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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

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

Floating Solar And Hydropower | Earth Wise

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Installing solar panels on the surface of reservoirs is an up-and-coming trend.  The arrays of solar panels produce renewable energy while at the same time shielding significant expanses of water from the sun’s heat, thereby reducing evaporation.  The panels also help to inhibit the growth of algae.

Two recent floating solar installations are demonstrating the synergy between solar power and hydroelectric power.

The Lazer floating solar plant in France comprises over 50,000 solar panels and is capable of producing 30 MW of power.  The reservoir serves a 16.5 MW hydropower plant.  During the summer, the water from Lazer Reservoir is used primarily for crop irrigation and the solar plant supplements power generation as the reservoir water level experiences variations.  This is the first facility of its kind to be installed in France.  The company that built it – the EDF Group – had already built four floating solar power plants in Israel and the US. 

In Colombia, the Aquasol solar project is installed at the 340 MW Urrá hydropower plant.  Its 2,800 solar panels produce enough power to offset the amount of energy it takes to operate the dam.  The floating solar system is designed to withstand water-level fluctuations of up to 120 feet.

Floating solar systems can help keep power flowing when low water levels or other adverse conditions reduce hydroelectric output.  About 60% of the world’s renewable energy comes from hydropower.  Given this fact, there are countless opportunities to deploy floating solar that maximizes zero-emission energy generation as well as diversifying clean energy sources.

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Floating solar and hydropower: A match made in renewable energy heaven

Photo, posted October 25, 2010, courtesy of Martin Abegglen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

 Restoring Biocrusts | Earth Wise

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Biocrusts are complex ecosystems that form a thin layer on the surface of soils in arid and semiarid environments.  They are composed of variety of microbes including cyanobacteria, green algae, fungi, lichens, and mosses.  Biocrusts play a crucial role in maintaining soil health and ecosystem sustainability.

Biocrusts are under assault from human activities including agriculture, urbanization, and off-road vehicle use. Climate change is also placing stress on biocrusts, which are struggling to adapt to increasing temperatures.

Researchers at Arizona State University have proposed a novel approach to restoring healthy biocrusts.  Their idea is to make use of solar energy farms as nurseries for generating fresh biocrust.  The arrays of solar panels serve as shields from excessive heat and allow biocrusts to flourish and develop.  The newly generated biocrusts can then be used to replenish arid lands where the existing biocrusts have been damaged or destroyed.

When such biocrusts are harvested, the natural recovery process is rather slow, taking around six or eight years to fully recuperate.  But the researchers found that when harvested areas are reinoculated with the microbes, the biocrust cover can reach near-original levels within a year.

The ASU researchers demonstrated the viability of the approach in a three-year study at a solar farm in Arizona’s lower Sonoran Desert.  Based on their results, they conclude that the use of large solar farms for this purpose could provide a low-cost, low-impact, and high-capacity method to regenerate biocrusts and enable soil restoration on a regional scale.  They have dubbed their new approach as “crustivoltaics.”

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Using solar farms to generate fresh desert soil crust

Photo, posted March 12, 2023, courtesy of Eric Peterson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

California: Drought Or No Drought? | Earth Wise

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Just a few months ago, millions of people in California were living under challenging water conservation rules.  The past three years were the driest on record and reservoirs were depleted, landscapes dried up, and the snowpack in the Sierras at very low levels.

But in recent months, a dozen atmospheric river storms have brought huge amounts of rain and snow to the state.  Twelve out of 17 major reservoirs in the state have been replenished, the snowpack is over 240% of normal, and brown hills are blooming once again.

So, is the California drought over?  According to the experts, the answer is:  sort of.

The record snowpack and heavy rains have erased the most severe aspects of the drought in many parts of the state.  Only 9% of the state is now experiencing “severe” or “exceptional” drought, down from 55% last fall.

