“I love a sunburnt country”, the opening sentence of the second stanza of Dorothea Mackellar’s iconic poem Our Country, is now much of an oxymoron. The romanticism and rugged splendour of the Australian landscape are becoming sunburnt beyond recognition as summer firestorms more and more ravage the country. It’s the blistering summer heat, however, that will most impact Australia’s house construction industry, which was worth $69.8 billion in 2023.
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Traditional construction methods (predominantly stick built construction) are coming to an end. Built on the block and fully exposed to the elements, it is no longer viable through increasingly hotter summers. Adverse health effects of extreme heat exposure are predicted to increase globally in correlation with a warming climate, urban induced warming, and an aging population much less resilient to extreme heat and humidity.
A 2023 study by Associate Professor of Human Biometeorology Jennifer Vanos and colleagues from Arizona State University showed that human survivability to extreme heat using the traditional 35 degrees Celsius wet bulb temperature (Tw) threshold (maximum safe, sustained activity for an extended period of up to six hours) under current and future climates significantly underestimates a physiology based model.
It is broadly accepted that humans can tolerate up to 35 °C before beginning to overheat. But when physiological and biophysical principles are applied — age, body weight and size, level of fitness and healthiness, living conditions and lifestyle, for example — the threshold causing young and older adults to overheat and potentially suffer heatstroke death is reduced to Tw~25.8 to 34.1 °C for young adults and ~21.9 to 33.7 °C for older adults, which is 0.9 to 13.1 °C lower than a Tw of 35 °C.
For older female adults, estimates are ~7.2 to 13.1 °C lower than a Tw of 35 °C. What’s more, the 35 °C Tw limit refers to a threshold for human survivability or adaptability for the best case scenario: humans that are fit, nude, and in well ventilated and shaded conditions. Moreover, can we keep increasing the retirement age wherein older outdoor workers start dropping like flies in the oppressive heat? The lesson still to be learned in these turbulent times is not to rely on the past as a window to the future — prepare for the unprecedented and pre-adapt accordingly.
71 per cent of the working population is exposed to excessive heat
On 25 July 2024, The International Labour Organisation released the report, Heat at work: implications for safety and health, a global review of the science, policy, and practice. It showed that “at least 2.41 billion workers — 71 per cent of the working population — are exposed to excessive heat, resulting in 22.85 million injuries and 18,970 deaths annually”.
These figures should be enough to motivate trade unions and all levels of government to collaboratively launch a genuine nationwide endeavour to implement a commensurate climate change OHS framework now rather than later, as things could quickly go awry. Prevention is immensely better than cure.
Although there are numerous training programmes and organisations that have implemented OHS campaigns — the Victorian Chamber of Commerce and Industry’s Health, Safety and Wellbeing guide for employers about the dangers of excessive workplace heat, for example — it’s past time to get deadly serious about excessive heat exposure on building sites as a consequence of human induced climate change.
To summarise, the report emphasised that heat stress can quickly impact workers on the job, causing heat exhaustion, heatstroke, and possible death. Prolonged exposure risks developing serious and debilitating chronic diseases, affecting the kidneys and cardiovascular and respiratory systems. Heat stress combined with inappropriate personal protective equipment also causes diminished cognitive performance, resulting in an increase in accidents and injuries.
Workers in all sectors are susceptible to heat stress, but some face significantly higher risks. High risk workers include migrant and informal workers, pregnant women, indoor workers in poorly ventilated environments, and outdoor workers engaged in physically demanding roles.
One of those particularly demanding physical and predominantly outdoor roles is construction work. As Australia embarks on a major house building program — 1.2 million new homes in Australia over the next five years as part of the National Housing Accord – thousands of construction workers will be exposed to excessive heat.
Is it time to legislate?
The report notes, “There is a high incidence of heat-related illnesses and accidents in outdoor workers in occupations that involve work in the sun during the hottest hours of the day, such as in agriculture or construction.” And if workers’ wellbeing is not enough to inspire our politicos, OHS measures to prevent occupational injuries related to excessive heat are estimated to save over US$361 (AUD 543) billion globally.
Is it time Australia legislated adequate work breaks in the summer months? Or even ban outdoor construction during the hottest part of summer. Legislating it now would eliminate the raft of reviews usually undertaken and save millions of dollars in compensation claims.
Or alternatively, revert to modular homes built in air-conditioned factories and delivered to the site? For example, about 84 per cent of Swedish detached homes have prefabricated elements. This is compared to Japan at 15 per cent and the US, UK, and Australia at 5 per cent. Sweden’s prefab and modular homebuilders lead the way in off site construction and have configured it to mass scale production, something other countries have failed to emulate. Notably, 96 per cent of Swedish houses are built off-site, and the average energy consumption is 50 per cent less than that of American homes.
Climate proofing agriculture by introducing OHS measures is more complicated. Although indoor market gardens are opening in some metropolitan areas, large indoor crop growing would require a major transition cost. This could be accomplished with some human ingenuity and technical innovation.
How hot will it get?
The European Union’s Copernicus Climate Change Service reported that Sunday, 21 July 2024, was the hottest day on record. Monday, 22 July 2024, was even hotter. Tuesday, 23 July 2024, was about the same.
To provide some science-based insight, Joëlle Gergis, an Australian climate scientist and lead author on the IPCC’s Sixth Assessment report, gives an insider’s account of what the weather has in store for humanity in her 2022 book Humanity’s moment: a climate scientist’s case for hope:
Beyond 2 °C of global warming, maximum summer temperatures will reach 50 °C across all continents, with projected temperatures above 60 °C in hotspots like Pakistan, Iraq and Saudi Arabia. By 2050, Madrid’s climate will resemble Marrakech’s climate today, London will feel like Barcelona, and Seattle more like San Francisco. … Most continental areas will warm well above the global mean. For example, under a worst-case scenario, average land temperatures along the eastern seaboard of North America are projected to rise by 6.5 °C above pre-industrial levels by the end of the century, with all models simulating a range of 4.7 to 8.7 °C. In northern European regions like the United Kingdom, average temperatures warm by 6.3 °C, with projected temperatures ranging between 4.3 and 9.0 °C by 2100.
An increase in the Earth’s mean surface temperature of 3 to 4 °C above pre-industrial levels would make the world’s people and possessions uninsurable. As heat related mortality and morbidity continue to climb, a 2022 analysis by Associate Research Professor Joan Ballester and colleagues from the Barcelona Institute for Global Health forecast that without adequate adaptation, heat-related mortality could become a regular occurrence, averaging 68,000 deaths across the European continent alone every summer by 2030. Henceforth, dark days and excessive heat are upon us. Consecutive days/weeks of 50 °C plus are about to become the summer norm.
“You May Find Yourself Living in an Age of Mass Extinction”
And so, I shall give the last word to dark ecologist Timothy Morton and his essay And you may find yourself living in an age of mass extinction (from his 2021 book All art is ecological), a play on Talking Heads’ 1981 song Once in a Lifetime — written by lead singer David Byrne about living in an unconscious state, half-awake and in a zombie state: “The end of the world is correlated with the Anthropocene, its global warming and subsequent drastic climate change, whose precise scope remains uncertain while its reality is verified beyond question.”
There is an ominous inevitability about Morton’s dark synopsis. Climate change, or global warming as Morton prefers, is probably too big to fix precisely because it is a human problem of fundamentally human flaws: hubris, complacency, and greed. Still, as the saying goes — attributed to the great English novelist George Eliot, aka Mary Ann Evans — “It’s never too late to be what you might have been.” Let’s just hope, as it relates to humankind, he’s right.