Scientists are more likely to study bold and beautiful blooms, but ugly flowers matter too


Myricaria germanica is a rare and endangered species hit hard by climate change, but little research is undertaken to help save it.
Martino Adamo, Author provided

Kingsley Dixon, Curtin UniversityWe all love gardens with beautiful flowers and leafy plants, choosing colourful species to plant in and around our homes. Plant scientists, however, may have fallen for the same trick in what they choose to research.

Our research, published today in Nature Plants, found there’s a clear bias among scientists toward visually striking plants. This means they’re more likely chosen for scientific study and conservation efforts, regardless of their ecological or evolutionary significance.

To our surprise, colour played a major role skewing researcher bias. White, red and pink flowers were more likely to feature in research literature than those with dull, or green and brown flowers. Blue plants — the rarest colour in nature — received most research attention.

But does this bias matter? Plants worldwide are facing mass extinction due to environmental threats such as climate change. Now, more than ever, the human-induced tide of extinction means scientists need to be more fair-handed in ensuring all species have a fighting chance at survival.

Hidden plants in carpets of wildflowers

I was part of an international team that sifted through 280 research papers from 1975 to 2020, and analysed 113 plant species found in the southwestern Alps in Europe.

The Alps is a global biodiversity hotspot and the subject of almost 200 years of intensive plant science. But climate change is now creating hotter conditions, threatening many of its rarest species.

White flower with mountains in background
Edelweiss is a charismatic plant of the Alps that heralds spring.
Shutterstock

Carpeted in snow for much of the year, the brief yet explosive flowering of Europe’s alpine flora following the thaw is a joy to behold. Who was not bewitched when Julie Andrews danced in an alpine meadow in its full spring wildflower livery in The Sound of Music? Or when she sung “edelweiss”, one of the charismatic plants of the Alps that heralds spring?




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People are ‘blind’ to plants, and that’s bad news for conservation


Hidden in these carpets of bright blue gentians and Delphiniums, vibrant daisies and orchids, are tiny or dull plants. This includes small sedges (Carex species), lady’s mantle (Alchemilla species) or the snake lily (Fritillaria) with its sanguine drooping flowers on thin stems.

Many of these “uncharismatic plants” are also rare or important ecological species, yet garner little attention from scientists and the public.

Close-up of a blue flower
Bellflowers (Campanula) are conspicuous and prominent in the Alps.
Martino Adamo, Author provided

The plants scientists prefer

The study asked if scientists were impartial to good-looking plants. We tested whether there was a relationship between research focus on plant species and characteristics, such as the colour, shape and prominence of species.

Along with a bias towards colourful flowers, we found accessible and conspicuous flowers were among those most studied (outside of plants required for human food or medicine).

Blue flowers
Bold and beautiful flowers in alpine meadows win scientific attention.
Martino Adamo, Author provided

This includes tall, prominent Delphinium and larkspurs, both well-known garden delights with well-displayed, vibrant flowers that often verge on fluorescent. Stem height also contributed to how readily a plant was researched, as it determines a plant’s ability to stand out among others. This includes tall bellflowers (Campanula species) and orchids.

But interestingly, a plant’s rarity didn’t significantly influence research attention. Charismatic orchids, for example, figured prominently despite rarer, less obvious species growing nearby, such as tiny sedges (Cypreaceae) and grass species.

The consequences of plant favouritism

This bias may steer conservation efforts away from plants that, while less visually pleasing, are more important to the health of the overall ecosystem or in need of urgent conservation.

In this time of urgent conservation, controlling our bias in plant science is critical. While the world list of threatened species (the IUCN RED List) should be the basis for guiding global plant conservation, the practice is often far from science based.

Mat rush with brown flowers
Mat rushes are home for rare native sun moths.
Shutterstock

We often don’t know how important a species is until it’s thoroughly researched, and losing an unnoticed species could mean the loss of a keystone plant.

In Australia, for example, milkweeds (Asclepiadaceae) are an important food source for butterflies and caterpillars, while grassy mat rushes (dull-flowered Lomandra species) are now known to be the home for rare native sun moths. From habitats to food, these plants provide foundational ecological services, yet many milkweed and mat rush species are rare, and largely neglected in conservation research.




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Likewise, we can count on one hand the number of scientists who work on creepy fungal-like organisms called “slime molds”, compared to the platoons of scientists who work on the most glamorous of plants: the orchids.

Yet, slime molds, with their extraordinary ability to live without cell walls and to float their nuclei in a pulsating jelly of cytoplasm, could hold keys to all sorts of remarkable scientific discoveries.

Yellow slime on tree trunk
Slime molds could hold the key to many scientific discoveries, but the organisms are understudied.
Shutterstock

We need to love our boring plants

Our study shows the need to take aesthetic biases more explicitly into consideration in science and in the choice of species studied, for the best conservation and ecological outcomes.

While our study didn’t venture into Australia, the principle holds true: we should be more vigilant in all parts of the conservation process, from the science to listing species for protection under the law. (Attractiveness bias may affect public interest here, too.)

So next time you go for a bushwalk, think about the plants you may have trodden on because they weren’t worth a second glance. They may be important to native insects, improve soil health or critical for a healthy bushland.




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These 3 tips will help you create a thriving pollinator-friendly garden this winter


The Conversation


Kingsley Dixon, John Curtin Distinguished Professor, Curtin University

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

A great start, but still not enough: why Victoria’s new climate target isn’t as ambitious as it sounds


Anita Foerster, Monash University; Alice Bleby, UNSW, and Anne Kallies, RMIT UniversityIn a great start towards net zero emissions by 2050, the Victorian Government recently released their Climate Change Strategy, committing to halving greenhouse emissions by 2030.

Victoria’s leadership, alongside commitments from other Australian states and territories, stands in stark contrast to the poor climate performance of our federal government.

But is it enough? Climate scientists are urging Australia to do more to reduce emissions and to do it quicker if we’re going to avert dangerous global warming. In fact, a recent Climate Council report claims achieving net zero emissions by 2050 is at least a decade too late.

We think the Victorian government has the legal mandate to do more. But we also recognise that ambitious climate action at the state level is hindered by a lack of commitment at the federal level.

Using law to drive emissions reductions

Victoria’s new strategy was developed under the Climate Change Act 2017, state legislation requiring the government to set interim emissions reduction targets on the way to net zero by 2050.

It spreads the job of achieving these targets across the economy, with different ministers responsible for pledging emissions reductions actions and reporting on progress over time.

