Anatomy of a heatwave: how Antarctica recorded a 20.75°C day last month

Dana M Bergstrom, University of Wollongong; Andrew Klekociuk, University of Tasmania; Diana King, University of Wollongong, and Sharon Robinson, University of Wollongong

While the world rightfully focuses on the COVID-19 pandemic, the planet is still warming. This summer’s Antarctic weather, as elsewhere in the world, was unprecedented in the observed record.

Our research, published today in Global Change Biology, describes the recent heatwave in Antarctica. Beginning in late spring east of the Antarctic Peninsula, it circumnavigated the continent over the next four months. Some of our team spent the summer in Antarctica observing these temperatures and the effect on natural systems, witnessing the heatwave first-hand.

Antarctica may be isolated from other continents by the Southern Ocean, but has worldwide impacts. It drives the global ocean conveyor belt, a constant system of deep-ocean circulation which transfers oceanic heat around the planet, and its melting ice sheet adds to global sea level rise.

Antarctica represents the simple, extreme end of conditions for life. It can be seen as a ‘canary in the mine’, demonstrating patterns of change we can expect to see elsewhere.

A heatwave in the coldest place on Earth

Most of Antarctica is ice-covered, but there are small ice-free oases, predominantly on the coast. Collectively 0.44% of the continent, these unique areas are important biodiversity hotspots for penguins and other seabirds, mosses, lichens, lakes, ponds and associated invertebrates.

This summer, Casey Research Station, in the Windmill Islands oasis, experienced its first recorded heat wave. For three days, minimum temperatures exceeded zero and daily maximums were all above 7.5°C. On January 24, its highest maximum of 9.2°C was recorded, almost 7°C above Casey’s 30-year mean for the month.

The arrival of warm, moist air during this weather event brought rain to Davis Research Station in the normally frigid, ice-free desert of the Vestfold Hills. The warm conditions triggered extensive meltwater pools and surface streams on local glaciers. These, together with melting snowbanks, contributed to high-flowing rivers and flooding lakes.

By February, most heat was concentrated in the Antarctic Peninsula at the northernmost part of the continent. A new Antarctic maximum temperature of 18.4°C was recorded on February 6 at Argentina’s Esperanza research station on the Peninsula – almost 1°C above the previous record. Three days later this was eclipsed when 20.75°C was reported at Brazil’s Marambio station, on Seymour Island east of the Peninsula.

What caused the heatwave?

The pace of warming from global climate change has been generally slower in East Antarctica compared with West Antarctica and the Antarctic Peninsula. This is in part due to the ozone hole, which has occurred in spring over Antarctica since the late 1970s.

The hole has tended to strengthen jet stream winds over the Southern Ocean promoting a generally more ‘positive’ state of the Southern Annular Mode in summer. This means the Southern Ocean’s westerly wind belt has tended to stay close to Antarctica at that time of year creating a seasonal ‘shield’, reducing the transfer of warm air from the Earth’s temperate regions to Antarctica.

But during the spring of 2019 a strong warming of the stratosphere over Antarctica significantly reduced the size of the ozone hole. This helped to support a more ‘negative’ state of the Southern Annular Mode and weakened the shield.

Other factors in late 2019 may have also helped to warm Antarctica. The Indian Ocean Dipole was in a strong ‘positive’ state due to a late retreat of the Indian monsoon. This meant that water in the western Indian Ocean was warmer than normal. Air rising from this and other warm ocean patches in the Pacific Ocean provided energy sources that altered the path of weather systems and helped to disturb and warm the stratosphere.

Is a warming Antarctica good or bad?

Localised flooding appeared to benefit some Vestfold Hills’ moss banks which were previously very drought-stressed. Prior to the flood event, most mosses were grey and moribund, but one month later many moss shoots were green.

Given the generally cold conditions of Antarctica, the warmth may have benefited the flora (mosses, lichens and two vascular plants), and microbes and invertebrates, but only where liquid water formed. Areas in the Vestfold Hills away from the flooding became more drought-stressed over the summer.

High temperatures may have caused heat stress in some organisms. Antarctic mosses and lichens are often dark in colour, allowing sunlight to be absorbed to create warm microclimates. This is a great strategy when temperatures are just above freezing, but heat stress can occur once 10°C is exceeded.

On King George Island, near the Antarctic Peninsula, our measurements showed that in January 2019 moss surface temperatures only exceeded 14°C for 3% of the time, but in 2020 this increased fourfold (to 12% of the time).

Based on our experience from previous anomalous hot Antarctic summers, we can expect many biological impacts, positive and negative, in coming years. The most recent event highlights the connectedness of our climate systems: from the surface to the stratosphere, and from the monsoon tropics to the southernmost continent.

Under climate change, extreme events are predicted to increase in frequency and severity, and Antarctica is not immune.

Dana M Bergstrom, Principal Research Scientist, University of Wollongong; Andrew Klekociuk, Adjunct Senior Lecturer, University of Tasmania; Diana King, Research officer, University of Wollongong, and Sharon Robinson, Professor, University of Wollongong

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The world’s best fire management system is in northern Australia, and it’s led by Indigenous land managers

Rohan Fisher, Charles Darwin University and Jon Altman, Australian National University

The tropical savannas of northern Australia are among the most fire-prone regions in the world. On average, they account for 70% of the area affected by fire each year in Australia.

But effective fire management over the past 20 years has reduced the annual average area burned – an area larger than Tasmania. The extent of this achievement is staggering, almost incomprehensible in a southern Australia context after the summer’s devastating bushfires.

The success in northern Australia is the result of sustained and arduous on-ground work by a range of landowners and managers. Of greatest significance is the fire management from Indigenous community-based ranger groups, which has led to one of the most significant greenhouse gas emissions reduction practices in Australia.

