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Lakes Are Shrinking | Earth Wise

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A study by the University of Colorado Boulder has found that more than half of the world’s largest lakes have shrunk over the last three decades.  This is a very big problem because about one-quarter of the Earth’s population lives in the basin of a drying lake.  People depend on lakes for drinking water and irrigation and lakes are central to the survival of local ecosystems as well as migrating birds.  Lakes cover only about 3% of the planet, but they hold nearly 90% of the liquid surface freshwater.

The study used satellite observations from 1992 to 2020 to estimate the area and water levels of nearly 2,000 freshwater bodies.  These account for 96% of Earth’s total natural lake storage and 83% of that in man-made reservoirs.  About 53% of the world’s lakes have clearly shrunk, while only 22% have gained water.  The study estimates that about 160 trillion gallons of water has been lost over the 28-year period.  That’s about 17 times the maximum capacity of Lake Mead, the largest reservoir in the United States.

Many of the world’s most significant lakes have been shrinking. The dramatic declines in Lake Mead have been headline news for years.  The Caspian Sea, which is the world’s largest inland body of water – has long been declining.

The main causes of the decline in natural lakes are climate change and human consumption.  Reservoirs face an additional major problem of sediment buildup which reduces their storage capacity and diminishes their benefits of water supply, flood control, and hydropower.

Lake loss is a big problem.

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More than half of the world’s largest lakes are drying up

Photo, posted April 10, 2018, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar Panels On Canals | Earth Wise

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There has been growing interest in installing solar panels on top of reservoirs to make use of the available space to make electricity and reduce evaporation.  There has been far less interest in installing solar on canals and aqueducts.  But that is changing and a new project in California is part of that change.

A study by the University of California, Merced estimates that 63 billion gallons of water would be saved by covering California’s 4,000 miles of canals with solar panels.  All that installed solar would generate a significant amount of electricity.

The idea is going to be tested in the Turlock Irrigation District in Central California with Project Nexus, which is the installation of solar panels over 1.8 miles of canals that are between 20 and 110 feet wide.  The panels will sit between 5 and 15 feet off the ground.  UC Merced researchers will study impacts ranging from evaporation to water quality and use the results to make recommendations with respect to wider use of the technology.

California isn’t the first place to put solar on a canal.  India pioneered it on one of the largest irrigation projects in the world.  The Sardar Sarovar dam and canal project brings water to hundreds of thousands of villages in the dry, arid region of India’s Gujarat State.

Meanwhile, the Gila River Indian Community in Arizona received funding from the Bipartisan Infrastructure Law to install solar panels on their canals in an effort to save water and reduce stress on the struggling Colorado River.

The world of water infrastructure does not embrace change easily but covering canals with solar panels is an idea whose time may have come.

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Solar panels on water canals seem like a no-brainer. So why aren’t they widespread?

Photo, posted December 11, 2005, courtesy of Dave Parker via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

City Greenery And Carbon Emissions | Earth Wise

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According to the United Nations, more than half of the world’s population currently lives in cities.  Projections show that the combination of urbanization and global population growth could add another 2.5 billion people to cities by 2050. 

Unsurprisingly, cities are a major contributor to climate change.  According to U.N. estimates, cities are responsible for 75% of global carbon dioxide emissions, with transportation and buildings being among the largest contributors. 

According to a new study of vegetation across New York City and some adjoining urban areas, photosynthesis by trees and grasses on many summer days absorbs all the carbon emissions produced by cars, trucks and buses, and then some.  In fact, on many summer days, the total carbon uptake in the region equaled up to 40% of a summer afternoon’s total emissions from all sources in the City. The results, which were recently published in the journal Environmental Research Letters, further highlights the critical importance of urban greenery.

Most previous studies have analyzed the carbon uptake of vegetation by looking at the contiguous tracts of green spaces, but this only comprises about 10% of metro areas.  Using detailed aerial radar imagery of New York City that mapped vegetation in unprecedented 6-inch grids, the researchers were able to include the other 90% of the metro area typically left out in most models. 