Laws like this are emerging around the world to set targets and hold governments accountable for delivering on them. They’re a key tool to deliver on international commitments under the Paris Agreement to limit global warming to well below 2℃.

Although Australia has set a national target for emissions reduction under the Paris Agreement, it’s widely considered to be inadequate, and there’s currently no framework climate law at the national level. Independent Zali Steggall introduced such a bill in 2020, but the Morrison government hasn’t supported it.

Victoria’s new strategy lacks detail

Victoria’s Climate Change Strategy contains many exciting climate policy announcements, including:

  • renewable energy zones and big batteries in the regions
  • all government operations including schools and hospitals powered by 100% renewables by 2025
  • targets and subsidies for electric vehicle uptake
  • commitments to support innovation in hard-to-abate sectors such as agriculture.

It also recognises the need to phase out natural gas and accelerate Victoria’s renewable hydrogen industry.

These policies are designed to reduce emissions while supporting economic growth and job creation. Yet they are scant on detail.

There’s heavy reliance on achieving emissions reductions in the energy sector — arguably, this is the low-hanging fruit. Policies in transport and agriculture are far less developed, with no quantification of targeted emissions reductions to 2030.

Cows in a paddock
Victoria has committed to support innovation in hard-to-abate sectors such as agriculture.
Shutterstock

This makes it difficult to assess whether the sector pledges will drive enough change to achieve the government’s interim targets (ambitious or otherwise) and support a trajectory to net zero.

It has taken several years to develop the Climate Change Strategy. This makes the lack of detail and the undeveloped nature of some pledges a big concern.

There are also few safeguards in the Climate Change Act to ensure pledges add up to achieving targets, or that ministers across sectors deliver on them. Much depends on the political will of the government of the day.

Why Victoria’s targets aren’t enough

The Victorian Government proposes targets to reduce emissions by 28–33% on 2005 levels by 2025, and by 45–50% on 2005 levels by 2030.

The government claims these targets are ambitious. Compared to current federal government targets, this is true.




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However, the target ranges are lower than those recommended in 2019 by the Independent Expert Panel, established under the Climate Change Act to advise the government on target setting.

The panel recommended targets of 32–39% by 2025 and 45–60% by 2030 as Victoria’s “fair share” contribution to limiting warming to well below 2℃ in accordance with Paris Agreement goals. And it acknowledged these recommended ranges still wouldn’t be enough to keep warming to 1.5℃, in the context of global efforts.

Solar panels on a roof
Reducing emissions in the energy sector is low-hanging fruit.
Shutterstock

Ultimately, Victoria’s targets don’t match what scientists are now telling us about the importance of cutting emissions early to avoid the worst impacts of climate change.

A pragmatic approach or a missed opportunity?

In setting the targets, the state government has clearly taken a politically pragmatic approach.

The government claims the targets are achievable and suggests they would’ve set more ambitious targets if the federal government made a stronger commitment to climate action.

Yes, the current lack of climate ambition at the federal level in Australia is a very real constraint on progress in some areas such as energy, where a coordinated approach is crucial. But this shouldn’t outweigh aligning to best available science.

State governments have many regulatory, policy and economic levers at their disposal, with opportunities to drive significant change and innovation. And Victoria has already demonstrated strong progress in emissions reduction and renewables in the energy sector, easily meeting and exceeding previous targets.

Under the Climate Change Act, the Victorian Government will need to set new, more ambitious targets in five years.

But waiting five years goes against Victoria’s aim to lead the nation on climate action and contribute fairly to global efforts to mitigate global warming. More ambitious, science-aligned targets now would’ve been a valuable signal for industry and a sign of real climate leadership.

We need stronger laws

Without doubt, the new Climate Change Strategy is a significant step forward on an issue that’s plagued Australian politics for years. Victoria has showed framework climate laws can drive government action on climate change.




Read more:
Conservative but green independent MP Zali Steggall could break the government’s climate policy deadlock


But there are also opportunities to bolster the Climate Change Act by aligning targets to science, strengthening legal obligations to drive timely progress, and including an ongoing role for independent experts to advise on target setting and oversee progress.

Finally, it’s important to get on with the job at a federal level.

Zali Steggall’s Climate Change Bill 2020 picks up on best practice climate laws from around the world. It’s also supported by industry groups and investors.

Victoria’s experience suggests it’s surely time for Australia to take this important step.The Conversation

Anita Foerster, Senior Lecturer, Monash University; Alice Bleby, PhD Candidate, UNSW, and Anne Kallies, Senior Lecturer, RMIT University

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

The government has pledged over $800m to fight natural disasters. It could be revolutionary — if done right


Shutterstock

Paul Barnes, UNSWTo help Australia adapt to climate change and manage the disasters that come with it, the federal government this week pledged A$600 million towards establishing the National Recovery and Resilience Agency, and $210 million for the Australian Climate Service initiative.

The sizeable investments make sense, as Australia’s threat landscape has changed. Climate change, drought, land clearing, urban growth and other activities have significantly increased the chances of natural hazards and disasters Australia-wide. All of which are costly to recover from.

The new organisations could deliver revolutionary benefits to Australia by better aligning policy and practice in a more agile way that matches the complex set of threats we face.

There are, however, issues that warrant attention. It’s not yet clear how the government plans to bring together Australia’s best experts — including policy thinkers, emergency managers, researchers and practitioners — to address the complex, evolving threats. Currently, it seems the role of universities has not been adequately defined.

Australia’s recent disasters

The 2019-20 bushfire season was arguably the most extreme in living memory. It started earlier than what might normally have been expected and made history for its severity and widespread damage to life, property and the environment.

Bushfires weren’t the only natural hazard Australia dealt with during this period. Insurance claims from hailstorms, flooding and bushfire damage for the 2019-20 period exceeded $5.19 billion.

A man and woman use a kayak to travel up a flooded street.
The March floods in western Sydney peaked at a staggering 12.9 metres.
Shutterstock

Then came the severe flooding across New South Wales in March, which peaked at 12.9 metres. As of March 23, policyholders had lodged up to 11,700 insurance claims associated with these storms.




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The world endured 2 extra heatwave days per decade since 1950 – but the worst is yet to come


While these recent disasters were unprecedented in their scale and impact, we can expect disasters in the future to worsen due to climate change, from longer heatwaves to intensifying cyclones and a range of cascading and cumulative impacts on society.

This is why the federal government’s announcement this week is extremely important.

So what will these initiatives do?

The new organisations are in response to recommendations from the recent bushfire royal commission, and as part of next week’s federal budget.

