10.16.25

Episode Transcript

Speaker 1 (00:01):
Welcome to Radioized Diary of Science and Nature. Your reader's
Kelly Taylor. I'll have articles on the topics of science
and nature, but first a reminder that RADIOI is a
reading service intended for people who are blind or have
other disabilities that make it difficult to read printed material.
Today we'll start with an article from Time magazine. The

(00:23):
headline is the world's first climate tipping point has been crossed.
This is dated October twelfth. The exact moment when Earth
will reach its tipping points, moments at which human induced
climate change will trigger irreversible planetary changes, has long been

(00:44):
a source of debate for scientists, but they might be
closer than we think. A report published today says that
the Earth has passed its first climate tipping point. The
second Global Tipping Points Report, published by the University of
Exeter found that warm water coral reefs are passing their

(01:04):
tipping point. Rising ocean temperatures, acidification, overfishing, and pollution are
combining to cause coral bleaching and mortality, meaning that a
large number of coral reefs will be lost unless the
global temperature returns towards one degree warming or below. Quote.

(01:25):
We're in a new climate reality, said Tim Linton, founding
director at the Global Systems Institute at the University of Exeter,
who led the report. Quote, We've crossed a tipping point
in the climate system, and we're now sure we're going
to carry on through one and a half degrees celsius
of global warming above the prior industrial level, and that's

(01:48):
going to put us in danger for crossing more climate
tipping points. In quote, the planet is predicted to cross
the one point five degree celsius threshold within the next
five years, according to a report from the World Meteorological
Association or organization. Once that threshold is reached, the planet

(02:09):
will seem more frequent and intense extreme weather and strains
on food production and water access impacts many nations vulnerable
to climate change are already seeing. The authors define a
tipping point as occurring when changes in a system become
self perpetuating and difficult to reverse beyond a threshold, leading

(02:32):
to substantial, widespread impacts. Scientists have found as many as
twenty five major tipping points, including the Amazon rainforest transforming
from a lush forest that stores carbon emissions to a
dry savannah, and the permanent melting of polar ice whereby
the dark open water absorbs more heat compared to white snow,

(02:55):
encouraging further melting. One hundred and sixty scientists in twenty
three countries compile the latest data and literature on the
topic and found that in the years since launching the
report in twenty twenty three, reefs around the world have
begun passing their thermal tipping point. Quote. We've seen eighty
percent of coral reefs experience unprecedented heat waves, bleaching events,

(03:21):
and die back, said Linton. The widespread collapse of reef
ecosystems would be devastating for marine and human life. Reefs
help support fisheries and protect coastlines from storm searches and
rising sea levels. Of all the tipping points, coral reefs
have one of the lowest thresholds for rising temperatures, meaning

(03:44):
it's no surprise that it's the first to be breached.
There are other measures of the environment's health that scientists
are also watching. A September report found that we've already
passed seven of the nine planetary boundaries, including the ocean
becoming more acidic and the transformation of natural landscapes. These

(04:06):
are thresholds that keep Earth's systems hospitable to life and
protect against breaching a tipping point. Today's report also found
that the global temperature threshold required to triggle the trigger
the widespread dieback of the American rainforest is lower than
previously thought, with the lower end of the estimated range

(04:29):
now at one point five degree c. The authors emphasize
the need for urgent action to avoid this fate, including
targeted investments in conservation and restoration to preserve the forest
for the more than hundred million people who depend on it.
They also warned that the National merid Meridional n HUM

(04:52):
Atlantic Meridional overturning circulation OH, I know it is, Atlantic
meridianal overturning circulation, a system of ocean currents that circulates
water within the Atlantic Ocean, is at risk of collapse
below an increase of two degrees sea of global warming
above pre industrial temperatures. If this happens, it would trigger

(05:15):
harsher winters in Northwest Europe, disrupt the West African and
Indian monsoons, and decrease agricultural yields in much of the world.
A number of positive changes are being made around the world,
of course, as green alternatives like electric vehicles and solar
panels become more widely adopted and affordable. Quote, there is

