Climate scientists explore hidden ocean beneath Antarctica’s largest ice shelf



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The team used hot-water drilling gear to melt a hole through Antarctica’s Ross Ice Shelf to explore the ocean below.
Christina Hulbe, CC BY-ND

Craig Stevens and Christina Hulbe

Antarctica’s Ross Ice Shelf is the world’s largest floating slab of ice: it’s about the size of Spain, and nearly a kilometre thick.

The ocean beneath, roughly the volume of the North Sea, is one of the most important but least understood parts of the climate system.

We are part of the multi-disciplinary Aotearoa New Zealand Ross Ice Shelf programme team, and have melted a hole through hundreds of metres of ice to explore this ocean and the ice shelf’s vulnerability to climate change. Our measurements show that this hidden ocean is warming and freshening – but in ways we weren’t expecting.

Instruments travelling 360m down a bore hole, from the snow-covered surface of the Ross Ice Shelf through to the ocean below the ice. After splash-down at about 60m, they move through the bubble-rich upper ice and down into the dark bubble-free lower reaches of the ice – passing embedded sediment that left the coast line centuries ago.



Read more:
Antarctic glacier’s unstable past reveals danger of future melting


A hidden conveyor belt

All major ice shelves are found around the coast of Antarctica. These massive pieces of ice hold back the land-locked ice sheets that, if freed to melt into the ocean, would raise sea levels and change the face of our world.

An ice shelf is a massive lid of ice that forms when glaciers flow off the land and merge as they float out over the coastal ocean. Shelves lose ice by either breaking off icebergs or by melting from below. We can see big icebergs from satellites – it is the melting that is hidden.

Because the water flowing underneath the Ross Ice Shelf is cold (minus 1.9C), it is called a “cold cavity”. If it warms, the future of the shelf and the ice upstream could change dramatically. Yet this hidden ocean is excluded from all present models of future climate.

This satellite map shows the camp site on the Ross Ice Shelf, Antarctica.
Ross Ice Shelf Programme, CC BY-ND

There has only been one set of measurements of this ocean, made by an international team in the late 1970s. The team made repeated attempts, using several types of drills, over the course of five years. With this experience and newer, cleaner, technology, we were able to complete our work in a single season.

Our basic understanding is that seawater circulates through the cavity by flowing in at the sea bed as relatively warm, salty water. It eventually finds its way to the shore – except of course this is a shoreline under as much as 800 metres of ice. There it starts melting the shelf from beneath and flows across the shelf underside back towards the open ocean.

Peering through a hole in the ice

The New Zealand team – including hot water drillers, glaciologists, biologists, seismologists, oceanographers – worked from November through to January, supported by tracked vehicles and, when ever the notorious local weather permitted, Twin Otter aircraft.

As with all polar oceanography, getting to the ocean is often the most difficult part. In this case, we faced the complex task of melting a bore hole, only 25 centimetres in diameter, through hundreds of metres of ice.

A team of ice drillers from Victoria University of Wellington used hot water and a drilling system developed at Victoria to melt a hole through hundreds of metres of ice.
Craig Stevens, CC BY-ND

But once the instruments are lowered more than 300m down the bore hole, it becomes the easiest oceanography in the world. You don’t get seasick and there is little bio-fouling to corrupt measurements. There is, however, plenty of ice that can freeze up your instruments or freeze the hole shut.

A moving world

Our camp in the middle of the ice shelf served as a base for this science, but everything was moving. The ocean is slowly circulating, perhaps renewing every few years. The ice is moving too, at around 1.6 metres each day where we were camped. The whole plate of ice is shifting under its own weight, stretching inexorably toward the ocean fringe of the shelf where it breaks off as sometimes massive icebergs. The floating plate is also bobbing up and down with the daily tides.

The team at work, preparing a mooring.
Christina Hulbe, CC BY-ND

Things also move vertically through the shelf. As the layer stretches toward the front, it thins. But the shelf can also thicken as new snow piles up on top, or as ocean water freezes onto the bottom. Or it might thin where wind scours away surface snow or relatively warm ocean water melts it from below.