The National Recovery and Resilience Agency will be led by former Northern Territory chief minister Shane Stone, and brings together the responsibilities of the national agencies in charge of flood and bushfire recovery.

Its job is to oversee $600 million that will go towards new programs for disaster preparation and mitigation. It’ll focus on minimising disruptive impacts on communities and assist in making them ready to face future disasters. It will also administer the $2 billion National Bushfire Recovery Fund on an ongoing basis.




Read more:
Sydney’s disastrous flood wasn’t unprecedented: we’re about to enter a 50-year period of frequent, major floods


A key enabler of this is the National Climate Resilience and Adaptation Strategy, which is currently getting updated after its first release in 2015. The new strategy will be released later this year, and should be vital in underpinning the direction of the new agency.

The government must ensure the strategy provides guidance that matches the goals of the new agency – in particular that of building resilience. It’s important to recognise that while disaster response is generally similar across the board, the effects of disasters vary depending on the community, urban and physical features, as well as socioeconomic levels and access to services.

And the Australian Climate Service initiative will, according to Environment Minister Sussan Ley:

help provide an environmental road map in our planning for infrastructure, housing and basic services like power, telecommunications, and water [and in] anticipating and adapting to the impacts of [a] changing climate.

Together, the benefits of both new organisations have the potential to be revolutionary.

They — along with a new national research centre focused on hazard resilience and disaster risk reduction (announced in July last year) — may be the largest realignments in disaster management policy and practice for a generation.

But how they’re implemented and coordinated will, ultimately, determine this.

There’s more to do

A potential issue with the Australian Climate Service Initiative that might limit its effectiveness is its emphasis on the roles of the Bureau of Meteorology, CSIRO, the Australian Bureau of Statistics and Geoscience Australia.

This collaboration means the initiative has access to huge amounts of data, information resources, and links to the National Environmental Science Program and Great Barrier Reef Restoration and Adaptation initiatives.




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‘We know our community better than they do’: why local knowledge is key to disaster recovery in Gippsland


But we shouldn’t forget many Australian universities have considerable relevant expertise at their disposal, too. Not including the network of expertise and experience of universities means we may be shooting ourselves in the foot.

What’s more, the National Recovery and Resilience Agency intends to provide accredited training for people working in disaster recovery. The deep training and development expertise of universities is a perfect fit for this goal.

To really embed the benefits, we need to break down historical silos between national, state and local agencies. On-the-ground efforts for disaster risk reduction, emergency management and response, and the broad social aspects of recovery are largely state and local government responsibilities.

Crisis response planning and action is a team-based sport, so getting the federal, state and local governments — and the private sector — involved will help streamline the application of the new disaster policies and protocols embodied in the announced changes across the continent.




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We saw this type of team-based effort at a national level when the emergency national cabinet was established to oversee collaborative decision-making in response to the COVID-19 pandemic. It’s joined-up thinking that enables rapid and more complete decision- making.

In short, we need better collaboration. How we can work together and utilise all our capabilities and capacities are questions that need to be at the forefront of national thinking.


This story is part of a series The Conversation is running on the nexus between disaster, disadvantage and resilience. You can read the rest of the stories here.The Conversation

Paul Barnes, Research Fellow (Disaster & Urban Resilience), UNSW

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

Trailing giants: clues to how people and giraffes can thrive together


Masai giraffes in northern Tanzania.
Sonja Metzger

Monica Bond, University of ZürichThe giraffe (Giraffa camelopardalis) is an iconic megaherbivore whose populations are declining across Africa, the only continent where they are found. Giraffe numbers have plummeted from an estimated 150,000 in 1985 to fewer than 100,000 today.

Like many species of African wildlife, giraffes face numerous threats. The biggest threats are hunting for bushmeat markets and loss of habitat due to deforestation and the spread of farms.

Giraffes shape and sustain healthy ecosystems. For example, woody plant spines, such as thorn trees, are a response to giraffe browsing. Giraffes are also a big attraction for tourists.

The best way to reverse giraffe population declines is to monitor individual animals and learn why they do better in one place over another. This helps to pinpoint threats and evaluate conservation strategies, such as how the presence of people influences giraffes and whether community conservation areas work.

Fortunately, giraffes are a good study species for this type of research. Each animal has a unique and unchanging spot pattern for its entire life, like a human thumbprint. Giraffes can therefore be easily identified from photographs without any need for dangerous captures.

In 2011, my colleagues and I launched the Masai Giraffe Project to learn what helps and what harms giraffes, and how people and giraffes can thrive together. Although the giraffe is still considered a single species, genetic information suggests there may be three species with Masai giraffes a separate species.

The Masai Giraffe Project is a partnership between the Wild Nature Institute, the University of Zurich, Pennsylvania State University and the Tanzania Wildlife Research Institute. It has become one of the biggest studies of a large mammal, with nearly 3,000 individuals identified in a vast, 4,500-km2 area of the Tarangire ecosystem in Tanzania.

To date we’ve published more than 10 original studies about giraffe survival, movements and behaviour in relation to human disturbances – specifically human settlements.

The Tarangire ecosystem features two distinctive types of human settlements: towns – whose inhabitants include farmers and bushmeat poachers – and small, traditional homesteads, inhabited by members of the livestock-keeping Maasai community.

We revealed that survival of giraffes is influenced by how close they live to towns. Adult female survival was higher within national parks and community-based conservation areas, away from towns which brought them closer to farming and poaching. These results were not surprising, but we were encouraged to also discover that traditional homesteads are compatible with giraffe conservation. They were even a benefit to mothers with small calves.

Our findings help wildlife authorities understand where and why giraffe numbers are stable, increasing or declining.

Giraffes and people: a future in the balance

Our study area includes two national parks, a large cattle and ecotourism ranch, two community-managed wildlife areas as well as unprotected lands with towns and traditional homesteads. The entire area has no fences so giraffes can roam freely around their large home ranges, which average about 130 hectares.

The giraffe’s habitat outside the parks is affected by human activities which include farming, charcoal making and livestock. Giraffe habitat throughout Africa has become similarly fragmented. Thus, our study area is representative of the diversity of threats and conservation opportunities facing giraffes.

We found that the probability of adult female giraffe survival was higher in protected areas than less-protected areas where poaching for bushmeat markets was prevalent.

We also learned that community-based conservation is helping giraffes. For instance, the survival rates of giraffes in community conservation areas adjacent to national parks improved. These areas also had higher giraffe population densities than outside the protected zones.

