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No birdsong, no water in the creek, no beating wings: how a haven for nature fell silent

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Tuesday, April 16, 2024

The tale starts 30 years ago, when Bernie Krause made his first audio clip in Sugarloaf Ridge state park, 20 minutes’ drive from his house near San Francisco. He chose a spot near an old bigleaf maple. Many people loved this place: there was a creek and a scattering of picnic benches nearby.As a soundscape recordist, Krause had travelled around the world listening to the planet. But in 1993 he turned his attention to what was happening on his doorstep. In his first recording, a stream of chortles, peeps and squeaks erupt from the animals that lived in the rich, scrubby habitat. His sensitive microphones captured the sounds of the creek, creatures rustling through undergrowth, and the songs of the spotted towhee, orange-crowned warbler, house wren and mourning dove.Back then, Krause never thought of this as a form of data-gathering. He began recording ecosystem sounds simply because he found them beautiful and relaxing. Krause has ADHD and found no medication would work: “The only thing that relieved the anxiety was being out there and just listening to the soundscapes,” he says.Bernie Krause ‘out there and listening to the soundscapes’ in Sugarloaf Ridge state park. Photograph: Cayce Clifford/The GuardianKrause began recording natural environments because the sounds helped his ADHD symptoms. Photograph: Cayce Clifford/The GuardianInadvertently, he had begun to gather a rich trove of data. Over the next three decades he would return each April to the spot at the bigleaf maple, set his recorder down and wait to hear what it would reveal.But in April last year, Krause played back his recording and was greeted with something he had not heard before: total silence. The recorder had run for its usual hour, but picked up no birdsong, no rush of water over stones, no beating wings. “I’ve got an hour of material with nothing, at the high point of spring,” says Krause. “What’s happening here is just a small indication of what’s happening almost everywhere on an even larger scale.”A rich weave of sound fadesAnimals produce a vast array of sounds: to find mates, protect territories, identify offspring or simply by moving about. But traditionally, ecologists have measured environmental health by looking at habitats rather than listening to them. Krause developed the idea that the sound of healthy ecosystems contained not only the calls of individual animals, but a dense, structured weave of sounds that he called the “biophony”.In 2009, when Krause listened through his archive, he realised a story was emerging: a subtle but noticeable loss in the density and variety of natural sounds.At the same time, he began observing odd things happening in Sugarloaf Ridge park. Leaves on some tree species were unfurling two weeks earlier than documented in historical records. The change in bloom meant migrating birds following the Pacific Flyway were out of sync with sources of food along their route. Winter rain patterns had changed. Then in 2012, exceptional drought conditions started. California had been getting little rain and record hot temperatures, which pushed the parched land into unprecedented territory.By 2014, northern California was experiencing its most serious drought in 1,200 years, and the bird song in Krause’s recording becomes muted.In 2015, the quiet sets in. There is no stream flow or wind in the audio. In 2016, the hush is broken only by the call of a purple finch.“A great silence is spreading over the natural world even as the sound of man is becoming deafening,” Krause wrote in 2012, in his book The Great Animal Orchestra. “The sense of desolation extends beyond mere silence.”Life swept away by fireThen, in 2017, the Tubbs fire struck, the most destructive wildfire in northern California’s modern history.Krause happened to be awake at 2.30am on the October morning when the flames reached his home. He and his wife had to run through a wall of fire surrounding the house. “Except for us, not one single item that we had amassed over the arc of our lives survived,” he says. “As we raced toward the car, a fire tornado seethed with a voice of rage.“That sound haunts us to this day,” he says. “I rarely make it through a night without awakening to frightful sonic nightmares.”Propelled by gusts of 78mph, the fire incinerated entire neighbourhoods. Krause’s cats, Seaweed and Barnacle, died. He lost 70 years of letters, photographs and field journals, in flames so intense they left the refrigerator an unrecognisable puddle of aluminium and steel. His precious recording archive survived, in copies stored elsewhere.The Tubbs fire burned 80% of Sugarloaf Ridge park. John Roney, the park manager, managed to evacuate 50-60 campers as the fire roared towards them.‘It’s a loss, and there’s a longing’: Breck Parkman, a retired senior state parks archaeologist. Photograph: Cayce Clifford/The GuardianThe bigleaf maple survived. It stood up to the fire,” says Breck Parkman, a retired state parks archaeologist. “It lost branches and got partially stunted, but it survived.” But in September 2020, the Glass fire hit: one of nearly 30 wildfires across California that month.“That pretty much finished off what was left of that tree,” says Parkman. He remembers once taking Clint Eastwood to look at it, as well as some botanists trying to establish if it was the biggest maple in the American west - they never confirmed its status. “It didn’t really matter, though. The birds knew the tree was grand. For them, this was the tree of life,” he says.He believes the tree should have lived for a few hundred more years and likens it to an elder at family gatherings who brings wonderful food. One day that person disappears. “It’s a type of sadness – it’s hard to describe,” he says.