity at all, and the stuff is slightly alkaline, which will help reduce ocean acidification.

Reusing the filter requires cleaning it with a sodium hydroxide solution, which can be created from seawater using electricity generated by waves, wind, or sun.

The filter, called DeCarbonHIX, is attracting interest from companies based in countries around the world.

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Path to net-zero carbon capture and storage may lead to ocean

Photo, posted March 10, 2007, courtesy of Gail 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

Powering Future Ships By Wind | Earth Wise

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An innovative project out of the UK seeks to reduce carbon emissions at sea by retrofitting large ocean vessels with ultramodern wing-sails to reduce the amount of fuel required to travel the oceans.

Powering ships by wind is certainly nothing new.  However, almost every large ship today is powered entirely by fossil fuels.  A company called Smart Green Shipping has developed retrofit wing-sails called FastRigs that can be installed on existing vessels to reduce fuel consumption. They are also working on additional wind-based technology that can supply all the power required for ships.

FastRig technology is designed to be retrofitted to existing commercial vessels with available deck space – typically bulkers and tankers.  There are about 40,000 such ships that are suitable for conversion to this hybrid power system.  Installing FastRigs is estimated to reduce greenhouse gas emissions by at least 20%.

The company and the UK’s University of Southampton have been funded to investigate the potential of the technology to reduce emissions from existing ships.  The research project will develop software tools to investigate the complex interactions between the wing-sails and ship hydrodynamics to accurately assess the impact on vessel performance.  The software tools will be able to predict the fuel savings delivered by wing-sails.

Smart Green Technologies is developing technology for 100% renewable-powered, new-build ships.  The goal is to create quieter, emission-free ships in the future that do no harm to ocean environments and improve air quality in ports, towns, and cities.  Wind power harnessed using sophisticated digital software and advanced engineering represents a promising way to reduce fuel consumption and related emissions from large ocean vessels.

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Future ships could be powered by wind to fight climate change

Photo, posted October 27, 2017, courtesy of Bernard Spragg 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.

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