When you add it all up, every particle in the shelf is moving. Indeed, our camp was not so far (about 160km) from where Robert Falcon Scott and his two team members were entombed more than a century ago during their return from the South Pole. Their bodies are now making their way down through the ice and out to the coast.

What the future might hold

If the ocean beneath the ice warms, what does this mean for the Ross Ice Shelf, the massive ice sheet that it holds back, and future sea level? We took detailed temperature and salinity data to understand how the ocean circulates within the cavity. We can use this data to test and improve computer simulations and to assess if the underside of the ice is melting or actually refreezing and growing.

Our new data indicate an ocean warming compared to the measurements taken during the 1970s, especially deeper down. As well as this, the ocean has become less salty. Both are in keeping with what we know about the open oceans around Antarctica.

We also discovered that the underside of the ice was rather more complex than we thought. It was covered in ice crystals – something we see in sea ice near ice shelves. But there was not a massive layer of crystals as seen in the smaller, but very thick, Amery Ice Shelf.

Instead the underside of the ice held clear signatures of sediment, likely incorporated into the ice as the glaciers forming the shelf separated from the coast centuries earlier. The ice crystals must be temporary.

None of this is included in present models of the climate system. Neither the effect of the warm, saline water draining into the cavity, nor the very cold surface waters flowing out, the ice crystals affecting heat transfer to the ice, or the ocean mixing at the ice fronts.

The ConversationIt is not clear if these hidden waters play a significant role in how the world’s oceans work, but it is certain that they affect the ice shelf above. The longevity of ice shelves and their buttressing of Antarctica’s massive ice sheets is of paramount concern.

Craig Stevens, Associate Professor in Ocean Physics and Christina Hulbe, Professor and Dean of the School of Surveying (glaciology specialisation)

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

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We need to ‘climate-proof’ our sports stadiums


Paul J Govind, Macquarie University

For many Australians summer is synonymous with cricket and tennis. But as Australian summers become more prone to extreme heat conditions, sustainable and climate-adaptable stadium design has become a leading consideration for both sporting codes and governments.

The final Ashes test played at the Sydney Cricket Ground recently showed that the cricketing community must adapt to heatwaves made worse by climate change.


Read more: Just not cricket – how climate change will make sport more risky


And in recent years the Australian Open has produced many stories of both tennis players and spectators suffering in extreme heat. And more are expected over the two weeks of the current tournament.

As the New South Wales government embarks on a hugely expensive rebuild of major stadiums across Sydney, now is a good time to ask whether major Australian sports venues are adequately “climate-proofed” for a warming future.

Climate change is literally a ‘game changer’

The Climate Council released a report in 2016 detailing the risks of extreme heat to human health, exacerbated by climate change. It recommends that extreme heat adaptation is incorporated into urban planning and building design policies.

Following the final Ashes Test, the International Cricket Council (ICC) was criticised for failing to provide a clear policy protecting players in conditions of extreme heat.

Other sporting codes have considered how a game should be managed in conditions of extreme heat but have mostly focused exclusively on the welfare of players and field officials.

Spectators are also vulnerable to extreme heat

As the 2018 Australian Open is now under way, it’s worth a look back at the 2014 event, when the tennis players and spectators suffered as temperatures soared over 41ºC.

Accounts emerged of spectators collapsing and attendances declined as Melbourne endured a catastrophic heatwave. Subsequent renovations to Melbourne Park featured important heat management aspects.

In 2015, Margaret Court Arena received LEED (Leadership in Energy and Environmental Design) Gold Certification. LEED is the world-leading rating system for green buildings.

LEED certification provides a framework to measure sustainability through the design, construction and operation of a building through its life cycle. This is achieved by incentivising reductions in energy, water and building materials consumption, while at the same time enhancing the health of occupants.

In order to manage heatwaves the stadium redesign included a retractable roof, allowing air conditioning and lighting to be reduced, and reflective roof coating to reflect over 70% of the sun’s heat.

A larger open space that provides more shade and indoor areas was included in Rod Laver Arena for the benefit of both tennis fans and concertgoers.

Taking the LEED in Sydney

The new Western Sydney Stadium is the first NSW stadium to undergo such a reconstruction to bring it up to LEED standards.