“It’s a loss, and there’s a longing. I would suspect the birds still miss that tree. I do.”Desirae Harp, an educator at the park and member of the local Mishewal Wappo tribe. Photograph: Cayce Clifford/The GuardianMany forest ecosystems are reliant on fire to decompose dead wood and old leaves but historically these tended to be smaller fires. They did not typically burn the tree canopy, so insects and other animals could take refuge without getting scorched. The larger fires in recent years are much hotter and threaten endangered species that have restricted ranges.Desirae Harp, an educator at the state park and member of the local Mishewal Wappo tribe, says the silence that fell after the fires broke her heart.“Hearing that silence, of all those native plants and animals, is heartbreaking because those are our relatives. I feel like when human beings die we call it genocide. But when we destroy whole ecosystems, we don’t always understand the weight of that.”A silent message to the worldThe spot in Sugarloaf Ridge park where Krause made his recordings. Not only birdsong fell silent but the sound of the creek too. Photograph: Cayce Clifford/The GuardianOne of the most significant environmental books of the 20th century is Silent Spring by Rachel Carson. Published in 1962, it warned that if people did not stop their destruction of nature, especially through the use of pesticides such as DDT, the number of birds and other wild creatures would continue to decline and silence would begin to fall over the natural world.In Krause’s recording from April 2023, not only is the birdsong missing, but there is no water in the creek either. “We’re watching this in our own lifetime, which is startling,” he says.Comparison of 2003 and 2023:In 2019, Krause argued that the climate crisis could be “changing the Earth’s natural acoustic fabric”. He drew an analogy between the natural world and a concert hall: if the heat and moisture of the concert hall changed, so too would the players’ ability to perform.“The same is happening for Earth’s orchestra. New atmospheric conditions are detuning natural sounds,” he wrote. “Only major mitigation actions will help preserve Earth’s beat.”One of the reasons people were first drawn to Sonoma county, where most of the state park lies, was to go fishing, hunting and swim in the creeks. In the 1970s there were many places to swim, says Steven Lee, a research manager at Sonoma Ecology Center. “People don’t swim in the creeks here any more. Why not? Because there’s not enough water.”The biodiversity associated with the streams has also been lost. Chinook salmon and steelhead trout are unable to reach their spawning grounds if there is no water. “It’s definitely drastic,” says Lee, about Krause’s latest recording. “The pessimist in me would say that we’re probably going to see a lot of these declines continue to happen.”Waterways are critical lifelines for wildlife in dry places such as California, with a whole cascade of life depending on them. Droughts mean this lifeblood no longer flows through the landscape.Caitlin Cornwall, a project manager at the Sonoma Ecology Center, says: “There is a direct link between reversing climate change and having more birds in Bernie’s recordings.She calls Sugarloaf “a relatively mid-range example of what happens when you have an extreme drought”.The drought is not the only pressure. Across the state, human activity is cutting into animal food sources and habitats. Wild places are being converted into farmland and urban areas, and invasive species are becoming more common. Some of the songbirds Krause captured in 1993, such as the orange-crowned warbler, are now in widespread decline.In decline: an orange-crowned warbler. Photograph: Minden Pictures/AlamySteven Lee, research manager at Sonoma Ecology Center, says streams are drying up in the park. Photograph: Cayce Clifford/The GuardianMany of the birds captured in Krause’s recordings are migrant species “living on a knife-edge”, says Cornwall. “If a year’s cohorts have died in a particular place, then next year the young – and even the adults – might not come back.” It could take generations for them to recolonise a habitat – assuming they survive elsewhere.Krause, who has been recording ecosystems from Africa to Latin America to Europe, says it is depressing to hear how the places he visits have changed. His personal library contains more than 5,000 hours of recordings, taken over 55 years from all over the world. He estimates that 70% of his archive is from habitats that have now disappeared.“The changes are profound,” he says. “And they are happening everywhere.”“I’ve got to this point in my life now where I just don’t know quite how to handle it, or how to express it, or what to say – yet I’ve got to tell people what I see and what I hear. Actually, I don’t need to say anything – the messages are revealed through the soundscapes.”There have been some optimistic signs at Sugarloaf Ridge. Roney has 40 cameras around the park, which have taken 60,000 photos in the past five years. He says there are hopeful indications, such as black bears and mountain lions moving into the area. Krause is 85 now and says his hearing days are numbered: he is almost totally deaf in his right ear and has some hearing loss in his left. He can no longer hear subtle changes in sound like he used to. “That’s a loss that I quite regret but have learned to live with,” he says.Still, he looks forward to spring and to his next recording in Sugarloaf Ridge. He is hopeful that this year there could be signs of a resurgence. “The stories conveyed through the voices of these critters will tell us all we need to know that’s worthwhile,” he says. “When we finally learn how to listen.”Krause, 85, intends to continue his recordings in the park each spring. Photograph: Cayce Clifford/The GuardianFind more age of extinction coverage here, and follow biodiversity reporters Phoebe Weston and Patrick Greenfield on X for all the latest news and features