Since carbon uptake by vegetation only occurs during the growing season, green spaces in cities situated in warmer climates likely play a larger role in carbon uptake. 

As city populations swell around the world, every bit of urban greenery is critical in the fight against climate change. 

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New York City’s greenery absorbs a surprising amount of its carbon emissions

68% of the world population projected to live in urban areas by 2050, says UN

Photo, posted October 5, 2009, courtesy of David Orban via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Whales Eating Plastic | Earth Wise

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Plastic waste has been accumulating in the world’s oceans in greater and greater quantities and much of it is in the form of microplastic particles.  Many kinds of whales – the largest creatures on Earth – feed by gulping up mouthfuls of krill and other tiny creatures and then straining the seawater through bristly filter structures called baleens.  As they do this, they are likely to be swallowing large amounts of plastic.

Scientists at Stanford University recently estimated just how much plastic whales are ingesting by tracking the foraging behavior of 65 humpback whales, 29 fin whales, and 126 blue whales in the Pacific Ocean.  Each of the whales was tagged with a camera, microphone, and GPS device suction-cupped to their back.

After accounting for the concentration of microplastics in parts of the Pacific Ocean, the researchers were able to estimate the amount of plastic the whales were consuming.  Humpback whales likely consume 4 million microplastic pieces each day, adding up to about 38 pounds of plastic waste.  Fin whales swallow an estimated 6 million pieces each – amounting to 57 pounds of plastic.  Blue whales, which are the largest creatures on Earth, eat an estimated 10 million microplastic pieces, or as much as 95 pounds of plastic waste each day.

Despite their enormous size, whales actually eat rather low on the food chain, which puts them close to where the plastic is in the water.   Krill eats plastic and whales eat the krill.   Many marine animals are at risk of eating microplastics, but whales are unique in that they can consume so much of it.  It is just one more way in which the ocean plastic situation is a global crisis.

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Blue Whales Swallowing 95 Pounds of Plastic Daily, Scientists Estimate

Photo, posted October 21, 2005, courtesy of Tobias Begemann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Green Steel | Earth Wise

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The Inflation Reduction Act provides $369 billion in investments to ramp up renewable energy generation and manufacturing of solar panels, wind turbines, energy storage, and electric vehicles. 

Every megawatt of solar power deployed requires 35 to 45 tons of steel.  Every megawatt of wind power uses 120 to 180 tons of steel.   Estimates are that it will take 1.7 billion tons of steel just to build all the wind turbines needed to reach net zero emissions by 2050.

This is a big problem because steel production accounts for roughly 10% of global carbon emissions and is one of the most carbon-intensive industries in the world.

Making steel is a complex and age-old process that hasn’t changed much over time.  Green steel is steel made with little or no carbon emissions.  There are a few ways to do it.  One is called the direct reduced iron method that uses green hydrogen instead of fossil fuel gas to produce iron and then a renewable-powered electric arc furnace to make the steel. 

Molten Oxide Electrolysis is an alternative green steel approach that doesn’t depend on having a green hydrogen infrastructure.  It uses electrolysis, powered by renewable energy, to separate the bonds of iron ore and produce liquid metal while releasing only oxygen in the process.

Green steel solutions rely on the availability of renewable energy, but the ultimate success of renewable energy will depend on the success of green steel.  The U.S. steel industry will leverage about $6 billion under the Inflation Reduction Act to make progress on it.

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Building tomorrow’s clean energy systems on green steel

Photo, posted October 30, 2008, courtesy of Paul Bica via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Atmospheric Plastic Polluting The Ocean | Earth Wise

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According to estimates, by 2040 there will likely be nearly 90 million tons of plastic pollution entering the environment each year.  Particles of plastic have been found in virtually all parts of our planet including the land, the water, and even the air.  Tiny plastic particles have been found in the Arctic, the Antarctic, and at the tops of the highest mountains.

