FOR many decades now, we have been hearing about the precipitous and ongoing decline of Earth’s systems. Our climate is warming, species extinction rates are tens to hundreds of times higher than background rates, and soon plastic rubbish will outweigh fish in our oceans (here, here and here). It has also long been known that this broad scale environmental change, particularly climate change, will increasingly threaten human health, wellbeing and survival.

What is new is that the medical community is now realising that the health effects of climate change are more far reaching than ever thought. Climate change is not just an unprecedented public health threat, but also a threat to multiple organ systems.

This is clearly shown in renal medicine. Studies across continents, including from Australia, have demonstrated increased acute kidney injury during heatwaves (here, here, here, here, here and here). During the severe European heatwave in 2003, acute kidney injury was a major cause of excess mortality. Susceptible individuals include those well known to nephrologists: the elderly, individuals with underlying chronic kidney disease, and those taking medications that impair thermoregulation (eg, diuretics and renin-angiotensin system antagonists).

Increased temperatures may also promote urinary tract infections and increase the risk of kidney stones. It has been suggested that the US will see an extra two million lifetime cases of nephrolithiasis by 2050. This is likely to cost the US health care system somewhere in the order of US$0.9–1.3 billion annually.

Of even greater concern, recent years have seen epidemics of chronic kidney disease in some of the hottest parts of the world. These have been observed in regions of Central America, Sri Lanka, India, the Middle East, Africa and North and South America. While those affected are typically young adult men from agricultural communities required to perform strenuous manual labour under very hot conditions, cases have also been observed in women and children. The usual presentation is with an elevated serum creatinine, low-grade or no proteinuria and no known risk factors for kidney disease.

The definitive underlying cause of chronic kidney disease in these cases remains unproven. However, there is consensus that heat is involved, possibly acting alone, or exacerbating damage from an, as yet unidentified, infectious or toxic agent. The mechanism is thought to be repeated subclinical acute kidney injury from heat stress and dehydration cumulatively causing chronic damage (here and here).

Because of limited or no treatment options in most of the affected regions, the death toll is high, recorded at 83% in Guatemala. Across Central America, the total number of fatalities is believed to have exceeded 20 000, while in Nicaragua and El Salvador, chronic kidney disease is now the leading cause of death. These data turn climate change from being an abstract, distant health threat, to one that is all too real and present now.

The nephrology sector also knows well the havoc extreme weather events can cause when they disrupt health care delivery. Dialysis patients are among the most vulnerable because of their reliance on functioning health services for life-sustaining dialysis.

In 2005, the devastating Hurricane Katrina, which hit New Orleans, forced 94 US haemodialysis centres to close for at least one week, affecting over 6000 dialysis patients. Forty-four per cent of these patients missed one dialysis session, while 17% missed three or more. In 2011, flooding, followed by Cyclones Yasi and Anthony in Queensland caused statewide disruption to renal services, including necessitating the evacuation of one of Australia’s largest dialysis facilities from Cairns down to Brisbane. While all this remarkably took place without loss of life, a major lesson was still learnt. In the face of ever-increasing extreme weather events from climate change, we must be prepared.

But, it is not just nephrologists who need to pay attention. As stated in a recent New England Journal of Medicine special edition on the climate crisis and health: “[Climate change’s] consequences directly affect the practice of medicine in every specialty and are projected to threaten the stability of our health care systems”. Along with multiple must-read reviews and perspectives, this edition includes an interactive feature that allows doctors to explore the myriad effects of climate change on health and health care from the perspective of their own specialty.

An editorial simultaneously reminds that us that: “Neither the gravity and enormity of climate change nor the unfortunate politicization of this health emergency should cause us to shy away from action”. Instead, these things must galvanise us to act, and to do so now.

At the individual level, doctors should lead by example – walking, cycling and solar powering our homes. We must also educate our patients and colleagues about health-related climate risks and address the carbon impact of the care we provide.

Most importantly though, we have a moral and professional duty of care to our patients to speak out whenever public health is threatened. We must exert our influence where decisions are made, realising both the strength of our message and the power of our social position as doctors. These tactics have been instrumental in battles against tobacco, asbestos, HIV/AIDS and more.

This means talking to legislators, joining health-based advocacy groups such as Doctors for the Environment Australia, and on 20 September 2019, as our children strike for a safe climate future and for their health, it means standing by their sides.

Associate Professor Katherine Barraclough is a nephrologist and the Victorian Chair of Doctors for the Environment Australia.


The statements or opinions expressed in this article reflect the views of the authors and do not represent the official policy of the AMA, the MJA or InSight+ unless so stated.

14 thoughts on “Kidneys and extreme heat: a climate consequence

  1. Skeptic scientist says:

    I think it may be time to cancel my AMA membership – it has become a Green/left propaganda arm.
    Global warming/climate change is crap.