The stadium rebuild is legally a “major project” and classified as State Significant Development under the Environmental Planning and Assessment Act 1979 (NSW) (EP&A Act). This means the NSW planning minister was responsible for assessing and approving the rebuilding of the stadium.

The NSW government pointed out that the new stadium will feature a Gold LEED energy and environment rating.

The stadium and the surrounds are designed to reduce the occurrence of “heat islands”. Measures to cool heat islands include planting over 200 trees in the surrounding precinct and using softer and cooler pavement materials.

The minister noted in the assessment report that the LEED certification targets reduced energy and water consumption through efficient air conditioning and a design that maximises natural ventilation and insisted that the stadium increase its own supply of renewable energy to power air conditioning and refrigerants.

The gold standard in environmental design

While some headway is being made in Australia, LEED has already been widely applied to stadium design and construction in North America. At least 30 certified stadiums have been constructed.

HOK’s stadium in Atlanta is officially the first LEED Platinum-certified professional sports stadium in the United States.
HOK

The new HOK-designed stadium in Atlanta is the first LEED Platinum-certified sports stadium. Aside from its retractable roof for extreme heat protection, the 185,000-square-metre venue is designed to conserve water and energy. It uses 47% less water than baseline standards and includes a five-hectare adjacent green space, 4,000 solar panels, bike valets and charging stations for electric cars.

Stadium design needs to plan for climate change

The recent Ashes Test matches and current Australian Open are stark reminders that approvals for stadium design need to consider the relationship between climate change adaptation and extreme heat. If the LEED certification fails to provide for human health it is incumbent upon government to insist that more is done for the welfare of spectators.


Read more: Extreme heat in sport: why using a fixed temperature cut-off isn’t as simple as it seems


Climate change will continue to increase the risks from extreme heat to levels not previously experienced. The design of our sporting stadiums must manage heatwaves with the welfare of both players and spectators in mind as temperatures continue to rise in the future.

The ConversationThe impacts of extreme heat during the 2018 Ashes series presented a serious challenge – and the Australian sporting summer is far from over.

Paul J Govind, Lecturer in Enviromental Law, Macquarie University

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

Climate politics in 2018: another guide for the perplexed


Marc Hudson, University of Manchester

As I predicted a year ago, 2017 was another vicious and bloody-minded year in Australian climate politics. Yet the political bickering belied the fact that it was actually a great year for green energy.

Nowhere was that more in evidence than in South Australia, which got its big battery inside 100-day deadline, with the world’s biggest solar thermal plant set to begin construction this year. Elsewhere, Prime Minister Malcolm Turnbull talked up the prospects of the Snowy 2.0 hydro storage project.

Yet the politics remain as rancorous as ever. The federal government unveiled its National Energy Guarantee in November, after Chief Scientist Alan Finkel’s Clean Energy Target proved too rich for some in the Coalition. Just before Christmas, the long-awaited climate policy review was released, and immediately branded as weak.

Both issues are unresolved, and are set to loom large on the landscape this year. But what else is on the horizon?

Domestic bliss

We should always expect the unexpected. But perhaps the most predictable “unexpected” event would be a heatwave, prompting one or more of our creaking coal-fired power stations to have a meltdown. Maybe the “Big Banana” (as Elon Musk’s battery has been branded) will step in again, as it already has.

If fossil fuel power stations fail again, expect to see the culture war heat up again, with coal’s defenders using ever more twisting logic to defend their dear dinosaur technology.

Barring the apocalypse, on March 17 South Australians will go to the polls. Will Premier Jay Weatherill be returned to power, to continue his long-running stoush with federal energy minister Josh Frydenberg? Will heatwaves and power outages help or hinder him? At the moment, polls have former senator Nick Xenophon as putative premier. My crystal ball is hazy on what this would mean for energy policy.

In April there will be a meeting of the COAG Energy Council at which the NEG proposal will come under scrutiny. Expect it to be bloody. State governments have demanded more modelling, so they can compare the NEG to Finkel’s Clean Energy Target that Finkel suggested, and an emissions intensity scheme.