As the soundscape of the natural world began to disappear over 30 years, one man was listening and recording it allRead more: World faces ‘deathly silence’ of nature as wildlife disappears, warn expertsThe tale starts 30 years ago, when Bernie Krause made his first audio clip in Sugarloaf Ridge state park, 20 minutes’ drive from his house near San Francisco. He chose a spot near an old bigleaf maple. Many people loved this place: there was a creek and a scattering of picnic benches nearby.As a soundscape recordist, Krause had travelled around the world listening to the planet. But in 1993 he turned his attention to what was happening on his doorstep. In his first recording, a stream of chortles, peeps and squeaks erupt from the animals that lived in the rich, scrubby habitat. His sensitive microphones captured the sounds of the creek, creatures rustling through undergrowth, and the songs of the spotted towhee, orange-crowned warbler, house wren and mourning dove. Continue reading...

The tale starts 30 years ago, when Bernie Krause made his first audio clip in Sugarloaf Ridge state park, 20 minutes’ drive from his house near San Francisco. He chose a spot near an old bigleaf maple. Many people loved this place: there was a creek and a scattering of picnic benches nearby.

As a soundscape recordist, Krause had travelled around the world listening to the planet. But in 1993 he turned his attention to what was happening on his doorstep. In his first recording, a stream of chortles, peeps and squeaks erupt from the animals that lived in the rich, scrubby habitat. His sensitive microphones captured the sounds of the creek, creatures rustling through undergrowth, and the songs of the spotted towhee, orange-crowned warbler, house wren and mourning dove.

Back then, Krause never thought of this as a form of data-gathering. He began recording ecosystem sounds simply because he found them beautiful and relaxing. Krause has ADHD and found no medication would work: “The only thing that relieved the anxiety was being out there and just listening to the soundscapes,” he says.

Bernie Krause ‘out there and listening to the soundscapes’ in Sugarloaf Ridge state park. Photograph: Cayce Clifford/The Guardian
Krause began recording natural environments because the sounds helped his ADHD symptoms. Photograph: Cayce Clifford/The Guardian

Inadvertently, he had begun to gather a rich trove of data. Over the next three decades he would return each April to the spot at the bigleaf maple, set his recorder down and wait to hear what it would reveal.

But in April last year, Krause played back his recording and was greeted with something he had not heard before: total silence. The recorder had run for its usual hour, but picked up no birdsong, no rush of water over stones, no beating wings. “I’ve got an hour of material with nothing, at the high point of spring,” says Krause. “What’s happening here is just a small indication of what’s happening almost everywhere on an even larger scale.


A rich weave of sound fades

Animals produce a vast array of sounds: to find mates, protect territories, identify offspring or simply by moving about. But traditionally, ecologists have measured environmental health by looking at habitats rather than listening to them. Krause developed the idea that the sound of healthy ecosystems contained not only the calls of individual animals, but a dense, structured weave of sounds that he called the “biophony”.

In 2009, when Krause listened through his archive, he realised a story was emerging: a subtle but noticeable loss in the density and variety of natural sounds.

At the same time, he began observing odd things happening in Sugarloaf Ridge park. Leaves on some tree species were unfurling two weeks earlier than documented in historical records. The change in bloom meant migrating birds following the Pacific Flyway were out of sync with sources of food along their route. Winter rain patterns had changed. Then in 2012, exceptional drought conditions started. California had been getting little rain and record hot temperatures, which pushed the parched land into unprecedented territory.

By 2014, northern California was experiencing its most serious drought in 1,200 years, and the bird song in Krause’s recording becomes muted.

In 2015, the quiet sets in. There is no stream flow or wind in the audio. In 2016, the hush is broken only by the call of a purple finch.

“A great silence is spreading over the natural world even as the sound of man is becoming deafening,” Krause wrote in 2012, in his book The Great Animal Orchestra. “The sense of desolation extends beyond mere silence.”


Life swept away by fire

Then, in 2017, the Tubbs fire struck, the most destructive wildfire in northern California’s modern history.

Krause happened to be awake at 2.30am on the October morning when the flames reached his home. He and his wife had to run through a wall of fire surrounding the house. “Except for us, not one single item that we had amassed over the arc of our lives survived,” he says. “As we raced toward the car, a fire tornado seethed with a voice of rage.

“That sound haunts us to this day,” he says. “I rarely make it through a night without awakening to frightful sonic nightmares.”

Propelled by gusts of 78mph, the fire incinerated entire neighbourhoods. Krause’s cats, Seaweed and Barnacle, died. He lost 70 years of letters, photographs and field journals, in flames so intense they left the refrigerator an unrecognisable puddle of aluminium and steel. His precious recording archive survived, in copies stored elsewhere.

The Tubbs fire burned 80% of Sugarloaf Ridge park. John Roney, the park manager, managed to evacuate 50-60 campers as the fire roared towards them.

‘It’s a loss, and there’s a longing’: Breck Parkman, a retired senior state parks archaeologist. Photograph: Cayce Clifford/The Guardian

The bigleaf maple survived. It stood up to the fire,” says Breck Parkman, a retired state parks archaeologist. “It lost branches and got partially stunted, but it survived.” But in September 2020, the Glass fire hit: one of nearly 30 wildfires across California that month.