But the changes are basically all at the surface.  Groundwater in the state is still extremely low and the state’s cities and farms are still using more of it than is appropriate.  The state has been unwisely overusing its groundwater aquifers because of the drought and this one year of heavy rains cannot replenish levels that have been dropping for years.

California has been rolling back many of the most severe drought restrictions that had been imposed but has not entirely lifted the drought emergency status.  Meanwhile, the massive snowpack in the mountains will begin to melt as the weather warms and, in many areas, Californians will face flooding.  Water is a complicated business in California.

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Drought or no drought? California left pondering after record winter deluge

Photo, posted August 28, 2019, courtesy of Joyce Cory via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Canada Lynx And Climate Change | Earth Wise

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Canada lynx are medium-sized North American big cats known for their long, black ear tufts, and their ability to hunt across the surface of deep snow.  Historically, the predator’s habitat ranged across Alaska, Canada, and much of the Northern United States.  But in the contiguous U.S. today, the Canada lynx exists only in several disjunct populations in Maine, Minnesota, Colorado, Idaho, Washington and Montana. 

While Glacier National Park in Montana is famous for its grizzly bears and mountain goats, the park also holds a surprising number of Canada lynx, and could serve as a much-needed climate refuge for the big cats in the future.

Glacier National Park is one of the few, large, protected areas located within the Canada lynx range in the Lower 48.  Using an array of 300 motion-sensitive cameras on hiking trails throughout Glacier, researchers from Washington State University conducted the first parkwide occupancy survey for Canada lynx inside the park.  They were surprised to find that Glacier is home to roughly 50 Canada Lynx.  In fact, the researchers found that the iconic predator resides across most of the park’s 1,600 square-mile landscape, although at lower densities than in the core of its range further north.

The researchers also found that Canada lynx are distributed at lower elevations inside Glacier.  Since the cats are a cold-adapted species that need the deep snow, within Glacier, they have a lot of room to climb in elevation as the climate warms.      

The researchers hope their survey can serve as a baseline population estimate to help their collaborators with the National Park Service keep tabs on the numbers of Canada lynx in Glacier.

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Glacier National Park could be climate haven for Canada lynx

Photo, posted February 22, 2014, courtesy of Eric Kilby via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Turning Carbon Into Stone | Earth Wise

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A start-up company in Oman called 44.01 was recently awarded a $1.2 million Earthshot Prize by Prince William of the U.K.  The company, whose name corresponds to the molecular weight of carbon dioxide, is working on speeding up natural chemical reactions that take carbon from the air and lock it into solid mineral form.

The company’s location in Oman is no random occurrence.  The mountains of northern Oman and along the coast of the United Arab Emirates are the site of a huge block of oceanic crust and upper mantle that was thrust upward some 96 million years ago.  The tilted mass of rock is over 200 miles long and is the largest surface exposure of the Earth’s mantle in the world.

This type of rock, called peridotite, is rich in olivine and pyroxene, which react with water and carbon dioxide to form calcium-based minerals like serpentine and calcite that permanently lock in carbon. Other kinds of rock also are capable of carbon-storing mineralization, but this mantle rock is the most effective for the purpose. It only exists at the Earth’s surface in a few places, including Papua New Guinea and some spots in California and Oregon.

The 44.1 company is planning to use solar-powered direct air capture devices to remove CO2 from the air, use it to produce carbonated water, and inject the water into the reactive rocks.  The company will operate a couple of pilot systems during 2023.  Ultimately, the company believes it can scale up the process to be able to permanently sequester as much as a billion tons of CO2 a year by the year 2040 without needing to inject the gas into deep caverns or find other places to store it.

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With Major Prize, a Project to Turn Carbon Emissions to Stone Gains Momentum

Photo, posted August 10, 2018, courtesy of JM McBeth via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Triple La Niña | Earth Wise

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La Niña is an oceanic phenomenon consisting of cooler than normal sea-surface temperatures in the central and eastern tropic Pacific.  It is essentially the opposite of the better-known El Niño.   These sea-surface phenomena affect weather across the globe.  As one oceanographer put it:  when the Pacific speaks, the whole world listens.