Current SA treasurer Tom Koutsantonis has raised several concerns with the NEG, arguing that it doesn’t give a big enough boost to renewables, and would do nothing to break up the power of the big “gentailers”, who generate and sell electricity.

“To proceed, the NEG would require unanimous support at COAG, so this policy is either years away, or won’t happen at all,” Koutsantonis said. Expect a long-running pitched battle if Weatherill and Koutsantonis are still about, and perhaps even if they’re not.

Funding issues

In the May budget the Turnbull government is going to have to decide what to do about the Emissions Reduction Fund, the centrepiece of former prime minister Tony Abbott’s Direct Action policy, which replaced his predecessor Julia Gillard’s carbon price.

The fund, which lets companies bid for public money to implement emissions-reduction projects, started at A$2.55bn, and there is about A$260 million left.

Connected to these decisions are questions over whether and how the fund’s “safeguard mechanism”, which is supposed to stop the system being gamed, will be modified.

Among the many criticisms levelled at the government’s 2017 climate policy review, released with little fanfare the week before Christmas, was the proposal to make the already flexible mechanism even more flexible, so as to “reduce the administrative and auditing costs” for businesses.

The government’s climate review also says that in 2018 it will start the process of developing a long-term emissions-reduction strategy, to be finalised by 2020. It has promised to “consult widely” with businesses, the community, states and territories, and other G20 nations. Time will tell exactly how wide this consultation turns out to be, although anything would be better than the Trump Adminstration’s systematic removal of the term “climate change” from federal websites.

Overseas business

The climate review suggests that the Turnbull government will push for more international carbon trading. An unlikely alliance has formed against the idea, consisting of those who view carbon credits as buck-passing, as well as Tony Abbott, who thinks Australian money “shouldn’t be going offshore into dodgy carbon farms in Equatorial Guinea and Kazakhstan”.

His stance has already been branded as nonsensical by the business lobby – who, it must be said, stand to benefit significantly from carbon trading.

On the diplomatic front, the United Nations will hold a “2018 Talanoa dialogue” process, featuring a series of meetings in which major economies will come under pressure to upgrade their climate commitments to meet the Paris target.

As Giles Parkinson notes, Australia had probably thought that they could get away with no climate target upgrades until around 2025.

In October the Intergovernmental Panel on Climate Change will release a report on the impacts of global warming of 1.5℃ – the more ambitious of the Paris Agreement’s twin goals – and the emissions pathways we would need to follow to get there. Expect climate deniers to get their retaliation in first.

The next UNFCCC Conference of the Parties (number 24 in a never-ending series) will be held in December in Katowice, in Poland’s coal heartland.

Others’ predictions and my own

So, prediction is very difficult, but most of us like to indulge. Reneweconomy asked Frydenberg, his opposite number Mark Butler, and the Greens’ climate spokesperson Adam Bandt what they thought was coming up.

Frydenberg talked up “innovative projects” like this summer’s demand response trial and Snowy 2.0.

Butler gloomily forecasted more policy chaos and renewables-blaming, while Bandt was sunnier, predicting that 2018 will be “the year of energy storage” as the economics for commercial and household batteries begin to stack up.

Bandt also thinks the public debate will heat up as extreme weather hits, and the national security implications become (more) obvious.

Well, it will be fun to watch whether the Minerals Council pulls its horns in under the threat of BHP pulling out. Early signs would suggest not.

Will other mining companies defect?

Will battery storage get a grip on the grid?

Will Adani pull the plug on Carmichael under continuing pressure from campaigners?

Well, here are some safe predictions.

Donald Trump will continue being Donald Trump. Liberal and National backbenchers will put pressure on Turnbull to do what John Howard did when George W. Bush was in the Oval Office – namely, get into the United States’ slipstream and take advantage of the lowered ambition.

There will be further stunning developments in energy storage, and the prices of solar and wind will continue to plummet.

The ConversationMeanwhile, Australia’s emissions will continue to rise, as will the atmosphere’s carbon dioxide concentrations.