“That pretty much finished off what was left of that tree,” says Parkman. He remembers once taking Clint Eastwood to look at it, as well as some botanists trying to establish if it was the biggest maple in the American west - they never confirmed its status. “It didn’t really matter, though. The birds knew the tree was grand. For them, this was the tree of life,” he says.

He believes the tree should have lived for a few hundred more years and likens it to an elder at family gatherings who brings wonderful food. One day that person disappears. “It’s a type of sadness – it’s hard to describe,” he says.

“It’s a loss, and there’s a longing. I would suspect the birds still miss that tree. I do.”

Desirae Harp, an educator at the park and member of the local Mishewal Wappo tribe. Photograph: Cayce Clifford/The Guardian

Many forest ecosystems are reliant on fire to decompose dead wood and old leaves but historically these tended to be smaller fires. They did not typically burn the tree canopy, so insects and other animals could take refuge without getting scorched. The larger fires in recent years are much hotter and threaten endangered species that have restricted ranges.

Desirae Harp, an educator at the state park and member of the local Mishewal Wappo tribe, says the silence that fell after the fires broke her heart.

“Hearing that silence, of all those native plants and animals, is heartbreaking because those are our relatives. I feel like when human beings die we call it genocide. But when we destroy whole ecosystems, we don’t always understand the weight of that.”


A silent message to the world

The spot in Sugarloaf Ridge park where Krause made his recordings. Not only birdsong fell silent but the sound of the creek too. Photograph: Cayce Clifford/The Guardian

One of the most significant environmental books of the 20th century is Silent Spring by Rachel Carson. Published in 1962, it warned that if people did not stop their destruction of nature, especially through the use of pesticides such as DDT, the number of birds and other wild creatures would continue to decline and silence would begin to fall over the natural world.

In Krause’s recording from April 2023, not only is the birdsong missing, but there is no water in the creek either. “We’re watching this in our own lifetime, which is startling,” he says.

Comparison of 2003 and 2023:

In 2019, Krause argued that the climate crisis could be “changing the Earth’s natural acoustic fabric”. He drew an analogy between the natural world and a concert hall: if the heat and moisture of the concert hall changed, so too would the players’ ability to perform.

“The same is happening for Earth’s orchestra. New atmospheric conditions are detuning natural sounds,” he wrote. “Only major mitigation actions will help preserve Earth’s beat.”

One of the reasons people were first drawn to Sonoma county, where most of the state park lies, was to go fishing, hunting and swim in the creeks. In the 1970s there were many places to swim, says Steven Lee, a research manager at Sonoma Ecology Center. “People don’t swim in the creeks here any more. Why not? Because there’s not enough water.”

The biodiversity associated with the streams has also been lost. Chinook salmon and steelhead trout are unable to reach their spawning grounds if there is no water. “It’s definitely drastic,” says Lee, about Krause’s latest recording. “The pessimist in me would say that we’re probably going to see a lot of these declines continue to happen.”

Waterways are critical lifelines for wildlife in dry places such as California, with a whole cascade of life depending on them. Droughts mean this lifeblood no longer flows through the landscape.

Caitlin Cornwall, a project manager at the Sonoma Ecology Center, says: “There is a direct link between reversing climate change and having more birds in Bernie’s recordings.

She calls Sugarloaf “a relatively mid-range example of what happens when you have an extreme drought”.

The drought is not the only pressure. Across the state, human activity is cutting into animal food sources and habitats. Wild places are being converted into farmland and urban areas, and invasive species are becoming more common. Some of the songbirds Krause captured in 1993, such as the orange-crowned warbler, are now in widespread decline.

In decline: an orange-crowned warbler. Photograph: Minden Pictures/Alamy
Steven Lee, research manager at Sonoma Ecology Center, says streams are drying up in the park. Photograph: Cayce Clifford/The Guardian

Many of the birds captured in Krause’s recordings are migrant species “living on a knife-edge”, says Cornwall. “If a year’s cohorts have died in a particular place, then next year the young – and even the adults – might not come back.” It could take generations for them to recolonise a habitat – assuming they survive elsewhere.

Krause, who has been recording ecosystems from Africa to Latin America to Europe, says it is depressing to hear how the places he visits have changed. His personal library contains more than 5,000 hours of recordings, taken over 55 years from all over the world. He estimates that 70% of his archive is from habitats that have now disappeared.

“The changes are profound,” he says. “And they are happening everywhere.”

“I’ve got to this point in my life now where I just don’t know quite how to handle it, or how to express it, or what to say – yet I’ve got to tell people what I see and what I hear. Actually, I don’t need to say anything – the messages are revealed through the soundscapes.”

There have been some optimistic signs at Sugarloaf Ridge. Roney has 40 cameras around the park, which have taken 60,000 photos in the past five years. He says there are hopeful indications, such as black bears and mountain lions moving into the area. Krause is 85 now and says his hearing days are numbered: he is almost totally deaf in his right ear and has some hearing loss in his left. He can no longer hear subtle changes in sound like he used to. “That’s a loss that I quite regret but have learned to live with,” he says.

