In relation to this article responding to Climate Council CEO Amanda McKenzie’s claim that heatwaves are “worsening” and “hot days” have doubled in Australia in the last 50 years, a spokesperson for the Climate Council gave the following responses. Questions from The Conversation are in bold.
Could you please provide a source, or sources, to support Ms McKenzie’s statement that heatwaves are “worsening” and hot days have doubled in the last 50 years?
Specifically, there has been an increase of 0.2 days/year since 1957 which means, on average, that there are almost 12 more days per year over 35°C.
What did Ms McKenzie mean by the terms “heatwaves” and “hot days”?
Hot days – the number of hot days, defined as days with maximum temperatures greater than 35°C.
Heatwaves – three days or more of high maximum and minimum temperatures that is unusual for that location.
Furthermore, heatwaves have several significant characteristics. These include (i) frequency characteristics, such as the number of heatwave days and the annual number of summer heatwave events; (ii) duration characteristics, such as the length of the longest heatwave in a season; (iii) intensity characteristics, such as the average excess temperature expected during a heatwave and the hottest day of a heatwave; and (iv) timing characteristics, including the occurrence of the first heatwave event in a season.
Is there any other comment you would like us to include in the article?
Climate change – driven largely by rising atmospheric carbon dioxide concentrations from the burning of coal, oil and gas – is increasing temperatures and cranking up the intensity of extreme weather events globally and in Australia.
Temperature records tumbled yet again during Australia’s ‘Angry Summer’ of 2016/17. In just 90 days, more than 205 records were broken around Australia.
Heatwaves and hot days scorched the major population centres of Adelaide, Brisbane, Canberra, Melbourne and Sydney, as well as the rural and regional heartlands of eastern Australia. The most severe heatwave of this Angry Summer began around January 31 and continued until February 12, with the highest temperatures recorded from February 9-12.
This heatwave was made twice as likely to occur because of climate change, while the extreme heat in New South Wales over the entire summer season was at least 50 times as likely to occur because of climate change.
The severe heatwave of February 2017 that spread across much of Australia’s south, east and interior caused issues for the South Australian and New South Wales energy systems. In New South Wales around 3,000MW of coal and gas capacity was not available when needed in the heatwave (roughly the equivalent of two Hazelwood Power Stations).
In South Australia, 40,000 people were left without power for about half an hour in the early evening while temperatures were over 40°C. This heatwave highlights the vulnerability of our energy systems to extreme weather.
In Australia, the most commonly used definition (and the one used by the Climate Council) is from the Bureau of Meteorology (BOM). It provided the first national definition of a heatwave in January 2014, describing it as:
A period of at least three days where the combined effect of excess heat and heat stress is unusual with respect to the local climate. Both maximum and minimum temperatures are used in this assessment.
The BOM uses a metric called the “excess heat factor” to decide what heat is “unusual”. It combines the average temperature over three days with the average temperature for a given location and time of year; and how the three day average temperature compares to temperatures over the last 30 days.
Researchers, including Australian climate scientist Dr Sarah Perkins-Kirkpatrick, are trying to standardise the definitions of “heatwaves” and “hot days” and create a framework that allows for more in-depth studies of these events.
Are heatwaves ‘worsening’?
There’s not a large body of research against which to test this claim. But the research we do have suggests there has been an observable increase in the frequency and intensity of heatwaves in Australia. Research published in 2013 found a trend towards more heat waves in Australia between 1951 and 2008.
A review paper published in 2016 assessed evidence from multiple studies and found that heatwaves are becoming more intense and more frequent for the majority of Australia.
The following chart shows heatwave days per decade from 1950 to 2013, highlighting a trend toward more heatwave days in Australia over time:
Have hot days ‘doubled’ in the last 50 years?
While the number of “hot days” (as defined by the BOM) has not doubled over the last 50 years, as McKenzie said, the number of “record hot days” certainly has. “Record hot days” are days when the maximum temperature sets a new record high.
Given that McKenzie made her statement on a fast paced live TV show, it’s reasonable to assume she was referring to the latter. Let’s look at both figures.
The BOM defines “hot days” as days with a maximum temperature higher than 35°C. The BOM data show there were more hot days in Australia in 2013, 2014, 2015 and 2016 than in any of the 50 years from 1966 to 2016 (the last year for which data are available).
