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.
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.
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 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.
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.
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 impacts of extreme heat during the 2018 Ashes series presented a serious challenge – and the Australian sporting summer is far from over.
In the northern part of Australia’s Great Barrier Reef, the future for green sea turtles appears to be turning female.
A recent study has revealed that climate change is rapidly leading to the feminisation of green turtles in one of the world’s largest populations. Only about 1% of these juvenile turtles are hatching male.
Among sea turtles, incubation temperatures above 29ºC produce more female offspring. When incubation temperatures approach 33ºC, 100% of the offspring are female. Cooler temperatures yield more males, up to 100% near a lower thermal limit of 23ºC. And if eggs incubate at temperatures outside the range of 23-33ºC the risk of embryo malformation and mortality becomes very high.
As current climate change models foresee increases in average global temperature of 2 to 3ºC by 2100, the future for these turtles is in danger. Worryingly, warmer temperatures will also lead to ocean expansion and sea-level rise, increasing the risk of flooding of nesting habitats.
How scientists are tackling the problem
Green sea turtles’ sensitivity to incubation temperatures is such that even a few degrees can dramatically change the sex ratio of hatchlings.
Sea turtles are particularly vulnerable because they have temperature-dependent sex determination, or TSD, meaning that the sex of the offspring depends on the incubation temperature of the eggs. This is the same mechanism that determines the sex of several other reptile species, such as the crocodilians, many lizards and freshwater turtles.
Scientists and conservationists are well aware of how future temperatures may threaten these species. For the past two decades they have been investigating the incubation conditions and resulting sex ratios at several sea turtle nesting beaches worldwide.
This is mostly done using temperature recording devices (roughly the size of an egg). These are placed inside nest chambers among the clutch of eggs, or buried in the sand at the same depth as the eggs. When a clutch hatches (after 50 to 60 days) the device is recovered and the temperatures recorded are analysed.
Research has revealed that most nesting beaches studied to date have sand temperatures that favour female hatchling production. But this female bias is not immediately a bad thing, because male sea turtles can mate with several females (polygyny). So having more females actually enhances the reproductive potential of a population (i.e. more females equals more eggs).
But given that climate change will likely soon increase this female bias, important questions arise. How much of a female bias is OK? Will there be enough males? What is the minimum proportion of males to keep a sustainable population?
These questions are being investigated. But, in the meantime, alarming reports of populations with more than 99% of hatchlings being female stress the urgency of science-based management strategies. These strategies must be designed to promote (or maintain) cooler incubation temperatures at key nesting beaches to prevent population decline or even extinction.
The challenge of reversing feminisation
There are two general approaches to the problem:
mitigate impacts at the most endangered nesting beaches
Several studies emphasise that the natural shading native vegetation provides is essential to maintain cooler incubation temperatures. Thus, a key conservation action is to protect beach vegetation, or reforest nesting beaches.
Coastal vegetation also protects the nesting beach against wave erosion during storms, which will worsen under climate change. This strategy further requires coastal development to allow for buffer zones. Construction setback regulations should be enforced or implemented.
When natural shading is not an option, clutches of eggs can be moved either to more suitable beaches, or to hatcheries with artificial shading. Researchers have tested the use of synthetic shade cloth and found it is effective in reducing sand and nest temperatures.
Other potential strategies involve adding light-coloured sand on top of nests. This can help by absorbing less solar radiation (heat) compared to darker sand. Beach sprinklers have also been tested to simulate the cooling effect of rainfall.
The effectiveness of these actions has yet to be fully tested, but there is concern about some potential negative side effects. For example, excess water from sprinklers may cause fungal infections on eggs.
Finally, as much as mitigation measures are important, these are always short-term solutions. In the long run, prevention is always the best strategy, i.e. protecting the nesting beaches that currently produce more males from deforestation, development and habitat degradation.
Our recent research on the largest green turtle population in Africa reports unusually high male hatchling production. We found almost balanced hatchling sex ratios (1 female to 1.2 males). We attributed this mostly to the cooling effect of the native forest.
This, and similar nesting beaches, should be designated as priority conservation sites, as they will be key to ensuring the future of sea turtles under projected global warming scenarios.
Sea turtles face an uncertain future
Sea turtles are resilient creatures. They have been around for over 200 million years, surviving the mass extinction that included the dinosaurs, and enduring dramatic climatic changes in the past.
There is potential for these creatures to adapt, as they did before. This could be through, for example, shifting the timing of nesting to cooler periods, changing their distribution to more suitable habitats, or evolution of critical incubation temperatures that produce males.
But the climate today is changing at an unprecedented rate. Along with the feminisation of these turtles in the northern Great Barrier Reef, sea turtles globally face many threats from humans. These include problems associated with by-catch, poaching, habitat degradation and coastal development, plus a history of intense human exploitation.