Marc Hudson, PhD Candidate, Sustainable Consumption Institute, University of Manchester

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

Australia’s climate in 2017: a warm year, with a wet start and finish


Linden Ashcroft, Australian Bureau of Meteorology; Blair Trewin, Australian Bureau of Meteorology, and Skie Tobin, Australian Bureau of Meteorology

The Bureau of Meterology’s Annual Climate Statement, released today, confirms that 2017 was Australia’s third-warmest year on record, and our maximum temperature was the second-warmest. Globally, 2017 is likely to be one of the world’s three warmest years on record, and the warmest year without an El Niño.


Read more: Explainer: El Niño and La Niña


But looking at the big picture can obscure some regional record-breaking features. Victoria experienced its driest June on record, and September saw New South Wales and the Murray–Darling Basin record their driest September since nationwide records begin in 1900. Sydney’s Observatory Hill had its driest September since records started there in 1858.

The southwest of Western Australia had its warmest maximum temperatures on record for June. Northern Australia also recorded its warmest dry season for maximum temperature.

A field in Moree, New South Wales. The state had its driest September on record.
Bureau of Meteorology, Author provided

This warm year occurred despite the fact that, unlike 2016, there was no strong El Niño or La Niña pattern in the Pacific Ocean for much of the year, and the Indian Ocean Dipole remained neutral.


Read more: What is the Indian Ocean Dipole?


Wet in the northwest, dry in the east

Australia’s average total rainfall in 2017 was 504mm, somewhat above average. But the annual average hides large swings from very dry months to damaging downpours, and large differences from the east to the west of the country.

The year began wet, particularly in the west. Tropical lows brought heavy rainfall across the Northern Territory, South Australia and Western Australia during January and February, and many places in Western Australia set new records for their wettest summer day. It was our fourth-wettest January on record nationally.

Severe Tropical Cyclone Debbie crossed the south Queensland coast in late March and tracked southwards delivering torrential rainfall along the east coast. Several locations received up to a metre of rainfall in two days, and major flooding occurred from Bowen, in Queensland, to Lismore, in New South Wales.

The west of Western Australia was dry for much of autumn and early winter. Winter rainfall was also low across southern Australia under the effect of a subtropical ridge stronger and further south than usual.

Heavy rain across much of Queensland and northern New South Wales during October meant that Bundaberg received more than 400% of its average rainfall for October in the first three weeks of the month.

In late December, Tropical Cyclone Hilda became the first cyclone to make landfall in the 2017-18 Australian cyclone season, bringing heavy rains around Broome.

Australia’s rainfall in 2017.
Bureau of Meteorology, Author provided

A hot start

It might not have always felt like it, but 2017 was much warmer than average. It was the third-warmest year on record for Australia, 0.95℃ above average, and the warmest on record for Queensland and New South Wales. Sea surface temperatures were also much warmer than average around Australia, although not as warm as 2016.

Australia’s average temperatures in 2017.
Bureau of Meteorology, Author provided

New South Wales experienced its warmest summer on record, and heatwaves affected much of eastern Australia during the first two months of the year. At the same time, rain kept summer temperatures below average in the west.

The high temperatures around eastern Australia continued into autumn, over both land and sea. Coral bleaching affected the Great Barrier Reef again, the first time mass bleaching events have occurred in consecutive years.

Warm days but chilly winter nights

As winter set in, the lack of rainfall and clouds led to warm sunny days. The southwest of Western Australia had its warmest maximum temperatures on record for June.


Read more: Australia’s record-breaking winter warmth linked to climate change


However the clear skies also meant frosty mornings across much of Victoria, southern New South Wales, South Australia and Tasmania. Canberra, which is known for its chilly nights, had its lowest winter mean minimum temperature since 1982. Some locations, including Sale in Victoria, and Deniliquin and West Wyalong in New South Wales, had their coldest night on record during the first few days of July.

Meanwhile, northern Australia recorded its warmest dry season on record for maximum temperature. The mean maximum temperature for northern Australia was 2℃ above average for the five months from May to September, beating the previous record set in 2013 by almost half a degree.

A warm finish

In September, northerly air flow brought the warm air over to the east of the country, with the month culminating in a week of exceptional heat. New South Wales recorded its first ever 40℃ in September – not once, but on two separate days – and some places beat their previous hottest September day on record by more than 3 degrees.

