Earth Wise

By Randy SimonScience Education Self-Improvement Natural Sciences Nature

Earth Wise episodes

August 30, 2019 Refugee Corals
As climate change warms the ocean, subtropical environments are becoming more favorable for corals than the equatorial waters where they traditionally thrived. As a result, drifting coral larvae are settling and growing in new regions.
According to new research in the journal Marine Ecology Progress
Series, the number of young corals on tropical reefs has declined by 85%
over the past 40 years. At the same time,
the numbers on subtropical reefs has doubled.
Only certain types of coral can reach these new subtropical
locations. That depends on how far the
microscopic larvae can swim and drift on currents before they exhaust their
limited fat stores. Thus, the reef
ecosystems that develop have new blends of species that have previously never
coexisted. It is not clear how long it
will take for the new systems to reach equilibrium.
Coral reefs are complicated systems that depend on the interplay
between species to enable their healthy functioning. Apart from the corals themselves, there are
the coraline algae that symbiotically coexist with them. How all of this will play out in these
evolving ecosystems is unknown.
In the meantime, the research has found that these refugee corals are
settling at latitudes up to 35 degrees both north and south of the
equator. It is no longer so clear what
constitute native species in the reefs.
It remains to be seen whether new reefs in subtropical oceans can
support the incredible biodiversity seen in tropical reefs. But ultimately, these changing ecosystems
could potentially bring new resources and opportunities, such as fishing and
tourism, to places where they never existed before.
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Coral Reefs Shifting Away from Equatorial Waters
Photo, posted March 22, 2011, courtesy of Simone Lovati via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
August 29, 2019 Shifting Ecosystems
The Great Plains ecosystem has been shifting northward over the past fifty years, driven by climate change, wildfire suppression, energy development, land use changes, and urbanization. The ecosystem is an area historically rich with grasslands and shrub steppe and is prime habitat for grassland birds.
According to a recent study published in the journal Nature Climate
Change, the northernmost ecosystem boundary of the Great Plains has moved
more than 365 miles north since 1970, amounting to about 8 miles a year. The region’s southernmost ecosystem boundary
has shifted 160 miles north, or about 4 miles a year.
The study used bird distribution data as an indicator of shifting
ecosystem boundaries. The researchers
analyzed 46 years of data for 400 bird species across a 250-mile-wide strip
stretching from Texas to North Dakota.
They tracked how the birds’ distributions changed as a measure of how
these ecosystems were shifting.
While climate change has been a major driver of these ecosystem shifts
since the 1970s, several other factors such as wildfire trends, land use
changes, and invasion of tree species into grassland habitat have also played a
role. Like most things in ecological
systems, the changes are likely to have multiple causes. One cannot really separate causes like tree
invasions, warming climate, and wildfires, as they are all interrelated.
Using bird distribution patterns for tracking ecosystem shifts could
be a useful tool for scientists and land managers in the coming decades to give
them an early warning of how habitats are changing in response to rising global
temperatures and therefore allow them to take action to protect vulnerable species.
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Great Plains’ Ecosystems Have Shifted 365 Miles Northward Since 1970
Photo, posted March 24, 2017, courtesy of Rick Bohn / USFWS via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
August 28, 2019 Controlling Malaria Without Chemicals
Nearly half of the world’s population lives in areas vulnerable to malaria. The disease kills roughly 450,000 people each year, most of them children and pregnant women. Malaria is spread by Anopheles mosquitoes and, over time, the mosquitoes have been developing resistance to the chemical insecticides that are used to control them. In addition, there is great concern about the toxic side effects of the chemicals used on the mosquitoes.
About 30 years ago, scientists identified a type of bacteria that kills
Anopheles, but the mechanism was not understood. As a result, the bacteria could not be
replicated or used as an alternative to chemical insecticides.
But now, an international research team, headed by researchers at UC
Riverside, has identified the neurotoxin produced by the bacteria and has
determined how it kills Anopheles. The
work is described in a paper published in Nature Communications.
