Heatwaves and flash floods: yes, this is Britain’s ‘new normal’


Hayley J. Fowler, Newcastle University

“It’s hard to believe, isn’t it, that we had a heatwave just last week?”

Those words were spoken by a BBC news presenter, in front of graphic images of fire service rescues, as heavy rain caused floods and landslides which closed many roads and railway lines. In recent days there have dramatic floods across the north of England, particularly around Manchester, the Peak District and Yorkshire.

For me, this is personal, as I am from the worst affected area. I went to high school where people spent the night in their Civic Hall. Three miles away from where I grew up, a dam holding back Toddbrook Reservoir has been at risk of collapse and the town of Whaley Bridge was evacuated. But I’m not surprised that we are seeing flash flooding and I expect it to get worse in the future.

I am a professor at Newcastle University, where I lead a large research group focused on understanding changes to intense rainfall events and flash floods. Over the past eight years we’ve been working closely with colleagues at the UK Met Office to develop new very high-resolution climate models that can simulate these very intense summer storms and therefore predict what might happen in a warming climate.

Our models tell us that by 2080 summers in the UK will be much hotter and drier. Heatwaves will be more common. In fact a report released by the Met Office on the same day as the latest flash floods tells us that heatwaves are already happening more often. When Cambridge recently hit 38.7℃, the UK became one of 12 countries to break its national temperature record this year.

The world is warming. But although UK average summer rainfall is predicted to decrease, our models tell us that when it does rain it will be more intense than has been the case. Flash flooding in the UK is generally caused by intense rainstorms, where more than 30mm falls in an hour. Climate models predict these will happen five times more often by 2080.

Part of the reason for this is the simple fact that warmer air can hold more moisture. But that’s too simple: the availability of moisture also increases in areas close to warm oceans – warmer sea surface temperatures cause more moisture to be evaporated into the atmosphere, providing additional fuel for these intense storms. And here’s the scary bit: the Atlantic Ocean provides a vast source of moisture for storms in the UK.

But that’s not the whole story. Heavy, short rain storms are intensifying more rapidly than would be expected with global warming (what we call the Clausius-Clapeyron relationship). Research also suggests that more intense storms can themselves grow bigger, and with both the intensity of the rainfall and the spatial footprint of the storm increasing, the total rainfall in an “event” could double.

What’s more, the larger storms seem to have an ability to draw in more moisture from the surrounding area and become even more intense: the additional energy (heating) fuelling the uplift of air within the storm’s core draws in even more moisture from the surface, allowing them to grow even larger, with more potential for flooding. These also provide the perfect ingredients for large hail storms.

So, it is entirely consistent that we might expect both more heatwaves and more intense summer thunderstorms in a warmer climate. We also know which areas of the country are already susceptible to these flash floods from our analysis of historical records of flooding. Newspapers have reported on the dramatic impacts of these floods for centuries and this has allowed my team to reconstruct a flash-flooding history of the UK.

Certain parts of the country are highly vulnerable as their rivers respond quickly to rainstorms. These rivers tend to be found in steep, upland catchments underlain by non-permeable rocks, mainly in the north and west of the UK. High-risk catchments also include urban areas where the ground is also non-permeable, for entirely different reasons.

Many of the towns reported to have suffered “biblical” flooding recently have suffered repeated flooding through history, but perhaps not within living memory. For example, Whaley Bridge is mentioned twice in the flood chronologies for events in June 1872 and July 1881:

On 19th [June 1872] the Goyt was 12 to 14 feet above its normal level. At Whaley Bridge houses near the river were completely flooded and people were taken into the chapel and inns … in Macclesfield a woman and child were drowned when the river Bollin overflowed. Two reservoirs burst in the vicinity.

This rich archive of knowledge, including the prevalence of flooding in certain towns, even specific roads, is something we should draw upon in planning both the emergency response to these flash floods and for reducing their future impact. We can learn a lot from the past in how to manage the greater risks of flooding the future will bring.The Conversation

Hayley J. Fowler, Professor of Climate Change Impacts, Newcastle University

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

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New research could lead to a pregnancy test for endangered marsupials



Knew you were coming: a koala cub on the back of the mother.
Shutterstock/PARFENOV

Oliver Griffith, University of Melbourne

Many women realise they are pregnant before they’ve even done the test – perhaps feeling a touch of nausea, or tender, larger-than-usual breasts.