(05:40):
growing evidence of what we call positive tipping points, where
the change to zero emission technologies and behaviors is also
becoming self propelling, Linton says. But if we want to
avoid crossing further climate tipping points, there's more progress to
be made. He adds, we know we need the solutions
to accelerate if we're going to limit warming to a

(06:02):
level that could limit the risks from the bad tipping
points and the climate now. Next, we have an article
from BBC Wildlife ecosystem Killers. Ten destructive, brutal animals that
destroy entire habitats. This is from October thirteenth, Indiscriminate predators,

(06:26):
insatiable grazers, ecosystem engineers, flagrant opportunists and invasive horrors. Here's
our pick of the animals great and small that can
change the world around them beyond recognition and not in
a good way. Ten animals that destroy the entire ecosystems. First,

(06:47):
the brown tree snake. The remote Pacific island of Guam
was serpent free until around nineteen fifty, when the brown
tree snake arrived from somewhere in its native range to
the south. However, it got there, most likely as a
stowaway on a boat or plane. It found a land
teeming with birds, reptiles, and bats that had no defenses

(07:08):
against its predatory instincts. By the time authorities started monitoring
the situation in the nineteen eighties, there were more than
one hundred snakes per hectare, and much of the damage
had already been done. By nineteen ninety, just three species
of native vertebrates, all small lizards, remained in significant numbers

(07:29):
in the island's forests. The snake wiped out twelve of
the twenty two native bird species, including the Guam flycatcher,
which was found nowhere else in the world, and reduced
numbers of another eight species by at least ninety percent.
It drove six native lizards to extinction and is also

(07:50):
implicated in the disappearance of the endemic Guam flying fox,
which was last seen in nineteen sixty eight. Surprisingly, this
ecological disaster has had dramatic consequences for the island's wider ecology.
Bird pollinated plants are now setting fewer seeds, and loss

(08:10):
of the vertebrates that disperse seeds is changing the species
composition of the island's forests. Meanwhile, spider populations have increased
fortyfold during the wet season since their avian predators disappeared
the cane toad. Sometimes a cure can be more dangerous
than the disease it's meant to be treating. That is

(08:32):
surely the case with the cane toad, a native of
South and Central America that was transported to Australia in
the nineteen thirties to control beetles plaguing the sugar cane crops. Unfortunately,
these gluttonous amphibians hunt on the ground, so they made
little impact on the beetles, which feed high up in
the plants. Instead, the toads turned their attentions to the

(08:57):
native wildlife, swallowing pretty much anything that would fit in
their mouths insects, frogs, reptiles, and small birds and mammals.
But cane toads are not only dangerous in discriminate predators,
they also are lethal prey quoals. Those are predatory marsupials, goanas,

(09:18):
a type of large monitor lizard, snakes, and even freshwater
crocodiles can be killed by the potent toxins secreted by
glands on the frog's skin. In many invaded areas, quoals
have vanished and goanas have crashed by more than ninety percent.

(09:38):
The cane toad is a species that can wreak havoc
at both ends of the food chain. Beaver, this big
bucktooth rodent, is hailed for its ability to create to
create habitats rather than destroy them by felling trees and
damming streams. It engineers wetland ecosystems that boost aquatic biodiversity

(09:59):
and as natural food defenses. But you can't make an
omelet without breaking eggs. Valleys that once held bubbling streams,
shady woodland, and wildflower meadows became quite literally swamped by
standing water. Trees die dams block the passage of migratory fish,

(10:20):
and species that require flowing water quietly disappear in the
beaver's native ranges. These trade offs are part of long
established ecological processes in places where beavers don't belong, though
the downsides can be more striking. Beavers introduced from North
to South America have destroyed swaths of native beech forest

(10:43):
in Tierra del Fuego. Whether you see the activities of
these quintessential ecosystem engineers as creative or destructive depends on
where you stand when the water starts to rise. Rosy
wolf snail the vast majority of terrestrial snails or vegetarians,

(11:03):
and for good reason. Predators need to be fast, and
yet speed is not something snails are known for. The
rosy wolf snail, though, is very much a hunter. While
it's not exactly nippy, it is crucially faster than its prey,
other snails, which it hunts down by following their slime trails.
Native to the southeastern United States, the rosy wolf snail