Late-season frosts in early November caused damage to crops in western Victoria, but the cold was soon replaced by prolonged heat thanks to a slow moving high pressure system parked over the Tasman Sea.

The northerly winds and sunny days meant that many places in Victoria and Tasmania had record runs of days warmer than 25℃, and nights warmer than 15℃. It was Tasmania’s warmest November on record, with temperatures more typical of late summer than late spring.

The long-lived weather system led to record-breaking November sea surface temperatures between Tasmania and New Zealand, which also had a very warm and dry November. The southeast of the country finished 2017 with our first heatwave of the summer in mid-December.

The bigger picture

Global mean temperature anomalies relative to 1961-1990, 1880–2017.
Bureau of Meteorology, Author provided

The World Meteorological Organization releases the final global mean temperature for 2017 in mid-January. This enables it to collect as many observations as possible from different countries. But the January to November global average can give a pretty good idea of where 2017 will sit: one of the world’s three warmest years on record.

The planet has seen plenty of extreme weather events over the past year, including hurricanes, flooding, and devastating bushfires.

The ConversationGlobal temperatures have increased by about one degree since 1900. Mean global temperatures have been above average every year since 1985, and all of the ten warmest years have occurred between 1998 and the present. Seven of Australia’s ten warmest years have now occurred since 2005.

Linden Ashcroft, Climatologist, Australian Bureau of Meteorology; Blair Trewin, Climate scientist, Australian Bureau of Meteorology, and Skie Tobin, Climatologist, Australian Bureau of Meteorology

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

Climate scientists and policymakers need to trust each other (but not too much)



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Trust is everything.
oneinchpunch/Shutterstock.com

Rebecca Colvin, Australian National University; Christopher Cvitanovic, University of Tasmania; Justine Lacey, CSIRO, and Mark Howden, Australian National University

At a time when the effects of climate change are accelerating and published science overwhelmingly supports the view that humans are responsible for the rate of change, powerful groups remain in denial across politics, the media, and industry. Now more than ever, we need scientists and policymakers to work together to create and implement effective policy which is informed by the most recent and reliable evidence.

We know that trust between scientists and policymakers is important in developing policy that is informed by scientific evidence. But how do you build this trust, and how do you make sure that it genuinely leads to positive outcomes for society?


Read more: Nature v technology: climate ‘belief’ is politics, not science


In response to these questions, our recent Perspective in Nature Climate Change explores the dynamics of trust at the interface of climate science and policy.

We suggest that while trust is an important component of the science-policy dynamic, there can be such a thing as “too much” trust between scientists and policymakers.

Understanding this dynamic is crucial if we are to deliver positive outcomes for science, policy, and the society that depends on their cooperation.

What happens when there is ‘too much’ trust?

Trust between climate scientists (researchers in a range of disciplines, institutions, and organisational settings) and policymakers (civil servants in government departments or agencies who shape climate policy) is useful because it enhances the flow of information between them. In a trusting relationship, we can expect to see a scientist explaining a new finding directly to a policymaker, or a policymaker describing future information needs to a scientist.

Together, this arrangement ideally gives us science-led policy, and policy-relevant science.

But as scholars of trust have warned, there is a point beyond which these positive benefits of trust can turn sour.

Think about a hypothetical situation in which a scientist and policy-maker come to trust each other deeply. What happens if one of them starts to become loose with the facts, or fails to adhere to professional standards? Is their trusting counterpart more, or less, likely to identify the poor behaviour and respond appropriately?

Over time, a trusting relationship may evolve into a self-perpetuating belief of trustworthiness based on the history of the relationship. This is where scientists and policymakers may find themselves in a situation of “too much” trust.

We know that science advances by consensus, and that this consensus is shaped by rigorous research and review, and intense debate and scrutiny. But what if (as in the hypothetical example described above) a policy-maker’s trust in an individual scientist means they bypass the consensus and instead depend on that one scientist for new information? What happens if that scientist is – intentionally or unintentionally – wrong?

More trust is not always best. ‘Too much’ trust can cause perverse outcomes at the science-policy interface.
Adapted from Stevens et al. (2015)

When you have “too much” trust, the benefits of trust can instead manifest as perverse outcomes, such as “blind faith” commitments between parties. In a situation like this, a policymaker may trust an individual scientist so much that they do not look for signs of misconduct, such as the misrepresentation of findings.