There is currently a La Niña underway, and it is the third consecutive northern hemisphere winter that has had one.  This so-called triple-dip event is rather rare.  The only other times they have been recorded over the past 70 years were in 1954-56, 1973-76, and 1998-2001.

La Niñas appear when strong easterly trade winds increase the upwelling of cooler water from the depths of the eastern tropical Pacific Ocean near the equator.  This causes large-scale cooling of the ocean surface.  The cooler ocean surface modifies the moisture content of the atmosphere across the Pacific and can cause shifts in the path of jet streams that intensifies rainfall in some places and causes droughts in others.

These weather effects tend to include floods in northern Australia, Indonesia, and southeast Asia and, in contrast, drought in the American southwest.  In North America, cooler and stormier conditions often occur across the Pacific Northwest while the weather becomes warmer across the southern US and northern Mexico.

In the spring, the tropic Pacific essentially resets itself and starts building toward whatever condition will happen in the following winter, be it another La Niña or possibly an El Niño.   For the time being, forecasters expect the current La Niña to persist through February.

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La Niña Times Three

Photo, posted March 10, 2007, courtesy of Gail via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Windows To Cool Buildings | Earth Wise

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About 15% of global energy consumption is for cooling buildings.  Because of this, there is an ever- growing need for technologies that can more efficiently cool buildings.   Researchers at Notre Dame University have used advanced computing technology and artificial intelligence to design a transparent window coating that is able to lower the temperature inside buildings without using any energy.

The idea is to create a coating that blocks the sun’s ultraviolet and near-infrared light, which are parts of the solar spectrum that otherwise pass through glass and help to heat an enclosed room.  Cooling needs can be reduced further if the coating can radiate heat from the surface of the window so it can pass through the atmosphere into space.  Designing a coating that does both of those things simultaneously while transmitting visible light is difficult.  Coatings should not interfere with the view out the window.

The Notre Dame researchers used advanced computer modeling to create a so-called transparent radiative cooler that meets these goals.  The coating consists of alternating layers of common materials like silicon dioxide, silicon nitride, and aluminum oxide or titanium dioxide on top of a glass base and topped with a film of polydimethylsiloxane.  The computing method was able to optimize this structure far faster and better than conventional design techniques.

The researchers say that in hot, dry cities, the coating could potentially reduce cooling energy consumption by 31% compared with conventional windows.  The same materials could be used in other applications, such as car and truck windows.  In addition, the quantum computing-enabled optimization method used for this work could be used to design other composite materials.

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Clear window coating could cool buildings without using energy

Photo, posted September 6, 2015, courtesy of Robert Otmn via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Environmental DNA | Earth Wise

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Marine protected areas are sections of the ocean where governments place limits on human activity.  They are intended to provide long-term protection to important marine and coastal ecosystems.  MPAs are important because they can protect depleted, threatened, rare, and endangered species and populations.

In January 2020, the Republic of Palau in the western Pacific Ocean created one of the world’s largest marine protected areas.  The Palau National Marine Sanctuary covers 80% of the country’s economic zone and prohibits all extractive activity like fishing and mining over a 183,000 square mile area in order for the island nation to ensure its food security and grow its economy in the face of climate change.

The Marine Sanctuary is an ambitious enterprise.  The question is how Palau can evaluate whether and how well it is working?

A team of scientists from Stanford University and Palau-based colleagues are making use of Environmental DNA – or eDNA – technology to monitor the large-scale marine protected area.  eDNA is the cells, waste, viruses, and microorganisms that plants and animals leave behind.  Samples of marine eDNA effectively provide a fingerprint of the organisms that have recently passed through the water in a given area.  This gives scientists a way to assess an ecosystem’s biodiversity and keep track of the types of species inhabiting a specific area.  Using eDNA, it is possible to keep track of all the  organisms that live below the surface and learn about things we can’t even see.