(11:27):
was introduced to a number of Pacific islands, including Tahiti
and Hawaii in the mid twentieth century in the hope
that it would control the giant African land snail, which
had become an invasive agricultural pest after its own introduction. Tragically,
the rosy wolf snail turned out to prefer easier pickings

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the small, delicate native snails that had been evolving in
splendid isolation on the various islands for hundreds of thousands
of years. A massacre ensued. More than one hundred native
snail species were driven to extinction within decades. Rats opportunistic

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and adaptable. Rats seem to flourish wherever life takes them.
They are agile climbers, strong swimmers, fiercely intelligent, prolific breeders,
catholic in their tastes, and have a knack for availing
themselves of human modes of transportation between them. The black rat,

(12:31):
brown rat, and pacific rat, all originally native to South
and Eastern Asia, now infest more than eighty percent of
the world's islands, and the transformation of habitats begins as
soon as they have hopped ashore. Globally, rats are implicated
in the extinction of more than seventy vertebrate species in

(12:54):
the Chagos Archipelago. In the Indian Ocean, the densities of
seabirds on on rat free islands are seven hundred sixty
times higher than on infested ones. This has had dramatic
effects on the wider ecosystem, which has historically been nourished
by the guano depositing by the resident bird colonies. Even

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the coastal waters are affected to the extent that the
coral reefs fringing rat free islands support around fifty percent
more fish. The nile perch. Few introductions have caused such
havoc as the nile perch's release into Lake Victoria in
East Africa in the nineteen fifties. This giant predator, growing

(13:39):
more than two meters long, was meant to boost fisheries.
Arguably it succeeded, but at a huge ecological cost. In
the fifteen thousand years since, climate changes created the world's
second largest lake, evolution has worked its magic on a
population of ciclid fish that arrived there soon after its formation.

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These founding mothers and fathers multiplied, dispersed, and diversified to
fill a multitude of specialized niches. While some took to
hunting in the open water or scraping algae from rocks,
others strained particles from the sediment, crushed mollusks, or scavenged
at the surface. A few even specialized in nibbling the

(14:21):
fins and scales of their neighbors. Add to that the
gaudy colors and elaborate courtship rituals that set species apart,
and the result was a living evolutionary laboratory unrivaled anywhere
in fresh water. To the nile perch, though it was
all just food. Within a few decades, as many as
two hundred of the lake's cyclid species were extinct. Many

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others now cling on in tiny populations, while some survive
only in aquaria. The European rabbit. Don't be fooled by
the endearing, twitchy nose and photogenic dandelion nibbling. The European
rabbit has proved capable of causing ecological devastation around the world.

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Native to the Iberian Peninsula, it has been introduced to
all continents except Antarctica for its fur and as a
game animal. Most infamously, perhaps a handful released in Australia
in the eighteen fifties soon became hundreds of millions, which
gnawed through crops and native vegetation, stripping landscapes bare and

(15:26):
turning fertile soils to dust. The problem was so overwhelming
that authorities built the rabbit Proof Fence, the longest continuous
barrier in the world at the time, over three thousand
kilometers long, in a vain attempt to hold back the tide.
New Zealand fared little better, and the destruction was compounded

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by efforts to control them with introduced stoats and weasels.
These had a modest effect on the rabbits, but tragic
consequences for native birds, including the laughing owl, which was
driven into extinction by the early twentieth century. The domestic
cat people have long enjoyed having cats around the place,

(16:09):
not only for their company but also for their rodent
control skills. Unfortunately, they don't stop it eating just vermin.
In the US alone, pet and feral cats kill an
estimated one point three to four billion birds every year,
and cats introduced to islands around the world are implicated
in fourteen percent of all the bird, mammal, and reptile

(16:32):
extinctions in modern times. Take what happened on Stephens Island
in the Cook Strait between New Zealand's North and South Islands.
Until the eighteen nineties, it was an uninhabited, pristine refuge
for many species that had already been ravaged by the
Polynesian rat, which had arrived with the Mayoris. But when
a new lighthouse was switched on in eighteen ninety four,