Still, he looks forward to spring and to his next recording in Sugarloaf Ridge. He is hopeful that this year there could be signs of a resurgence. “The stories conveyed through the voices of these critters will tell us all we need to know that’s worthwhile,” he says. “When we finally learn how to listen.”

Krause, 85, intends to continue his recordings in the park each spring. Photograph: Cayce Clifford/The Guardian

Find more age of extinction coverage here, and follow biodiversity reporters Phoebe Weston and Patrick Greenfield on X for all the latest news and features

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Cairngorms estate goes back on sale after criticism of ‘green laird’ owner

Campaigners say sudden sale suggests Abrdn’s use of Scottish countryside was ‘get-rich-quick scheme’A Scottish estate that became a lightning rod for disputes over wealthy “green lairds” buying up the Highlands has been unexpectedly put up for sale.The Far Ralia estate in the Cairngorms has gone on the market for £12m, three years after it was bought for £7.5m by an investment trust run by Standard Life, now Abrdn, as a way to offset carbon emissions from its properties. Continue reading...

A Scottish estate that became a lightning rod for disputes over wealthy “green lairds” buying up the Highlands has been unexpectedly put up for sale.The Far Ralia estate in the Cairngorms has gone on the market for £12m, three years after it was bought for £7.5m by an investment trust run by Standard Life, now Abrdn, as a way to offset carbon emissions from its properties.Its purchase led to a row with land reform campaigners, who argue this approach treats the Highlands as a commodity for wealthy absentee investors, driving up land prices while exploiting public subsidies and tax breaks for private gain.The estate, a former grouse- and deer-shooting estate covering 1,462 hectares (3,613 acres) in the Cairngorms national park, was bought by the trust as a long-term carbon offsetting, sequestration and nature recovery project.Now known as Abrdn Property Income Trust, it has so far planted 1.2m native trees including Scots pine, birch, oak, rowan and aspen, after winning £2.56m in public subsidies to help cover its costs. It has a further 200 hectares of damaged peatland to restore.In an effort to demonstrate its environmental credentials and counter criticisms of its construction work, the trust hired biodiversity specialists at the Natural History Museum to evaluate the project’s biological benefits.The museum’s team said Far Ralia’s “biodiversity intactness index” would increase from 51% at present to 94% in about 75 years – a figure land reform campaigners with Parkswatch Scotland decried as crude and badly evidenced.The estate agency Knight Frank has told potential buyers they can use it to sell carbon credits, a mechanism corporations use to continue emitting CO2. A Guardian investigation last year found most carbon offset projects were “likely junk”.Knight Frank forecasts that up to 1.5m trees can be planted, offsetting 346,000 tonnes of carbon over the next 100 years. Unusually, the estate’s next owner will have very little work to do to earn the carbon credits because nearly all the planting is completed or under way.The trust is selling all its properties and investments after a steep fall in profits from property and rising costs. Abrdn and its predecessor Standard Life had run the trust for 20 years. It was seen as one of its flagship investment vehicles.Fraser Green, Abrdn’s head of natural capital investment, said: “Stakeholders of all kinds, including investors, are increasingly conscious of the need to better manage their carbon footprint and investing in environmentally beneficial projects can play a useful role in helping them do that.”Andy Wightman, a land reform campaigner, said the sudden sale suggested Far Ralia was simply “another get-rich-quick scheme”.“National parks should be centres of excellence in nature restoration but this is best done by placing legal duties on all landowners to restore nature rather than relying on financial schemes by offshore property investors.”

Oxygen discovery defies knowledge of the deep ocean

The discovery that lumps of metal on the seafloor produce oxygen raises questions over plans to mine the deep ocean.