As Willie Rioli, a Tiwi Islander and Indigenous Carbon Industry Network steering committee member recently said:

Fire is a tool and it’s something people should see as part of the Australian landscape. By using fire at the right time of year, in the right places with the right people, we have a good chance to help country and climate.

Importantly, people need to listen to science – the success of our industry has been from a collaboration between our traditional knowledge and modern science and this cooperation has made our work the most innovative and successful in the world.

A tinder-dry season

The 2019 fire season was especially challenging in the north (as it was in the south), following years of low rainfall across the Kimberly and Top-End. Northern Australia endured tinder-dry conditions, severe fire weather in the late dry season, and a very late onset of wet-season relief.

Despite these severe conditions, extensive fuel management and fire suppression activities over several years meant northern Australia didn’t see the scale of destruction experienced in the south.

A comparison of two years with severe fire weather conditions. Extensive early dry season mitigation burns in 2019 reduced the the total fire-affected areas.

This is a huge success for biodiversity conservation under worsening, longer-term fire conditions induced by climate change. Indigenous land managers are even extending their knowledge of savanna burning to southern Africa.

Burn early in the dry season

The broad principles of northern Australia fire management are to burn early in the dry season when fires can be readily managed; and suppress, where possible, the ignition of uncontrolled fires – often from non-human sources such as lightning – in the late dry season.

Traditional Indigenous fire management involves deploying “cool” (low intensity) and patchy burning early in the dry season to reduce grass fuel. This creates firebreaks in the landscape that help stop larger and far more severe fires late in the dry season.

Relatively safe ‘cool’ burns can create firebreaks.
Author provided

Essentially, burning early in the dry season accords with tradition, while suppressing fires that ignite late in the dry season is a post-colonial practice.

Savannah burning is different to burn-offs in South East Australia, partly because grass fuel reduction burns are more effective – it’s rare to have high-intensity fires spreading from tree to tree. What’s more, these areas are sparsely populated, with less infrastructure, so there are fewer risks.

Satellite monitoring over the last 15 years shows the scale of change. We can compare the average area burnt across the tropical savannas over seven years from 2000 (2000–2006) with the last seven years (2013–2019). Since 2013, active fire management has been much more extensive.

The comparison reveals a reduction of late dry season wildfires over an area of 115,000 square kilometres and of all fires by 88,000 square kilometres.

How fire has changed in northern Australia.
Author provided

Combining traditional knowledge with western science

The primary goals of Indigenous savanna burning projects remain to support cultural reproduction, on-country living and “healthy country” outcomes.

Savanna burning is highly symbiotic with biodiversity conservation and landscape management, which is the core business of rangers.

Ensuring these gains are sustainable requires a significant amount of difficult on-ground work in remote and challenging circumstances. It involves not only Indigenous rangers, but also pastoralists, park rangers and private conservation groups. These emerging networks have helped build new savanna burning knowledge and innovative technologies.

While customary knowledge underpins much of this work, the vast spatial extent of today’s savanna burning requires helicopters, remote sensing and satellite mapping. In other words, traditional burning is reconfigured to combine with western scientific knowledge and new tools.

For Indigenous rangers, burning from helicopters using incendiaries is augmented by ground-based operations, including on-foot burns that support more nuanced cultural engagement with country.

On-ground burns are particularly important for protecting sacred sites, built infrastructure and areas of high conservation value such as groves of monsoonal forest.

Who pays for it?

A more active savanna burning regime over the last seven years has led to a reduction in greenhouse gas emissions of more than seven million tonnes of carbon dioxide equivalent.

This is around 10% of the total emission reductions accredited by the Australian government through carbon credits units under Carbon Farming Initiative Act. Under the act, one Australian carbon credit unit is earned for each tonne of carbon dioxide equivalent that a project stores or avoids.

By selling these carbon credits units either to the government or on a private commercial market, land managers have created a A$20 million a year savanna burning industry.

How Indigenous Australians and others across Australia’s north are reducing emissions.

What can the rest of Australia learn?

Savanna fire management is not directly translatable to southern Australia, where the climate is more temperate, the vegetation is different and the landscape is more densely populated. Still, there are lessons to be learnt.

A big reason for the success of fire management in the north savannas is because of the collaboration with scientists and Indigenous land managers, built on respect for the sophistication of traditional knowledge.

This is augmented by broad networks of fire managers across the complex cross-cultural landscape of northern Australia. Climate change will increasingly impact fire management across Australia, but at least in the north there is a growing capacity to face the challenge.

Rohan Fisher, Information Technology for Development Researcher, Charles Darwin University and Jon Altman, Emeritus professor, School of Regulation and Global Governance, ANU, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

What ‘Walden’ can tell us about social distancing and focusing on life’s essentials

Walden Pond in Concord, Massachusetts.
ptwo/Wikipedia, CC BY

Robert M. Thorson, University of Connecticut

Seeking to bend the coronavirus curve, governors and mayors have told millions of Americans to stay home. If you’re pondering what to read, it’s easy to find lists featuring books about disease outbreaks, solitude and living a simpler life. But it’s much harder to find a book that combines these themes.

As the author of three books about essayist, poet and philosopher Henry David Thoreau, I highly recommend “Walden,” Thoreau’s 1854 account of his time living “alone” in the woods outside Concord, Massachusetts. I qualify “alone” because Thoreau had more company at Walden than in town, and hoed a bean field daily as social theater in full view of passersby on the road.

Published in over 1,000 editions and translated into scores of languages, “Walden” is the scriptural fountainhead of the modern environmental movement, a philosophical treatise on self-reliance and a salient volume of the American literary canon. In his introduction to the Princeton edition, John Updike claims that Thoreau’s masterpiece “contributed most to America’s present sense of itself” during the cultural renaissance of the mid-19th century, yet “risks being as revered and unread as the Bible.”

Another reason to read or reread “Walden” during trying times is that it gushes with sorely needed optimism and is laced with wit. And Thoreau befriends you by writing in the first person.