It took the team 10 years to achieve a breakthrough in understanding
the bacteria. Modern gene sequencing techniques
were the key.
While many neurotoxins target vertebrates and are highly toxic to humans, the neurotoxin that kills Anopheles mosquitoes does not affect humans, vertebrates, fish, or even other insects. Known as PMP1, the substance is not even toxic to mice when given by direct injection.
The team has applied for a patent on this discovery and hopes to find
partners to help them develop the bacteria-based insecticide.
There is a high likelihood that PMP1 actually evolved to kill the Anopheles mosquito. This finding opens the door to new avenues of research into other environmentally friendly insecticides that would be targeted at other disease-spreading pests.
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Controlling deadly malaria without chemicals
Photo, posted June 9, 2018, courtesy of Mario Yardanov via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
August 27, 2019 The Hottest Month Ever
European climate researchers announced that July was the hottest July ever recorded and since July is generally the hottest month of the year, it was indeed the hottest month ever recorded. It just barely beat out the previous record set in July 2016. There are multiple agencies that track temperatures around the world, and it is possible that some of them may report slightly different results.
But whatever July’s ultimate ranking is, it is part of a long-term
trend. The past five years have been the
hottest on record. The 10 hottest years
ever recorded have all occurred during the past twenty years.
This June was also the warmest on record, and the previous five months
were all among the four warmest for their respective months. All of that puts this year on track to be in
the top five warmest years, or perhaps the hottest ever.
The highest above-average conditions were recorded across Alaska,
Greenland, and large areas of Siberia.
Large parts of Africa and Australia were warmer than normal, as was much
of central Asia. New temperature records
were set in Belgium, the Netherlands, and Germany with temperatures over 104
degrees Fahrenheit. Great Britain saw an
all-time record of 101.7 degrees and Anchorage, Alaska stayed above 79 degrees
for a record six days in a row.
Wildfires have raged across the Russian Arctic, India has suffered
heatwaves and severe water shortages, and Japan saw more than 5,000 people seek
hospital treatment during a heatwave.
While scientists cannot directly link any particular heatwave to
climate change, the trend for new heat records is likely to continue and
accelerate unless we do something about curbing greenhouse gas emissions.
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How Hot Was July? Hotter Than Ever, Global Data Shows
Photo, posted May 25, 2019, courtesy of Jakob Montrasio via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
August 26, 2019 Exotic Pets Can Become Problems
Each year, millions of exotic animals are sold as pets around the world. The term “exotic” lacks a set definition but is generally used to refer to an animal that’s wild or more unusual than standard pets, like cats and dogs.
The exotic pet trade is a multi-billion dollar industry, involving tens of millions of individual
animals from thousands of species, including reptiles, amphibians, fish, birds,
and mammals.
Some of the exotic pet trade is legal, but a lot of it isn’t. Many animals are illegally captured from the
wild to meet the global demand for exotic pets.
People often purchase exotic animals without completely understanding the consequences. Some exotic pets, for example, can live nearly twice as long as the average dog. Caring for exotic pets can be both expensive and risky, since they are largely undomesticated (and therefore can have unpredictable behavior).
As a result, it’s not uncommon for owners to release exotic pets
intentionally. When this happens, the
consequences can be catastrophic.
Sometimes the animal dies from starvation or predation, but in other
instances, the animal proliferates and becomes an invasive species.
Invasive species are the second largest driver of biodiversity loss
worldwide, and they cost the U.S. $120 billion a year.
According to an academic review recently published in the journal Frontiers in Ecology and the Environment, the exotic pet trade is one of the primary causes of the spread of invasive species and has fueled the establishment of hundreds of them. Tegus, Burmese pythons, and red lionfish are examples of pets-turned-pests.
The best way to combat this trend is through education, detection, and
rapid response.