In 2018, the prevalence of these species depends now more than ever on the effectiveness of conservation measures.
Both issues are unresolved, and are set to loom large on the landscape this year. But what else is on the horizon?
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.
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.
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.
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.
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.
A major challenge for managing such a large increase in sea level is our limited understanding of what impact this scale of change might have on humanity.
While there are excellent online resources to model the local physical impacts of sea level rise, the recent geological past can provide important insights into how humans responded to dramatic increases in sea level.
The last ice age
At the height of the last ice age some 21,000 years ago, not only were the Greenland and Antarctic ice sheets larger than they are today, but 3km-high ice sheets covered large parts of North America and northern Europe.
This sucked vast amounts of water out of our planet’s oceans. The practical upshot was sea level was around 125m lower, making the shape of the world’s coastlines distinctly different to today.
As the world lurched out of the last ice age with increasing temperatures, the melting ice returned to the ocean as freshwater, dramatically increasing sea levels and altering the surface of our planet.
Arguably nowhere experienced greater changes than Australia, a continent with a broad continental shelf and a rich archaeological record spanning tens of millennia.
A bigger landmass
For most of human history in Australia, lower sea levels joined mainland Australia to both Tasmania and New Guinea, forming a supercontinent called Sahul. The Gulf of Carpentaria hosted a freshwater lake more than twice the size of Tasmania (about 190,000km2).
Our study shows that lower sea levels resulted in Australia growing by almost 40% during this time – from the current landmass of 7.2 million km2 to 9.8 million km2.
The coastlines also looked very different, with steep profiles off the edge of the exposed continental shelf in many areas forming precipitous slopes and cliffs.
Imagine the current coastline where the Twelve Apostles are on Victoria’s Great Ocean Road and then extend them around much of the continent. Many rivers flowed across the exposed shelf to the then distant coast.
When things warmed up
Then between 18,000 and 8,000 years ago, global climate warmed, leading to rapid melting of the ice sheets, and seeing sea levels in the Australian region rising from 125m below to 2m above modern sea levels.
Tasmania was cut off with the flooding of Bass Strait around 11,000 years ago. New Guinea was separated from Australia with the flooding of Torres Strait and creation of the Gulf of Carpentaria around 8,000 years ago.
We found that 2.12 million square km, or 20-29% of the landmass – a size comparable to the state of Queensland – was lost during this inundation. The location of coastlines changed on average by 139km inland. In some areas the change was more than 300km.
Much of this inundation occurred over a 4,000-year period (between 14,600 and 10,600 years ago) initiated by what is called Meltwater Pulse 1A, a period of substantial ice sheet collapse releasing millions of cubic litres of water back into the oceans.
During this period, sea levels rose by 58m, equivalent to 14.5mm per year. On the ground, this would have seen movement of the sea’s edge at a pace of about 20-24m per year.
Impacts of past sea level rise
The potential impacts of these past sea-level changes on Aboriginal populations and societies have long been a subject of speculation by archaeologists and historians.
Most tribal groups on the coast 18,000 years ago must have slowly lost their entire territory […] a succession of retreats must have occurred. The slow exodus of refugees, the sorting out of peoples and the struggle for territories probably led to many deaths as well as new alliances.
Archaeologists have long recognised that Aboriginal people would have occupied the now-drowned continental shelves surrounding Australia, but opinions have been divided about the nature of occupation and the significance of sea-level rise. Most have suggested that the ancient coasts were little-used or underpopulated in the past.
Our data show that Aboriginal populations were severely disrupted by sea-level change in many areas. Perhaps surprisingly the initial decrease in sea level prior to the peak of the last ice age resulted in people largely abandoning the coastline, and heading inland, with a number of archaeological sites within the interior becoming established at this time.
During the peak of the last ice age, there is evidence on the west coast that shows people continued to use marine resources (shellfish, fish etc) during this time, albeit at low levels.
A shrinking landmass
With the onset of the massive inundation after the end of the last ice age people evacuated the coasts causing markedly increased population densities across Australia (from around 1 person for every 355 square km 20,000 years ago, to 1 person every 147 square km 10,000 years ago).
Rising sea levels had such a profound impact on societies that Aboriginal oral histories from around the length of the Australian coastline preserve details of coastal flooding and the migration of populations.
We argue that this squeezing of people into a landmass 22% smaller – into inland areas that were already occupied – required people to adopt new social, settlement and subsistence strategies. This may have been an important element in the development of the complex geographical and religious landscape that European explorers observed in the 18th and 19th centuries.
Following the stabilisation of the sea level after 8,000 years ago, we start to see the onset of intensive technological investment and manipulation of the landscape (such as fish traps and landscape burning).
We also see the formation of territories (evident by marking of place through rock art) that continues to propagate up until the present time. All signs of more people trying to survive in less space.