A new study has shown that winds can carry plastic particles over great distances and in fact can bring them from their point of origin to the most remote places in a matter of days.   As a result, micro- and nanoplastics can penetrate the most remote and otherwise largely untouched regions of the planet

How does plastic get into the atmosphere?  Particles produced by tires and brakes in road traffic or ones in the exhaust gases from industrial processes rise into the atmosphere, where they are transported by winds.  There is also evidence that a substantial number of these particles are transported by the marine environment.  Microplastic from the coastal zone finds its way into the ocean through beach sand.  A combination of sea spray, wind, and waves forms air bubbles in the water containing microplastic.  When the bubbles burst, the particles find their way into the atmosphere.

Understanding the interactions between the atmosphere and ocean is important because the atmosphere turns out to be a major mechanism in depositing substantial amounts of plastic into a broad range of ecosystems.

The impact of plastic particles on ecosystems is not well understood.  Neither is the effect of plastic particles in the air upon human health.  In a recent British study, microplastic was detected in the lungs of 11 out of 13 living human beings.

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Micro- and nanoplastic from the atmosphere is polluting the ocean

Photo, posted April 25, 2016, courtesy of Bo Eide via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Methane Leaks Are Worse Than We Thought | Earth Wise

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Methane leaking from oil and gas wells is a real problem for the environment because methane is far more potent at trapping heat than carbon dioxide.   The EPA has estimated that about 1.4% of the methane produced by wells nationally leaks into the atmosphere.   However, environmental experts and energy industry engineers have been concerned that leaks from mines, wells, refineries, storage facilities, and pipelines are vastly underreported.  But until recently, there really wasn’t a good way to find out.

Researchers at Stanford University have developed a technique based on the use of hyperspectral cameras mounted to airplanes.  The cameras measure sunlight reflected off of chemicals in the air that are invisible to the human eye.  Each chemical, including methane, has a unique fingerprint.  Using these sensors, methane is easy to spot and the technique can measure the output of individual wells.

The researchers performed a study of almost every oil and gas asset in the New Mexico Permian Basin, one of the largest and highest-producing oil and gas regions in the world.  They surveyed the sites for an entire year.  They estimate that more than 9% of all methane produced in the region is being leaked into the skies, far more than EPA estimates.

The positive outcome of the survey is that the researchers found that fewer than 4% of the 26,000 sites studied produced half of all the methane emissions observed.  Being able to identify the so-called super-emitter sites and dealing with them could lead to a major improvement in the situation.

The new technique is more accurate, faster, and more cost-effective than current ways to monitor emissions.

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Stanford-led study: Methane leaks are far worse than estimates, at least in New Mexico, but there’s hope

Photo, posted July 10, 2016, courtesy of Ken Lund via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tree Diversity | Earth Wise

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Scientists have estimated that there are more than 8 million species of plants and animals in existence.  Amazingly, only about 1.2 million of them have been identified and described so far and most of those are actually insects.  Millions of other organisms have yet to be discovered.

One would imagine that most of these unknown species are tiny things that are hard to spot or encounter.  But our ignorance of species even applies to trees, which are pretty easy to spot if you encounter them.

A new study involving more than 100 scientists across the globe has produced an estimate of the number of tree species on the Earth.  The new global estimate is that there are 73,000 tree species, which is about 14% more than previously thought.  Based on a combination of data from two global datasets, the study yielded a total of 64,100 documented tree species worldwide.  The researchers then used novel statistical methods to estimate the total number of unique tree species at biome, continental, and global scales, which includes species yet to be discovered and described by scientists.  Therefore, the estimate predicts that there are likely to be over 9,000 tree species still to be found.

Roughly 40% of the undiscovered tree species are likely to be in South America, which is the continent with the highest number of rare tree species and the highest number of continentally endemic tree species – meaning those found only on that continent.  Hot spots of undiscovered tree species are likely the tropical and subtropical moist forests of the Amazon basin and the Andes-Amazon interface.