Reality lies within us

Henry David Thoreau, 1856.
National Portrait Gallery/Wikipedia

As governments mandate social distancing to protect public health, many readers may be coming to grips with solitude. Thoreau devotes a chapter to it, extolling the virtue of getting to know yourself really well.

“Why should I feel lonely?” he asks, “is not our planet in the Milky Way?” Elsewhere he clarifies the difference between what we need and what we think we need, writing, “My greatest skill has been to want but little.”

“Walden” doesn’t have to be read straight through like a novel. For readers who have previously given up on it, I suggest rebooting in the middle with “The Ponds,” which opens thus: “Sometimes, having had a surfeit of human society and gossip, and worn out all my village friends, I rambled still farther westward than I habitually dwell…” Thoreau then retreats away from the mindless distractions of community life toward an immersion into Nature, with water at its spiritual center.

Next, flip back to the earlier chapter “Where I Lived and What I Lived For.” Here Thoreau invites readers on a downward journey, from the fleeting shallows of their social lives to the solid depths of their individual lives:

“Let us settle ourselves, and work and wedge our feet downward through the mud and slush of opinion, and prejudice, and tradition, and delusion, and appearance, that alluvion which covers the globe, through Paris and London, through New York and Boston and Concord, through Church and State, through poetry and philosophy and religion, till we come to a hard bottom and rocks in place, which we can call reality…”

Our brains build that reality – yours, mine, everyone’s – by integrating external sensory signals with internal memories. Thoreau’s point – which is supported by 21st-century cognitive and neuroscience research – is that the real you precedes the social you. Your world is built from the inside of your skull outward, not vice versa.

‘Walden’ is a book about breaking away and focusing on the essential facts of life.

The elusive simple life

Thoreau’s retreat to Walden Pond is often mistaken for a hermit’s flight deep into the woods. Actually, Thoreau put some distance between himself and his home and village so that he could understand himself and society better. When not in town, he swapped human companionship for the “beneficent society” of Nature for long enough to make “the fancied advantages of human neighborhood insignificant.”

Today mandatory social distancing is wrecking the global economy, based on traditional metrics like gross domestic product and stock prices. Viewed through “Walden,” this wreckage may look like a long-overdue correction for an unsustainable system.

Thoreau feared that the economy he saw was headed in the wrong direction. His opening chapter, “Economy,” is an extended rant against what he viewed as a capitalistic, urbanizing, consumption-driven, fashion-conscious 19th-century New England.

Of his neighbors, Thoreau wrote, “By a seeming fate, commonly called necessity, they are employed, as it says in an old book” – meaning the Christian Bible – “laying up treasures which moth and rust will corrupt and thieves break through and steal. It is a fool’s life, as they will find when they get to the end of it, if not before.”

In contrast, his recipe for a good economy is one of “Walden”‘s most famous quotes: “Simplicity, simplicity, simplicity! I say, let your affairs be as two or three, and not a hundred or a thousand.”

Thoreau’s family operated a flourishing pencil manufacturing business in the 1840s.
University of Florida, CC BY

That was easier said than done, even for Thoreau. When he conceived “Walden,” he was an unemployed, landless idealist. By the time it was published, he lived in a big house that was heated with Appalachian coal, earning income by manufacturing pulverized graphite and surveying for land developers.

Since then, the world’s population has more than quintupled and developed nations have built a global economy approaching US$100 trillion per year. Human impacts on the planet have become so powerful that scientists have coined the term Anthropocene to describe our current epoch.

Finding perspective in solitude

Some Americans have tried at least halfheartedly to follow “Walden”’s idealistic advice by living deliberately, being more self-reliant and shrinking their planetary footprints. Personally, although I’ve downsized my house, walk to work, fly only for funerals and cook virtually every meal from scratch, in my heart I know I’ve also contributed to the world’s swelling population, burn fracked natural gas and am hopelessly embedded in a consumer economy.

Nevertheless, after several weeks of social distancing, I’m rediscovering the value of two of Thoreau’s key points: Solitude is helping me recalibrate what matters most, and the current economic slowdown offers short-term gains and a long-term message for the planet.

These benefits don’t compensate for the incalculable personal losses and grief that COVID-19 is inflicting worldwide. But they are consolation prizes until things stabilize in the new normal. On my daily solitary walk in the woods, I am mindful of Thoreau’s words: “Next to us is not the workman whom we have hired, with whom we love so well to talk, but the workman whose work we are.”

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Robert M. Thorson, Professor of Geology, University of Connecticut

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Coronavirus has finally made us recognise the illegal wildlife trade is a public health issue

Simon Evans, Anglia Ruskin University

There will be few positives to take from coronavirus. But the global pandemic may yet prove to be an important moment in the attempts to address the illegal wildlife trade.

The media has generally concentrated on effects rather than causes, in particular the global implications for public health and economies. But it is also vital to unravel the timeline of the pandemic and categorically determine its initial cause.

What we do know to date is that the epicentre of the disease was in the Chinese city of Wuhan, an important hub in the lucrative trade in wildlife – both legal and illegal. The outbreak is believed to have originated in a market in which a variety of animal-derived products and meats are widely available, including peacocks, porcupines, bats and rats. It’s also a market where regulatory and welfare standards are rudimentary at best.

Some of this trade is legal under Chinese domestic law but the existence of a parallel illegal trade – often within the very same market or stall – allows some traders to launder illicit wildlife products into the system. This situation is very difficult to regulate and control.

We are also reasonably certain that the spill-over event involved the crossover of the virus from animals to humans, similar to the situation with previous contagions like the Ebola and SARs viruses. In each of these cases, the existence of large, unsanitary and poorly-regulated wildlife markets provided an ideal environment for diseases to cross over between species. In a country like China, where wildlife consumption is
so deeply embedded in culture, such contamination can, and did, spread
rapidly.