Favouritism and “capture” may mean that some policymakers provide information about future research support only to selected scientists, denying these opportunities to others. At the same time, scientists may promote only their own stream of research instead of outlining the range of perspectives in the field to the policymakers, narrowing the scope of what science enters the policy area.

“Cognitive lock-in” might result, where a policymaker sticks to a failing policy because they feel committed to the scientist who first recommended the course of action. For example, state-of-the-art climate forecasting tools are available in the Pacific but are reportedly underused. This is partly because the legacy of trusting relationships between scientists and policymakers in the region has led them to continue relying on less sophisticated tools.

“Too much” trust can also lead to overly burdensome obligations between scientists and policymakers. A scientist may come to hold unrealistically high expectations of the level of information a policymaker can share, or a policymaker may desire the production of research by an unfeasible deadline.

What’s the right way to trust?

With this awareness of the potentially negative outcomes of “too much” trust, should we abandon trust at the climate science-policy interface all together?

No. But we can – and should – develop, monitor, and manage trust with acknowledgement of how “too much” trust may lead to perverse outcomes for both scientists and policy-makers.

We should aim for a state of “optimal trust”, which enjoys the benefits of a trusting relationship while avoiding the pitfalls of taking too trusting an approach.

We propose five key strategies for managing trust at the climate science-policy interface.

  • Be explicit about expectations for trust in a climate science-policy relationship. Climate scientists and policy-makers should clarify protocols and expectations about behaviour through open discussion as early as possible within the relationship.

  • Transparency and accountability, especially when things go wrong, are critical to achieving and maintaining a state of optimal trust. When things do go wrong, trust repair can right the relationship.

  • Implement systems for monitoring trust, such as discussion groups within scientific and policy organisations and processes of peer review. Such approaches can help to identify the effects of “too much” trust – such as capture, cognitive lock-in, or unrealistically high expectations.

  • Manage staff churn in policy and scientific organisations. When scientists or policy-makers change role or institution, handing over the trusting relationships can help positive legacies and practices to carry on.

  • Use intermediaries such as knowledge brokers to facilitate the flow of information between science and policy. Such specialists can promote fairness and honesty at the science-policy interface, increasing the probability of maintaining ‘optimal trust’.


Read more: Is this the moment that climate politics and public opinion finally match up?


Embracing strategies such as these would be a positive step toward managing trust between scientists and policymakers, both in climate policy and beyond.

The ConversationIn this time of contested science and highly politicised policy agendas, all of us in science and policy have a responsibility to ensure we act ethically and appropriately to achieve positive outcomes for society.

Rebecca Colvin, Knowledge Exchange Specialist, Australian National University; Christopher Cvitanovic, Research Fellow, University of Tasmania; Justine Lacey, Senior Social Scientist, CSIRO, and Mark Howden, Director, Climate Change Institute, Australian National University

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

What’s the net cost of using renewables to hit Australia’s climate target? Nothing


Andrew Blakers, Australian National University; Bin Lu, Australian National University, and Matthew Stocks, Australian National University

Australia can meet its 2030 greenhouse emissions target at zero net cost, according to our analysis of a range of options for the National Electricity Market.

Our modelling shows that renewable energy can help hit Australia’s emissions reduction target of 26-28% below 2005 levels by 2030 effectively for free. This is because the cost of electricity from new-build wind and solar will be cheaper than replacing old fossil fuel generators with new ones.


Read more: Want energy storage? Here are 22,000 sites for pumped hydro across Australia


Currently, Australia is installing about 3 gigawatts (GW) per year of wind and solar photovoltaics (PV). This is fast enough to exceed 50% renewables in the electricity grid by 2030. It’s also fast enough to meet Australia’s entire carbon reduction target, as agreed at the 2015 Paris climate summit.

Encouragingly, the rapidly declining cost of wind and solar PV electricity means that the net cost of meeting the Paris target is roughly zero. This is because electricity from new-build wind and PV will be cheaper than from new-build coal generators; cheaper than existing gas generators; and indeed cheaper than the average wholesale price in the entire National Electricity Market, which is currently A$70-100 per megawatt-hour.