Extensive knowledge of tree richness and diversity is key to preserving the stability and functioning of ecosystems.

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Number of Earth’s tree species estimated to be 14% higher than currently known, with some 9,200 species yet to be discovered

Photo, posted November 5, 2017, courtesy of Deensel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon In The Ocean | Earth Wise

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

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

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

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

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

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

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Ocean carbon uptake widely underestimated

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

Earth Wise is a production of WAMC Northeast Public Radio.

Fresh Water Under The Sea

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A new survey of the sub-seafloor off the U.S. Northeast coast has revealed the existence of a gigantic aquifer of relatively fresh water trapped in porous sediments lying beneath the salty ocean.  This appears to be the largest such formation ever found.

The newly-discovered aquifer stretches from the shore at least from Massachusetts to New Jersey and extends more-or-less continuously out about 50 miles to the edge of the continental shelf.   The deposits begin at around 600 feet below the ocean floor and bottom out at about 1,200 feet.  If all that water was found on the surface, it could create a lake some 15,000 miles in area.  The researchers estimate that the region holds at least 670 cubic miles of fresh water.

Researchers made use of innovative measurements of electromagnetic waves to map the water, which had not been detected by other technologies.   It was already known that fresh water existed in places under the sea bottom as a result of oil drilling as far back as the 1970s.  But there was previously no hint of the extent of the undersea aquifer. 

The water probably was trapped by sediments deposited during the last ice age when sea levels were much lower.  But modern subterranean runoff from land sources might also be a contributor.

If water from the aquifer was to be withdrawn, it would still have to be desalinated for most uses, but the cost would be much less than processing ordinary seawater.  There is probably no need to do this in the Northeastern US, but the discovery suggests that such aquifers probably lie off many other coasts worldwide and could provide desperately needed water in places like southern California, Australia, the Mideast or Saharan Africa.

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Scientists Map Huge Undersea Fresh-Water Aquifer Off U.S. Northeast

Photo, courtesy of August 1, 2015, courtesy of Michael Vadon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildfire Pollution

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California’s record-breaking wildfires this past season have been an unmitigated disaster with respect to loss of life, property, impact on human health, and in multiple other ways.  And as if all of that was not bad enough, the impact on carbon emissions into the atmosphere was equally catastrophic.  The wildfires were deadly and cost billions of dollars but were also terrible for the environment and for the public’s health.

According to estimates from the U.S. Department of the Interior, the California wildfires released emissions equivalent to about 68 million tons of carbon dioxide into the atmosphere.  That is equal to the emissions from generating one year’s worth of electricity in the state, or about 15% of the total annual emissions in the state of California.

It is a vicious circle in which the changes to the climate that have lengthened the fire season and shortened the precipitation season are creating additional contributions to the warming of the climate.

Over the past century, California has warmed by about 3 degrees Fahrenheit.  That extra-warmed air sucks water out of plants and soils, resulting in trees, shrubs, and rolling grasslands that are dry and primed to burn. That vegetation-drying effect compounds with every additional degree of warming.  Plants lose their water more efficiently as temperatures get higher.

The result is that wildfires are increasing in size both in California and across the western United States. Fire experts at Columbia University estimate that since the 1980s, the warming climate has contributed to an extra 10 million acres of burning in western forests – an area about the size of Massachusetts and Connecticut combined.

It’s a bad situation that is getting worse.

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California’s 2018 Wildfires Have Emitted A Year’s Worth of Power Pollution

Photo, posted October 11, 2017, courtesy of Bob Dass via Flickr. 

Earth Wise is a production of WAMC Northeast Public Radio.

Environmental Impact of Wind Power

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A recent study by Harvard University researchers published in two papers looked at the environmental impact of installing sufficient wind power to meet all the energy needs of the US.  While doing so would be far better for the environment than burning coal, it would not have negligible impacts. 

[Read more…] about Environmental Impact of Wind Power

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