For a long time, biologists had thought most marsupials lacked a way to recognise a pregnancy.

But new research published today shows a marsupial mum knows – in a biological sense – when she’s carrying a young one before they make their journey to the pouch.




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This knowledge changes how we think pregnancy evolved in mammals. It may also help in breeding programs for threatened or endangered marsupials by contributing to new technologies such as a marsupial pregnancy test.

Marsupials do things differently

When people think of marsupials – animals that mostly rear their young in a pouch (although not all marsupials have a pouch) – kangaroos and koalas tend to spring to mind. But marsupials come in a range of shapes and sizes.

A red-necked wallaby with a joey.
Pixabay/sandid

Australia has about 250 species of marsupials, including wombats, possums, sugar gliders, the extinct Tasmanian tiger, and several endangered species such as the Tasmanian devil.

In addition to Australia’s marsupial diversity, there are also 120 marsupial species in South America – most of which are opossums – and just one species in North America, the Virginia opossum.

One thing all marsupials have in common is they give birth to very small, almost embryonic, young.

An opossum with two day old young.
Oliver Griffith, Author provided

Because marsupial pregnancy passes so quickly (12-40 days, depending on the species), and marsupial young are so small and underdeveloped at birth, biologists had thought the biological changes required to support the fetus through a pregnancy happened as a follow on from releasing an egg (ovulation), rather than a response to the presence of a fetus.

Marsupial pregnancy is quick

One way to explore the question of whether it is an egg or a fetus that tells the marsupial female to be ready for pregnancy is to look at the uterus and the placenta.

In marsupials, just like in humans, embryos develop inside the uterus where they are nourished by a placenta.

Previously, biologists thought all of the physiological changes required for pregnancy in marsupials were regulated by hormones produced in the ovary after ovulation.

If this hypothesis is right, then the uterus of pregnant opossums should look the same as the uterus of opossums that ovulate but don’t have the opportunity to mate with a male.

To test this hypothesis, my colleagues at Yale’s Systems Biology Institute and I examined reproduction in the grey short-tailed opossum.

Grey short tailed opossum with young.
Oliver Griffith

Signs of pregnancy

We looked at two groups of opossums: females that were exposed to male pheromones to induce ovulation, and females that were put with males so they could mate and become pregnant.

We then used microscopy and molecular techniques to compare females from the two groups. Contrary to the current dogma, we found that the uterus in pregnancy looked very different to those females that did not mate.

In particular, we found the blood vessels that bring blood from the mother to the placenta interface were only present in pregnancy. We also noticed that the machinery responsible for nutrient transport (nutrient transporting molecules) from the mother to the fetus was only produced in pregnancy.

While hormones may be regulating some aspects of maternal physiology, the mother is certainly detecting the presence of embryos and responding in a way that shows she is recognising pregnancy.

How this knowledge can help others

Given that recognition of pregnancy has now been found in both eutherian (formerly known as placental) mammals like ourselves and marsupials with the more ancestral reproductive characters, it appears likely that recognition of pregnancy is a common feature of all live bearing mammals.




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But this knowledge does more than satisfy our curiosity. It could lead to new technologies to better manage marsupial conservation. Several marsupials face threats in the wild, and captive breeding programs are an important way to secure the future of several species.

Two Tasmanian devils.
Pixabay/pen_ash

One such species is the Tasmanian devil, which faces extinction from a dangerous contagious cancer. Captive breeding programs may be one of the only mechanisms to ensure the species survives.

But management can be made more difficult when we don’t know which animals are pregnant. Our research shows that maternal signals are produced in response to the presence of developing embryos. With a bit more research, it may be possible to test for these signals directly.