Oxygen discovery defies knowledge of the deep oceanGetty ImagesUntil this discovery, it was believed that oxygen could not be produced without sunlightScientists have discovered “dark oxygen” being produced in the deep ocean, apparently by lumps of metal on the seafloor.About half the oxygen we breathe comes from the ocean. But, before this discovery, it was understood that it was made by marine plants photosynthesising - something that requires sunlight. Here, at depths of 5km, where no sunlight can penetrate, the oxygen appears to be produced by naturally occurring metallic “nodules” which split seawater - H2O - into hydrogen and oxygen. Several mining companies have plans to collect these nodules, which marine scientists fear could disrupt the newly discovered process - and damage any marine life that depends on the oxygen they make.NOC/NHM/NERC SMARTEX The potato-sized metal nodules look like rocks, littering parts of the deep seabed“I first saw this in 2013 - an enormous amount of oxygen being produced at the seafloor in complete darkness,” explains lead researcher Prof Andrew Sweetman from the Scottish Association for Marine Science. “I just ignored it, because I’d been taught - you only get oxygen through photosynthesis.“Eventually, I realised that for years I’d been ignoring this potentially huge discovery,” he told BBC News.He and his colleagues carried out their research in an area of the deep sea between Hawaii and Mexico - part of a vast swathe of seafloor that is covered with these metal nodules. The nodules form when dissolved metals in seawater collect on fragments of shell - or other debris. It's a process that takes millions of years. And because these nodules contain metals like lithium, cobalt and copper - all of which are needed to make batteries - many mining companies are developing technology to collect them and bring them to the surface. But Prof Sweetman says the dark oxygen they make could also support life on the seafloor. And his discovery, published in the journal Nature Geoscience, raises new concerns about the risks of proposed deep-sea mining ventures.Science Photo Library/NOAAThe scientists worked out that the metal nodules are able to make oxygen precisely because they act like batteries.“If you put a battery into seawater, it starts fizzing,” explained Prof Sweetman. “That’s because the electric current is actually splitting seawater into oxygen and hydrogen [which are the bubbles]. We think that’s happening with these nodules in their natural state.”“It's like a battery in a torch,” he added. “You put one battery in, it doesn't light up. You put two in and you've got enough voltage to light up the torch. So when the nodules are sitting at the seafloor in contact with one another, they’re working in unison - like multiple batteries.”The researchers put this theory to the test in the lab, collecting and studying the potato-sized metal nodules. Their experiments measured the voltages on the surface of each metallic lump - essentially the strength of the electric current. They found it to be almost equal to the voltage in a typical AA-sized battery. This means, they say, that the nodules sitting on the seabed could generate electric currents large enough to split, or electrolyse, molecules of seawater.The researchers think the same process - battery-powered oxygen production that requires no light and no biological process - could be happening on other moons and planets, creating oxygen-rich environments where life could thrive.Camille BridgewaterThe researchers measured the voltages on the surfaces of the metallic nodulesThe Clarion-Clipperton Zone, where the discovery was made, is a site already being explored by a number of seabed mining companies, which are developing technology to collect the nodules and bring them to a ship at the surface.The US National Oceanographic and Atmospheric Administration has warned that this seabed mining could “result in the destruction of life and the seabed habitat in the mined areas”. More than 800 marine scientists from 44 countries have signed a petition highlighting the environmental risks and calling for a pause on mining activity.New species are being discovered in the deep ocean all the time - it is often said that we know more about the surface of the Moon than we do about the deep sea. And this discovery suggests that the nodules themselves could be providing the oxygen to support life there.Prof Murray Roberts, a marine biologist from the Univerisity of Edinburgh is one of the scientists who signed the seabed mining petition. “There’s already overwhelming evidence that strip mining deep-sea nodule fields will destroy ecosystems we barely understand,” he told BBC News.“Because these fields cover such huge areas of our planet it would be crazy to press ahead with deep-sea mining knowing they may be a significant source of oxygen production.”Prof Sweetman added: “I don't see this study as something that will put an end to mining.“[But] we need to explore it in greater detail and we need to use this information and the data we gather in future if we are going to go into the deep ocean and mine it in the most environmentally friendly way possible.”

Decoding Titan’s Hydrocarbon Seas: Cassini’s Latest Radar Revelations on Saturn’s Largest Moon

Researchers from Cornell University have utilized bistatic radar data from Cassini’s flybys of Titan to analyze the surface properties of its hydrocarbon seas. The study...

