Earth Wise

By Randy SimonScience Education Self-Improvement Natural Sciences Nature

Earth Wise episodes

March 29, 2019 Rigs To Reefs
There are about 6,000 offshore oil platforms in the world’s oceans. They have an immense presence physically, financially and environmentally. As these massive structures extract hydrocarbons from deep beneath the sea, they also undergo a remarkable transformation under the water. The enormous substructures that support the platforms become vertical reefs, home to millions of individual plants and animals.
Over time, many oil platforms are decommissioned, and their owners are
faced with the choice of either removing them entirely or transitioning them
into permanent reefs. Traditional
practice was to restore the site to its original condition, but more recently
the idea of “reefing” old platforms has gained popularity. As of 2016, more than 11% of decommissioned
platforms in the U.S. portion of the Gulf of Mexico have become permanent
reefs.
Decommissioning and completely removing a platform is a daunting and
pricey proposition. The most recent
estimate for removing all platforms off the coast of California alone totals $8
billion. Modifying the platforms to
serve as permanent reefs cuts these costs significantly, especially those
associated with hauling, cleaning and disposing of the underwater support
structure, which will have thousands of tons of sea-life clinging to it by the
time it is removed.
Converting the structure into a permanent reef means making it free of
any hydrocarbons or other hazardous materials. But this is still a far cheaper
venture than total removal. Studies of
oil rigs as underwater habitats have shown them to be some of the most
productive in the world. They are
3-dimensional reefs whose open construction allows currents to pass through
bringing lots of nutrients.
Over time, more and more oil platforms will be decommissioned. Many
may end up remaining as permanent homes for undersea life.
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Rigs to Reefs
Photo, posted August 21, 2011, courtesy of Marianne Muegenburg via Flickr
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
March 28, 2019 Protection From Toxic Algae
Toxic algal blooms have been a growing problem in recent years associated with warming waters and nutrient-rich agricultural runoff in lakes, rivers, and oceans. In 2014, an algal bloom in Lake Erie left half a million residents of Toledo, Ohio without safe drinking water for three days.
The most common toxic substance released by algal blooms in the lake is called microcystin, which is closely linked to liver cancer and other diseases. Toxicologists measure microcystin and other contaminants using the metric of parts per billion. The EPA recommends that young children not drink water containing more than 0.3 parts per billion and adults no more than 1.6 parts per billion of microcystin.
Scientists at the University of Toledo have been working on developing
a biofilter that uses naturally occurring Lake Erie bacteria to remove microcystin
released by algal blooms and thereby reduce or eliminate the use of chlorine
and other chemicals.
They have successfully isolated a number of types of bacteria that degrade microcystin toxin at a daily rate of up to 19 parts per billion. To their knowledge, such bacteria have not been previously used to fight algal blooms in other parts of the world. Based on the recorded toxin levels in Lake Erie in recent years, the bacteria would be able to effectively remove microcystin from water supplies. None of the 13 bacterial isolates they found have any association with human disease so their use in future water-purifying biofilters should not pose a public health concern.
The researchers are now developing and testing biofilters, which are water filters containing the specialized bacteria that will degrade the toxins from lake water as it flows through the filter.
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Scientists advance new technology to protect drinking water from Lake Erie algal toxins
Photo, posted April 30, 2014, courtesy of NOAA via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
March 27, 2019 Thoreau And Climate Change
Henry David Thoreau was a 19th-century American naturalist, philosopher, poet, essayist, and social reformer. He is best known for “Civil Disobedience,” an essay advocating for the rebellion against an unjust government, and for “Walden,” a book about his experiences living simply in nature. Now, Thoreau’s observations from “Walden” are the foundation of a new study exploring the effects of climate change on tree leaf-out and the emergence of spring wildflowers.
This research, which was recently published in the journal Ecology
Letters, relies on Thoreau’s scientific observations gathered during the 1850s
when he spent 26 months living in isolation at Walden Pond in Concord,
Massachusetts. These observations from
Thoreau were combined with current research to measure tree and wildflower
leaf-out dates for 37 different years between 1852 and 2018. “Leaf out” refers to the time in spring when
plants and trees begin producing leaves.