The team has embarked on a program of periodic sampling of the waters off Palau and hope to be able to monitor the results of establishing the Marine Sanctuary.

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eDNA: Bringing biodiversity to the surface

Photo, posted June 12, 2013, courtesy of Gregory Smith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Methane From Thawing Permafrost | Earth Wise

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The Arctic permafrost contains a massive amount of carbon in the form of frozen soil, which contains remnants of plants and animals that died millennia ago.  Estimates are that there is 2 ½ times as much carbon trapped in this Arctic soil than there is in total in the atmosphere today.

As the Arctic warms, the permafrost is starting to thaw.  Once that happens, microbes begin to consume the previously frozen organic matter trapped in the soil.  As part of this process, the microbes produce large amounts of methane, which is an extremely potent greenhouse gas.   Thus, there continues to be great concern that wide-scale thawing of the permafrost would result in massive amounts of methane being released into the atmosphere.

A recent study in northern Sweden revealed a glimmer of hope.  The study gauged methane emissions from a swath of permafrost that thawed in the 1980s and another that thawed 10 or 15 years later. 

In the first area, as ice melted underground, water on the surface sank down into the soil.  As the surface dried out, new plants emerged that helped to keep methane emissions buried underground.

Grasses found in wet areas have straw-like structures that convey oxygen to their roots.  The straws also allow methane in the soil to escape into the atmosphere.  As the areas dry out, other plants lacking the straws can sometimes replace the grasses.  When methane can’t escape, soil bacteria break it down into carbon dioxide.

The result is that the permafrost releases only a tenth of the methane as expected.  The hope is that changes in plant cover driven by climate change may limit methane emissions from thawing permafrost.

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Thawing Permafrost In Sweden Releases Less Methane Than Feared, Study Finds

Photo, posted July 7, 2014, courtesy of NPS Climate Change Response via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Floating Solar | Earth Wise

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The largest floating solar array in Europe, 12,000 panels sitting on top of the Alqueva Reservoir in Portugal – will come online in July.  Installing floating solar arrays, which are sometimes called “floatovoltaics”, produce renewable energy while shielding significant expanses of water from the sun’s heat.  These dual benefits have led to floatovoltaic projects in multiple countries around the world.

The city of Cohoes, in New York’s Albany County, has proposed an 8,000-panel floating solar array on the city reservoir.  Federal funding of $3 million for the project was obtained by local Congressman Paul Tonko and, in May, utility National Grid donated $750,000 towards the project.  Engineering work will shortly be underway on the 3.2 megawatt grid of solar panels.

The city of Cohoes pumps its drinking water supplies from the Mohawk River into the 10-acre, manmade reservoir.  The surface of the water is the largest undeveloped open space in the city.  Such reservoirs constitute prime sites for solar arrays since the space cannot be used for other purposes.  In addition, covering the water’s surface with the solar panels greatly reduces evaporation and helps to inhibit the growth of algae.

There are currently only 14 floating solar arrays in the U.S. and all of those are privately owned.  The Cohoes municipal array will be the first of its kind.  There are nearly 500 reservoirs in New York State and 24,000 nationwide that could be sites for floating arrays.   Drought-stricken Western reservoirs like Lake Mead and Lake Powell could be ideal locations of solar arrays.  Those reservoirs lose huge amounts of water to evaporation.  There are estimates that floating arrays could provide as much as 10% of the nation’s electrical needs.

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National Grid gives Cohoes $750,000 for floating solar array project

Photo, posted August 25, 2010, courtesy of Martin Abegglen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Is It Really Getting Warmer? | Earth Wise

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The primary indicator of global climate change is the Global Mean Surface Temperature of the Earth and the world’s nations are trying to keep its increase below 1.5 degrees Celsius over the pre-industrial level.   That rise in temperature is called the Global Surface Temperature Anomaly and it actually reached an all-time high in 2016 at 1.02 degrees before going back down.