Survival of breeding females in long-lived species like giraffes is absolutely critical to sustain populations. Lower survival rates of adult females outside protected areas resulted in population declines.

In contrast to adult giraffes, survival of calves was lower inside protected areas where predator densities are highest. However, the seasonal presence of migratory wildebeests and zebras attracted predation away from giraffe calves. This means that conservation of giraffes requires the safeguarding of all the other animals in the savanna.

Different lifestyles

One of the most promising results from our research is that some human lifestyles seem to be more compatible with giraffe conservation. Most giraffes tended to avoid human areas altogether, however giraffe mothers didn’t always. They stayed far from towns but actually preferred to be closer to traditional homesteads.

We discovered that female giraffes living near traditional homesteads had weaker social relationships, but this did not reduce their survival. Closer to towns, adult female giraffes had lower survival and their home ranges were larger in size. This indicated that they had to roam farther to evade poachers and obtain necessary resources, like food and water.

Giraffe mothers were more likely to be found near traditional homesteads where predators on calves – like lions and hyenas – were fewer. This was probably due to pastoralists eliminating predators and disrupting predator behaviour to protect their livestock.

Ways forward

Our 10 years of research on giraffes in a human-natural landscape revealed constructive ways forward for giraffe conservation. Livestock-keeping and farming people have different influences on giraffes, yet both have important roles to play in saving giraffes from extinction.

We can help the tallest of the megaherbivores by giving them enough living space in the savanna. By limiting habitat loss and expanding community-based conservation areas, and eating livestock rather than bushmeat, we can ensure a future where both humans and giraffes will thrive.The Conversation

Monica Bond, Research associate, University of Zürich

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

From baby blue-tongues to elephant doulas: motherhood across the animal kingdom


Diana Robinson, Author provided

Oliver Griffith, Macquarie University and Jessica Suzanne Dudley, Macquarie UniversityWith Mother’s Day around the corner, it’s a good opportunity to ask what being a mother looks like across the animal kingdom. Most of us have a solid concept of human motherhood, but in nature maternal care comes in many forms.

Let’s take a closer look at the diversity of ways animals provide care, to give young the best chance of success.

The power of the placenta

For many species, life begins in the womb. One of the most significant ways mothers support their young before birth is via a placenta, the temporary organ that grows inside the uterus to support a fetus. Placentas not only act as the interface between mother and baby, but can provide all fetal nutrition, allow for exchange of oxygen and carbon dioxide with the mother, and even remove the fetus’s waste.




Read more:
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While our close relatives (eutherian or placental mammals) are known for having a placenta, we are not unique in having one. In fact, the placenta has evolved more than 100 times independently in the animal kingdom!

Blue-tongued lizard with her newborn young.
National Parks and Wildlife Service, South Australia

Other placental species include some reptiles such as the blue-tongued lizard, and many sharks including the Australian sharpnose. Even marsupials have a placenta, although it typically only supports young for a few days.

Marsupial mothers

Outside the womb, the queens of maternal care are marsupials such as kangaroos, koalas and Tasmanian devils. Marsupial mothers provide food and protection from predators through a prolonged period of lactation inside the pouch.

In marsupials, pregnancy is relatively short but young spend a long time in the pouch afterwards. For example, tammar wallabies’ pregnancy can be as short as four weeks, but mothers can provide milk to their young in the pouch for almost a year. During this time the babies increase in weight 2,000-fold. In comparison, human infants increase in weight threefold during their first year of life.

A kangaroo mother, looking after her joey in the pouch.
Ethan Brooke/www.pexels.com

Egg-layers

An African rock python, looking after her eggs. Python mothers will coil around their eggs while they incubate, and can even shiver to keep the eggs warm.
J. Lanki/wikimedia

In contrast to animals that develop a placenta, egg-laying animals typically lay nutrient-rich eggs to support development. Parents of some species consider their job done after the eggs are laid, but others continue to care for their young by protecting the eggs and providing food once the babies hatch.

A Port Jackson Shark egg. After laying eggs, mothers carry them in their mouth and screw them into a secure rock crevice, hoping they will be protected for their 10-12 months of development.
Kate Bunker/flickr

Some egg-laying sharks continue to provide care after birth. Port Jackson sharks carry their eggs in their mouths until they find a protected rock crevice to hide them in.

Hummingbird mothers look after their young without any paternal support.
Mike’s Birds

In birds, mothers provide warmth and protection while incubating their eggs. In some bird species such as hummingbirds, only the mother provides care after birth. However, in other cases, such as penguins, it’s a team effort with mothers and fathers providing food and protection to their offspring.

For some, it takes a village

For some animals, motherhood extends beyond looking after your own children. Like humans, orcas (killer whales) forgo the potential to reproduce later in life by going through menopause.

Menopause may prevent them from raising any more children, but it allows them to divert their efforts to raising the next generation by looking after their grandchildren.

Orcas and a few of their close relatives (including beluga whales and narwhals) are one of the few non-human mammals that forgo reproduction later in life and enter menopause. This allows mothers to continue to support the next generation by looking after their grandchildren.
Gregory ‘Slobirdr’ Smith/flickr

Many animals need even more support, so some species form societies where the whole community will care for the young, rather than just the parents. Meerkats live in groups of up to 30 individuals where parental duties are shared.

Meerkat mother keeping an eye out for predators with one of her pups.
Theo Stikkelman

Younger females will “babysit” the pups while the rest of the mob forage for food, sometimes having to put their own lives in danger to protect the younger members of the group.

Within elephant herds, the mothers provide milk for their babies but other members of the herd (known as doulas, they can be either male or female) provide encouragement and physical support to both the mother and the growing calves. This same behaviour is seen in dolphins, as well as in several primates including chimpanzees and gorillas.

Pregnant male Hippocampus whitei. Seahorse fathers experience male pregnancy, providing nutrition, gas exchange and protection to developing embryos within his pouch.
Marine Explorer

In a few species, it is the father that provides the most care for offspring. For example, seahorses exhibit male pregnancy, providing nutrition and protection from predators while inside his pouch. For a seahorse mother, her care responsibilities end once she has deposited her eggs into the male’s pouch.

If we can learn anything from the animal kingdom, it’s that motherhood comes in many forms.The Conversation

Oliver Griffith, Lecturer, Macquarie University and Jessica Suzanne Dudley, Postdoctoral Fellow, Macquarie University

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

What are waterspouts, and how do they form? An expert explains


Joseph Golden / NOAA
Dean Narramore, Australian Bureau of Meteorology

Waterspouts are extraordinary, impressive weather events. Observers describe them as looking like “the start of an alien invasion” and post their snaps across social media.