The Chinese government has long advocated a “sustainable utilisation” approach to the country’s wildlife. It nonetheless responded to the current crisis by enacting a temporary ban on such markets, effectively closing down a significant sector of its domestic wildlife trade.

Biosecurity, public health and economic impact

In the longer term, the pandemic may provide the impetus to properly address the issue. This is because, while the illegal wildlife trade was once criticised almost purely in terms of conservation, it is now also being considered in relation to broader themes of biosecurity, public health and economic impact.

It is only in the wake of the COVID-19 outbreak that the full scale of China’s industry is emerging, with the temporary ban covering some 20,000 captive breeding enterprises and 54 different species allowed to be traded domestically. A report by the Chinese Academy of Engineering estimates the wildlife farming industry is worth around US$57 billion annually. These breeding centres are allowed to operate under loopholes in Chinese domestic law, arguably against the spirit of the Convention on International Trade in Endangered Species of Wild Fauna and Flora.

The parallel illegal trade is less easy to quantify, but globally it is valued by the UN at around US$23 billion. Given the resulting pandemic could cost as much as US$2.7 trillion, even on purely economic grounds there is a strong case for increased regulation.

There are compelling arguments for dismantling the trade anyway: animals are kept in abject conditions, and the trade hastens their demise in the wild. But in China the temporary ban remains just that – temporary. Critics argue that we have been there before with SARS and once the dust settled on that particular outbreak, China resumed business as usual.

What would seriously tackling the wildlife trade actually mean in practice? First, breeding centres for endangered species like tigers or pangolins would be permanently closed. This would make it much harder for their products to be laundered through legal channels and sold as more valuable “wild-caught”. Enforcement agencies currently need to monitor these centres closely to check against laundering, and shutting them down would free up resources to disrupt the supply of illegal products entering China from outside.

Such a move would also help reduce demand. Public education campaigns tell people about how the wildlife trade (both legal and illegal) harms endangered species, but the message is mixed: the presence of a parallel legal market still provides such products with legitimacy and sends a message that it is OK to purchase them, thereby increasing rather than decreasing demand.

In any case the new Chinese ban excludes products such as tiger bones that are used in traditional medicines. Some conservationists and activists are concerned that this exemption will lead to legalised trade under the assumption that better regulation will protect against future outbreaks. This argument is extremely difficult to validate and most conservationists continue to favour blanket trade bans.

Another worry is that, given humans have short memories, once the danger has passed public concern will turn to the next big problem. COVID-19 clearly represents an unparalleled opportunity to combat the wildlife trade, and ensure that animal-borne diseases do not mutate and cross over to humans. But only time will tell whether this opportunity will be taken or put off once again until the emergence of the next – perhaps even more virulent – pandemic poses an even graver global threat.

Simon Evans, Principal Lecturer in Ecotourism, Anglia Ruskin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

It’s wrong to blame bats for the coronavirus epidemic

A small colony of Townsend’s big eared bats at Lava Beds National Monument, Calif.
Shawn Thomas, NPS/Flickr

Peter Alagona, University of California, Santa Barbara

Genomic research showing that the COVID-19 coronavirus likely originated in bats has produced heavy media coverage and widespread concern. There is now danger that frightened people and misguided officials will try to curb the epidemic by culling these remarkable creatures, even though this strategy has failed in the past.

As an environmental historian focusing on endangered species and biological diversity, I know that bats provide valuable services to humans and need protection. Instead of blaming bats for the coronavirus epidemic, I believe it’s important to know more about them. Here’s some background explaining why they carry so many viruses, and why these viruses only jump infrequently to humans – typically, when people hunt bats or intrude into places where bats live.

The challenges of life as a bat

It’s not easy being the world’s only flying mammal. Flying requires a lot of energy, so bats need to consume nutritious foods, such as fruits and insects.

As they forage, bats pollinate around 500 plant species, including mangoes, bananas, guavas and agaves (the source of tequila). Insect-eating bats may consume the equivalent of their body weight in bugs each night – including mosquitoes that carry diseases like Zika, dengue and malaria.

Grey-headed flying fox feeding on flower nectar, Queensland, Australia. Its face is covered with yellow pollen, which it will spread to other flowers.
Andrew Mercer/Wikipedia, CC BY

Bats convert these foods into droppings called guano, which nourish entire ecosystems, have been harvested for centuries as fertilizer, and have been used to make soaps and antibiotics.

Since fruits and insects tend to follow seasonal boom-and-bust cycles, most bats hibernate for long periods, during which their core body temperatures may fall as low as 43 degrees Fahrenheit (6 degrees Celsius). To conserve warmth, they gather in insulated places like caves, use their wings as blankets and huddle together in colonies.

When fruits ripen and insects hatch, bats wake up and flutter out of their roosts to forage. But now they have a different problem: Flying requires so much energy that their metabolic rates may spike as high as 34 times their resting levels, and their core body temperatures can exceed 104 degrees F.

To stay cool, bats have wings filled with blood vessels that radiate heat. They also lick their fur to simulate sweat and pant like dogs. And they rest during the heat of the day and forage in the cool of night, which makes their ability to navigate by echolocation, or reflected sound, handy.

The Congress Avenue Bridge in Austin, Texas, houses the largest urban bat colony in the world.

Diverse and unique

Humans are more closely related to bats than we are to dogs, cows or whales. But bats seem more alien, which can make it harder for people to relate to them.

Bats are the most unusual of the world’s 26 mammal orders, or large groups, such as rodents and carnivores. They are the only land mammals that navigate by echolocation, and the only mammals capable of true flight.

Many bats are small and have rapid metabolisms, but they reproduce slowly and live long lives. That’s more typical of large animals like sharks and elephants.

And a bat’s internal body temperatures can fluctuate by more than 60 degrees Fahrenheit in response to external conditions. This is more typical of cold-blooded animals that take on the temperature of their surroundings, like turtles and lizards.