New reproductive technologies are likely crucial for improving outcomes of conservation programs, and this work shows, that to do this we first need a better understanding of the biology of the animals we are trying to save.The Conversation

Oliver Griffith, ARC DECRA Fellow, University of Melbourne

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

Cannibalism helps fire ants invade new territory



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Fire ant stings can be deadly to people who have an allergic reaction to their venom.
Forest and Kim Starr/Flickr, CC BY-SA

Pauline Lenancker, James Cook University and Lori Lach, James Cook University

Tropical fire ants (Solenopsis geminata), originally from central and South America, are a highly aggressive, invasive ecological pest. Our new research has shed light on how they successfully establish new colonies.

An allergic reaction to painful tropical fire ant bites.
Pauline Lenancker, Author provided

While we don’t know exactly how widespread tropical fire ants are in Australia, they are well established around Darwin and Katherine, as well as on Christmas Island and Ashmore Reef. Disturbing one of their nests will result in many workers inflicting painful stings on the intruder, and can trigger an allergic reaction in some people.

When invasive ants move to a new region, the pioneers may be one or a few colonies. Because these pioneers are isolated, they often inbreed, which causes genetic problems in their offspring. But our new research, published in Scientific Reports, reveals how tropical fire ants use cannibalism to survive and spread, despite their low genetic diversity.




Read more:
Eradicating fire ants is still possible, but we have to choose now


Sons and daughters

Founding new colonies is how fire ants spread. Queens fly off to start their own colonies just after they have mated. It is a perilous journey – they need to avoid predators and find a good spot to start laying eggs. If queens do not quickly rear daughters that can forage, called workers, they will starve to death.

Queens can lay two different types of eggs: fertilised eggs, which will develop into workers, and unfertilised eggs, which will develop into males. Therefore, female workers have two copies of each gene (diploid), while males have a single copy of each gene (haploid). However, when an ant queen and her mate are closely related, a flaw in the sex determination system of ants causes half of the fertilised eggs to develop into diploid males instead of workers.

The role of males is only to mate with queens – they do not forage, and they die after they have mated. Queens founding a colony have no interest in producing males, because males will not feed them. What’s more, diploid males are often sterile, and their larvae are larger than worker larvae. Therefore, queens can waste precious resources feeding fat useless sons instead of workers.

We wanted to find out how common diploid males are in field colonies, and how queens could successfully start colonies despite them. Understanding how tropical fire ants spread, we hope, can help us stop them expanding their range.

Abandoned and eaten

Our field sampling of tropical fire ant colonies around Darwin revealed eight out of ten colonies produced diploid males.

We collected 1,187 queens that had just mated, and assigned them to start colonies on their own or with other queens.

We observed that in 34% of colonies producing diploid males, diploid male larvae were placed in the colony trash pile by the queens instead of being kept with the worker larvae. It is usual for ants to keep dead individuals away from the rest of the colony, but when we looked at some of these abandoned larvae under a microscope, we realised they were still alive.




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Curious Kids: do ants have blood?


Queens not only abandoned their sterile sons, they ate them. Three-quarters of the 109 sterile male larvae disappeared from the colonies within 12 days of when we first observed them. Because the queens were the only adult ants present in the colony, this means the queens were eating their diploid males or feeding them to their worker larvae.

This cannibalistic behaviour allowed the queens to redirect nutrients towards themselves or productive members of their colony. Diploid male larvae require more food than worker larvae to develop, so we expected queens from diploid male producing colonies to lose more weight than queens from colonies that only produced workers, but we found that was not the case. Queens with diploid males lost less weight or as much weight as queens from regular colonies, probably because they ate their sterile sons.

We also found queens who worked together in groups to start a colony reared more workers. Therefore, queens in groups would likely have a better chance of survival even if they produced sterile males. But in 6% of colonies, queens did not tolerate having housemates and dismembered other queens.

A queen dismembered by a tetchy rival.
Pauline Lenancker, Author provided

For tropical fire ants, cannibalising sterile sons and cooperative brood rearing among queens are two behavioural mechanisms for avoiding inbreeding costs. A third possible mechanism for the queens is to “sleep around”.

Promiscuity would increase the chance of mating with a genetically different male, and reduce the likelihood of producing diploid sons.

Queens only mate right before starting their colony and store the sperm in an organ called the spermatheca. We genetically analysed sperm from the spermatheca of 40 queens, but found no evidence queens had mated with more than one male.

