Life On Earth Is Under Assault—But There’s Still Hope

National Geographic - Stephen Leahy

A major international report on biodiversity warns of serious threats to all living things, but many solutions are available.

The world has a staggering number of species. But many are going extinct. It's not too late to reverse the trend, scientists warn. Photograph by Frans Lanting, National Geographic Creative
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Medellin, Colombia - The Earth’s life support system is failing. Nearly everywhere, the various forms of non-human life are in decline, according to a series of landmark international reports released Thursday in Medellin, Colombia. This ongoing decline endangers economies, livelihoods, food security, and the quality of life of people everywhere. But at the same time, there is considerable room for hope, based on many solutions with proven track records, the reports say.
The tremendous variety of living species—collectively known as biodiversity—forms the bedrock of our food, clean water, air and energy. “Biodiversity is at the heart not only of our survival, but of our cultures, identities, and enjoyment of life,” said Robert Watson, chair of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).
IPBES is the intergovermental group working to safeguard the world’s biodiversity. For the past three years, more than 550 leading experts from more than 100 countries have reviewed more than 10,000 studies and completed four regional scientific assessments of biodiversity—covering the entire planet except the poles and open oceans. These assessments also looked at the causes of biodiversity declines and how government policies could help slow them down and even reverse them. The reports were approved in a final plenary meeting Thurday by the 129 countries that are members to IPBES.


Related: See How Marine Reserves Protect Biodiversity

“There is no question the continued loss of biodiversity undermines human well-being. Everyone will suffer, but especially the poor,” Watson said in an interview.
These losses are driven mainly by unsustainable consumption of resources, including deforestation and expansion of agriculture, along with pollution, climate change, and impacts of invasive alien species.
One of the studies in the assessment, published in the journal Science, found that 58 percent of Earth's land surface—where 71 percent of all humans live—has already lost enough biodiversity "to question the ability of ecosystems to support human societies.”
But the IPBES assessment also documents conservation success stories and identifies key strategies that can be applied elsewhere.

Global Threats
The Americas are home to 40 percent of global nature today, but they have experienced significant declines since Western colonization. If Christopher Columbus were to come to the Americas today, he would find 30 percent less biodiversity than in 1492. Today, another 23 to 24 percent of the region’s species are currently at risk of extinction, said Jake Rice, co-chair of the Americas assessment. That threatens nature’s land-based contributions to the peoples of the Americas, which is estimated to be worth more than $24 trillion per year. That’s equivalent to the region’s GDP, said Rice.
Expansion of agriculture, deforestation, resource extraction, pollution, and increasing urbanization are driving these declines. The people of the Americas consume three times as much of nature’s services as the global average, the assessment found. Changing this unsustainable rate of consumption will require fundamental changes in how we live, Rice said.
“We keep making choices to borrow from the future to live well today,” said Rice. “We don’t need to make those choices.”

Can You Spot These Hidden Animals?

Eastern Screech Owl. Okefenokee Swamp, Georgia.

Photograph by Graham McGeorge, National Geographic Your Shot

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We need to eat a more balanced diet, with less meat and less food waste, to take pressure off biodiversity, said Watson. We also need to choose to be more efficient in our water use, particularly in agriculture, and reduce our use of toxic chemicals. We have to drastically cut fossil-fuel use by using more mass transit, electric vehicles, and increasing energy efficiency, because climate change impacts biodiversity, the report notes. Without cuts to fossil fuel consumption, climate change will have as big an impact on biodiversity declines as land use change by 2050.

Public Involvement
“As citizens, we need to vote and lobby for political leaders and policies that support these choices,” said Emma Archer of South Africa, co-chair of the African assessment.
Africa is the last place on Earth with a wide range of large mammals, but some 190,000 square miles (500,000 square kilometers) of land is badly degraded by overexploitation. More pressure is coming as the number of people on the continent is expected to double, from 1.25 billion to 2.5 billion, by 2050. Today’s threats include poaching, unplanned urbanization, and agricultural expansion. By 2100, climate change could lead to the loss of more than half of African bird and mammal species, the report concluded.
At the same time, some of Africa’s threatened species have recovered or at least stabilized, thanks to efforts involving local communities. “The question is how to expand this, and how to enable all of us to live with nature,” said Archer.
It is clear that indigenous and local knowledge can be an invaluable asset in helping us learn to live with nature, said Watson. He added that biodiversity issues also need to receive much higher priority in policy making and development planning at every level. Cross-border collaboration is also essential, given that biodiversity challenges recognize no national boundaries.
“We know what we need to do,” he said. “There is no reason to not act now.”