At this point, you might be saying, “hold on there…  it hasn’t gotten larger over the past 5 years?”  What’s going on?

The global climate is pretty complicated and there are many things that influence it.  One of the most significant factors is the El Niño Southern Oscillation or, more familiarly, the El Niño.  The El Niño is a periodic and irregular variation in the sea surface temperature of the tropical eastern Pacific Ocean driven by persistent westerly winds.  When an El Niño is happening, currents move to the west coast of South America and warm the tropics and subtropics.  This causes a spike in the global mean temperature.  There was a strong El Niño in 2016.

On the other hand, when easterly winds dominate to form a La Niña, cool water comes up from the depths of the Pacific and cools the atmosphere.  In 2017 and 2018, there was a fairly strong La Niña, lowering the global mean temperature.  2020 had no El Niño or La Niña, and the global temperature went back up to its previous peak.  Last year, there was again a La Niña and the temperature dipped again.

The global mean surface temperature has been rising in the industrial era, but it also fluctuates with the complicated dynamics of the Pacific Ocean.

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Why Isn’t It Getting Warmer?

Photo, posted February 12, 2016, courtesy of Amit Patel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

January Climate Report Card | Earth Wise

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January was the sixth-warmest January in the 143 years of global climate record keeping.  The global land and ocean surface temperature was 1.6 degrees Fahrenheit above the 20th century average.

Meanwhile, the United States had its coolest January since 2014, although the month still ranked nearly a degree above the long-term average across the nation.  This January was also the driest January in eight years and was one of the top- 15 driest Januarys on record.  That being said, there was the so-called Bomb Cyclone late in the month that dumped 1-2 feet of snow and brought blizzard conditions along the eastern seaboard and set a one-day snowfall record in Boston.

Global conditions and regional and local conditions can be very different.  In the big picture, January was the 46th consecutive January and the 445th consecutive month with temperatures above the 20th century average.

And while the US had a fairly cool January, South America saw its second-warmest January on record, Asia had its fourth warmest, and Oceania had its seventh warmest.

Apart from temperatures, Antarctic sea ice coverage was the second smallest January extent in 44 years.  Arctic ice was 208,000 square miles below the 1981-2010 average, although it was the largest since 2009.

Even as the global climate warms, local and regional climate conditions will continue to have unique and variable characteristics over the course of time.  Every time there’s a bout of cold weather, it isn’t time to stop being concerned about climate change.

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January 2022 was Earth’s 6th warmest on record

Photo, posted January 6, 2013, courtesy of Christopher Michel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Threat From Thwaites | Earth Wise

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The Thwaites Glacier in Antarctica is the widest glacier in the world. It is about 80 miles across and in places extends to a depth of about 2,600 to 3,900 feet.  The glacier is roughly the size of Florida, and it currently contributes 4% of annual global sea level rise as it continues to retreat from a warming ocean.

The International Thwaites Glacier Collaboration is a team of nearly 100 scientists dedicated to studying the glacier.  According to the scientists, Thwaites has doubled its outflow speed within the last 30 years.  The glacier in its entirety holds enough water to raise global sea levels by over two feet, which would be catastrophic.

A third of the glacier flows more slowly than the rest because it is braced by a floating ice shelf that is held in place by an underwater mountain.  The concern is that the brace of ice slowing the glacier may not last for long.

Beneath the surface, warmer ocean water is attacking the glacier from all angles.  The water is melting the ice directly beneath the glacier causing it to lose its grip on the underwater mountain.  Massive fractures have formed and are growing.

Warm water is also a threat for what is called the grounding zone, which is the area where the glacier lifts off the seabed. There are many possible scenarios under which there could be a major ice loss from the glacier.  It is unclear how quickly it could occur.  It might take decades, or it could be centuries.  The threat is large enough and real enough that continued observation and research is essential.