Tropical fire ants are currently established on Ashmore Reef, a protected Australian Marine Park which is an important breeding site for seabirds and turtles. The invasive ant threatens this sanctuary by attacking seabird and turtle hatchlings. Accidental spreading of tropical fire ants to suitable habitats in the Northern Territory, Queensland and Western Australia would threaten invaluable ecosystems as well as our health and lifestyles.




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The current eradication program for the closely related red imported fire ant (Solenopsis invicta) in Queensland has been granted A$411 million over ten years, and failure to eradicate red imported fire ants could cost Australia A$1.65 billion per year in damaged crops, livestock harmed and people treated. The more we learn about invasive ant biology, the closer we are to new methods of preventing their spread.The Conversation

Pauline Lenancker, PhD student in biology and ecology, James Cook University and Lori Lach, Associate Professor, James Cook University

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

Guns, snares and bulldozers: new map reveals hotspots for harm to wildlife


File 20190312 86699 k7wj98.jpg?ixlib=rb 1.1
Human activity threatens many species across Africa’s savannahs.
Paul Mulondo/WCS, Author provided

James Allan, The University of Queensland; Christopher O’Bryan, The University of Queensland, and James Watson, The University of Queensland

The biggest killers of wildlife globally are unsustainable hunting and harvesting, and the conversion of huge swathes of natural habitat into farms, housing estates, roads and other industrial activities. There is little doubt that these threats are driving the current mass extinction crisis.

Yet our understanding of where these threats overlap with the locations of sensitive species has been poor. This limits our ability to target conservation efforts to the most important places.




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In our new study, published today in Plos Biology, we mapped 15 of the most harmful human threats – including hunting and land clearing – within the locations of 5,457 threatened mammals, birds and amphibians globally.

We found that 1,237 species – a quarter of those assessed – are impacted by threats that cover more than 90% of their distributions. These species include many large, charismatic mammals such as lions and elephants. Most concerningly of all, we identified 395 species that are impacted by threats across 100% of their range.

Mapping the risks

We only mapped threats within a species location if those threats are known to specifically endanger that species. For example, the African lion is threatened by urbanisation, hunting and trapping, so we only quantified the overlap of those specific hazards for this species.

This allowed us to determine the parts of a species’ home range that are impacted by threats and, conversely, the parts that are free of threats and therefore serve as refuges.

We could then identify global hotspots of human impacts on threatened species, as well as “coolspots” where species are largely threat-free.

The fact that so many species face threats across almost all of their range has grave consequences. These species are likely to continue to decline and possibly die out in the impacted parts of their ranges. Completely impacted species certainly face extinction without targeted conservation action.

Conversely, we found more than 1,000 species that were not impacted by human threats at all. Although this is positive news, it is important to note that we have not mapped every possible threat, so our results likely underestimate the true impact. For example, we didn’t account for diseases, which are a major threat to amphibians, or climate change, which is a major threat to virtually all species.

Hotspots and coolspots

We produced the first global map of human impacts on threatened species by combining the parts of each species range that are exposed to threats.
The overwhelmingly dominant global hotspot for human impacts on threatened species is Southeast Asia.

This region contains the top five countries with the most threats to species.
These include Malaysia, Brunei, Singapore, Indonesia and Myanmar.

The most impacted ecosystems include mangroves and tropical forests, which concerningly are home to the greatest diversity of life on Earth.

Hotspots of threats and threatened species richness.
Allan et al. Plos Biol., Author provided

We also created a global map of coolspots by combining the parts of species ranges that are free from human threats. This map identifies the last vestiges of wild places where threatened species have shelter from the ravages of guns, snares and bulldozers. As such, these are crucial conservation strongholds.

Coolspots include parts of the Amazon rainforest, the Andes, the eastern Himalayas, and the forests of Liberia in West Africa.

In many places, coolspots are located near hotspots. This makes sense because in species-rich areas it is likely that many animals are impacted whereas many others are not, due to their varying sensitivity to different threats.

Coolspots of unimpacted species richness.
Allan et al. Plos Biol., Author provided

What next?

There is room for optimism because all the threats we map can be stopped by conservation action. But we need to make sure this action is directed to priority areas, and that it has enough financial and political support.