This composite image shows an infrared view of Saturn’s moon Titan from NASA’s Cassini spacecraft, acquired during the mission’s “T-114” flyby on November 13, 2015. New research on Titan’s seas using Cassini’s radar data shows varied surface compositions and slight roughness differences, highlighting complex environmental interactions on Saturn’s moon. Credit: NASAResearchers from Cornell University have utilized bistatic radar data from Cassini’s flybys of Titan to analyze the surface properties of its hydrocarbon seas. The study identifies variations in surface roughness and composition, suggesting diverse geological and meteorological processes at work.A new study of radar experiment data from the Cassini-Huygens mission to Saturn has yielded fresh insights related to the makeup and activity of the liquid hydrocarbon seas near the north pole of Titan, the largest of Saturn’s 146 known moons.The key takeaway: Using data from several bistatic radar experiments, a Cornell University-led research team was able to separately analyze and estimate the composition and roughness of Titan’s sea surfaces, something previous analyses of monostatic radar data were unable to achieve. This will help pave the way for future combined examinations of the nature of Titan’s seas using Cassini data. Valerio Poggiali, research associate at Cornell University, is lead author of “Surface Properties of the Seas of Titan as Revealed by Cassini Mission Bistatic Radar Experiments,” which was published on July 16 in Nature Communications.Artist’s depiction of NASA’s Cassini during its 2017 “grand finale,” in which the spacecraft dove between Saturn and its rings multiple times before purposefully crashing into the planet’s atmosphere. Credit: NASA/JPL-CaltechBistatic Radar ExperimentsA bistatic radar experiment involves aiming a radio beam from the spacecraft at the target – in this case Titan – where it is reflected toward the receiving antenna on Earth. This surface reflection is polarized – meaning that it provides information collected from two independent perspectives, as opposed to the one provided by monostatic radar data, where the reflected signal returns to the spacecraft.“The main difference,” Poggiali said, “is that the bistatic information is a more complete dataset and is sensitive to both the composition of the reflecting surface and to its roughness.”Findings From Titan’s Polar SeasThe current work used four bistatic radar observations, collected by Cassini during four flybys in 2014 – on May 17, June 18, October 24, and in 2016 – on November 14. For each, surface reflections were observed as the spacecraft neared its closest approach to Titan (ingress), and again as it moved away (egress). The team analyzed data from the egress observations of Titan’s three large polar seas: Kraken Mare, Ligeia Mare, and Punga Mare.Ligeia Mare, shown in here in data obtained by NASA’s Cassini spacecraft, is the second largest known body of liquid on Saturn’s moon Titan. It is filled with liquid hydrocarbons, such as ethane and methane, and is one of the many seas and lakes that bejewel Titan’s north polar region. Credits: NASA/JPL-Caltech/ASI/CornellSurface Composition and DynamicsTheir analysis found differences in the composition of the hydrocarbon seas’ surface layers, dependent on latitude and location (near rivers and estuaries, for example). Specifically, the southernmost portion of Kraken Mare shows the highest dielectric constant – a measure of a material’s ability to reflect a radio signal. For example, water on Earth is very reflective, with a dielectric constant of around 80; the ethane and methane seas of Titan measure around 1.7.The researchers also determined that all three seas were mostly calm at the time of the flybys, with surface waves no larger than 3.3 millimeters. A slightly higher level of roughness – up to 5.2 mm – was detected near coastal areas, estuaries, and interbasin straits, possible indications of tidal currents.Larger than the planet Mercury, Huge moon Titan is seen here as it orbits Saturn. Below Titan are the shadows cast by Saturn’s rings. This natural color view was created by combining six images captured by NASA’s Cassini spacecraft on May 6, 2012. Credit: NASA/JPL-Caltech/Space Science InstituteImplications and Future Research“We also have indications that the rivers feeding the seas are pure methane,” Poggiali said, “until they flow into the open liquid seas, which are more ethane-rich. It’s like on Earth, when fresh-water rivers flow into and mix with the salty water of the oceans.”“This fits nicely with meteorological models for Titan,” said co-author and professor of astronomy Philip Nicholson, “which predict that the ‘rain’ that falls from its skies is likely to be almost pure methane, but with trace amounts of ethane and other hydrocarbons.”Poggiali said more work is already underway on the data Cassini generated during its 13-year examination of Titan. “There is a mine of data that still waits to be fully analyzed in ways that should yield more discoveries,” he said. “This is only the first step.”Reference: “Surface properties of the seas of Titan as revealed by Cassini mission bistatic radar experiments” by Valerio Poggiali, Giancorrado Brighi, Alexander G. Hayes, Phil D. Nicholson, Shannon MacKenzie, Daniel E. Lalich, Léa E. Bonnefoy, Kamal Oudrhiri, Ralph D. Lorenz, Jason M. Soderblom, Paolo Tortora and Marco Zannoni, 16 July 2024, Nature Communications.DOI: 10.1038/s41467-024-49837-2Other contributors to this work are from the Università di Bologna; the Observatoire de Paris; NASA’s Jet Propulsion Laboratory (JPL); the California Institute of Technology; and the Massachusetts Institute of Technology.Support for this research came from NASA and the Italian Space Agency.

Colombia gives assurances over UN biodiversity summit after rebels’ threat

Organisers working to ensure safe environment for attenders in October after guerrillas’ warning of disruptionColombian authorities have insisted it will be safe to attend a UN biodiversity summit in Cali later this year, after a dissident rebel group threatened to disrupt the event.This week Central General Staff (EMC), a guerrilla faction that rejected the country’s 2016 peace agreement, said the UN nature summit Cop16 would “fail”, in a post on X addressed to the Colombian president, Gustavo Petro.Find more age of extinction coverage here, and follow the biodiversity reporters Phoebe Weston and Patrick Greenfield on X for all the latest news and features. Continue reading...

Colombian authorities have insisted it will be safe to attend a UN biodiversity summit in Cali later this year, after a dissident rebel group threatened to disrupt the event.This week Central General Staff (EMC), a guerrilla faction that rejected the country’s 2016 peace agreement, said the UN nature summit Cop16 would “fail”, in a post on X addressed to the Colombian president, Gustavo Petro.The warning comes amid a government clampdown on the EMC, which is active in the region near Cali where the summit will be held.The Colombian defence ministry said on Tuesday it had ended a ceasefire with parts of the EMC due to ongoing violence. A series of bombings and shootings have been blamed on the group.The Cop16 organising committee said it was working with local and national authorities to ensure a safe environment during the summit, which is due to begin on 21 October. They said they were closely monitoring the situation and working to establish the validity of the messages circulating on social media.“The safety and wellbeing of all participants, attendees and collaborators are our top priority. All security guarantees are in places to have a successful and smooth conference. We convey to all participants, delegates, media and stakeholders a message of reassurance,” the statement read.About 12,000 soldiers and police are expected to be deployed for the summit, which Colombia announced it would host during UN climate talks at the end of last year.The new UN biodiversity chief, Astrid Schomaker, said she was satisfied that Colombian authorities were taking the situation seriously and she was in regular contact with the Colombian government.She said: “We’ve all watched the recent tweets and other manifestations of armed groups in Colombia. The Colombian government is taking that very seriously. They’re trying to track where this is coming from. There are a lot of conversations going on. I am confident that the Colombians are taking it seriously and that everything is being put in place to make Cop16 a safe and successful event.”The 2016 peace deal between the Colombian government and the country’s biggest guerrilla army, the Revolutionary Armed Forces of Colombia (Farc), formally ended the longest-running war in the western hemisphere, which killed more than 260,000 people and forced 7 million from their homes. Thousands of rebel fighters demobilised but about 1,500 refused to sign up to the deal, and many more are likely to have returned to arms.Under Petro’s presidency, Colombia has positioned itself as an international leader on environmental issues, becoming the first major oil, gas and coal producer to join an alliance calling for a fossil fuel non-proliferation treaty at Cop28 last year.Petro’s government has had success in reducing deforestation. But the progress has been hampered this year by El Niño and tensions with the EMC, which controls large areas of rainforest and has been encouraging people to cut down trees.At the last UN biodiversity summit, Cop15 in Montreal in 2022, governments agreed a once-in-a-decade deal to halt the destruction of Earth’s ecosystems.