Bats carry a range of viruses that can sicken other mammals when they jump species. These include at least 200 coronaviruses, some of which cause human respiratory diseases like SARS and MERS. Bats also host several filoviruses, including some that in humans manifest as deadly hemorrhagic fevers like Marburg and probably even Ebola.

Normally, these viruses remain hidden in bats’ bodies and ecosystems without harming humans. People raise the risk of transmission between species when they encroach on bats’ habitats or harvest bats for medicine or food. In particular, humans pack live bats into unsanitary conditions with other wild species that may serve as intermediate hosts. This is what happened at the Wuhan wet market where many experts believe COVID-19 emerged.

With a few exceptions, such as rabies, bats host their pathogens without getting sick. Recent media coverage attempting to explain this riddle has focused on a 2019 study suggesting that bats carry a gene mutation, which may enable them to remain healthy while harboring such viruses. But while the mutation may be of interest from a public health perspective, understanding where this novel coronavirus came from requires understanding what makes a bat a bat.

The blood vessels in bats’ wings (shown: fruit bats, Northern Territory, Australia) radiate some of the heat they generate while flying.
shellac/Flickr, CC BY

Why do bats carry so many diseases but seem unaffected by them? Genetic mutations that boost their immune systems may help. But a better answer is that bats are the only mammals that fly.

With thousands of bats crowded together licking, breathing and pooping on one another, bat caves are ideal environments for breeding and transmitting germs. But when bats fly, they generate so much internal heat that, according to many scientists, their bodies are able to fight off the germs they carry. This is known as the “flight as fever hypothesis.”

Bats at risk

Bats may not always be around to eat insect pests, pollinate fruit crops and provide fertilizer. According to the International Union for the Conservation of Nature and Bat Conservation International, at least 24 bat species are critically endangered, and 104 are vulnerable to extinction. For at least 224 additional bat species, scientists lack the data to know their status.

Overharvesting, persecution and habitat loss are the greatest threats that bats face, but they also suffer from their own novel diseases. Since it was first documented in upstate New York in 2007, the fungal pathogen Pseudogymnoascus destructans (Pd), which causes white-nose syndrome, has infected 13 North American bat species, including two listed as endangered.

Nobody knows where Pd came from, but the fact that several bat species seem never to have encountered it before suggests that people probably introduced or spread it. The fungus thrives in cool, damp places like caves. It grows on bats while they’re hibernating, causing such irritation that they become restless, wasting precious energy during seasons when little food is available. White-nose syndrome has killed millions of bats, including more than 90% of the bats in some populations.

Bats are extraordinary creatures that benefit people in myriad ways, and our world would be a poorer, duller and more dangerous place without them. They need protection from the cruel treatment and wasteful exploitation that also threatens human health.

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Peter Alagona, Associate Professor of History, Geography and Environmental Studies, University of California, Santa Barbara

This article is republished from The Conversation under a Creative Commons license. Read the original article.

I studied what happens to reef fish after coral bleaching. What I saw still makes me nauseous

Jodie L. Rummer, James Cook University

The Great Barrier Reef is suffering its third mass bleaching event in five years. It follows the record-breaking mass bleaching event in 2016 that killed a third of Great Barrier Reef corals, immediately followed by another in 2017.

While we don’t know if fish populations declined from the 2016 bleaching disaster, one 2018 study did show the types of fish species on some coral reefs changed. Our study dug deeper into fish DNA.

I was part of an international team of scientists that, for the first time, tracked wild populations of five species of coral reef fish before, during, and after the 2016 marine heatwave.

From a scientific perspective, the results are fascinating and world-first.

Marine heatwaves are now becoming more frequent and more severe with climate change. Corals are bleaching, as pictured here.
Jodie Rummer, Author provided

We used gene expression as a tool to survey how well fish can handle hotter waters. Gene expression is the process where a gene is read by cell machinery and creates a product such as a protein, resulting in a physical trait.

We know many tropical coral reef fish are already living at temperatures close to their upper limits. Our findings can help predict which of these species will be most at risk from repeated heatwaves.

But from a personal perspective, I still feel nauseous thinking about what the reef looked like during this project. I’ll probably feel this way for a long time.

Rewind to November 2015

We were prepared. Back then we didn’t know the reef was about to bleach and lead to widespread ecological devastation. But we did anticipate that 2016 would be an El Niño year. This is a natural climate cycle that would mean warm summer waters in early 2016 would stick around longer than usual.

But we can’t blame El Niño – the ocean has already warmed by 1°C above pre-industrial levels from continued greenhouse gas emissions. What’s more, marine heatwaves are becoming more frequent and severe with climate change.

Given this foresight, we took some quick liver biopsies from several coral reef fish species at our field site in December 2015, just in case.

Coral bleaching at Magnetic Island, March 2020.
Victor Huertas, Author provided

A couple months later, we were literally in hot water

In February 2016, my colleague and I were based on Lizard Island in the northern part of the Great Barrier Reef working on another project.

The low tides had shifted to the afternoon hours. We were collecting fish in the shallow lagoon off the research station, and our dive computers read that the water temperature was 33°C.

We looked at each other. These are the temperatures we use to simulate climate change in our laboratory studies for the year 2050 or 2100, but they’re happening now.

Over the following week, we watched corals turn fluorescent and then bone-white.

The water was murky with slime from the corals’ immune responses and because they were slowly exuding their symbiotic zooxanthellae – the algae that provides corals with food and the vibrant colours we know and love when we think about a coral reef. The reef was literally dying before our eyes.

A third of the corals on the Great Barrier Reef perished after the 2016 heatwave.
Jodie Rummer, Author provided

Traits for dealing with heatwaves

We sampled fish during four time periods around this devastating event: before, at the start, during, and after.