An alteration in this timing can have a domino effect throughout an
ecosystem.
Over the past century, temperatures in Concord, Massachusetts have
warmed five degrees Fahrenheit. As a
result, leaf-out dates have changed significantly. According to researchers, wildflowers are
leafing out about one week earlier, while trees are leafing out about two weeks
earlier than they did 160 years ago.
Ground-dwelling plants like wildflowers have a narrow window to
accomplish growth, photosynthesis, and reproduction, before the canopy trees
leaf out and block the sunlight.
Temperature-driven shifts in the timing of tree leaf-out between
Thoreau’s time and now are likely already hindering wildflower abundance and
flowering.
As the climate continues to warm, the already small window of time between wildflower emergence and tree leaf-out will likely shorten further.
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Using Thoreau, scientists measure the impact of climate change on wildflowers
Photo, posted August 13, 2008, courtesy of Adam Pieniazek via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
March 26, 2019 Defusing The Methane Time Bomb
Permafrost is defined as soil that remains frozen for two or more consecutive years. It is generally composed of rock, soil, sediments, and varying amounts of ice that binds it all together. The permafrost of the Arctic represents one of the largest reservoirs of organic carbon in the world. It covers vast regions of Siberia, northern Canada, Alaska and Greenland.
When permafrost thaws, microbes in the previously-frozen soil go to work digesting organic materials and release carbon dioxide and methane, both of which are greenhouse gases. Methane is 25 times more effective in trapping heat in the atmosphere than carbon dioxide, so it represents the greater threat. The massive amounts of methane that could be released by thawing permafrost have been described as a ticking time bomb threatening the world’s climate. Unfortunately, the permafrost in the Arctic is already starting to thaw as a result of climate change.
A new study by researchers at the
International Institute for Applied Systems Analysis looked into the prospects
for neutralizing the threat posed by the release of methane from thawing
permafrost. They analyzed the relative
contributions of potential methane emissions from the permafrost and existing
ones from human activities. Human-caused
methane emissions from fossil fuel activities, waste dumps, and livestock
constitute a major source of the gas.
Their conclusion is that if we can greatly reduce human-generated methane release, the effects of uncontrolled Arctic methane emissions could be mitigated. It is unclear whether we can do much to stave off the Arctic methane release at this point, but the release of methane from human activities is something we can do something about. But the clock is ticking.
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Diffusing the methane bomb: We can still make a difference
Photo, posted August 14, 2011, courtesy of Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
March 25, 2019 Glaciers And Water Supply
The world has roughly 150,000 glaciers covering about 200,000 square miles of the earth’s surface. Over the last 40 years they’ve lost the equivalent of a layer of ice 70 feet thick. Most of them are getting shorter as well. Some have shrunk to nothing; many smaller glaciers in places like the Rockies and the Andes have disappeared entirely.
Glaciers represent the snows of centuries, compressed over time to form flowing rivers of ice. They always change over time, accumulating snow in winter and losing ice to melting in summer. But in recent times, the warming climate has allowed the melting to outpace the accumulation.
Much of the discussion about the retreating glaciers relates to sea
level rise, catastrophic floods, debris flow, and the effects on rivers and
ecosystems.
But in some places, the biggest impact of the loss of glaciers is on the supply of water for people and agriculture. In Kazakhstan, Almaty, the country’s largest city depends on glacier-fed rivers for drinking water for its 2 million people and for irrigation water for crops. All across the Tibetan Plateau and the Himalayan and Karakmoram mountain ranges, hundreds of millions of people rely on glacier-fed rivers for their water supplies.
A melting glacier can at first increase stream flow but eventually
reaches a tipping point and meltwater begins to taper. In the short term, the melting glaciers may
provide increased amounts of water coming down from the mountains, but
eventually the flow in the rivers will begin to decline and populations will
face a crisis.