Our cities’ secret gardens: we connect with nature in neglected green spaces just as much as in parks

The tangle of greenery along railway lines, flowers growing on vacant lots, or unmown grassy patches under power lines, it turns out people in cities engage with nature in all these spaces.

doublelee/ShutterstockAccess to nature is essential for our health and wellbeing. However, as our cities become increasingly crowded, it becomes more and more challenging to find ways to connect with nature in urban spaces. We know urban parks are key places to engage with nature. However, our research suggests informal green spaces – despite being unplanned, untended and often overlooked – are equally important. We have found people use informal green spaces, such as vacant lots and vegetated areas along railway lines, to engage with nature just as much as in formal green spaces. This raises the question: should we be doing more to embrace these neglected spaces? The vegetation growing along railway lines throughout our cities is an important example of informal green space. Jason Vanajek/Shutterstock Being connected with nature is good for us People living in cities are increasingly disconnected from nature. This has potentially far-reaching consequences. Studies have shown regular interaction with nature can be important for mental and physical health. Time in nature reduces stress and encourages mental restoration. Access to the natural environment is important for children’s mental and social development. People who do not interact regularly with nature have been shown to be less likely to engage with broader environmental issues. It’s a worrying trend, given the environmental crises we are facing. Despite the known benefits, interacting with nature is becoming increasingly difficult for people in cities. Urban areas are becoming more densely populated, increasing pressure on accessible green spaces. At the same time, the amount of green space in many cities is declining. This is due to rising urban density as well as changing housing trends. Traditional backyards are shrinking in countries such as Australia. In light of this, there is a growing need to use the green space available to us more effectively. Population growth and increasing density are putting pressure on green spaces in our cities. POC/Shutterstock The neglected value of informal green spaces Informal green spaces are the overlooked areas of vegetation scattered throughout our cities and towns. Think of the tangle of greenery thriving along railway lines, flowers growing on vacant lots, or the unmown grassy patches under power lines. These areas are not usually recognised or managed as part of a city’s official green infrastructure, but provide a unique type of green space. People report liking these spaces for their wild, unmanaged nature, in contrast to more neatly manicured parks. We know people use these spaces for a range of activities, from taking shortcuts or dog walking to creating community gardens. However, the extent to which people use informal green space to engage with nature has not been well understood until now. Our recent study sheds light on the importance of informal green space for access to nature in urban areas. We analysed data from citizen science apps such as iNaturalist. This enabled us to study how often people recorded sightings of animal and plant species in informal green spaces compared to their more formal counterparts, such as parks. It provided a measure of their interaction with nature. We found people use informal green spaces to engage with nature just as much as formal green spaces. Areas along railway lines and utility corridors were most popular. This may be due to their fixed land tenure. It allows people to become familiar with them and gives nature a better chance to establish on these sites. Street verges were also important. The data suggest they are as popular as private gardens for connecting with nature. While parks remain crucial, these findings highlight the important role of informal green spaces in giving people access to nature in cities. People often connect with nature in informal green space, such as this land left vacant after old homes were demolished in Perth. Purple Wyrm/Flickr, CC BY-NC-SA Rethinking how we manage green space in cities Our works shows the need to expand our thinking about how to improve people’s connection to nature in cities. It’s important to start recognising informal green spaces as a legitimate part of urban green space networks. We can then begin to consider how best to manage these spaces to support biodiversity while encouraging public use. This will present its own challenges. We’ll need to balance the needs of people with the need to leave enough quiet spaces for nature to thrive. A majority of the world’s people already live in cities. As urban populations continue to grow, so will the need for accessible green space. Formal parks will always be important to ensure people have regular, meaningful interactions with nature for the sake of their health and wellbeing. But we need to broaden our perspective to include a more diverse selection of green spaces. By valuing and integrating informal green spaces better into existing green space networks, we can ensure nature remains part of urban life. Allowing urban residents to connect with nature will promote healthier, happier and more environmentally engaged communities. Holly Kirk receives funding from the Australian Research Council and Ian Potter Foundation. Hugh Stanford does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

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