So what are the lessons of the past for today? Thankfully, we can show that past societies survived rapid sea level change at rates slightly greater than those projected in our near future, albeit with population densities far lower than today.
But we can also see that sea level rise resulted in drastic changes to where people lived, how they survived, what technology they used, and probable modifications to their social, religious and political ways of life.
In today’s world with substantially higher population densities, managing the relocation of people inland and outside Australia, potentially across national boundaries, may provide to be one of the great social challenges of the 21st century.
On Wangkumarra land, in the corner-country near the borders of Queensland, New South Wales and South Australia, stands an ancient stone arrangement. It has been placed to the side of a huge complex, rivalling Stonehenge, featuring megaliths polished, carved and placed to balance precariously on each other.
They should fall, but they don’t, as this is a place where time runs differently. In contrast to the Western “arrow of time”, the small rock formation pictured shows the non-linear, infinitely interconnected cycle of time followed by the First People who built the site and used it over millennia. It is a stone calendar, aligned within a fraction of a millimetre to the points of the compass.
The key to understanding this temporal reality is the shape of the stone calendar. It is round, not a continuum. There is no beginning or end, and as such, there is no “New Year”. Seasons do not serve as a basis for linear metaphors of new life in spring to death in winter.
Instead, both seasons and humans are viewed as components of cycles. Around Australia, Indigenous languages vary in both the number of season words in their lexicon and their precise meaning. This is at least partly due to the very different kinds of weather experienced around the year in different parts of the country.
A tour of the seasons
In the Tiwi islands just to the north of Darwin there are three major seasons named in the Tiwi language: Kumunupunari (the dry season of fire and smoke); Tiyari (the season of hot, humid weather); and Jamutakari (the wet season of daily rain and full rivers). These three seasons subsume 13 overlapping, more precisely defined seasons.
For example, in the Mumpikari season (which overlaps with the start of the Jamutakari “wet season”) the first rains after the dry time make the ground soft and muddy enough to retain the footprints left by possums returning to their trees, which makes the possums easier to track when hunting.
Understanding the meaning of a word like Mumpikari “season of muddy possum tracks” entails knowledge of the type of weather experienced at that time (first rains following a long dry spell), consequent changes in the local ecology (muddy ground), as well as changes in human behaviour and potential sources of food (it’s a good time to hunt and eat possums).
The changes in weather, ecology and potential food sources over the course of the year are dramatic, but vary significantly across a continent as large as Australia. The season experienced in tropical Cape York in January is very different to January in Tasmania. Likewise, the middle of the year brings radically different weather patterns to the tropical north, temperate south and central desert regions respectively.
The definitions of seasonal terms tell us a lot about the ecology that a language is spoken within and how speakers interact with it. In the Warlpiri language of the Tanami Desert, for example, several seasonal terms (such as karapurda) make reference to the prominent westerly winds that blow at the onset of the hot season.
Common food sources also feature prominently in the definitions of season terms, such as mangkajingi, “season of year when goannas are easily found in shallow burrows”. In the Bardi language of the Dampier Peninsula (WA), the build up to the wet season is named Lalin and colloquially referred to as “married turtle season”, because the mating turtles are a prized food source at this time.
In Gulumoerrgin (Larrakia) language group, spoken around Darwin, the year is divided into seven named seasons. Each of these seasons is associated with distinctive patterns of weather, but also changes in flora, fauna, and human activity. The Gurrulwa season, or “big wind time”, is heralded by the flowering of wattles, which in turn indicates that the local stingrays are plentiful and good to eat. The flowering of the Yellow Kapok at this time in turn indicates that it is the time for important traditional ceremonies to be held.
These connections between species are often cemented in language by using a single word. In the Dalabon language of Arnhem land, the word yawok has two meanings: (1) a species of yam (Dioscorea bulbifera); and (2) a species of grasshopper (Caedicia spp.). To the untrained observer, the yam and grasshopper might appear to have little in common.
But for Dalabon speakers, this naming practice is a useful mnemonic that helps them remember that the yam is ripe for harvest precisely at that time of year when the grasshopper’s mating call can be heard. Similar principles have been found to underpin the naming of plant and animal species in languages such as Bininj Gun-Wok and Ndjébbana.
The words of any language tell us a lot about the history of its speakers; who they’ve been in contact with, where and how they have lived. This is certainly true of the English calendar months. It is also seen in the number and nature of the seasons named by different Indigenous communities, from the tropical north of Australia to the chillier climates down south.
With around 370 languages and many hundreds more dialects originally spoken in Australia, it is impossible to do justice to the wealth and variety of traditional systems of tracking time and seasons. But a recurrent theme is the interconnectedness of human activities and the cycle of changes in flora and fauna that attend the tilting of the earth’s axis.