  2. Margaret Trudgen says:

    As most of the peasants in third world countries like India have no power at all due to lack if infrastructure to deliver power to remote areas the phasing out of fossil fuels will not affect them at all. In fact, with the developement of alternative environmental friendly power sources they could well be better off as the price of these sources will come down and local energy could be provided without expensive infrastructure to convey power form centralised power stations.

  3. Anonymous says:

    Climate change is a false religion.
    CO2 is plant food.
    We are in an Interglacial period – so temperatures are SLOWLY rising…
    Nothing Australia does will make any difference to the temperature of Planet Earth.

  4. Dr Roger BURGESS says:

    We all held our breath when the year 2000 rolled into the frame. Global “Warming” is just such a con. Sadly, I will be long gone before this becomes apparent, Dream on kind lady,

  5. Andrew Jamieson says:

    Isn’t the main problem that there are too many humans on this planet to be sustainable? Of course if this is true we, the medical profession are only exacerbating the problem. Humans demand resources and take them away from other species resulting in extinctions. Humans are the prime polluters – whether CO2, plastics, heavy metals or whatever else is blamed for earth’s demise. 50 years ago the catchphrase was ‘populate or perish’ – we need a new slogan – ‘populate and perish’!

  6. Kim Loo says:

    Thank you for this excellent article which shows that the impacts on human health are multiple .
    There is now ample evidence in the medical sphere to show that we need to act collectively in the health sector to educate those around us colleagues , family, friends and patients .
    The health sector is well respected and we need to be vocal .

  7. Marcus Aylward says:

    To be fair to Canute, his demonstration was in order to prove his inability to hold back the waves, an insight so far lacking in his modern equivalents holding positions of power.
    It is hard to escape the conclusion that the cycle of articles on global warming in MJA Insight is deliberately timed to freshen up the catastrophism every month or so, with each specialty allocated its turn to step up to the plate with its own tale of woe, and with supportive comments scheduled in to follow as well.
    One might almost postulate that a clandestine group of medical activists exists, co-ordinating this and various public glue-ins etc. to ensure saturation of the message. “Don’t think we’ve done global warming rashes yet: can we ask Derm to do it next month?”.
    Such a cabal sounds like conspiracy theorising – “what, from scientists??; surely not!” – until one googles something like ‘University of East Anglia’ or ‘Phil Jones’ and reads the hacked email trails about efforts by peer reviewers to keep articles not supportive of their global warming orthodoxy out of the scientific literature.
    I would like to read instead the articles from those peasants in China and India indicating their preparedness to return to an early mortality and the state of poverty from which they have just emerged – given the apparent necessity for them to give up cheap power – in order to satisfy the ineffectual pseudo-moralistic grandstanding of affluent medicos in First World countries. To discount them for the sake of ‘future generations’ is a particularly callous misanthropy.

  8. Kingsley Faulkner. says:

    This excellent article draws to our attention an underappreciated aspect of the impact of climate change upon health.
    There are many other health impacts and they are becoming increasingly apparent as global warming and associated aspects of climate change become worse.
    The scientific evidence is overwhelmingly powerful, innovations and technological advances are supplying economically feasible solutions and the community is wanting to see urgent and effective government policies to address the present and future dangers.
    I respect the warnings of David Attenborough far more than the scepticism of the correspondent who mentioned King Canute.

  9. Anonymous says:

    Remember King Canute…he ordered the waves to turn back!!
    When are clear thinking people going to realize that they have no control over the weather and that the small increase in CO2 into the atmosphere is not going to make the slightest difference. Doctors should look after patients and stop being brainwashed by highly paid pundits with incorrect computer projections forecasting gloom and doom.

  10. John Van Der Kallen says:

    Excellent article. All doctors should understand the health impacts of climate change. Doctors need to warn their patients and advocate for urgent political action on climate change.

  11. Graeme McLeay says:

    The issue of extreme heat and renal disease seems to have largely gone under the radar-the author has highlighted an important consequence of the heatwaves we can expect more of as global temperature continues to rise. It is a timely article following the AMA declaration of a a climate health emergency.

  12. Colin Baker says:

    Health professionals are learning so much about cause and risk. When will all this knowledge be delivered to patients being monitored for renal failure?

  13. Ben Ewald says:

    Thanks Dr Barraclough.
    Despite increasingly urgent problems the federal government remains asleep at the wheel without a credible climate policy. How can we expect good governance when federal ministers openly lie about the trend of Australia’s CO2 emissions? When the politicians abandon governance, it falls to other groups to speak up.

  14. Richard Yin says:

    The article is timely with the AMA declaring a climate and health emergency. It’s really time the health minister stood up and heed the call of the health community demanding urgent action.

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