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the island became home to three lighthouse keepers, their families,
nature for the children, and a succession of pet cats
that quickly spawned a feral population that feasted on the
island's bird life and reptiles, such as the tuatara, the
sole living representative of an ancient lineage of lizard like

(17:15):
animals that had already been eliminated from the mainland. The
Stephens Island wren, a tiny, flightless songbird found nowhere else
on Earth, was first described from a specimen killed by
one of the cats, and seems to have disappeared completely
by eighteen ninety nine. The feral cats were finally eradicated
from the island by twenty twenty five, in a pioneering

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effort that provided an early lesson in how habitats can
be restored to their former glory. Sea bird and reptile
populations have rebounded, and the tuatara recovered to the point
that individuals could be shipped to other islands. The wren, though,
is gone forever the feral goat. A century after the

(18:00):
removal of cats from Stephen's Island, habitat restoration efforts have
been become increasingly ambitious. A case in point is Project Isabella,
which aims to eradicate hundreds of thousands of feral goats
from the Galapagos Archipelago. When goats arrived in the islands
during the sixteen hundreds, deposited there by passing sailors as

(18:23):
a living food store. The only native terrestrial mammals were
a few species of bat. The islands would later become
famous for the endemic birds and reptiles that were so
influential on the development of Darwin's ideas on the mechanism
of evolution. But as the goats multiplied, they posed an
increasing threat to the native habitats on which the iconic

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finches and giant tortoises depend. Goats are hardy and adaptable,
and their digestive systems can deal with plant toxins that
would kill other herbivores, allowing them to eat anything and
everything a botanical nature. On some islands, vast tracks have
been stripped of vegetation and turned to dust, while forest

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trees have been unable to reproduce because the goats eat
each and every seedling. Project Isabella is not yet complete.
More than one hundred forty thousand goats have been removed
from four hundred thousand hectares of land at a cost
of at least ten and a half million dollars, but
they continue to roam on three islands. The red grouse.

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It is neither an invader nor especially destructive in its
own right, but the red grouse has managed to reconfigure
the landscape of pretty much an entire country, or, more accurately,
perhaps the landscape has been reconfigured around it. Native to
the uplands of Britain and Ireland, and indeed found nowhere
else in the world, the bird has long been hunted

(19:54):
as game, and grouse shooting has become increasingly commercialized over
the last couple of centuries to keep grouse numbers high.
Vast tracts of the Scottish Highlands are managed as heather moorland.
Since the mid nineteenth century, the heather itself has been
burned in rotation, a practice known as mure burn, to

(20:18):
provide the birds with young shoots to eat and other
stands for cover, giving the hills a distinctive patchwork appearance.
Trees are discouraged. Saplings that survive the flames are grazed
by sheep and deer. Historically, predators such as raptors, foxes
and stoats have been trapped or shot, and some illegal
persecution continues today. They might be bonnie, but Scotland's heather

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clad hillsides are low and biodiversity, poor at storing carbon,
and prone to erosion and flooding. They look wild, but
they are managed intensively to serve the interests of a
single species until the twelfth of August at least, which
is when the shoe starts. Now from the Guardian we

(21:06):
have this article which is headlined a new island erupted
from the sea. Can it show us how nature works
without human interference? This is dated October thirteenth. The crew
of the Ilafer Ilafer iiO had just finished casting their

(21:26):
nets off the coast of southern Iceland when they realized
something was wrong. In the early morning gloom in November
nineteen sixty three, a dark mass filled the sky over
the Atlantic Ocean. They rushed to the radio, thinking that
another fishing vessel was burning at sea, but no boats
in the area were in distress. Then their trawler began

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to drift unexpectedly, unnerving the crew further. The cook scrambled
to wake the captain, thinking they were being pulled into
a whirlpool. Finally, through binoculars they spotted calm of ash
bursting from the water and realized what was going on.
A volcano was erupting in the ocean below. By the

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time the sun had risen, dark ash filled the sky
and a ridge was forming just below the surface of
the water. By the next morning it was ten meters high.
A day later it was forty meters an island was
being born. Two months later the rock was more than
a kilometer long and one hundred and seventy four meters