But what are these enigmatic offshore twisters, and what causes them to form?

What is a waterspout?

A waterspout is a spinning column of air that sucks up water (usually from the ocean) to make a twisting funnel of water and cloud connecting the sea and the sky.

They are spectacular but short lived, usually lasting no more than five minutes (but occasionally up to ten minutes). Winds inside the waterspout can be faster than 100 kilometres per hour, and they can do great damage to boats at sea.

If they drift ashore, waterspouts can create even more havoc: the Lennox Head tornado in 2010 destroyed a dozen homes in northern NSW.

Waterspouts are in some ways like the tornadoes that form over land. But where tornadoes are associated with huge supercell thunderstorms, waterspouts can form during smaller storms or even just showers or the presence of the right kind of clouds.


Read more: Tornadoes in Australia? They’re more common than you think


How do waterspouts form?

Waterspouts can form when winds blowing in two different directions run into each other. Along the line where the two winds meet (called a “convergence line” or “shear line”), there is a lot of rotating air near the surface.

The collision of the two winds makes air move upwards because it has nowhere else to go. This rising air carries water vapour high into the sky where it creates rain showers, storms and cumulus clouds.

Waterspouts off the coast at Harrington in NSW. Sue McDonald, Author provided

As the air rises, it can tilt some of the horizontal spinning air near the surface into the vertical direction. When this vertical spin concentrates at a particular point it starts sucking up water — and you have yourself a waterspout.

Because waterspouts form on the line where two winds meet, you sometimes see a line of waterspouts in a row where the spinning low-level air is sucked upwards at a few different points.

When and where are waterspouts most common?

In Australia, waterspouts are most common along the NSW and Queensland coast.

Most mornings, cooler nighttime air blowing off the land meets warmer air sitting out to sea. Usually this results in a line of clouds sitting offshore where the two air masses meet.

Under the right conditions — most often in autumn and winter, when the land gets colder but the sea stays relatively warm — the collision becomes more dramatic and waterspouts appear.

Can we forecast waterspouts?

Waterspouts look very big and impressive to the casual viewer, but to a meteorologist looking at the world’s weather patterns they are quite small. This makes them very hard to forecast with any level of confidence.


Read more: Curious Kids: how do people know what the weather will be?


We know the kind of weather conditions that can lead to waterspouts, so if we see those conditions forming we might know there is a chance we’ll see some. But the small scale and short life of waterspouts mean forecasting the location or timing is almost impossible.The Conversation

Dean Narramore, Senior meteorologist, Australian Bureau of Meteorology

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

Climate explained: when Antarctica melts, will gravity changes lift up land and lower sea levels?


Shutterstock/Nickolya

Robert McLachlan, Massey University


CC BY-ND

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz


I’ve heard the gravity changes when Antarctica melts will lower the seas around New Zealand. Will that save us from sea level rise?

The gravitational changes when Antarctica melts do indeed affect sea levels all over the world — but not enough to save New Zealand from rising seas.

The ice ages and their effects on sea level, geology, flora and fauna were topics of intense scientific and public interest all through the 19th century. Here’s how James Croll explained the “gravity effect” of melting ice in his 1875 book Climate and Time in their Geologic Relations:

Let us now consider the effect that this condition of things would have upon the level of the sea. It would evidently tend to produce an elevation of the sea-level on the northern hemisphere in two ways. First, the addition to the sea occasioned by the melting of the ice from off the Antarctic land would tend to raise the general level of the sea. Secondly, the removal of the ice would also tend to shift the earth’s centre of gravity to the north of its present position – and as the sea must shift along with the centre, a rise of the sea on the northern hemisphere would necessarily take place.

His back-of-the-envelope calculation suggested the effect on sea level from ice melting in Antarctica would be about a third bigger than average in the northern hemisphere and a third smaller in the south.

A more detailed mathematical study by Robert Woodward in 1888 has falling sea level as far as 2000km from Antarctica, but still rising by a third more than average in the north.




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Sea-level fingerprints

Woodward’s method is the basis of determining what is now called the “sea-level fingerprint” of melting ice. Two other factors also come into play.

  1. The elasticity of the earth’s surface means the land will bounce up when it has less ice weighing it down. This pushes water away.
  2. If the ice is not at the pole, its melting shifts the south pole (the axis of rotation), redistributing water.

Combining these effects gives the sea-level fingerprints of one metre of sea-level rise from either the West Antarctic Ice Sheet (WAIS) and Greenland (GIS), as shown here:

Red areas get more than the average sea level rise, blue areas get less.
Fingerprints of sea-level change following melting of ice from West Antartica (WAIS) and Greenland (GIS) equivalent to one metre of sea-level rise on average. Red areas get up to 40% more than the average sea-level rise, blue areas get less.
Author provided, CC BY-SA

Woodward’s method from 1888 holds up pretty well – some locations in the northern hemisphere can get a third more than the average sea level rise. New Zealand gets a little bit below the average effect from Antarctica, and a little more than average from Greenland. Overall, New Zealand can expect slightly higher than average sea level rise.

Combining the sea-level fingerprints of all known sources of melting ice, together with other known changes of local land level such as subsidence and uplift, gives a good fit to the observed pattern of sea level rise around the world. For example, sea level has been falling near West Antarctica, due to the gravity effect.

Changes in sea level around the world, 1993-2019

NOAA

Sea-level rise is accelerating, but the future rate is uncertain

The global average rise in sea level is 110mm for 1900-1993 and 100mm for 1993–2020. The recent acceleration is mostly due to increased thermal expansion of the top two kilometres of the oceans (warm water is less dense and expands) and increased melting of Greenland.

But the Gravity Recovery and Climate Experiment satellite has revealed the melting of Antarctica has accelerated by a factor of five in recent decades. Future changes in Antarctica represent a major source of uncertainty when trying to forecast sea levels.

Much of West Antarctica lies below sea level and is potentially subject to an instability in which warming ocean water melts the ice front from below. This would cause the ice sheet to peel off the ocean floor, accelerating the flow of the glacier towards the sea.

In fact, this has been directly observed, both in the location of glacial “grounding lines”, some of which have retreated by tens of kilometres in recent decades, and most recently by the Icefin submersible robot which visited the grounding line of the Thwaites Glacier, 2000km east of Scott Base, and found the water temperature to be 2℃ above the local freezing point.