An obvious first step is to secure threat-free refuges for particular species, via actions such as protected areas, which are paramount for their survival.




Read more:
An end to endings: how to stop more Australian species going extinct


To ensure the survival of highly impacted species with little or no access to refuges, “active threat management” is needed to open enough viable habitat for them to survive. For example, tiger numbers in Nepal have doubled since 2009, mainly as a result of targeted anti-poaching efforts.

Tackling threats and protecting refuges are complementary approaches that will be most effective if carried out simultaneously. Our study provides information that can help guide these efforts and help to make national and global conservation plans as successful as possible.


The authors acknowledge the contributions of Hugh Possingham, Oscar Venter, Moreno Di Marco and Scott Consaul Atkinson to the research on which this article is based.The Conversation

James Allan, Postdoctoral research fellow, School of Biological Sciences, The University of Queensland; Christopher O’Bryan, PhD Candidate, School of Earth and Environmental Sciences, The University of Queensland, and James Watson, Professor, The University of Queensland

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

Microplastics are getting into mosquitoes and contaminating new food chains



File 20180918 158240 1dtiepp.jpg?ixlib=rb 1.1

khlungcenter/Shutterstock

Amanda Callaghan, University of Reading and Rana Al-jaibachi, University of Reading

There is no doubt that plastic pollution in oceans is a growing worldwide problem. The internet is full of images of seabirds and other marine animals entangled in plastic waste, and animals starve because their guts are blocked with plastic bags.

But the problem goes much deeper than this. Much plastic pollution is in the form of microplastics, tiny fragments less than five micrometres in size and invisible to the naked eye. Our new research shows that these microplastics are even getting into tiny flying insects such as mosquitoes. And this means the plastic can eventually contaminate animals in a more unlikely environment: the air.

Microplastics can come from larger plastic items as they break down, but are also released directly into waste water in their millions in the form of tiny beads found in many cosmetic products including face wash and toothpaste (though these are now banned in many countries). Many tiny animals can’t tell the difference between their food and microplastics so end up eating them. Once inside an animal, the plastic can transfer via the food chain into fish and other creatures and eventually become a potential health problem for humans.

Mosquitoes leave the water and take microplastics with them.
Shaun Wilkinson/Shutterstock

By studying mosquitoes, we have found a previously unknown way for plastic to pollute the environment and contaminate the food chain. Our new paper, published in Biology Letters, shows for the first time that microplastics can be kept inside a water-dwelling animal as they grow from one life stage to another.

Although most microplastic research has focused on the sea, plastic pollution is also a serious problem in freshwater, including rivers and lakes. Much of the freshwater research has concentrated on animals that live in the water throughout their life. But freshwater insects such as mosquitoes start their lives (as eggs) in water and, after several stages, eventually fly away when they grow up.

Testing the mosquitoes

It occurred to us that aquatic insects might carry plastics out of the water if they were able to keep the plastics in their body through their development. We tested this possibility by feeding microplastics to mosquito larvae in a laboratory setting. We fed the aquatic young in their third larvae stage food with or without microplastic beads.

We then took samples of the animals when the larvae shed their skin to become larger fourth-stage larvae, when they transformed into a non-feeding stage called a pupa, and when they emerged from the water as a flying adult. We found the beads in all the life stages, although the numbers went down as the animals developed.

Plastics were retained as the mosquitoes went through different life stages.
Blue Ring Media/Shutterstock

We were able to locate and count the microplastic beads because they were fluorescent. We found beads in the gut and in the mosquito version of the kidney, an organ that we know survives the development process intact. This shows that not only do aquatic insects such as mosquitoes eat both sizes of microplastics, they can keep them in their gut and kidney as they develop from a feeding juvenile larva up to a flying adult.

In this way, any flying insect that spends part of its life in water can become a carrier of plastic pollution. And flying insects are eaten in their thousands by predatory insects in the air such as dragonflies as well as by birds and bats.

Our results have important implications since any aquatic insect that can eat microplastics in the water could potentially carry them in their body to their flying stage where they can move the plastics into new food chains. As a result, freshwater plastic pollution is a problem that has implications far beyond those of water quality and eventual marine pollution.