(22:30):
high at its peak. It was named Sertsee after the
fire giant Seerter from norths Mythology Islanders and fissures from
the nearby vest Manner Archipelago watched as lightning struck the
volcanic eruption, which waxed and waned, and its intensity lighting

(22:51):
up the winter half light. It would be two years
before it stopped erupting completely. Quote. It is very rare
to have an eruption where an island forms and is
long lasting. It happens once every three thousand to five
thousand years in this area, says Olga colbryn Villemordort, a
geographer with the Natural Science Institute of Iceland. Those that

(23:14):
do form are often quickly washed away by the ocean.
She says, the emergence of Certsee presented researchers with a
precious scientific opportunity. They could observe how life colonizes and
spreads on an island away from human interference that has
overtaken much of the Earth. Other islands have emerged since

(23:35):
the nineteen sixties, but scientists say they have not been
as ecologically stable. The last time something similar took place
before Certsei's emergence was the birth of Annak Krakatoa, Indonesia
in nineteen twenty seven, but it was quickly contaminated by humans.
Icelandic researchers were adamant that this time would be different.

(23:58):
In nineteen sixty five, was placed under formal protection by
the government. Only researchers and the odd journalists under strict
supervision would be allowed to visit. No sheep would ever
be allowed to graze there. The same year, the first
plant was spotted, a clump of sea rocket brought over
the waves from the Icelandic mainland. The first scientists that

(24:20):
stepped on Certseey in nineteen sixty four could see that
seeds and plant residues had been washed ashore. Birds were
even coming to the island to see what was going on.
The eruption was still going on. When they spotted the
first plant, it was very quick, says Oga. Scientists had
expected algae and mosses to be the first colonizers, building

(24:42):
up a base of soil that would eventually support vascular plants,
but that step was skipped completely. More plants were washed
ashore in following years, and some clung to the island's
bare volcanic rock, but after a decade the changes seemed
to stall. Pauvel Voskowitz, director of botany at the Natural

(25:04):
Science Institute, says people thought what now. Around ten species
had colonized Certsei. At that point the plant cover was
really scarce. But then the birds arrived. In the early
nineteen eighties, black backed gulls started to nest on sections
of the island, sheltering in one of the stormiest parts

(25:24):
of the Atlantic Ocean. Their arrival kicked off in explosion
of life. Guano carried seeds that quickly spread grasses along
the island, fed in turn by the nutrients from the birds.
For the first time, the whole areas of bare rock
became green. Voskovitch says, it's surprising. From the times of Darwin,

(25:45):
biologists thought it was just plant species with fleshy fruits
that could travel with birds, but the species on Certsi
do not have fleshy fruits. Almost all of the seeds
on Sertsi were brought in the feces of the gullste our.
A lesson from this living laboratory is that recovery after
disturbance does not always follow a single predictable path. He says, instead,

(26:09):
it is shaped by multiple, sometimes surprising forces. Today, gray
seals are the latest arrivals to change to cause changes
in the island's biodiversity. The volcanic rock has become a
crucial haulout site where seals come ashore to rest and molt,
as well as a breeding ground where they can raise

(26:31):
their young safe from the orcas lurking nearby. Their feces
urine en placentas from birth are bringing nitrogen to the island,
helping life spread further, but researchers warn that the colonization
of Certsi will one day go into reverse. The gray
seal haul out site is one of the areas slowly

(26:51):
being eroded by the ocean. By the end of the century,
scientists project that little will be left from that second
of the island. Its biodiversity will probably pique then fall
over time, eventually leaving a rock with sharp cliffs alone
in the Atlantic. But the researchers say that lessons will

(27:13):
remain search He demonstrates that even in the harshest environments,
resilience and renewal are possible. It offers hope and practical
lessons for rehabilitating ecosystems damaged by war, pollution, or exploitation.
If space is given, nature will always find ways to return,
often faster and more creatively than we expect. Well, that's

(27:38):
it for today's Diary of Science and Nature. Your reader
was Kelly Taylor. Now stay tuned for further programming on
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