In fact, there were more hot days in the years 2013-2016 than in any other year as far back as 1910. If we compare the decades 1966-76 and 2006-16, we see a 27% increase in the number of hot days.
The Bureau of Meteorology has issued its seasonal forecast for the winter, and it should be a warm one throughout southern Australia and the very tips of the Top End.
After a warm autumn, particularly in the east, this winter is forecast to be warmer and drier than usual – especially over the southern half of the continent.
Not your everyday weather forecast
Seasonal forecasts are very different from your standard weather forecast for the day or week ahead.
Instead of giving exact temperatures or rainfall totals, the bureau provides probabilities of above or below average conditions. So if the bureau says there’s a 70% chance of above-average temperatures, that’s the same as saying there’s a 30% chance it will be below average.
These probabilities are estimated by looking at what’s going on in the Pacific and Indian Oceans, as they strongly influence Australia’s weather, and by running a set, or “ensemble”, of forecasts through the bureau’s seasonal forecast model.
A very different winter from last year
Looking back to last year, while most of Australia experienced quite a warm winter, it was also very wet. Nationally, it was the second-wettest winter on record, with the centre and the east of the continent copping the brunt of the rain. Last winter’s weather was driven by very warm seas in the east Indian Ocean, which meant a lot more moisture was available to deliver rainfall across the country.
This year we are seeing roughly average temperatures in the Indian Ocean, and a slight El Niño in the Pacific. This increases the likelihood of warmer, drier weather for the winter as a whole.
Winter heatwaves on the way
So can we expect to keep the thick coats in the wardrobe and enjoy some winter warmth? Perhaps.
Of course, winter heatwaves aren’t going to bring 40℃ days to Melbourne and Sydney, but we could get warm spells and temperatures into the low twenties in Sydney or the high teens in Melbourne.
It’s also worth noting that the seasonal forecast only looks at whether we’re going to have temperatures above or below average. It’s harder to predict whether we will see bursts of heat, or if the weather will consistently be a little bit warmer than normal through much of the season.
We’ve seen an increase in heatwaves in late autumn and winter in Australia over the past few decades. Notably, in May 2014 Sydney and large areas of southeast Australia had much-warmer-than-average conditions. A study found that this heat event was made at least 20 times more likely by the human influence on the climate.
We’re also seeing trends towards less frequent cold conditions in winter, with frosts becoming much rarer over a substantial part of Australia. Most of Australia is also experiencing fewer cold days. These trends are in line with what we expect from climate change, and are projected to continue.
While winter warmth can be pleasant for most of us, it can also cause plenty of problems. Warmer and drier winters can worsen drought – an effect we saw during the Millennium Drought in southeast Australia – by increasing evaporation and reducing soil moisture.
So while many of us in the south will gladly welcome a warm winter, it’s not good news for everyone. If warm and dry conditions were to persist into spring and summer – which is a distinct possibility with an El Niño watch in place – that would pose even more problems in terms of bushfire prevention, among other hazards.
While it may not lead directly to impassioned critiques of climate governance, nor immediately sort the sceptics from the believers, talk of brewing storms or dried-up reservoirs now carries with it a whiff of trepidation about our collective forecasts.
Bridging the divide
Despite the growing politicisation of weather talk, weather and climate are usually understood as empirically distinct bodies of knowledge. Climate is, to quote British comedy duo Armstrong and Miller, “a long-term trend averaged over many years”, as opposed to weather, “which is what’s going on outside the window right now”.
The problem with this distinction is that climate change’s global reach and extended time scale can make it seem like it is happening somewhere else and to someone else (or, indeed, not at all). So perhaps the distinction is not useful for the cultural processes of adaptation. What might happen if we were to breach official definitions and disciplinary lines and think of the two things together?
Closing the distance between weather as event and climate as pattern can accomplish several things. Most obviously, it reminds us that there is a relationship between the two. Without weather, there would be nothing to amalgamate as climate.
While one heatwave does not equate to “climate change”, many and increasing ones give us pause to wonder. Leslie Hughes and Will Steffen are doing the data-driven work in this regard.
In other words, bringing climate and weather together can remind us that climate change is not only about abstract calculations on scales too big for our small and ultimately short-lived human forms to fathom.
Thinking about weather as part of climate underscores that we experience climate change with and on our bodies; climate change is lived by us at a very human scale, too.