Read more:
If warming exceeds 2°C, Antarctica’s melting ice sheets could raise seas 20 metres in coming centuries


The big question is whether this instability has been irreversibly set into motion. Some glaciologists say it has, but the balance of opinion, summarised by the IPCC’s report on the cryosphere, is that:

Observed grounding line retreat … is not definitive proof that Marine Ice Sheet Instability is underway. Whether unstable West Antarctic Ice Sheet retreat has begun or is imminent remains a critical uncertainty.

The IPCC special report on 1.5℃ concluded that “these instabilities could be triggered at around 1.5℃ to 2℃ of global warming”.

What’s in store for New Zealand

Predictions for New Zealand range from a further 0.46 metres of sea-level rise by 2100 (under a low-emission scenario, with warming kept under 2℃) to 1.05 metres (under a high-emission scenario).

A continued rise in sea levels over future centuries may be inevitable — there are 66m of sea level rise locked up in ice at present — but the rate will depend on how fast we can reduce emissions.

A five-year, NZ$7m research project, NZ SeaRise, is now underway, seeking to improve predictions of sea-level rise out to 2100 and beyond and their implications for local planning.The Conversation

Robert McLachlan, Professor in Applied Mathematics, Massey University

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

Paying Australia’s coal-fired power stations to stay open longer is bad for consumers and the planet


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Daniel J Cass, University of Sydney; Joel Gilmore, Griffith University, and Tim Nelson, Griffith UniversityAustralian governments are busy designing the nation’s transition to a clean energy future. Unfortunately, in a misguided effort to ensure electricity supplies remain affordable and reliable, governments are considering a move that would effectively pay Australia’s old, polluting coal-fired power stations to stay open longer.

The measure is one of several options proposed by the Energy Security Board (ESB), the chief energy advisor to Australian governments on electricity market reform. The board on Friday released a vision to redesign the National Electricity Market as it transitions to clean energy.

The key challenges of the transition are ensuring it is smooth (without blackouts) and affordable, as coal and gas generators close and are replaced by renewable energy.

The redesign has been two years in the making. The ESB has done a very good job of identifying key issues, and most of its recommendations are sound. But its option to change the way electricity generators and retailers strike contracts for electricity, if adopted, would be highly counterproductive – bad both for consumers and for climate action.

Electricity lines at sunset
One proposed reform to Australia’s electricity market would be bad for consumers and climate action.
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The energy market dilemma

The National Electricity Market (NEM) covers every Australian jurisdiction except Western Australia and the Northern Territory. It comprises electricity generators, transmission and distribution networks, electricity retailers, customers and a financial market where electricity is traded.

Electricity generators in the NEM comprise older, polluting technology such as gas- and coal-fired power, and newer, clean forms of generation such as wind and solar. Renewable energy, which makes up about 23% of our electricity mix, is now cheaper than energy from coal and gas.

Wind and solar energy is “variable” – only produced when the sun is shining and the wind is blowing. Technology such as battery storage is needed to smooth out renewable energy supplies and make it “dispatchable”, meaning it can be delivered on demand.

Some say coal generators, which supply dispatchable electricity, are the best way to ensure reliable and affordable electricity. But Australia’s coal-fired power stations, some of which are more than 40 years old, are becoming more prone to breakdowns – and so less reliable and more expensive – as they age. This has led to some closing suddenly.

Without a clear national approach to emissions targets, there’s a risk these sudden closures will occur again.




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Explainer: what is the electricity transmission system, and why does it need fixing?


Wind farm near coast
Wind and solar energy is variable.
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So what’s proposed?

To address reliability concerns, the ESB has proposed an option known as the “physical retailer reliability obligation”.

In a nutshell, the change would require electricity retailers to negotiate contracts for a certain amount of “dispatchable” electricity from specific generators for times of the year when reliability is a concern, such as the peak weeks of summer when lots of people use air conditioning.

Currently, the Australian Energy Market Operator has reserve electricity measures it can deploy when market supply falls short.

But under the new obligation, all retailers would also have to enter contracts for dispatchable supply. This would likely require buying electricity from the coal generators that dominate the market. This provides a revenue source enabling these coal plants to remain open even when cheaper renewable energy makes them unprofitable.

The ESB says without the change, the closure of coal generators will be unpredictable or “disorderly”, creating price shocks and reliability risks.

hand turns off light switch in bedroom
The ESWB says the recommendation would address concerns over electricity reliability.
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A big risk

Even the ESB concedes the recommendation comes with considerable risks. In particular, the board says it may:

  • impose increased barriers to retail competition and product innovation
  • lead to possible overcompensation of existing coal and gas generators.

In short, the policy could potentially lock in increasingly unreliable, ageing coal assets, stall new investment in new renewable energy storage such as batteries and pumped hydro and increase market concentration.

It could also push up electricity prices. Electricity retailers are likely to pass on the cost of these new electricity contracts to consumers, no matter how much energy that household or business actually used.

The existing market already encourages generators to provide reliable supply – and applies strong penalties if they don’t. And in fact, the NEM experiences reliability issues for an average of just one minute per year. It would appear little could be added to the existing market design to make generators more reliable than they are.

Finally, the market is dominated by three large “gentailers” – AGL, Energy Australia and Origin – which own both generators and the retail companies that sell electricity. The proposed change would disadvantage smaller electricity retailers, which in many cases would be forced to buy electricity from generators owned by their competitors.

Australia’s gentailers are heavily invested in coal power stations. The proposed change would further concentrate their market power while propping up coal.




Read more:
‘Failure is not an option’: after a lost decade on climate action, the 2020s offer one last chance


warning sign on fence
The proposed change brings a raft of risks to the electricity market.
Kelly Barnes/AAP

What governments should do

If coal-fired power stations are protected from competition, it will deter investment in cleaner alternatives. The recommendation, if adopted, would delay decarbonisation and put Australia further at odds with our international peers on climate policy.

The federal and state governments must work together to develop a plan for electricity that facilitates clean energy investment while controlling costs for consumers.

The plan should be coordinated across the states. Without this, we risk creating a sharper shock later, when climate diplomacy requires the planned retirement of coal plants. Other nations have acknowledged the likely demise of coal, and it’s time Australia caught up.