Some genes are always “switched on”, regardless of environmental conditions. Other genes switch on or off as needed, depending on the environment.

If we found these fish couldn’t regulate their gene expression in response to temperature stress, then the functions – such as metabolism, respiration, and immune function – also cannot change as needed. Over time, this could compromise survival.

The plasticity (a bit like flexibility) of these functions, or phenotypes, is what buffers an organism from environmental change. And right now, this may be the only hope for maintaining the health of coral reef ecosystems in the face of repeated heatwave events.

So, what were the fish doing?

We looked at expression patterns of thousands of genes. We found the same genes responded differently between species. In other words, some fish struggled more than others to cope with marine heatwaves.

*Ostorhinchus doederleini*, a species of cardinalfish, is bad at coping with marine heatwaves.
Göran Nilsson, Author provided

The species that coped the least was a nocturnal cardinalfish species (Cheilodipterus quinquelineatus). We found it had the lowest number of differentially expressed genes (genes that can switch on or off to handle different stressors), even when facing the substantial change in conditions from the hottest to the coolest months.

In contrast, the spiny damselfish (Acanthochromis polyacanthus) responded to the warmer conditions with changes in the expression of thousands of genes, suggesting it was making the most changes to cope with the heatwave conditions.

What can these data tell us?

Our findings not only have implications for specific fish species, but for the whole ecosystem. So policymakers and the fishing industry should screen more species to predict which will be sensitive and which will tolerate warming waters and heatwaves. This is not a “one size fits all” situation.

One of the species that showed the least amount of change under warming was *Cheilodipterus quinquelineatus*.
Moises Antonio Bernal de Leon, Author provided

Fish have been on the planet for more than 400 million years. Over time , they may adapt to rising temperatures or migrate to cooler waters.

But, the three recent mass bleaching events is unprecedented in human history, and fish won’t have time to adapt.

My drive to protect the oceans began when I was a child. Now it’s my career. Despite the progress my colleagues and I have made, my nauseous feelings remain, knowing our science alone may not be enough to save the reef.

The future of the planet, the oceans, and the Great Barrier Reef lies in our collective actions to reduce global warming. What we do today will determine what the Great Barrier Reef looks like tomorrow.

Jodie L. Rummer, Associate Professor & Principal Research Fellow, James Cook University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Here’s what the coronavirus pandemic can teach us about tackling climate change

Natasha Chassagne, University of Tasmania

Every aspect of our lives has been affected by the coronavirus. The global economy has slowed, people have retreated to their homes and thousands have died or become seriously ill.

At this frightening stage of the crisis, it’s difficult to focus on anything else. But as the International Agency has said, the effects of coronavirus are likely to be temporary but the other global emergency – climate change – is not.

Stopping the spread of coronavirus is paramount, but climate action must also continue. And we can draw many lessons and opportunities from the current health crisis when tackling planetary warming.

Action to reduce greenhouse gas emissions must not be compromised by the coronavirus pandemic.
EPA/MAST IRHAM

A ‘degrowing’ economy

S&P Global Ratings this week said measures to contain COVID-19 have pushed the global economy into recession.

Economic analyst Lauri Myllyvirta estimates the pandemic may have reduced global emissions by 200 megatonnes of carbon dioxide to date, as air travel grinds to a halt, factories close down and energy demand falls.

In the first four weeks of the pandemic, coal consumption in China alone fell by 36%, and oil refining capacity reduced by 34%.

In many ways, what we’re seeing now is a rapid and unplanned version of economic “degrowth” – the transition some academics and activists have for decades said is necessary to address climate change, and leave a habitable planet for future generations.

Degrowth is a proposed slowing of growth in sectors that damage the environment, such as fossil fuel industries, until the economy operates within Earth’s limits. It is a voluntary, planned and equitable transition in developed nations which necessarily involves an increased focus on the environment, human well-being, and capabilities (good health, decent work, education, and a safe and healthy environment).

Such a transformation would be profound, and so far no nation has shown the will to implement it. It would require global economies to “decouple” from carbon to prevent climate-related crises. But the current unintended economic slowdown opens the door to such a transition, which would bring myriad benefits to the climate.

The idea of sustainable degrowth is very different to a recession. It involves scaling back environmentally damaging sectors of the economy, and strengthening others.

Reduced air travel is helping drive global emissions down.
James Gourley/AAP

A tale of two emergencies

Climate change has been declared a global emergency, yet to date the world has largely failed to address it. In contrast, the global policy response to the coronavirus emergency has been fast and furious.

There are several reasons for this dramatic difference. Climate change is a relatively slow-moving crisis, whereas coronavirus visibly escalates over days, even hours, increasing our perception of the risks involved. One thing that history teaches us about politics and the human condition in times of peril, we often take a “crisis management” approach to dealing with serious threats.

As others have observed, the slow increase in global temperatures means humans can psychologically adjust as the situation worsens, making the problem seem less urgent and meaning people are less willing to accept drastic policy measures.

The human ability to adapt to climate change can make it seem less urgent.
CHAMILA KARUNARATHNE/EPA

Key lessons from coronavirus

The global response to the coronavirus crisis shows that governments can take immediate, radical emergency measures, which go beyond purely economic concerns, to protect the well-being of all.

Specifically, there are practical lessons and opportunities we can take away from the coronavirus emergency as we seek to tackle climate change:

Act early: The coronavirus pandemic shows the crucial importance of early action to prevent catastrophic consequences. Governments in Taiwan, South Korea and Singapore acted quickly to implement quarantine and screening measures, and have seen relatively small numbers of infections. Italy, on the other hand, whose government waited too long to act, is now the epicentre of the virus.

Go slow, go local: Coronavirus has forced an immediate scale-down of how we travel and live. People are forging local connections, shopping locally, working from home and limiting consumption to what they need.