Cheapest option

Electricity from new-build wind in Australia currently costs around A$60 per MWh, while PV power costs about A$70 per MWh.

During the 2020s these prices are likely to fall still further – to below A$50 per MWh, judging by the lower-priced contracts being signed around the world, such as in Abu Dhabi, Mexico, India and Chile.

In our research, published today, we modelled the all-in cost of electricity under three different scenarios:

  • Renewables: replacement of enough old coal generators by renewables to meet Australia’s Paris climate target

  • Gas: premature retirement of most existing coal plant and replacement by new gas generators to meet the Paris target. Note that gas is uncompetitive at current prices, and this scenario would require a large increase in gas use, pushing up prices still further.

  • Status quo: replacement of retiring coal generators with supercritical coal. Note that this scenario fails to meet the Paris target by a wide margin, despite having a similar cost to the renewables scenario described above, even though our modelling uses a low coal power station price.

The chart below shows the all-in cost of electricity in the 2020s under each of the three scenarios, and for three different gas prices: lower, higher, or the same as the current A$8 per gigajoule. As you can see, electricity would cost roughly the same under the renewables scenario as it would under the status quo, regardless of what happens to gas prices.

Levelised cost of electricity (A$ per MWh) for three scenarios and a range of gas prices.
Blakers et al.

Balancing a renewable energy grid

The cost of renewables includes both the cost of energy and the cost of balancing the grid to maintain reliability. This balancing act involves using energy storage, stronger interstate high-voltage power lines, and the cost of renewable energy “spillage” on windy, sunny days when the energy stores are full.

The current cost of hourly balancing of the National Electricity Market (NEM) is low because the renewable energy fraction is small. It remains low (less than A$7 per MWh) until the renewable energy fraction rises above three-quarters.

The renewable energy fraction in 2020 will be about one-quarter, which leaves plenty of room for growth before balancing costs become significant.

Cost of hourly balancing of the NEM (A$ per MWh) as a function of renewable energy fraction.

The proposed Snowy 2.0 pumped hydro project would have a power generation capacity of 2GW and energy storage of 350GWh. This could provide half of the new storage capacity required to balance the NEM up to a renewable energy fraction of two-thirds.

The new storage needed over and above Snowy 2.0 is 2GW of power with 12GWh of storage (enough to provide six hours of demand). This could come from a mix of pumped hydro, batteries and demand management.

Stability and reliability

Most of Australia’s fossil fuel generators will reach the end of their technical lifetimes within 20 years. In our “renewables” scenario detailed above, five coal-fired power stations would be retired early, by an average of five years. In contrast, meeting the Paris targets by substituting gas for coal requires 10 coal stations to close early, by an average of 11 years.

Under the renewables scenario, the grid will still be highly reliable. That’s because it will have a diverse mix of generators: PV (26GW), wind (24GW), coal (9GW), gas (5GW), pumped hydro storage (5GW) and existing hydro and bioenergy (8GW). Many of these assets can be used in ways that help to deliver other services that are vital for grid stability, such as spinning reserve and voltage management.


Read more: Will the National Energy Guarantee hit pause on renewables?


Because a renewable electricity system comprises thousands of small generators spread over a million square kilometres, sudden shocks to the electricity system from generator failure, such as occur regularly with ageing large coal generators, are unlikely.

Neither does cloudy or calm weather cause shocks, because weather is predictable and a given weather system can take several days to move over the Australian continent. Strengthened interstate interconnections (part of the cost of balancing) reduce the impact of transmission failure, which was the prime cause of the 2016 South Australian blackout.

The ConversationSince 2015, Australia has tripled the annual deployment rate of new wind and PV generation capacity. Continuing at this rate until 2030 will let us meet our entire Paris carbon target in the electricity sector, all while replacing retiring coal generators, maintaining high grid stability, and stabilising electricity prices.

Andrew Blakers, Professor of Engineering, Australian National University; Bin Lu, PhD Candidate, Australian National University, and Matthew Stocks, Research Fellow, ANU College of Engineering and Computer Science, Australian National University

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