Clearly these results raise a number of questions, including what effect microplastics have on the survival and development of mosquitoes through their life stages. And we still need to examine the effect of different types and sizes of plastics on more species to see how widespread an issue this could become.The Conversation

Amanda Callaghan, Associate Professor of Zoology, University of Reading and Rana Al-jaibachi, PhD researcher, University of Reading

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

Jupiter’s new moons: an irregular bunch with an extra oddball that’s the smallest discovered so far



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A moon shadow on Jupiter, the red planet now has a dozen more moons added to the list or such orbiting bodies.
NASA/JPL-Caltech/SwRI/MSSS

Jonti Horner, University of Southern Queensland and Christopher C.E. Tylor, University of Southern Queensland

Jupiter is the largest planet in the Solar system and has been studied intensively for hundreds of years, so you might think there would be little left to find.

But earlier this month, researchers announced that another 12 moons have been added to the number of such bodies orbiting the giant planet.




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That brings the tally for Jupiter to a whopping 79, the most moons for any known planet. But where did these newly discovered moons come from, and what do they tell us about Jupiter and its place in the Solar system?

Moons: regular and irregular

The Solar system’s giant planets have two types of moon: regular and irregular.

Regular moons orbit close to their host, follow nearly circular paths, and move in the same plane as the planet’s equator. In some ways, these moons resemble miniature planetary systems, and we think that they formed in much the same manner as the planets around the Sun.

As the giant planets gathered material from the disk of gas and dust that surrounded the young Sun – a process known as accretion – they were surrounded by their own miniature disks. Within those disks, the regular moons grew, all in the planet’s equatorial plane.

Artist’s impression of a protoplanetary disk – a place where planets are born. Around young giant planets, similar disks give birth to regular moons.
ESO/L. Calçada

But the irregular moons are another story.

Their orbits are highly eccentric (elliptical) and inclined relative to the plane of their host planet’s equator. Many even move on retrograde orbits, travelling in the opposite direction to the spin and orbital motion of their hosts. And they are located much farther from their planet than their regular cousins.

Where do the irregulars come from?

Because of their wild orbits, the irregular moons cannot have formed in the same way as their regular cousins. Instead, they are thought to have been captured by their host planets as the process of planet formation came to an end.

We think that each giant planet captured just a handful of irregular moons – a number far smaller than we see today. Over the billions of years since, those moons were pummelled and destroyed by passing asteroids and comets, and collisions with other members of their swarm.

The shattered fragments of those ancient satellites form families of smaller moons – the irregulars we see today. For example, among Jupiter’s satellites we see at least four distinct families of irregular moons, each named after their largest member.

The motion of Jupiter’s irregular moons around the giant planet. The main plot (bottom, left) shows the orbits looking top-down, while the other (right and top) plots show the movement out of the plane of the system. Moons of the same colour are members of the same family.
Christopher Tylor

What does the new discovery add to our understanding?

If we consider Jupiter’s moons in terms of their orbital distance, and the direction in which they move, we can break them into three distinct groups.

The first consists of the inner eight moons, including the famous Galilean moons Io, Europa, Ganymede and Callisto, whose orbits lie in the plane of Jupiter’s equator, at distances less than 2 million kilometres.

The second group lies significantly farther from the planet, and move on orbits tilted by between 25° and 56° relative to Jupiter’s equator. These are the prograde irregulars – ten moons orbiting at distances between 7 million and 19 million km. Two of the new discoveries are members of this group.

The final and most populous group is the retrograde irregulars – 60 moons located between 19 million and 29 million kilometres from Jupiter, all moving on orbits inclined by between about 140° and 170° to Jupiter’s equator.

In other words, they orbit backwards, in the opposite direction to everything else. Nine of the new discoveries fall into this category.

Plot showing the three groups of moons orbiting Jupiter.
Carnegie Institution for Science/Roberto Molar-Candamosa

So that covers 11 of our new moons. What of the 12th? Well, it turns out that the most exciting of the new moons is an oddball – an object that does not fit into any of the groups mentioned above.