The daily experience of weathering
So, what would it mean to harness the daily, mundane intrusions of weather as political? In contrast to terms like resilience (complicit with neoliberal incitements of bootstrapping) or sustainability (which suggests we get to keep something intact), weathering invites us to consider what we will lose along the way.
Weathered bodies, weathered houses, weathered cars, weathered clothes, weathered relationships, weathered dreams – these all bear scars of what has worn them down, and of what they have been asked to carry, to survive, and to hack.
Bringing this sense of lived climate change to our everyday perception is neither an easy nor comfortable thing. For one, discomfort is not a place we generally like to dwell for long. In a more political sense, though, paying attention to the weather as something in which we are intimately implicated, not just a disconnected backdrop to our human dramas, reminds us we are weather-makers too.
On a stable planet, nature provided a background against which the human drama took place; on the unstable planet we’re creating, the background becomes the highest drama.
This could be the epigraph for the Anthropocene.
Even in wealthy, climate-controlled places, weather inserts a reminder of one’s privilege, or luck, or vulnerability, or hardship, into those once mundane spaces. We may bemoan the slipping away of vacuous weather chats — “does everything have to be political?” — but perhaps noticing the weather can become an opening for everyday engagement in the politics of climate change instead.
In gender and cultural studies and the environmental humanities, rather than trying to leave weather-talk pregnant with fear, anticipation or political outrage, we are explicitly thinking with and through the weather to develop strategies for a rigorous and political response to climate change.
One way we are doing this is through a tactic or practice we call “weathering” – that is, cultivating attunement to how our own bodies, and bodies of others, experience weather. This includes how we and they manage it architecturally, technologically, professionally and socially.
We don’t all weather equally
Through the concept of “weathering”, our work forces a confrontation between large-scale climate data and embodied sociopolitical experiences that are too often treated as separate. It also underscores the politics and activism we hope this tactic can engender.
Such attentive acclimatisation reveals that, even though we’re all in the same planetary boat when it comes to global warming, we’re not all in it in the same way. This is something ecofeminists and environmental justice scholars have long known. Our work helps articulate how difference also marks our apparently banal encounters with the weather.
At a “Hacking the Anthropocence” symposium in Sydney this month, scholars, artists and activists are responding to the idea of “weathering”. The variety of experience that such a provocation reveals is astounding.
For Anne Werner’s and Genevieve Derwent’s work growing chickens on Autumn Farm and Cameron Muir’s reflections on life jackets for refugees, the weather holds a very different significance and function. Climate change is undoubtedly political – but all the more so because of these uneven individual and collective experiences of the weather.
Other kinds of bodily, socioeconomic, historical and geopolitical differences further complicate how we weather the world. When it comes to rising sea levels, or dried-up water holes, for example, racism, colonialism and gendered labour are all significant. Weathering as a concept thus asks us to think about what else, besides meteorological phenomena, one might be asked to weather.
Note that a more common meaning of “weathering” is as synonym for withstanding or enduring. Not only will different regions weather differently in a changing climate (drier, hotter in central Australia; more flooding on the US Atlantic coast; disappearing land in Pacific Islands), but people within those regions weather differently too.
Our human experiences of weather are linked to how the non-human world is weathering what we have forced it to carry. Artist Victoria Hunt will ask us to imagine with her “The Cry of Water”, while archaeologist Denis Byrne will explore the significance of seawalls, which are weathered by erosion. Human and non-human worlds weather together in a fraught and desirous intimacy.
The animal world is also constantly weathering. We know about catastrophic events such as the endangered bats that cannot cope with heat above 42℃. We’ve learned that the Great Barrier Reef is bleaching as water temperatures rise.
But what about the less-well-known water-holding frog or, indeed, ants and brine shrimp? How do they weather? At our symposium, Rebecca Giggs, Kate Wright and Emily O’Gorman (respectively) will let us know how, and suggest what we humans might learn about weathering the world differently.
These contributions invite us to explore how our experiences of the weather are highly mediated by a range of social, political and cultural forces. Anthropologist of institutions Tess Lea will investigate how bureaucracy (materialised as mountains of paperwork) orients different populations’ capacity to weather. Cli-fi expert and petrocultures scholar Stephanie LeMenager invites us to speculate on what a new kind of civic engagement might look like in this context.
