How did our galaxy form? How do galaxies evolve over time? Where did the Sun’s lost siblings end up?
Three hours north-east of Parkes lies a remote astronomical research facility, unpolluted by city lights, where researchers are collecting vast amounts of data in an effort to unlock some of the biggest questions about our Universe.
Siding Spring Observatory, or SSO, is one of Australia’s top sites for astronomical research. You’ve probably heard of the Parkes telescope, made famous by the movie The Dish, but SSO is also a key character in Australia’s space research story.
In this episode, astrophysics student and Conversation intern Cameron Furlong goes to SSO to check out the huge Anglo Australian Telescope (AAT), the largest optical telescope in Australia.
And we hear about Huntsman, a new specialised telescope that uses off-the-shelf Canon camera lenses – a bit like those you see sports photographers using at the cricket or the footy – to study very faint regions of space around other galaxies.
Listen in to hear more about some of the most fascinating space research underway in Australia – and how, despite gruelling hours and endless paperwork, astronomers retain their sense of wonder for the night sky.
“For me, it means remembering how small I am in this enormous Universe. I think it’s very easy to forget, when you go about your daily life,” said Richard McDermid, an ARC Future Fellow and astronomer at Macquarie University.
“It’s nice to get back into it to a dark place and having a clear sky. And then you get to remember all the interesting and fascinating things, the size, the grandeur and the peacefulness of being in the dark.”
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For the thousand or so farmers in Canberra in the past week venting their anger at the federal government, it’s the Murray-Darling Basin Plan to blame for destroying their livelihoods and forcing them off the land.
We can’t comment directly on their claims about the basin plan. But our research, looking at the years 1991 to 2011, suggests little association between the amount of water extracted from the Murray-Darling river system for irrigation and total farmer numbers.
That’s not to say there aren’t fewer farms in the basin now than a decade ago – there are – but our analysis points to the more important drivers being the longer-term influences of changing climate, economics and demographics.
Indeed our study predicts another 0.5℃ increase in temperature by 2041 will halve the current number of farmers in the basin.
Hostility to water recovery
Over many decades state governments in Queensland, New South Wales, Victoria and South Australia licensed to farmers more entitlements to water than the river system could sustain. The basis of the Murray-Darling Basin Plan, enacted in 2012, was to rectify this through buying back about a quarter of all water licences to ensure an environmental flow.
A water entitlement, despite its name, does not guarantee a licence holder a certain amount of water. That depends on the water available, and that is determined by the states, which make allocations to each type of licence based on its type of security and current conditions.
With drought, farmers have seen their allocations severely cut back, sometimes to nothing. And partly because they see there’s still water in the River Murray, some are very angry.
Hostility to water recovery in fact predates the plan’s enactment, to when the federal government began buying back water entitlements in 2008. The Commonwealth now holds about 20% of water entitlements across the basin. More than two-thirds of these licences were recovered between 2008 and 2012.
Lack of correlation
Our research thus covers the period of most significant water buybacks. It also covers the period of the Millennium Drought, from 2001 to 2009, when the amount of water extracted from the river system dropped by about 70%.
Yet we see little evidence reduced water extractions led to more farmers exiting the industry.
As a very broad overview of the situation, the following graph illustrates the lack of correlation between measured water extraction in the Murray-Darling Basin and decreasing farmer numbers.
Water extractions have varied significantly between years, with a big decline over the decade of the 2000s even while farmers’ need for irrigated water increased due to lack of rain. La Niña brought record rains in 2010-11. The current drought across the basin took grip from about 2017.
Yet farmer numbers have declined at a relative steady rate. Within the basin in the time-period we modelled, they fell from about 90,000 in 1991 to 70,000 in 2011. This can be seen as part of a wider trend, with total farmer numbers in the four basin states falling from more than 230,000 in 1976 to barely 100,000 in 2016.
It might be argued that because irrigated farms make up only a quarter of all farms, the overall numbers might mask a greater correlation between water extractions and decline in irrigated farms. While the specific impacts on irrigation farming in recent years warrant further study, there’s no signal in our data pointing to extractions making a discernible contribution to farmer numbers throughout the basin.