The oddball: Valetudo

The 12th new moon has tentatively been named Valetudo, after Jupiter’s mythological great granddaughter.

Valetudo is the dimmest of the newly discovered moons. At just a kilometre in diameter (or less), it is the smallest Jovian moon found to date.

The yellow lines point to the tiny moving speck of light, the newly discovered moon Valetudo.
Carnegie Institute for Science

In terms of its orbital distance, Valetudo lies bang in the middle of the retrograde irregulars – some 24 million kilometres from the giant planet. But its orbit is prograde – meaning that it moves in the direction of Jupiter’s rotation, and in the opposite direction to all other satellites in its vicinity.

Valetudo’s size and unusual orbit pose interesting questions.

How did something so small survive in the celestial firing range around Jupiter?

Could Valetudo be the final surviving remnant of a previously uncharted family, whittled to nothing by aeons of headlong flight into the retrograde irregulars?

Are there are other members of the Valetudo family out there, awaiting discovery?




Read more:
Water, water, everywhere in our Solar system but what does that mean for life?


Beyond these questions, Valetudo’s small size offers an important clue to the origin of the Jovian satellite system. Had Valetudo been on its current orbit while Jupiter was still accreting, it would have been too small to resist the drag of the inflowing gas. Like a ping pong ball in a gale, it would have been dragged inwards, to be devoured by the giant planet.

In other words, tiny Valetudo tells us that the process that created the irregular satellite families continued long after the formation of Jupiter was complete. In fact, that process likely continues even now, with occasional collisions tearing moons asunder, to birth new families of irregular worlds.

The ConversationWho knows? The next such collision might come when Valetudo runs into one of the retrograde irregulars. Given that their orbits cross, it may only be a matter of time.

Jonti Horner, Professor (Astrophysics), University of Southern Queensland and Christopher C.E. Tylor, PhD Candidate, Adjunct Lecturer, Assistant Examiner, University of Southern Queensland

This article was originally published on The Conversation. Read the original article.

New coal doesn’t stack up – just look at Queensland’s renewable energy numbers



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As the name suggests, Windy Hill near Cairns gets its fair share of power-generating weather.
Leonard Low/Flickr/Wikimedia Commons, CC BY

Matthew Stocks, Australian National University and Andrew Blakers, Australian National University

As the federal government aims to ink a deal with the states on the National Energy Guarantee in August, it appears still to be negotiating within its own ranks. Federal energy minister Josh Frydenberg has reportedly told his partyroom colleagues that he would welcome a new coal-fired power plant, while his former colleague (and now Queensland Resources Council chief executive) Ian Macfarlane urged the government to consider offering industry incentives for so-called “clean coal”.

Last month, it emerged that One Nation had asked for a new coal-fired power plant in north Queensland in return for supporting the government’s business tax reforms.

Is all this pro-coal jockeying actually necessary for our energy or economic future? Our analysis suggests that renewable energy is a much better choice, in terms of both costs and jobs.




Read more:
Solar PV and wind are on track to replace all coal, oil and gas within two decades


Renewables and jobs

Virtually all new generation being constructed in Australia is solar photovoltaics (PV) and wind energy. New-build coal power is estimated to cost A$70-90 per megawatt-hour, increasing to more than A$140 per MWh with carbon capture and storage.

Solar PV and wind are now cheaper than new-build coal power plants, even without carbon capture and storage. Unsubsidised contracts for wind projects in Australia have recently been signed for less than A$55 per MWh, and PV electricity is being produced from very large-scale plants at A$30-50 per MWh around the world.

Worldwide, solar PV and wind generation now account for 60% of global net new power capacity, far exceeding the net rate of fossil fuel installation.

As the graph below shows, medium to large (at least 100 kilowatts) renewable energy projects have been growing strongly in Australia since 2017. Before that, there was a slowdown due to the policy uncertainty around the Renewable Energy Target, but wind and large scale solar are now being installed at record rates and are expected to grow further.

Left axis/block colours: renewable energy employment by generation type in Australia; right axis/dotted lines: installed wind and large-scale solar generation capacity.
ABS/Clean Energy Council/Clean Energy Regulator, Author provided

As the graph also shows, this has been accompanied by a rapid increase in employment in the renewables sector, with roughly 4,000 people employed constructing and operating wind and solar farms in 2016-17. In contrast, employment in biomass (largely sugar cane bagasse and ethanol) and hydro generation have been relatively static.