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The Conversation


Daniel J Cass, Research Affiliate, Sydney Business School, University of Sydney; Joel Gilmore, Associate Professor, Griffith University, and Tim Nelson, Associate Professor of Economics, Griffith University

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

The 1.5℃ global warming limit is not impossible – but without political action it soon will be


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Bill Hare, Potsdam Institute for Climate Impact Research; Carl-Friedrich Schleussner, Humboldt University of Berlin; Joeri Rogelj, Imperial College London, and Piers Forster, University of LeedsLimiting global warming to 1.5℃ this century is a central goal of the Paris Agreement. In recent months, climate experts and others, including in Australia, have suggested the target is now impossible.

Whether Earth can stay within 1.5℃ warming involves two distinct questions. First, is it physically, technically and economically feasible, considering the physics of the Earth system and possible rates of societal change? Science indicates the answer is “yes” – although it will be very difficult and the best opportunities for success lie in the past.

The second question is whether governments will take sufficient action to reduce greenhouse gas emissions. This answer depends on the ambition of governments, and the effectiveness of campaigning by non-government organisations and others.

So scientifically speaking, humanity can still limit global warming to 1.5°C this century. But political action will determine whether it actually does. Conflating the two questions amounts to misplaced punditry, and is dangerous.

Women holds sign at climate march
Staying within 1.5℃ is scientifically possible, but requires government ambition.
Erik Anderson/AAP

1.5℃ wasn’t plucked from thin air

The Paris Agreement was adopted by 195 countries in 2015. The inclusion of the 1.5℃ warming limit came after a long push by vulnerable, small-island and least developed countries for whom reaching that goal is their best chance for survival. The were backed by other climate-vulnerable nations and a coalition of high-ambition countries.

The 1.5℃ limit wasn’t plucked from thin air – it was informed by the best available science. Between 2013 and 2015, an extensive United Nations review process determined that limiting warming to 2℃ this century cannot avoid dangerous climate change.

Since Paris, the science on 1.5℃ has expanded rapidly. An Intergovernmental Panel on Climate Change (IPCC) report in 2018 synthesised hundreds of studies and found rapidly escalating risks in global warming between 1.5℃ and 2℃.

The landmark report also changed the climate risk narrative away from a somewhat unimaginable hothouse world in 2100, to a very real threat within most of our lifetimes – one which climate action now could help avoid.

The message was not lost on a world experiencing ever more climate impacts firsthand. It galvanised an unprecedented global youth and activist movement demanding action compatible with the 1.5℃ limit.

The near-term benefits of stringent emissions reduction are becoming ever clearer. It can significantly reduce near-term warming rates and increase the prospects for climate resilient development.

Firefighter battles blaze
The urgency of climate action is not lost on those who’ve experienced its effects firsthand.
Evan Collins/AAP

A matter of probabilities

The IPCC looked extensively at emission reductions required to pursue the 1.5℃ limit. It found getting on a 1.5℃ track is feasible but would require halving global emissions by 2030 compared to 2010 and reaching net-zero emissions by mid-century.

It found no published emission reduction pathways giving the world a likely (more than 66%) chance of limiting peak warming this century to 1.5℃. But it identified a range of pathways with about a one-in-two chance of achieving this, with no or limited overshoot.

Having about a one-in-two chance of limiting warming to 1.5℃ is not ideal. But these pathways typically have a greater than 90% chance of limiting warming to well below 2℃, and so are fully compatible with the overall Paris goal.




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Scott Morrison holding a lump of coal in Parliament
Staying under 1.5℃ warming requires political will.
Lukas Coch/AAP

Don’t rely on carbon budgets

Carbon budgets show the amount of carbon dioxide that can be emitted for a given level of global warming. Some point to carbon budgets to argue the 1.5℃ goal is now impossible.

But carbon budget estimates are nuanced, and not a suitable way to conclude a temperature level is no longer possible.

The carbon budget for 1.5℃ depends on several factors, including:

  • the likelihood with which warming will be be halted at 1.5℃
  • the extent to which non-CO₂ greenhouse emissions such as methane are reduced
  • uncertainties in how the climate responds these emissions.

These uncertainties mean strong conclusions cannot be drawn based on single carbon budget estimate. And, at present, carbon budgets and other estimates do not support any argument that limiting warming to 1.5℃ is impossible.

Keeping temperature rises below 1.5℃ cannot be guaranteed, given the history of action to date, but the goal is certainly not impossible. As any doctor embarking on a critical surgery would say about a one-in-two survival chance is certainly no reason not to do their utmost.

Wind farm
Staying below 1.5°C is a difficult, but not impossible, task.
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Closer than we’ve ever been

It’s important to remember the special role the 1.5℃ goal plays in how governments respond to climate change. Five years on from Paris, and the gains of including that upper ambition in the agreement are showing.

Some 127 countries aim to achieve net-zero emissions by mid-century at the latest – something considered unrealistic just a few years ago. If achieved globally and accompanied by stringent near-term reductions, the actions could be in line with 1.5℃.

If all these countries were to deliver on these targets in line with the best-available science on net zero, we may have a one-in-two chance of limiting warming this century to 2.1℃ (but a meagre one-in-ten that it is kept to 1.5°C). Much more work is needed and more countries need to step up. But for the first time, current ambition brings the 1.5℃ limit within striking distance.

The next ten years are crucial, and the focus now must be on governments’ 2030 targets for emissions reduction. If these are not set close enough to a 1.5℃-compatible emissions pathway, it will be increasingly difficult to reach net-zero by 2050.

The United Kingdom and European Union are getting close to this pathway. The United States’ new climate targets are a major step forward, and China is moving in the right direction. Australia is now under heavy scrutiny as it prepares to update its inadequate 2030 target.

The UN wants a 1.5℃ pathway to be the focus at this year’s COP26 climate summit in Glasgow. The stakes could not be higher.




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The Conversation


Bill Hare, Director, Climate Analytics, Adjunct Professor, Murdoch University (Perth), Visiting scientist, Potsdam Institute for Climate Impact Research; Carl-Friedrich Schleussner, Research Group Leader, Humboldt University of Berlin; Joeri Rogelj, Director of Research and Lecturer – Grantham Institute Climate Change & the Environment, Imperial College London, and Piers Forster, Professor of Physical Climate Change; Director of the Priestley International Centre for Climate, University of Leeds

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

Watching a coral reef die as climate change devastates one of the most pristine tropical island areas on Earth


Sam Purkis, University of MiamiThe Chagos Archipelago is one of the most remote, seemingly idyllic places on Earth. Coconut-covered sandy beaches with incredible bird life rim tropical islands in the Indian Ocean, hundreds of miles from any continent. Just below the waves, coral reefs stretch for miles along an underwater mountain chain.