Modelling farmer movement
Our findings are based on a specialised data set of population and agricultural census information from statistical local areas from 1991 to 2011. We used climate risk measures from 1961 onwards.
The following infographic shows the exit pattern of farmers by local area between 1991 and 2011.
We included as many climate, economic, farming, water and socio-demographic characteristics as possible to capture historical farmer movements and create a model able to predict movements based on variables such as average temperature.
Need for a multifaceted response
Overall our modelling results suggests the most significant and largest influences on farmer exit are rising temperatures and increased drought risk, followed by the economic factors that have have been reducing the proportion of the population engaged in farming for more than a century.
Declining commodity prices, higher unemployment and urbanisation are strongly associated with farmer exit. Urbanisation, for example, has made it attractive for farmers on city fringes to sell their land to property developers and exit the industry.
Research suggests irrigators in psychological distress are more likely to want the basin plan suspended. Our research suggests their distress is probably not primarily driven by the federal government buying water entitlements from licence holders who sold them willingly. Water recovery and the basin plan is simply an easier focal point of blame than the longer-term trends making the farming lifestyle less viable.
Nothing will be gained by focusing on short-term “fixes” at the cost of longer-term environmental harm. The problems facing all farmers cannot be addressed in isolation from longer-term global climate and economic trends.
As a society we have to decide what we value: do we want to see such a mass exodus of farmers from the land in the face of a drying climate? If not, future policy for the Basin must consider the real long-term drivers of farm exit and take a multi-faceted approach to climate change, water, land, drought and rural development.
A grim summer is likely for the rivers of the Murray-Darling Basin and the people, flora and fauna that rely on it. Having worked for sustainable management of these rivers for decades, I fear the coming months will be among the worst in history for Australia’s most important river system.
The 34 months from January 2017 to October 2019 were the driest on record in the basin. Low water inflows have led to dam levels lower than those seen in the devastating Millennium drought.
No relief is in sight. The Bureau of Meteorology is forecasting drier-than-average conditions for the second half of November and December. Across the summer, rainfall is also projected to be below average.
So let’s take a look at what this summer will likely bring for the Murray Darling Basin – on which our economy, food security and well-being depend.
Not a pretty picture
As the river system continues to dry up and tributaries stop flowing, the damaging effect on people and the environment will accelerate. Mass fish kills of the kind we saw last summer are again likely as water in rivers, waterholes and lakes declines in quality and evaporates.
Three million Australians depend on the basin’s rivers for their water and livelihoods. Adelaide can use its desalination plants and Canberra has enough stored water for now. But other towns and cities in the basin risk running out of water.
Some towns such as Armidale in New South Wales have been preparing to truck water to homes, at great expense. Water costs will likely increase to pay for infrastructure such as pumps and pipelines. The shortages will particularly affect Indigenous communities, pastoralists who need water for domestic use and livestock, irrigation farmers and tourism business on the rivers.
Red gum floodplain forests and other wetland flora will continue to die. Most of these wetlands have not had a drink since 2011. The desiccation, due to mismanagement and drought, is likely to see the return of hypersalinity – a huge excess of salt in the water – with river flows too weak to flush the salt out to sea.
If drought-breaking rains do come, as they did in 2010-11, this would create a new threat. Floodwaters would inundate leaf litter on the floodplains, triggering a bacterial feast that depletes the water of oxygen. These so-called “blackwater” events kill fish, crayfish and other aquatic animals.
The risk of blackwater events has largely arisen because government authorities have failed to manage water as they had agreed. In particular, the NSW and Victorian governments have not worked with farmers to allow managed river flows to inundate floodplains.
Despite the decades-old warnings, water management authorities in some catchments favoured water extraction by irrigators over rural communities, pastoralists and the environment. For example, the NSW Natural Resources Commission in September found that state government changes to water regulations brought forward the drying up of the Darling River by three years.