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Why you should never release exotic pets into the wild
Photo, posted September 19, 2010, courtesy of Mike Baird via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
August 23, 2019 We’re Still Eating The Wrong Things
A new study published in the Journal of the Academy of Nutrition and Dietetics has found that despite efforts to increase public awareness of health issues related to diet, the amount of processed meat consumed by Americans has remained unchanged in the past 18 years. Furthermore, our intake of fish and shellfish has not increased. One quarter of US adults are still eating more unprocessed read meat than the recommended level, and less than 15% meet the current guidelines for fish and shellfish consumption.
About the only positive note is that Americans are eating less beef
and more chicken than they did 18 years ago and, in fact, for the first time,
the consumption of poultry exceeds that of unprocessed red meat.
Accumulating evidence has linked excessive consumption of processed
meat to increased risk of obesity, diabetes, cardiovascular diseases, and some
cancers. The study’s authors speculate
that public awareness of these linkages is not widespread enough to affect
change and, in any case, factors other than health – social, cultural, and
economic – have greater influence over Americans’ food choices. The top five consumed processed meats are
luncheon meat, sausage, hot dogs, ham, and bacon.
The low consumption of fish and shellfish among U.S. adults could be
due to high retail prices, lack of awareness of the health benefits, and
concerns about mercury contamination in certain types of fish.
Future research is needed to identify barriers to reducing processed
meat consumption and increased seafood consumption. Policies such as nutrition quality standards,
excise taxes, health warning labels, and other interventions need to be
explored.
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Americans still eat too much processed meat and too little fish
Photo, posted January 28, 2014, courtesy of Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
August 22, 2019 Concerns About Dam Safety
The United States has a total of 91,000 dams of various sizes and types. Many of them are aging and sorely in need of repairs. All that maintenance would add up to tens of billions of dollars. Experts are increasingly worried that as extreme precipitation events become increasingly common, dams are increasingly at risk of failure, threatening lives and posing environmental risks.
In 2017, Oroville Dam in California – the tallest dam in the country –
nearly collapsed. That incident forced
the evacuation of 190,000 people and cost the state of California $1.1 billion
in repairs. California is considered one
of the nation’s leading states in dam safety management and yet the partial
disintegration of Oroville’s two spillways during a heavy rainstorm was not
anticipated.
So far, federal and state dam safety officials have not been able to
get disinterested state legislatures and the U.S. Congress to fork up the money
needed for repairs to the nation’s aging dam infrastructure.
Th American Society of Civil Engineers gave the nation’s dams a D
grade on the latest infrastructure report card.
They estimate that the cost of rehabilitating dams whose failure would
threaten human life at nearly $45 billion, and the cost of fixing all dams in
need of repair at more than $64 billion.
Scientists say the likelihood of dam failures – which not only
threaten lives but also release toxic sediments trapped in reservoirs behind
many dams – will increase as extreme precipitation events become more frequent
in a warming world. Apart from about
1,500 dams owned by federal agencies, regulating dam safety is primarily the
responsibility of the states. So far,
states have not applied remotely sufficient resources to a growing problem.
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In an Era of Extreme Weather, Concerns Grow Over Dam Safety
Photo, posted August 20, 2014, courtesy of Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
August 21, 2019 Heat And Plastic Bottles
In the middle of July, Americans along the East Coast and in the
Midwest suffered through a massive heat wave that saw actual temperatures
soaring and so-called feels-like temperatures go much higher. The punishing heat had many of us reaching
for those plastic water bottles all day long as we tried to keep hydrated.
Studies have shown that those single-use plastic bottles do not handle
the heat very well. Most plastic items
release tiny amounts of chemicals into the beverages or food that they contain.
But the hotter it gets, the more the
substances in plastic can move into food or drinking water. As temperature and time increase, the
chemical bonds in plastics increasingly break down and chemicals are more
likely to leach.
A study at Arizona State University in 2008 looked at how heat sped up
the release of the element antimony in bottles made of the common plastic
PET. Antimony is used to manufacture the
plastic and can be toxic in high doses.