Links

• Climate Change and Water Woes Drove ISIS Recruiting in Iraq
• How Color-Changing Animals Are Rebelling Against Climate Change
• Climate Change Is Suffocating Large Parts of the Ocean
• Human Emissions Made Ocean Heat Wave 53 Times More Likely
• Century-Long Glacier Study May Help Us Crack Climate Change
• What the World Would Look Like if All the Ice Melted

Burning Coal May Have Caused Earth’s Worst Mass Extinction

The Guardian - Dana Nuccitelli

New geological research from Utah suggests the end-Permian extinction was mainly caused by burning coal, ignited by magma

Fossil of a Galesaurus, a cynodont that lived during the Permian period. Photograph: Iziko Museum of Natural History

Earth has so far gone through five mass extinction events – scientists are worried we’re on course to trigger a sixth – and the deadliest one happened 252 million years ago at the end of the Permian geologic period. In this event, coined “the Great Dying,” over 90% of marine species and 70% of terrestrial vertebrate species went extinct. It took about 10 million years for life on Earth to recover from this catastrophic event.
Scientists have proposed a number of possible culprits responsible for this mass extinction, including an asteroid impact, mercury poisoning, a collapse of the ozone layer, and acid rain. Heavy volcanic activity in Siberia was suspected to play a key role in the end-Permian event.
Recently, geologist Dr Benjamin Burger identified a rock layer in Utah that he believed might have formed during the Permian and subsequent Triassic period that could shed light on the cause of the Great Dying.

Sheep Creek Valley, Utah. Photograph: Benjamin Burger

During the Permian, Earth’s continents were still combined as one Pangea, and modern day Utah was on the supercontinent’s west coast. Samples from the end-Permian have been collected from rock layers in Asia, near the volcanic eruptions, but Utah was on the other side of Pangaea. Burger’s samples could thus provide a unique perspective of what was happening on the other side of the world from the eruptions. Burger collected and analyzed samples from the rock layer, and documented the whole process in a fascinating video:


Dr Burger’s ‘Rocks of Utah’ episode documenting his investigation of the Permian-Triassic Boundary geologic samples. 

Earth turned into a toxic hellscape

Burger’s samples painted a grim picture of Earth’s environment at the end of the Permian period. A sharp drop in calcium carbonate levels indicated that the oceans had become acidic. A similar decline in organic content matched up with the immense loss of life in the oceans during this period. The presence of pyrite pointed to an anoxic ocean (without oxygen), meaning the oceans were effectively one massive dead zone.

Bacteria ate the oversupply of dead bodies, producing hydrogen sulfide gas, creating a toxic atmosphere. The hydrogen sulfide oxidized in the atmosphere to form sulfur dioxide, creating acid rain, which killed much of the plant life on Earth. Elevated barium levels in the samples had likely been carried up from the ocean depths by a massive release of methane.

The culprit: burning coal
Levels of various metals in the rock samples were critical in identifying the culprit of this mass extinction event. As in end-Permian samples collected from other locations around the world, Burger didn’t find the kinds of rare metals that are associated with asteroid impacts. There simply isn’t evidence that an asteroid struck at the right time to cause the Great Dying.
However, Burger did find high levels of mercury and lead in his samples, coinciding with the end of the Permian period. Mercury has also been identified in end-Permian samples from other sites. Lead and mercury aren’t associated with volcanic ash, but they are a byproduct of burning coal. Burger also identified a shift from heavier carbon-13 to lighter carbon-12; the latter results from burning fossil fuels.
The Permian was the end of the Carboniferous period, which means “coal-bearing.” Many large coal deposits were created in the Carboniferous, including in Asia. Previous research has shown that the Permian mass extinction event didn’t coincide with the start of the Siberian volcanic eruptions and lava flows, but rather 300,000 years later. That’s when the lava began to inject as sheets of magma underground, where Burger’s data suggests it ignited coal deposits.
The coal ignition triggered the series of events that led to Earth’s worst mass extinction. Its sulfur emissions created the acid rain that killed forests. Its carbon emissions acidified the oceans and warmed the planet, killing most marine life. The dead bodies fed bacteria that produced toxic hydrogen sulfide gas, which in turn killed off more species. The warming of the oceans produced a large methane release, which accelerated global warming faster yet. As Burger put it,