Since the basin plan was adopted in 2012 our federal and state political leaders have reduced the volume of real water needed to keep the rivers healthy, supply water to people and flush salt out to sea. For example, in May 2018 the federal government and Labor opposition agreed to reduce water allocated to the environment by 70 billion litres a year on average, without a legitimate scientific basis.
For most people, continents are Earth’s seven main large landmasses.
But geoscientists have a different take on this. They look at the type of rock a feature is made of, rather than how much of its surface is above sea level.
In the past few years, we’ve seen an increase in the discovery of lost continents. Most of these have been plateaus or mountains made of continental crust hidden from our view, below sea level.
One example is Zealandia, the world’s eighth continent that extends underwater from New Zealand.
Several smaller lost continents, called microcontinents, have also recently been discovered submerged in the eastern and western Indian Ocean.
But why, with so much geographical knowledge at our fingertips, are we still discovering lost continents in the 21st century?
We may have found another
In August, we undertook a 28-day voyage on the research vessel RV Investigator to explore a possible lost continent in a remote part of the Coral Sea. The area is home to a large underwater plateau off Queensland, called the Louisiade Plateau, which represents a major gap in our knowledge of Australia’s geology.
On one hand, it could be a lost continent that broke away from Queensland about 60 million years ago. Or it could have formed as a result of a massive volcanic eruption taking place around the same time. We’re not sure, because nobody had recovered rocks from there before – until now.
We spent about two weeks collecting rocks from this feature, and recovered a wide variety of rock types from parts of the seafloor as deep as 4,500m.
Most were formed through volcanic eruptions, but some show hints that continental rocks are hiding beneath. Lab work over the next couple of years will give us more certain answers.
Down to the details
There are many mountains and plateaus below sea level scattered across the oceans, and these have been mapped from space. They are the lighter blue areas you can see on Google Maps.
However, not all submerged features qualify as lost continents. Most are made of materials quite distinct from what we traditionally think of as continental rock, and are instead formed by massive outpourings of magma.
A good example is Iceland which, despite being roughly the size of New Zealand’s North Island, is not considered continental in geological terms. It’s made up mainly of volcanic rocks deposited over the past 18 million years, meaning it’s relatively young in geological terms.
The only foolproof way to tell the difference between massive submarine volcanoes and lost continents is to collect rock samples from the deep ocean.
Finding the right samples is challenging, to say the least. Much of the seafloor is covered in soft, gloopy sediment that obscures the solid rock beneath.
We use a sophisticated mapping system to search for steep slopes on the seafloor, that are more likely to be free of sediment. We then send a metal rock-collecting bucket to grab samples.
The more we explore and sample the depths of the oceans, the more likely we’ll be to discover more lost continents.
The ultimate lost continent
Perhaps the best known example of a lost continent is Zealandia. While the geology of New Zealand and New Caledonia have been known for some time, it’s only recently their common heritage as part of a much larger continent (which is 95% underwater) has been accepted.
The granite lying in the middle of the deep ocean there looked similar to what you would find around Cape Leeuwin, in Western Australia.
Other lost continents
However, not all lost continents are found hidden beneath the oceans.
Some existed only in the geological past, millions to billions of years ago, and later collided with other continents as a result of plate tectonic motions.
Their only modern-day remnants are small slivers of rock, usually squished up in mountain chains such as the Himalayas. One example is Greater Adria, an ancient continent now embedded in the mountain ranges across Europe.
Due to the perpetual motion of tectonic plates, it’s the fate of all continents to ultimately reconnect with another, and form a supercontinent.
But the fascinating life and death cycle of continents is the topic of another story.
There is a widespread belief dingoes are as good as extinct in New South Wales and nearly all dog-like animals in the wild are simply wild dogs. This belief is bolstered by legislation and policies in NSW, which have removed the word dingo and refer only to “wild dogs”.
But our research, recently published in the journal Conservation Genetics, challenges this assumption. We performed DNA ancestry testing, much like the ancestry tests available to people, on 783 wild canines killed as part of pest control measures in NSW.
Roughly one in four of the animals we tested were pure dingoes, and most were genetically more than three-quarters dingo. Only 5 of the 783 animals we tested turned out to be feral domestic dogs with no dingo ancestry.