It will be essential for people in many places to carefully plan for
their future water needs in a changing world.
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Web Links
Glaciers Are Retreating. Millions Rely on Their Water.
Photo, posted September 16, 2011, courtesy of Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
March 22, 2019 Crop Diversity
A study at the University of Toronto suggests that on a global scale, we are growing more of the same kinds of crops, and this diminishing diversity presents major challenges for agricultural sustainability.
In some places, for example here in North America, crop diversity has actually increased. Back in the 1960s, North Americans grew about 80 crops. Now there are 93.
But on a global scale, more of the same kinds of crops are being grown on much larger scales. Just four crops – soybeans, wheat, rice and corn – occupy nearly 50% of the world’s entire agricultural lands. The remaining 152 crops cover the rest. Large industrial farms often grow one crop species – usually just a single genotype – across thousands of acres of land.
This decline in global crop diversity is problematic in several
ways. On a cultural level, it threatens
regional food sovereignty. If regional
crop diversity is threatened, it makes it more difficult for people to eat or
afford foods that are culturally significant to them.
On an ecological level, the dominance by a few genetic lineages of
crops makes the agricultural system increasingly susceptible to pests or
diseases. The deadly fungus that is
threatening the world’s banana plantations is a prime current example. The Irish potato famine in the 19th
century is a tragic historical example.
As large industrial-sized farms in Asia, Europe and the Americas start to look more and more alike, the dangers of large monocultures of crops that are commercially valuable will only increase. It will be important for global governments to consider the impact of policies that affect the diversity of the agricultural system and its sustainability in an increasingly hungry world.
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A small number of crops are dominating globally. And that’s bad news for sustainable agriculture
Photo, posted August 13, 2012, courtesy of Alasdair McKenzie via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
March 21, 2019 Another Way To Make Solar Cells
Millions of rooftops now contain solar panels and the majority of the solar cells that make up those panels today are made from silicon. Silicon solar cells require expensive, multi-step processing conducted at very high temperatures in special clean room facilities. Despite these complications, the price of solar panels has continued to drop dramatically over the years.
But even as the price of solar cells gets lower and lower, there are
still widespread efforts to find even better ways to make them. One of those ways is with perovskite solar
cells. Perovskites are materials with a
characteristic crystal structure and are quite common in nature. Perovskites can be formed with a wide range
of elements and can exhibit a variety of properties.
They were first used to make solar cells about 10 years ago and those
first cells were unimpressive in most respects.
However, there has been steady progress since that time. The potential advantages of perovskite solar
cells are that they can be made from low-cost materials and can be manufactured
using liquid chemistry, a far cheaper process than what is used to make silicon
cells.
Researchers at MIT and several other institutions have recently
published the results of research on how to tailor the composition of
perovskite solar cells to optimize their properties. What used to be a trial-and-error process can
now become much more engineered and should lead to perovskite solar cells with
performance that could exceed that of silicon cells.
Silicon solar panels are a huge, worldwide industry and displacing them
in favor of an alternative technology is a tall order. But if perovskite cells can be optimized for
large-scale manufacturability, efficiency and durability, they could definitely
give silicon a run for its money.
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Unleashing perovskites’ potential for solar cells
Photo courtesy of Ken Richardson/MIT.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
March 20, 2019 2018 Was A Wet Year
Recent news reports noted that 2018 was the fourth hottest year on record. But the changing climate is not just about temperature. 2018 was also the third-wettest year since 1895, when steady record-keeping began.
Overall, the U.S. recorded 4.68 inches more precipitation in 2018 than the 20th century average. But all that rain and snow was nothing like evenly distributed. The eastern half of the country – especially in places like North Carolina and Virginia – saw record amounts of precipitation, while most of the West remained stuck in drought.
The warming climate leads to precipitation extremes at both ends,
meaning that wet places are likely to get wetter and dry places drier. There has been a marked upward trend in
short-duration extreme events. For
example, Cyclone Mekunu dumped almost 13 inches of rain on Salalah, Oman in 36
hours, more than double its annual average rainfall.