Things went from bad to worse, and you can now begin to understand how life nearly died out. Global warming, acid oceans, anoxia, not to mention a toxic atmosphere. We are lucky to be alive at all!

Eerie similarities to today

Scientists are observing many of the same signs of dangerously rapid climate change today. There’s more lighter carbon-12 in the atmosphere because the increase in atmospheric carbon levels is due entirely to humans burning fossil fuels. There are an increasing number of dead zones in the oceans. Burning coal was causing acid rain, although we largely solved that problem through Clean Air Acts, and in the US, a sulfur dioxide cap and trade system implemented by a Republican administration.

We’ve had less success in tackling carbon dioxide pollution, which continues to rise. As a result, the oceans are becoming increasingly acidic, and temperatures increasingly hot. Scientists today also worry about potentially large releases of methane from the ocean floor and Arctic.
These are some of the similarities between the climate change that nearly wiped out life on Earth 252 million years ago and the climate change today. Both appear to have largely been caused by burning coal. A 2011 study found that over the past 500 years, species are now going extinct at least as fast as they did during the five previous mass extinction events.
It’s enough to make you think; maybe coal isn’t so beautiful and clean after all.

Links

• The Terrifying Phenomenon That Is Pushing Species Towards Extinction
• 'A National Disgrace': Australia's Extinction Crisis Is Unfolding In Plain Sight
• This Is How Your World Could End
• Climate Change Could Wipe Out A Third Of Parasite Species, Study Finds
• When Life on Earth Was Nearly Extinguished
• ‘The Models Are Too Conservative’: Paleontologist Peter Ward on What Past Mass Extinctions Can Teach Us About Climate Change Today
• Burning Fossil Fuels Almost Ended All Life On Earth

Threatened Blue Carbon Ecosystems Store Carbon 40 Times Faster Than Forests

ABC Science - Joanna Khan

Mangroves accumulate carbon in their soils and can store it for thousands of years. (Pixabay)

Capturing carbon Coastal plants capture CO2 through photosynthesis and land-based carbon sources Carbon can be stored in the soil of blue carbon habitats for thousands of years When these habitats are damaged or destroyed the carbon can be released as CO2 back into the atmosphere

They can stink like fish and rotten eggs, breed swarms of mosquitos and lack the glamour of coral reefs. But mangroves, with other coastal habitats, are vitally important to our climate — and they're under threat.
In just the past decade, scientists have discovered that some of our underappreciated coastal habitats — called "blue carbon ecosystems" — play a huge role in tackling CO2 emissions.
But human activities such as burning fossil fuels and coastal development have already caused half of them to disappear.

"They're like the armpits of our coastline, but they are really important," said Deakin University marine ecologist Peter Macreadie.

What is blue carbon?

Blue carbon coastal ecosystems — such as mangroves, seagrass meadows and tidal wetlands — are named for their place at the boundary between land and sea, and their unmatched ability to suck CO2 out of the atmosphere and store it in the ground below.

This process is called carbon sequestration.
It was intense carbon sequestration by ancient forests and algae millions of years ago that helped create the very deposits of coal and oil we tap into for fossil fuels today.
Nearby on the ecology colour palette are the better-known green carbon systems of trees and forests. While important, they aren't nearly as efficient at storing carbon as their blue counterparts.
"We know that forests are pretty good at [carbon sequestration], but their carbon stores are bound to the lifetime of the trees, for only 100 or so years, and then it is released back into the atmosphere," Dr Macreadie said.
As well as being a temporary carbon store, trees can only soak up so much carbon before they become "saturated".