This is not entirely surprising. Domestic pet and working dogs have lived alongside dingoes for centuries. Widespread killing of dingoes also increases the risk of hybridisation because it breaks family groups apart, giving domestic dogs the opportunity to mate with dingoes. Small populations also have a higher risk of hybridisation.
Hybridisation is generally considered detrimental to conservation because it alters the genome. In the case of dingoes, hybridisation is a problem because hybrids may be different to dingoes and “true” dingoes will eventually disappear.
While our results show dingoes still exist and their genes are predominate, their conservation will be greatly helped if we can prevent further interbreeding with domestic dogs.
Time to resurrect the dingo
Our study has important implications for both how we describe dingoes, and the future conservation of dingoes in NSW. Most of the animals labelled as wild dogs in NSW had predominantly dingo DNA, and fewer than 1% were actually feral dogs.
The term wild dog obfuscates the identity of wild animals whose genes are mostly dingo but sometimes carry dog genes. For all intents and purposes, these animals have dingo DNA, look like dingoes and behave like dingoes, and consequently should be labelled as dingoes rather than escaped pets gone wild.
Hotspots with high dingo ancestry have significant conservation value and urgently need new management plans to ensure these pure dingo populations are protected from hybridisation. These populations could be protected by restricting the killing of dingoes in these areas and restricting access to domestic dogs on public land such as state forests.
Further ancestry testing should be conducted in more areas to determine whether there are other pockets of high dingo purity in NSW.
Undeniably, dingoes can negatively impact livestock producers, especially sheep farmers. Non-lethal strategies such as electric or exclusion fencing, and livestock guarding animals such as dogs, llamas and donkeys, may balance the need to conserve dingoes and protect vulnerable livestock.
Sydney’s Inner West Council has a new policy that it is reported means “residents will no longer need to seek council approval to prune or remove trees within three metres of an existing home or structure”. Hold on, don’t reach for that chainsaw yet, because research shows good green infrastructure – trees, green roofs and walls – can add value to your home.
Green infrastructure offers significant, economic, social and environmental benefits. Urban greening is particularly important in dense urban areas like Sydney’s Inner West. Among its benefits, green infrastructure:
A 2017 study focusing on three Sydney suburbs found a 10% increase in street tree canopy could increase property values by A$50,000 on average. And the shading effect of trees can reduce energy bills by up to A$800 a year in Sydney. So retaining your green infrastructure – your trees, that is – can deliver direct financial gains.
On a larger scale, a collaborative project with Horticulture Innovation Australia Limited compared carbon and economic benefits from urban trees considering different landuses along sections of two roads in Sydney. Higher benefits were recorded for the Pacific Highway, with 106 trees per hectare and 58.6% residential land use, compared to Parramatta Road, with 70 trees per hectare and 15.8% residential.
For the Pacific Highway section, total carbon storage and the structural value of trees (the cost of replacing a tree with a similar tree) were estimated at A$1.64 million and A$640 million respectively. Trees were also valuable for carbon sequestration and removing air pollution.
Tree species, age, health and density, as well as land use, are key indicators for financial and wider ecosystem benefits. Specifically, urban trees in private yards in residential areas are vital in providing individual landowner and collective government/non-government benefits.
Challenges of growth
As populations grow, cities increase density, with less green infrastructure. The loss of greenery affects the natural environment and both human and non-human well-being.
Trees and other green infrastructure reduce some impacts of urban density. However, policies, government incentives and national priorities can produce progress in urban greening or lead to setbacks. In the case of the Inner West Council, for instance, the inability to fund monitoring of changes in tree cover could lead to reductions at the very time when we need more canopy cover.
Key concerns include installation and maintenance costs of green infrastructure (trees, green roofs and walls) in property development, and tree root damage. Knowledge and skills are needed to maintain green infrastructure. As a result, developers often consider other options more feasible.
In the short and long term, multiple performance benefits and economic and environmental values are needed to establish the viability of green infrastructure.