Although employment figures are higher during project construction than operation, high employment numbers will continue as long as the growth of renewable projects continues. As the chart below shows, a total of 6,400MW of new wind and solar projects are set to be completed by 2020.

Renewable energy projects expected to be delivered before 2020.
Clean Energy Regulator

The Queensland question

Australia’s newest coal-fired power plant was opened at Kogan Creek, Queensland in 2007. Many of the political voices calling for new coal have suggested that this investment should be made in Queensland. But what’s the real picture of energy development in that state?

There has been no new coal for more than a decade, but developers are queuing up to build renewable energy projects. Powerlink, which owns and maintains Queensland’s electricity network, reported in May that it has received 150 applications and enquiries to connect to the grid, totalling 30,000MW of prospective new generation – almost all of it for renewables. Its statement added:

A total of more than A$4.2 billion worth of projects are currently either under construction or financially committed, offering a combined employment injection of more than 3,500 construction jobs across regional Queensland and more than 2,000MW of power.

As the map below shows, 80% of these projects are in areas outside South East Queensland, meaning that the growth in renewable energy is set to offer a significant boost to regional employment.

Existing and under-construction (solid) and planned (white) wind and solar farms in Queensland.
Qld Dept of Resources, Mines & Energy

Tropical North Queensland, in particular, has plenty of sunshine and relatively little seasonal variation in its climate. While not as windy as South Australia, it has the advantage that it is generally windier at night than during the day, meaning that wind and solar energy would complement one another well.

Renewable energy projects that incorporate both solar and wind in the same precinct operate for a greater fraction of the time, thus reducing the relative transmission costs. This is improved still further by adding storage in the form of pumped hydro or batteries – as at the new renewables projects at Kidston and Kennedy.

Remember also that Queensland is linked to the other eastern states via the National Electricity Market (NEM). It makes sense to build wind farms across a range of climate zones from far north Queensland to South Australia because – to put it simply – the wider the coverage, the more likely it is that it will be windy somewhere on the grid at any given time.

This principle is reflected in our work on 100% renewable electricity for Australia. We used five years of climate data to determine the optimal location for wind and solar plants, so as to reliably meet the NEM’s total electricity demand. We found that the most cost-effective solution required building about 10 gigawatts (GW) of new wind and PV in far north Queensland, connected to the south with a high-voltage cable.

Jobs and growth

This kind of investment in northern Queensland has the potential to create thousands of jobs in the coming decades. An SKM report commissioned by the Clean Energy Council estimated that each 100MW of new renewable energy would create 96 direct local jobs, 285 state jobs, and 475 national jobs during the construction phase. During operation those figures would be 9 local jobs, 14 state jobs and 32 national jobs per 100MW of generation.

Spreading 10GW of construction over 20 years at 500MW per year would therefore deliver 480 ongoing local construction jobs and 900 ongoing local operation jobs once all are built, and total national direct employment of 2,400 and 3,200 in construction and operations, respectively.

But the job opportunities would not stop there. New grid infrastructure will also be needed, for transmission line upgrades and investments in storage such as batteries or pumped hydro. The new electricity infrastructure could also tempt energy-hungry industries to head north in search of cheaper operating costs.




Read more:
The government is right to fund energy storage: a 100% renewable grid is within reach


One political party with a strong regional focus, Katter’s Australia Party, understands this. Bob Katter’s seat of Kennedy contains two large renewable energy projects. In late 2017, he and the federal shadow infrastructure minister Anthony Albanese took a tour of renewables projects across far north Queensland’s “triangle of power”.

The ConversationKatter, never one to hold back, asked “how could any government conceive of the stupidity like another baseload coal-fired power station in North Queensland?” Judging by the numbers, it’s a very good question.

Matthew Stocks, Research Fellow, ANU College of Engineering and Computer Science, Australian National University and Andrew Blakers, Professor of Engineering, Australian National University

This article was originally published on The Conversation. Read the original article.