At mild temperatures, very little antimony is released. But PET and other plastics can leach a
variety of chemicals when exposed to higher temperatures.
According to the FDA, the amounts of chemicals released by plastics
are too miniscule to cause health problems.
However, scientists are still looking at the long-term effects of using
so much plastic. The question is whether
all those small doses can eventually add up to something not so harmless. Given that we don’t really know the
cumulative effect of being surrounded by plastics in the goods we buy as well
as the presence of microplastics in our water, it seems like a good idea to try
to limit our exposure when alternatives are available.
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Exposed to extreme heat, plastic bottles may ultimately become unsafe
Photo, posted June 7, 2013, courtesy of Tim Stahmer via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
August 20, 2019 Fighting Climate Change With Trees
We cut down forests all around the world for a myriad of reasons, including livestock grazing, agricultural production, timber, and urban development. But what if we stopped cutting down forests for these things and additionally grew new forests on vacant lots and any other available parcels of land on earth? What impact could this have on our survival?
For the first time, scientists have quantified what impact this plan could have. According to a new study by researchers at ETH Zurich – a university that specializes in science, technology, and engineering – the planet could support nearly 2.5 billion additional acres of forest without shrinking current cities and farms. When all those acres of forest mature, the trees could store an extra 200 gigatons of carbon. This reforestation could stave off the most devastating impacts of global climate change.
Russia could restore the most acres of forest – 373 million acres to
be precise – followed by the United States with 255 million acres and Canada
with 193 million acres. Australia,
Brazil, and China also have large areas well-suited for forest restoration.
The average global temperature has risen by 1.8 degrees Fahrenheit
since the start of the industrial age with its surge in greenhouse gas
emissions. Temperatures are projected to
rise even more in the coming years as the planet continues to warm.
Trees absorb CO2 from the atmosphere and store it in their roots and branches. The absorbed carbon becomes part of the soil when trees die and decompose, and it can linger there for millennia depending on things like temperature and soil management. Trees are critical in the fight against climate change.
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How trees could save the climate
Photo, posted June 18, 2011, courtesy of K.W. Barrett via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min
August 19, 2019 A Giant Seaweed Bloom
Scientists using data from NASA satellites have discovered and documented the largest bloom of seaweed in the world, stretching all the way from West Africa to the Gulf of Mexico. The gigantic macroalgae bloom has been dubbed the Great Atlantic Sargassum Belt.
The brown seaweed floats in surface water and in recent years has
become a problem to shorelines lining the tropical Atlantic, Caribbean Sea,
Gulf of Mexico, and east coast of Florida.
The stuff carpets popular beach destinations and crowded coastal waters.
In 2018, more than 20 million tons of it floated on the ocean surface.
Scientists have been studying the Sargassum algae using satellites
since 2006, but the major blooms have only started appearing since 2011. They have occurred every year between 2011
and 2018 except for 2013. Before 2011,
most of the free-floating Sargassum in the ocean was primarily found in patches
around the Gulf of Mexico and the Sargasso Sea located on the western edge of
the central Atlantic Ocean.
Sargassum provides habitat for turtles, crabs, fish and birds, and
produces oxygen via photosynthesis.
However, too much of it can crowd out many marine species.
According to researchers, the ocean’s chemistry must have changed in
order for the bloom to get so out of hand.
The factors involved include a large seed population left over from a
previous bloom, nutrient input from West Africa, and nutrient input from the
Amazon River. The increase in nutrients
may be a result of deforestation and fertilizer use.
Climate-change effects on precipitation and ocean currents ultimately do play a role in this, but increased ocean temperatures do not. Unfortunately, these giant seaweed blooms are probably here to stay.
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NASA Satellites Find Biggest Seaweed Bloom in the World
Photo courtesy of NASA.
Earth Wise is a production of WAMC Northeast Public Radio.
2 min

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