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The Threat from Thwaites: The Retreat of Antarctica’s Riskiest Glacier

Photo, posted October 16, 2012, courtesy of J. Yungel / NASA Ice via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fire And Ice | Earth Wise

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In recent years, there have been countless stories about the effects of the changing climate.  Many of those stories have been about the dwindling sea ice in the Arctic and many others have been about the worsening wildfires in the western United States.   According to a recent study published by the Pacific Northwest National Laboratory, those two things are very much related.

As sea ice in the Arctic melts from July to October, sunlight warms the surrounding land and sea surfaces.  The resulting differences in air pressure create and strengthens a vortex in the atmosphere above the heated area which spins counterclockwise like a cyclone.

The powerful vortex pushes the polar jet stream out of its typical pattern and diverts moist air away from the western United States.  With the jet stream moved off its usual course, a second vortex, this time spinning clockwise, forms under the ridge of the polar jet stream above the Western U.S.  This second vortex brings with it clear skies and dry conditions:  fire-favorable weather.

Arctic sea ice has continually declined at least since the late 1970s.  It is predicted that there will be periods of entirely iceless Arctic waters before the 2050s.  In turn, conditions in the already fire-ravaged West are likely to be further exacerbated.  More than three million acres have burned across California alone during the 2021 wildfire season.

Climate conditions in one part of the world can, over time, influence climate outcomes thousands of miles away.  The research at Pacific Northwest Laboratory reveals how regional land and sea surface warming caused by Arctic ice melting can trigger hotter and drier conditions in the West later in the year.

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Fire and Ice: The Puzzling Link Between Western Wildfires and Arctic Sea Ice

Photo, posted July 28, 2018, courtesy of Bob Dass via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Greenland Becoming Darker | Earth Wise

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According to research published by Dartmouth University, a weather pattern that pushes snowfall away from parts of Greenland’s ice sheet is causing the continent to become darker and warmer.

Reducing the amount of fresh, lighter-colored snow exposes older, darker snow on the surface of Greenland’s ice sheets.  Fresh snow is the brightest and whitest. The reflectivity of snow decreases fairly quickly as it ages. This decrease in albedo – or reflectivity – allows the ice sheet to absorb more heat and therefore melt more quickly. 

The research attributes the decrease in snowfall in Greenland to a phenomenon called atmospheric blocking in which persistent high-pressure systems hover over the ice sheet for up to weeks at a time.  Such systems have increased over Greenland since the mid-1990s.  They push snowstorms to the north, hold warmer air over Western Greenland, and reduce light-blocking cloud cover.

All of this contributes to Greenland melting faster and faster.  According to research cited in the study, the Greenland ice sheet has warmed by nearly 5 degrees Fahrenheit since 1982.  Overall, Greenland is experiencing the greatest melt and runoff rates in the last 450 years, at the minimum, and quite likely the greatest rates in the last 7,000 years.

The Greenland ice sheet is the second largest ice body in the world, after the Antarctic ice sheet.  It is 1,800 miles long and about 700 miles wide at its greatest width.  Its thickness is between 1.2 and 1.9 miles.  If the entire sheet were to melt, it would lead to a global sea level rise of 24 feet.  So, the darkening of Greenland is a source of great concern.

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Greenland Becoming Darker, Warmer as Snow Changes

Photo, posted April 3, 2012, courtesy of Francesco Paroni Sterbini via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Floating Solar In New York’s Capital Region | Earth Wise

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We have previously talked about installing solar arrays on the surface of bodies of water.  The idea is especially attractive in places like Japan where land resources are scarce.  There are several floating solar installations in the UK and the idea is starting to catch on elsewhere as well.

It is quite possible that the largest municipally owned floating solar array may get built in the city of Cohoes in New York’s Capital Region if a project under consideration for federal funding moves forward.

The proposal is for an installation of 8,000 solar panels to cover about 2/3 of the 10-acre Cohoes reservoir.  Cohoes has wanted to erect a solar installation to generate power for its buildings but needed to find suitable vacant land.  The 10-acre manmade reservoir could be an excellent location for a floating solar array.