Researchers have identified that fears about personal well-being represent a major barrier to political support for the degrowth movement to date. However with social distancing expected to be in place for months, our scaled-down lives may become the “new normal”. Many people may realise that consumption and personal well-being are not inextricably linked.

Stimulus spending should be directed to clean energy.
EPA

New economic thinking is needed. A transition to sustainable degrowth can help. We need to shift global attention from GDP as an indicator of well-being, towards other measures that put people and the environment first, such as New Zealand’s well-being budget, Bhutan’s gross national happiness index, or Ecuador’s social philosophy of buen vivir (good living).

Spend on clean energy: The International Energy Agency (IEA) says clean energy should be “at the heart of stimulus plans to counter the coronavirus crisis”.

The IEA has called on governments to launch sustainable stimulus packages focused on clean energy technologies. It says hydrogen and carbon-capture also need major investment to bring them to scale, which could be helped by the current low interest rates.

Governments could also use coronavirus stimulus packages to reskill workers to service the new “green” economy, and address challenges in healthcare, sanitation, aged care, food security and education.

More people are shopping locally during the pandemic.
AAP/STEFAN POSTLES

Looking ahead

As climate scientist Katharine Hayhoe said this month:

What really matters is the same for all of us. It’s the health and safety of our friends, our family, our loved ones, our communities, our cities and our country. That’s what the coronavirus threatens, and that’s exactly what climate change does, too.

The coronavirus crisis is devastating, but failing to tackle climate change because of the pandemic only compounds the tragedy. Instead, we must draw on the lessons of coronavirus to address the climate challenge.

Natasha Chassagne, University Associate, University of Tasmania, University of Tasmania

This article is republished from The Conversation under a Creative Commons license. Read the original article.

New ways of ‘being together apart’ can work for us and the planet long after coronavirus crisis passes

Random Thoughts

Andrew Glover, RMIT University and Tania Lewis, RMIT University

Most major corporate, academic and other networking events have been cancelled because of the risks of spreading the coronavirus while travelling or at the events themselves. This flurry of cancellations has even spawned a literally titled website: https://www.isitcanceledyet.com/. But the changes in behaviour now being forced upon us might benefit the planet in the long term as we find and get used to other ways of holding meetings.

The COVID-19 pandemic is driving the development of these alternatives to physical travel and meetings much more strongly than climate change had to date. With many countries closing their borders, limiting domestic travel and imposing restrictions on large gatherings, few conferences are likely to proceed in the coming months of 2020.

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We’ve just discovered two new shark species – but they may already be threatened by fishing

One of the newly discovered sixgilled sawshark species (*Pliotrema kajae*).
Simon Weigmann, Author provided

Per Berggren, Newcastle University and Andrew Temple, Newcastle University

Finding a species that’s entirely new to science is always exciting, and so we were delighted to be a part of the discovery of two new sixgill sawsharks (called Pliotrema kajae and Pliotrema annae) off the coast of East Africa.

We know very little about sawsharks. Until now, only one sixgill species (Pliotrema warreni) was recognised. But we know sawsharks are carnivores, living on a diet of fish, crustaceans and squid. They use their serrated snouts to kill their prey and, with quick side-to-side slashes, break them up into bite-sized chunks.

The serrated snout of a sixgill sawshark (*Pliotrema annae*).
Ellen Barrowclift-Mahon/Marine MEGAfauna Lab/Newcastle University., Author provided

Sawsharks look similar to sawfish (which are actually rays), but they are much smaller. Sawsharks grow to around 1.5 metres in length, compared to 7 metres for a sawfish and they also have barbels (fish “whiskers”), which sawfish lack. Sawsharks have gills on the side of their heads, whereas sawfish have them on the underside of their bodies.

A sixgill sawshark (*Pliotrema annae*) turned on its side, showing gills and barbels.
Ellen Barrowclift-Mahon, Author provided

Together with our colleagues, we discovered these two new sawsharks while researching small-scale fisheries that were operating off the coasts of Madagascar and Zanzibar. While the discovery of these extraordinary and interesting sharks is a wonder in itself, it also highlights how much is still unknown about biodiversity in coastal waters around the world, and how vulnerable it may be to poorly monitored and managed fisheries.

The three known species of sixgill sawshark. The two new species flank the original known species. From left to right: *Pliotrema kajae*, *Pliotrema warreni* (juvenile female) and *Pliotrema annae* (presumed adult female).
Simon Weigmann, Author provided

Fishing in the dark

Despite what their name might suggest, small-scale fisheries employ around 95% of the world’s fishers and are an incredibly important source of food and money, particularly in tropical developing countries. These fisheries usually operate close to the coast in some of the world’s most important biodiversity hotspots, such as coral reefs, mangrove forests and seagrass beds.

For most small-scale fisheries, there is very little information available about their fishing effort – that is, how many fishers there are, and where, when and how they fish, as well as exactly what they catch. Without this, it’s very difficult for governments to develop management programmes that can ensure sustainable fishing and protect the ecosystems and livelihoods of the fishers and the communities that depend on them.

Small-scale fishers of Zanzibar attending their driftnets.
Per Berggren/Marine MEGAfauna Lab/Newcastle University, Author provided

While the small-scale fisheries of East Africa and the nearby islands are not well documented, we do know that there are at least half a million small-scale fishers using upwards of 150,000 boats. That’s a lot of fishing. While each fisher and boat may not catch that many fish each day, with so many operating, it really starts to add up. Many use nets – either driftnets floating at the surface or gillnets, which are anchored close to the sea floor. Both are cheap but not very selective with what they catch. Some use longlines, which are effective at catching big fish, including sharks and rays.

In 2019, our team reported that catch records were massively underreporting the number of sharks and rays caught in East Africa and the nearby islands. With the discovery of two new species here – a global hotspot for shark and ray biodiversity – the need to properly assess the impact of small-scale fisheries on marine life is even more urgent.