In the southeast and eastern U.S., the trend toward stronger storm
events is mostly driven by strong warming of the oceans that fringe their shores. Warm oceans evaporate more water into the air
and warm air holds more water than cooler air.
Warmer, moisture-laden air acts like a blanket over the land, keeping
heat trapped near the ground. Many of
the states that had their wettest-ever years also set records for high minimum
temperatures – their coldest temperatures were less cold than in the past.
Air temperatures are projected to warm up even further in the coming
years and, as a result, many scientists are anticipating that extreme precipitation
events will only get more extreme. The
pattern of drought in the west and wetness in the east is likely to stay.
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2018 was the U.S.’s third-wettest year on record—here’s why
Photo, posted August 18, 2018, courtesy of Jim Lukach via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
March 19, 2019 Balloons And Seabirds
It’s no secret that there is a ton of plastic in the ocean – millions of tons, in fact. Scientists estimate that there is more 165 million tons of plastics swirling about in our oceans today, with an additional 8.8 million tons flowing in every year. As the oceans swell with plastic debris, many marine species wind up ingesting the stuff – often with dire consequences.
All this plastic trash winds up affecting more than just aquatic
species, too. According to researchers
from the University of Tasmania, a seabird that ingested a single piece of
plastic has a 20% chance of mortality.
This statistic jumps to 50% if the seabird consumes nine pieces of
plastic.
The study, which was recently published in the journal Scientific
Reports, also found that while hard plastics account for the majority of
plastic debris ingested, it’s far less likely to prove fatal than soft
plastics, such as balloons.
In fact, the researchers found that balloons or balloon fragments were
the number one marine debris risk of mortality for seabirds, killing almost one
in five of the seabirds that ingested them.
The leading cause of death among the seabirds studied was blockage of
the gastrointestinal tract. While soft
plastics only accounted for 5% of the ingested plastics, they were responsible
for more than 40% of seabird mortality.
But the researchers make clear that hard plastics were still responsible
for more than half of the study’s seabird deaths.
If we want to reduce the number of marine species dying from plastic
ingestion, we need to reduce the volume of plastic going into the ocean and do
what we can to remove what’s already there.
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Web Links
Balloons the number 1 marine debris risk of mortality for seabirds
Photo, posted July 24, 2014, courtesy of Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
March 18, 2019 Shrinking Arctic Glaciers
The glaciers on Baffin Island, located in Canada’s northeastern Arctic, have been shrinking as the climate warms. The melting, receding glaciers have exposed fragments of ancient plants that had frozen in the places where they once grew. New research has shown that these spots have not seen the light of day for at least 40,000 years.
The entire planet has been warming since humanity started flooding the
atmosphere with greenhouse gases at the start of the Industrial Revolution, but
the effects are not uniform across the globe.
Some regions – like the Arctic – are seeing temperature rises that are
greater and faster than anywhere else in the world. As a result, glaciers in the Arctic have been
melting away at rates never before observed in modern human history.
Researchers at the University of Colorado performed radiocarbon dating experiments in order to find out when the last time was that the Arctic was as warm as today. There have been natural variations in Arctic temperatures caused by the complicated way the Earth wobbles on its axis. For example, 10,000 years ago the northern latitudes pointed at the sun more directly during the summer than they do now, providing about 9% more sunshine during the summer.
The results of the study showed that the newly-uncovered plants had
died at least 40,000 years earlier, indicating that the glaciers had not melted
back to today’s size for at least that long.
Global measurements indicate that the planet as a whole has not been as
warm as it is today for about 115,000 years, back then again a result of the
orientation of the Earth.
Well, the Earth hasn’t wobbled recently. The Arctic is melting because we are dumping
massive amounts of greenhouse gases into the atmosphere.
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These Arctic glaciers are smaller than ever before in human history
Photo, posted September 1, 2010, courtesy of Doryce S. via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min

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From green business and new environmental legislation to how nature impacts our environment in ways never before considered, Earth Wise offers a look at our changing environment.