It’s a paradise. At least it was before the heat wave.

When I first explored the Chagos Archipelago 15 years ago, the underwater view was incredible. Schools of brilliantly colored fish in blues, yellows and oranges darted among the corals of a vast, healthy reef system. Sharks and other large predators swam overhead. Because the archipelago is so remote and sits in one of the largest marine protected areas on the planet, it has been sheltered from industrial fishing fleets and other activities that can harm the coastal environment.

But it can’t be protected from climate change.

A diver carries a plastic pipe for measuring while swimming over a variety of corals
A diver documents the coral reefs in the Chagos Archipelago.
Khaled bin Sultan Living Oceans Foundation

In 2015, a marine heat wave struck, harming coral reefs worldwide. I’m a marine biologist at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, and I was with a team of researchers on a 10-year global expedition to map the world’s reefs, led by the Khaled bin Sultan Living Oceans Foundation. We were wrapping up our work in the Chagos Archipelago at the time. Our report on the state of the reefs there was just published in spring 2021.

As the water temperature rose, the corals began to bleach. To the untrained eye, the scene would have looked fantastic. When the water heats up, corals become stressed and they expel the tiny algae called dinoflagellates that live in their tissue. Bleaching isn’t as simple as going from a living coral to a bleached white one, though. After they expel the algae, the corals turn fluorescent pinks and blues and yellows as they produce chemicals to protect themselves from the Sun’s harmful rays. The entire reef was turning psychedelic colors.

Two bright pink coral mounds
Just before they turned white, the corals turned abnormally bright shades.
Phil Renaud/Khaled bin Sultan Living Oceans Foundation

That explosion of color is rare, and it doesn’t last long. Over the following week, we watched the corals turn white and start to die. It wasn’t just small pieces of the reef that were bleaching – it was happening across hundreds of square miles.

What most people think of as a coral is actually many tiny colonial polyps that build calcium carbonate skeletons. With their algae gone, the coral polyps could still feed by plucking morsels out of the water, but their metabolism slows without the algae, which provide more nutrients through photosynthesis. They were left desperately weakened and more vulnerable to diseases. We could see diseases taking hold, and that’s what finished them off.

We were witnessing the death of a reef.

Rising temperatures increase the heat wave risk

The devastation of the Chagos Reef wasn’t happening in isolation.

Over the past century, sea surface temperatures have risen by an average of about 0.13 degrees Celsius (0.23 F) per decade as the oceans absorb the vast majority of greenhouse gas emissions from human activities, largely from the burning of fossil fuels. The temperature increase and changing ocean chemistry affects sea life of all kinds, from deteriorating the shells of oysters and tiny pteropods, an essential part of the food chain, to causing fish populations to migrate to cooler water.

Corals can become stressed when temperatures around them rise just 1 C (1.8 F) above their tolerance level. With water temperature elevated from global warming, even a minor heat wave can become devastating.

In 2015, the ocean heat from a strong El Niño event triggered the mass bleaching in the Chagos reefs and around the world. It was the third global bleaching on record, following events in 1998 and 2010.

Bleaching doesn’t just affect the corals – entire reef systems and the fish that feed, spawn and live among the coral branches suffer. One study of reefs around Papua New Guinea in the southwest Pacific found that about 75% of the reef fish species declined after the 1998 bleaching, and many of those species declined by more than half.

Research shows marine heat waves are now about 20 times more likely than they were just four decades ago, and they tend to be hotter and last longer. We’re at the point now that some places in the world are anticipating coral bleaching every couple of years.

That increasing frequency of heat waves is a death knell for reefs. They don’t have time to recover before they get hit again.

Where we saw signs of hope

During the Global Reef Expedition, we visited over 1,000 reefs around the world. Our mission was to conduct standardized surveys to assess the state of the reefs and map the reefs in detail so scientists could document and hopefully respond to changes in the future. With that knowledge, countries can plan more effectively to protect the reefs, important national resources, providing hundreds of billions of dollars a year in economic value while also protecting coastlines from waves and storms.

We saw damage almost everywhere, from the Bahamas to the Great Barrier Reef.

Some reefs are able to survive heat waves better than others. Cooler, stronger currents, and even storms and cloudier areas can help prevent heat building up. But the global trend is not promising. The world has already lost 30% to 50% of its reefs in the last 40 years, and scientists have warned that most of the remaining reefs could be gone within decades.

Diver with large sea turtle swimming over corals.
The author, Sam Purkis, dives near a hawksbill turtle in the Chagos Archipelago.
Derek Manzello/Khaled bin Sultan Living Oceans Foundation

While we see some evidence that certain marine species are moving to cooler waters as the planet warms, a reef takes thousands of years to establish and grow, and it is limited by geography.

In the areas where we saw glimmers of hope, it was mostly due to good management. When a region can control other harmful human factors – such as overfishing, extensive coastal development, pollution and runoff – the reefs are healthier and better able to handle the global pressures from climate change.

Establishing large marine protected areas is one of the most effective ways I’ve seen to protect coral reefs because it limits those other harms.

The Chagos marine protected area covers 640,000 square kilometers (250,000 square miles) with only one island currently inhabited – Diego Garcia, which houses a U.S. military base. The British government, which created the marine protected area in 2010, has been under pressure to turn over control of the region to the country of Mauritius, where former Chagos residents now live and which won a challenge over it in the International Court of Justice in 2020. Whatever happens with jurisdiction, the region would benefit from maintaining a high level of marine protection.

A warning for other ecosystems

The Chagos reefs could potentially recover – if they are spared from more heat waves. Even a 10% recovery would make the reefs stronger for when the next bleaching occurs. But recovery of a reef is measured in decades, not years.

So far, research missions that have returned to the Chagos reefs have found only meager recovery, if any at all.

We knew the reefs weren’t doing well under the insidious march of climate change in 2011, when the global reef expedition started. But it’s nothing like the intensity of worry we have now in 2021.

Coral reefs are the canary in the coal mine. Humans have collapsed other ecosystems before through overfishing, overhunting and development, but this is the first unequivocally tied to climate change. It’s a harbinger of what can happen to other ecosystems as they reach their survival thresholds.

This story is part of Oceans 21

Our series on the global ocean opened with five in-depth profiles. Look for new articles on the state of our oceans in the lead-up to the U.N.‘s next climate conference, COP26. The series is brought to you by The Conversation’s international network.The Conversation

Sam Purkis, Professor and Chair of the Department of Marine Sciences, University of Miami

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