Stockholm shares many issues found in Australian cities. Stockholm houses over 20% of Sweden’s inhabitants, is increasing in density and redeveloping land to house a growing population. Aiming to be fossil-free by 2050, Stockholm acknowledges the built environment’s role in limiting climate change and its impacts.
In a research project we intend to use virtual reality (VR) and electroencephalogram (EEG) technology to assess perceptions of green infrastructure and reactions to it in various spaces.
Our project combines VR with EEG hardware, which measures human reactions to stimuli, to learn how people perceive and value green infrastructure in residential development.
Identifying all the value of green infrastructure
The many benefits of green infrastructure are both tangible and non-tangible. Economic benefits include:
those that directly benefit owners, occupants or investors – stormwater, increased property values and energy savings
other financial impacts – greenhouse gas savings, market-based savings and community benefits.
The various approaches to evaluating net value present a challenge in quantifying the value of green infrastructure. The most common – cost-benefit analysis, triple bottom line, life cycle assessment and life cycle costing – are all inadequate for evaluating trade-offs between economic and environmental performance. Conventional cost-benefit analysis is insufficient for investment analysis, as it doesn’t include environmental costs and benefits.
This is salient for green infrastructure, as owners/investors incur substantial direct costs, whereas various shareholders share the value. Perhaps, in recognition of the shared value, a range of subsidies could be adopted to compensate investors. Discounted rates anyone?
Recent efforts to evaluate the business case for green infrastructure include attempts to identify and quantify the creation of economic, environment and community/social value. However, an approach that includes a more comprehensive set of value drivers is needed to do this. This is the gap we aim to fill.
The results of experiments using VR and EEG technology and semi-structured interviews will provide a comprehensive understanding of green infrastructure. This will be correlated with capital and rental values to determine various degrees of willingness to pay.
With this knowledge, property developers in Sweden and Australia will be able to make a more informed and holistic business case for increasing green infrastructure for more liveable, healthy cities.
Maybe we can then persuade more people, including those in the Inner West, to hang onto their trees and leave the chainsaws in the garage.
While this is a laudable aim, the Inspector General – currently former Australian Federal Police Commissioner Mike Keelty – cannot hope to do this job without knowing how much water is being used in the Basin, by whom it is used, and where.
We urgently need a comprehensive audit to track the water in the Murray Darling Basin, so Inspector General Keelty can effectively investigate what he has already described as a “river ripe for corruption”.
Up the creek
Back in 2004 all governments in Australia agreed to track and provide information on water in terms of planning, monitoring, trading, environmental management, and on-farm management.
But water accounts still lack many essential features including double-entry accounting. When applied to water, double-entry accounts means that when one person consumes more water, someone else must consume less.
As a recent report from the Natural Resources Commission shows, without proper accounting, too much water is taken upstream – seriously harming downstream communities.
Wide support for an audit
An independent Basin-wide water audit is supported by communities and some irrigators.
In July NSW farmers voted in support of a federal royal commission into “the failings of the Murray Darling Basin Plan”. In our view, this vote shows many farmers support much greater transparency about how much water is being consumed, and by whom.
Double-entry water consumption accounts would help identify whether the billions of dollars planned in subsidies to increase irrigation efficiency will actually deliver value for money. But irrigation improvements only generate public benefits when more water is left or returns to flow in streams and rivers. Such flows are essential to healthy rivers and sustainable Basin communities.
Irrigators’ crops benefit from increased efficiency, so subsidies help farmers greatly – but it is very unclear whether they do anything for the public good. In fact, they seem to reduce the amount of water that finds its way back into the rivers. Research also shows infrastructure subsidies to improve irrigation efficiency typically increases water consumption at the Basin level.
For the average taxpayer, who has to justify every dollar they get from the government, it’s hard to imagine how some corporations can be given millions of dollars in subsidies without actual measurements (before and after) of the claimed water savings.
If Newstart recipients need to report and manage their income and have a job plan, as part of a system of appropriate checks and balances, shouldn’t the Australian government also be checking whether billions spent on subsidies for irrigators actually saves water?