The oxygen-poor soil of seagrass meadows prevents microbes from decomposing the stored carbon and producing CO2. (Supplied: Michael Rule)

Blue carbon ecosystems, on the other hand, can store more carbon for longer — thousands of years — and at a far quicker rate.

"These blue carbon ecosystems store carbon around 40 times faster than green carbon ecosystems," Dr Macreadie said.

"So you need a lot more green carbon habitat to do the same amount of carbon offsetting."

Conservation gets weird
Some ecologists are worried that these ecosystems don't receive the attention they deserve and are now being lost faster than we can conserve them.
Dr Macreadie estimated that about half of the world's blue carbon ecosystems have already disappeared, thanks to human activities.
Seagrass meadows have shrunk at a rate of 1 per cent every year since the start of the 20th century.
In 2016 there was extensive die-back of mangroves in the Gulf of Carpentaria, but it coincided with the mass coral bleaching on the Great Barrier Reef, which received more attention.
To spur people into action to protect these "ugly duckling" habitats, Dr Macreadie and his team are getting creative with tea bags.
Around the world, citizen scientists have been burying tea bags in the soil of blue carbon ecosystems to find out how well the area stores carbon.

Blue carbon researchers have had to come up with unexpected ways to entice citizen scientists to their cause. (Deakin University: Donna Squire)

The tea leaves inside your everyday tea bag are carbon-based, which makes them a handy addition to the team's experimental toolkit.
If, after a few months of being buried in mud, the tea leaves are still there, then that might be a good spot for locking away carbon.
But if you dig the tea bags back up and the tea leaves have gone, it means the carbon has decomposed — indicating that area's not capable of carbon storage.
The project is uncovering how carbon storage ability varies even within blue carbon ecosystems.

Ticking carbon bombs: sinks become sources
Coastal development is the major danger to blue carbon habitats, and is now raising the issue that stored carbon will be emitted as CO2 back into the atmosphere.
"The really big threat is that the damaged ecosystems will release their ancient carbon stores," Dr Macreadie said.

"That's where you get the really big numbers."

An international team this week reported that a marine heatwave off Western Australia in 2010-11 that damaged seagrass meadows may have released of millions of tonnes of ancient carbon stores back into the atmosphere as CO2.
Oscar Serrano, a marine ecologist at Edith Cowan University involved in the research, said that the Shark Bay seagrass meadows accumulated around 144 million tonnes of carbon over the past 4,000 years.

Wading knee-deep in mud may not be glamorous, but scientists have now discovered how important habitats like mangroves are for mitigating climate change. (Deakin University: Simon Fox)

"We estimated that around 1,000 square kilometres of seagrass was lost due to the heatwave, which could have released between 2 and 9 million tonnes of CO2," Dr Serrano said.
It's a climate change double-whammy; losing carbon sequestration habitat while adding to our CO2 emissions at the same time.
However, scientists acknowledge that measuring CO2 emissions from blue carbon habitat loss is very challenging.
"We have to base our estimates on a number of assumptions, and the main uncertainty is the fate of the carbon stored in the system," Dr Serrano said.
"It's very hard to study mainly because of the time it takes for stored carbon to be converted back to CO2, and because it's such a complex system."
Dr Macreadie has been studying blue carbon ecosystems since the term was first coined around 9 years ago.
The field has grown exponentially since, but there's plenty more to discover about our coastal armpits, the benefits they provide and how to make sure they keep squirrelling away CO2.
"If we're going to keep burning fossil fuels, we need to find ways to pay for our carbon sins," he said.
"We need people to recognise the importance of these ecosystems and the weird things they do for us, and how they can form a sort of green infrastructure along our coasts."

Links

• Mangroves Protect Coastlines, Store Carbon – And Are Expanding With Climate Change
• 'They Died Of Thirst': Extreme Conditions Wipe Out Forest Over 1000 Kilometres
• 'Shocking images' reveal death of 10,000 hectares of mangroves across Northern Australia
• Can we manage coastal ecosystems to sequester more blue carbon?
• Shark Bay seagrass loss during ocean heatwave released up to 9m tonnes of CO2, scientists say