Cohoes would be the first community in the US to build and own a floating array on a manmade reservoir and could serve as a model for municipalities across the nation.  Such a project makes additional use of land that is already municipal property.  According to the city, the 3.2-megawatt array would generate over 4 million kilowatt hours of electricity per year, saving the city $300-350,000 annually.

Cohoes is seeking $4.59 million in federal funding to support the project and has the support of U.S. Representative Paul Tonko for possible inclusion in the 2022 federal budget. 

Apart from generating electricity, putting solar panels on the surface of a reservoir reduces evaporation, lowers algae growth, and actually improves solar panel performance because of the cooling effect of the water.

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Cohoes reservoir could be a floating solar power pioneer

Photo courtesy of Michael Coghlan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Radar Satellites And Hazard Mitigation | Earth Wise

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Scientists have concluded that the changing climate is primarily the result of increased human-caused greenhouse gas emissions.  Some of the effects of global climate change include melting glaciers, warming oceans, intensifying storms, and rising seas.

Another consequence of global climate change is natural disasters like floods and wildfires.  Climate change is increasing the frequency and severity of wildfires and increasing the odds of record-breaking floods in many parts of the United States and all around the world.

As a result, scientists in Australia have turned to technology for better assistance in keeping tabs on these climate change-driven natural disasters.  Researchers from Curtin University in Perth, Australia have found that satellites can improve the ability to detect, monitor, prepare for, and withstand natural disasters, including floods, wildfires, and earthquakes.

The research team used Synthetic Aperture Radar (SAR) data, which was acquired by the European Space Agency Sentinel-1 satellite.  The researchers also used data acquired by other satellites to evaluate these Australia-specific case studies.

According to the researchers, SAR data provides remote monitoring capabilities of Earth’s surface around the clock and in all weather, which is something that traditional optical Earth Observation (EO) imagery cannot do. The ability to function through fog, clouds, rainfall, and smoke is what makes SAR so valuable.

The research team says that the data can be used to improve how people track and respond to natural disasters, by precisely mapping topography, tracking movements of the ground, and mapping damage to infrastructure. 

As the climate continues to change, the ability to mitigate hazards like floods and wildfires will be increasingly important. 

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Radar satellites can better protect against bushfires and floods

Photo, posted May 11, 2007, courtesy of Bert Knottenbeld via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Harvesting Water From Air | Earth Wise

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Developing new technologies that harvest water from the air is a growing field of research driven by the fact that more and more people live in areas where fresh water is in short supply.  Estimates are that roughly half the world’s population lives in regions with severe freshwater shortages for at least one month each year.

We have previously discussed some of the novel approaches that researchers are taking to enhance water harvesting.  The work at UC Berkeley using metalorganic frameworks is a notable example.

One of the key problems in harvesting water from air is that many droplets that condense from water vapor in the air are too small to be collected and when they cover a surface, they can actually impede further condensation.

University of Texas at Dallas researchers have developed a novel surface that encourages tiny water droplets to move spontaneously into larger droplets.  The droplets actually self-climb along an oil, ramp-shaped meniscus.  The meniscus acts like a bridge along which microdroplets spontaneously climb upward and coalesce with larger water droplets.  They call this the coarsening droplet phenomenon.  It is enabled by a liquid lubricant with a unique hydrophilic nature.  They actually discovered the lubricant’s special properties by accident when in a lubricant test they observed smaller water droplets propel themselves into larger droplets.

Based on experimental data, the coarsening surface enhances the water harvesting rate 200% higher than other techniques.  The team continues to work on ways to use the new lubricant to make sustainable water harvesting systems that are mobile, smaller in size, lower in weight, and less expensive.  If they are successful, they will essentially be able to harvest water anywhere that has air.

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New Physical Phenomenon Aids Harvest of Water from Air

Photo, posted April 26, 2014, courtesy of Toukou Sousui 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...)