*Pliotrema kajae*, as it might look swimming in the subtropical waters of the western Indian Ocean.
Simon Weigmann, Author provided

How many other unidentified sharks and other species are commonly caught in these fisheries? There is a real risk of species going extinct before they’re even discovered.

Efforts to monitor and manage fisheries in this region, and globally, must be expanded to prevent biodiversity loss and to develop sustainable fisheries. There are simple methods available that can work on small boats where monitoring is currently absent, including using cameras to document what’s caught.

A selection of landed fish – including sharks, tuna and swordfish.
Per Berggren, Author provided

The discovery of two new sixgill sawsharks also demonstrates the value of scientists working with local communities. Without the participation of fishers we may never have found these animals. From simple assessments all the way through to developing methods to alter catches and manage fisheries, it’s our goal to make fisheries sustainable and preserve the long-term future of species like these sawsharks, the ecosystems they live in and the communities that rely on them for generations to come.

Per Berggren, Marine MEGAfauna Lab, Newcastle University and Andrew Temple, Postdoctoral Research Associate in Marine Biology, Newcastle University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Why marine protected areas are often not where they should be

Piers Dunstan, CSIRO; Natalie Dowling, CSIRO; Simone Stevenson, Deakin University, and Skipton Woolley, CSIRO

There’s no denying the grandeur and allure of a nature reserve or marine protected area. The concept is easy to understand: limit human activity there and marine ecosystems will thrive.

But while the number of marine protected areas is increasing, so too is the number of threatened species, and the health of marine ecosystems is in decline.

Why? Our research shows it’s because marine protected areas are often placed where there’s already low human activity, rather than in places with high biodiversity that need it most.

Not where they should be

Many parts of the world’s protected areas, in both terrestrial and marine environments, are placed in locations with no form of manageable human activity or development occurring, such as fishing or infrastructure. These places are often remote, such as in the centres of oceans.

And where marine protected areas have been increasing, they’re placed where pressures cannot be managed, such as areas where there is increased ocean acidification or dispersed pollution.

Limestone islands in the Coral Triangle. The marine protected areas.
Shutterstock

But biodiversity is often highest in the places with human activity – we use these locations in the ocean to generate income and livelihoods, from tourism to fishing. This includes coastal areas in the tropics, such as the Coral Triangle (across six countries including Indonesia, the Philippines and Malaysia), which has almost 2,000 marine protected areas, yet is also home to one of the largest shipping routes in the world and high fishing activity.

What’s more, many marine industries are already regulated through licences and quotas, so it’s hard to establish a new marine protected area that adds a different type of management on top of what already exists.

This leaves us with an important paradox: the places where biodiversity is under the most pressure are also the places humanity is most reluctant to relinquish, due to their social or economic value. Because of those values, people and industry resist changes to behaviour, leaving governments to try to find solutions that avoid conflict.

Lessons from the fishing industry

How can we resolve the paradox of marine protected areas? A strategy used in the fishing industry may show the way.

Fisheries have had experience in going beyond the limits of sustainability and then stepping back, changing their approach to managing species and ecosystems for better sustainability, while still protecting economic, social and environmental values.

In the past, many of the world’s fisheries regularly exceeded the sustainable limit of catches, and many species such as southern bluefin tuna declined significantly in number. But strong rules around how a fishery should operate mean declines have since been reversed.

Changes to fishery management have reversed population declines in southern bluefin tuna.
Shutterstock

So how did they do it? In recent decades, many of the world’s large-scale fisheries implemented formal “harvest strategies”. These strategies can flip downward trends of marine species in places not designated a marine protected area.

Harvest strategies have three steps. First is pre-agreed monitoring of species and ecosystems by fishers, regulators and other stakeholders. Second, regulators and scientists assess their impact on the species and ecosystems. And last, all stakeholders agree to put management measures in place to improve the status of the monitored species and ecosystems.

These measures may include changing how fishing is done or how much is done. It’s a commonsense strategy that’s delivered successful results with many fished species either recovering or recovered.

In Australia, the federal government introduced a formal harvest strategy policy to manage fisheries in 2007. It was evaluated in 2014, and the report found many (but not all) fish stocks are no longer overfished. This includes species such as orange roughy and southern bluefin tuna in Australia, which were overfished but are no longer so.

But unfortunately, this positive trend has not been replicated for biodiversity hit by the combinations of other human activities such as coastal development, transport, oil and gas extraction and marine debris.

A consistent strategy

We need to adapt the experience from fisheries and apply a single, formal, transparent and agreed biodiversity strategy that outlines sustainable management objectives for the places we can’t put marine protected areas.

This would look like a harvest strategy, but be applied more broadly to threatened species and ecosystems. What might be sustainable from a single species point of view as used in the fisheries might not sustainable for multiple species.

This would mean for our threatened species, we would be monitoring their status, assessing whether the total population was changing and agreeing on when and how we would change the way that they are impacted.

Such a strategy would also allow monitoring of whole marine ecosystems, even when information is limited. Information on trends in species and ecosystems often exists, but is hidden as commercial-in-confidence or kept privately within government, research or commercial organisations.

Looking ahead

Still, a lack of data shouldn’t limit decision making. Experience in fisheries without much data shows even rules of thumb can be effective management tools. Rules of thumb can include simple measures like gear restrictions or spatial or temporal closures that don’t change through time.

Moving forward, all stakeholders need to agree to implement the key parts of harvest strategies for all marine places with high biodiversity that aren’t protected. This will complement existing marine protected area networks without limiting economic activity, while also delivering social and environmental outcomes that support human well-being.

Our marine ecosystems provide fish, enjoyment, resources and and simple beauty. They must survive for generations to come.

Piers Dunstan, Principal Research Scientist, CSIRO; Natalie Dowling, Researcher, CSIRO; Simone Stevenson, PhD Candidate, Deakin University, and Skipton Woolley, Research scientist, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Old…

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Looking ahead

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