Weathering directly connects human social, cultural and economic structures such as racism, colonialism and gender oppression to climate change. It insists that we think about global warming on a massive scale as always textured by acute experiences of social phenomena.
We recognise that the weight of a changing climate will not be borne equally by bodies – across geographies, economic status, or species.
So next time you curse a forgotten umbrella as the skies open up, or welcome the sun shining on your kid’s birthday party in the park, remember that when it comes to the weather, the personal is getting more and more political.
Hacking the Anthropocene II: Weathering (May 25-31) is supported by the Sydney Social Sciences and Humanities Advanced Research Centre (SSSHARC); the Australian Research Council Centre of Excellence for the History of Emotions; the Sydney Environment Institute at the University of Sydney; the Planetary Health Initiative at the University of Sydney; and the Seed Box: a MISTRA-FORMAS Environmental Humanities Collaboratory (hosted at Linkoping University, Sweden).
The risk of more severe storms and cyclones in the highly urbanised coastal areas of Newcastle, Sydney and Wollongong might not be acute, but it is a real future threat with the further warming of the southern Pacific Ocean. One day a major storm – whether an East Coast Low or even a cyclone – could hit Sydney.
With higher ocean temperatures killing and bleaching coral along the Great Barrier Reef to the north, we could also imagine where the right temperatures for a coral reef would be in a warmer climate. Most probably, this would be closer to the limits of the low latitudes, hence in front of the Sydney metro area.
We should then consider whether it is possible to help engineer a natural defence against storms, a barrier reef, should warming oceans make conditions suitable here.
Ocean warming trend is clear
The oceans are clearly warming at an alarming rate, with the unprecedented extent and intensity of coral bleaching events a marker of rising temperatures. After the 2016-2017 summer, coral bleaching affected two-thirds of the Great Barrier Reef.
On the other side of the Pacific, sea surface temperatures off Peru’s northern coast have risen 5-6℃ degrees above normal. Beneath the ocean surface, the warming trend is consistent too.
The East Australian Current keeps the waters around Lord Howe Island warm enough to sustain Australia’s southernmost coral reef. The waters off Sydney are just a degree or two cooler.
On top of this, when we plot a series of maps since 1997 of cyclone tracks across the Pacific, it shows a slight shift to more southern routes. These cyclones occur only in the Tasman Sea and way out from the coast, but, still, there is a tendency to move further south. The northern part of New Zealand recently experienced the impacts this could have.
If we don’t want a storm surge entering Parramatta River, flooding the low-lying areas along the peninsulas, if we don’t want flash-flooding events as result of river discharges, if we don’t want our beaches to be washed away, if we want to keep our property along the water, and if we want to save lives, we’d better prepare to counter these potential events through anticipating their occurrence.
The coast is the first point where a storm impacts the city. Building higher and stronger dams have proven to be counterproductive. Once the dam breaks or overflows the damage is huge. Instead we should use the self-regenerating defensive powers nature offers us.
Thinking big, we could design a “Sydney Barrier Reef”, which allows nature to regenerate and create a strong and valuable coast.
The first 30-40 kilometres of the Pacific plateau is shallow enough to establish an artificial reef. The foundations of this new Sydney Barrier Reef could consist of a series of concrete, iron or wooden structures, placed on the continental shelf, just beneath the water surface. Intelligently composed to allow the ocean to bring plants, fish and sand to attach to those structures, it would then start to grow as the base for new coral.
This idea has not been tested for the Sydney continental flat yet. But in other parts of the world experiments with artificial reefs seem promising. At various sites, ships, metro carriages and trains seem to be working as the basis for marine life to create a new underworld habitat
The Sydney Barrier Reef will have the following advantages:
Over decades a natural reef will grow. Coral will develop and a new ecosystem will emerge.
This reef will protect the coast and create new sandbanks, shallow areas and eventually barrier islands, as the Great Barrier Reef has done.
It will increase the beach area, because the conditions behind the reef will allow sediments to settle.
It creates new surfing conditions as a result of the sandbanks.
It will protect Sydney from the most severe storm surges as it breaks the surge.
It will present a new tourist attraction of international allure.
Let’s create a pilot project as a test. Let’s start to design and model the pilot to investigate what happens in this particular location. Let’s simulate the increase of temperature over time and model the impact of a cyclone.
Let’s create, so when Sandy hits Sydney, we will be better protected.