Since 2015, researchers from some 43 research institutions and agencies have monitored how the world’s warming climate is affecting our health – across the globe and within countries.
This year’s report in the Lancet journal - The Lancet Countdown on Health and Climate Change: code red for a healthy future - is grim reading, not least for Australians.
It highlights that climate change is resulting in profound and worsening human health impacts, as well as exacerbating health and social inequities globally.
It documents escalating exposure to heatwaves, increasing climate-sensitive disease transmission like dengue and cholera, increasing population exposure to wildfires and drought, and accelerating threats to key crops and marine food security.
The situation in Australia is presented in a separate report we have co-authored and published in the Medical Journal of Australia (MJA) – Countdown on Health and Climate Change: Australia increasingly out on a limb.
It presents that latest evidence on climate change and health in Australia, and is the work of researchers across seven Australian institutions and in collaboration with University College London.
It highlights the real challenges we are facing in this country to our health, as we are increasingly exposed to excess heat, extreme weather and other climate risks.
Inaction by the Australian government is not an option; with the world currently on course to exceed heating of 1.5°C, there is no time for complacency in public policy.
Earlier this year, leaders from over 40 countries came together at a climate summit to set ambitious targets for mitigating climate change by reducing greenhouse gas (GHG) emissions over the coming decade. Australia’s woeful commitment – to reduce emissions by 26 to 28 per cent below 2005 levels by 2030 – remained unchanged.
In contrast, the majority of world leaders at the summit agreed to step up their emission reduction targets to keep the goal of limiting warming to 1.5°C within reach. Australia’s lack of action is a significant concern for all of us as we face escalating climate risks and the associated health consequences.
Our MJA report finds that Australia is increasingly vulnerable to heatwaves with escalating morbidity and mortality associated with extreme heat. For example, the report estimates that there were already 2300 heat-related deaths each year for the period 2000 to 2019.
It predicts a 36 per cent increase in heatwave intensity – a measurement based on the three-day-averaged daily mean temperatures – within the next 20 years, and a 103 per cent increase over the next 50 years.
Australia’s vulnerability to heat exposure far exceeds the global average.
In 2017, Australia’s Heat Exposure Vulnerability Index (HEVI) was 41.06 compared to a global average of 36. The index ranges from zero to 100, and higher scores represent greater vulnerability.
This index calculates vulnerability based on the proportion of population aged over 65 years, the prevalence of diseases in this subpopulation, and the proportion of the population living in urban areas where there are higher temperatures due to the urban heat island effect.
The Black Summer bushfires of 2019-2020 were a tragic indication of the risks of the climate crisis. The bushfires spanned a staggering 10 million hectares of land and destroyed 3000 homes.
They directly resulted in 33 deaths, but the hazardous air pollution from the fires is estimated to have led to a further 417 excess deaths, 1305 asthma presentations to emergency departments and 3151 hospital admissions.
The unprecedented scale and intensity of these catastrophic bushfires were amplified by numerous climate-related environmental circumstances including rising temperatures, extreme heat and persistent drought.
As highlighted in our MJA report, since 2001 there has been a steady upward trend in the combined total number of days per person that people are exposed to landscape fires (that is, the number of people exposed multiplied by the number of days of exposure, otherwise known as ‘person-days’).
In 2020, there were 190,774 person-days of exposure to bushfires which, while lower than the 2019 peak of 270,997, is in keeping with the rising trend since 2001.
Importantly, the report highlights that climate change disproportionately threatens the health of Indigenous Australians.
This reflects the substantial health inequities Indigenous Australians are subject to, including elevated rates of cardiovascular and respiratory disease, unemployment, and lack of access to health care, all of which can increase climate vulnerability and decrease their adaptive capacity.
Many strategies are available to reduce and adapt to the effects of climate change, but elimination of greenhouse gases (GHG) emissions must be a top priority. Despite that, our report finds that the carbon intensity of Australia’s total energy supply remains among the highest in the world, and that Australia produced 29 per cent of the world’s coal exports in 2019.
Transport must also become a government priority for cutting emissions. The sector accounts for approximately 19 per cent of Australia’s total GHG emissions and has one of the fastest growth rates in emissions.
We need to be transitioning to zero emission vehicles as an important priority to achieving a sustainable transport system, yet transport-related fossil fuel consumption continues to grow in Australia.
There needs to be a re-think of transport plans with ambitious policies that target reductions in GHG emissions, as well as the other adverse impacts from our current transport system, like congestion, urban sprawl and road infrastructure spreading across agricultural and environmental land.
The MJA report provides a stark national assessment of the threats that climate change poses to the health of Australians. But while the window is very rapidly closing – we still have time to transition to renewable energy and to slow the global climate crisis.
This is a matter of urgency for Australians, for our Pacific Island neighbours and for our world.
It’s imperative that we achieve net zero emissions by 2050 – in Australia and globally – and ensure a healthier future for all.
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