Extreme Medicine in a World of (Even More) Extremes - Dr Lachlan McIver

26 July 2023


Dr Lachlan McIver

Lachlan is an Australian rural generalist & public health physician, currently based in Switzerland, where he is the Tropical Diseases & Planetary Health Advisor at the Geneva headquarters of Médecins Sans Frontières.

Lachlan did his PhD on the health impacts of climate change while working for the World Health Organization. His first book, Life & Death Decisions, is out now.

July 2023 was the hottest month on Earth since records began[1]. 2023 is on track to be the hottest year. The last eight years have been the hottest on record[2]. We are living, increasingly, in a world of extremes. And we know why. The C-words.

Understanding the Urgency

In November 2023, the 28th annual Conference of Parties on climate change (COP28) will kick off in Dubai. COP is where the world’s governments convene to – ostensibly – reaffirm their commitments to tackling climate change. Sadly, what comes out of COP every year is mostly hot air (and not just from the hundreds of private planes the world’s supposed leaders take there[3]). If you have a sceptical eyebrow raised at the prospect of the United Arab Emirates – one of the world’s main oil producers – hosting a massive global meeting that is, fundamentally, about the need to stop burning fossil fuels, then you’re not alone. But we’ll come back to that. Let’s talk about climate change and health.

Several decades ago, scientists, public health experts and the World Health Organization (WHO) started sounding the alarm about the health impacts of climate change. Global heating was dangerous for humans, they warned. So was the expansion of habitats suitable for disease-spreading mosquitoes. So too the increasing frequency and severity of disasters such as droughts, floods, and tropical storms. The more research was done, the worse the news became. Climate change is a silent, insidious, ceaseless killer.

→ Watch The Ultimate Emergency – Dr. Lachlan McIver at WEM23

The Reality of Climate Change and Health

The ‘official’ WHO estimate of the global mortality due to climate change is around 250,000 avoidable deaths per year. That figure is, however, a gross underestimate. Why? Because it only considers four categories of climate-sensitive health problems: malaria, malnutrition, diarrhoeal disease and heat[4]. Unfortunately, the scale of climate-change-related illness and death goes far beyond that. The real burden includes impacts on a wide variety of other infectious diseases, as well as non-communicable diseases, physical trauma from extreme weather events, disruptions to health systems and the pernicious, impossible-to-measure impacts on mental health. Air pollution alone, which is inextricably linked to climate change, is responsible for approximately seven million deaths every year. That’s one in every six deaths[5]. Overall, according to the Intergovernmental Panel on Climate Change (IPCC) – the largest scientific collaboration in history – approximately 70% of global deaths every year are caused by diseases that are sensitive to changes in climate[6].

The former WHO Director-General, Dr Margaret Chan, declared climate change to be ‘the greatest threat to global health in the twenty-first century’[7]. She wasn’t wrong. We’ve been a bit distracted lately (what with the other C-word), but climate change hasn’t gone away. In fact, climate change is widely acknowledged as a key factor contributing to the phenomenon of zoonotic spillovers (where pathogens such as viruses jump from animals to humans) that cause most pandemics[8].

The Role of the Extreme Medicine Community

Climate change, pollution, deforestation, biodiversity loss (humans wiping out other species) and pretty much all other forms of environmental degradation impact negatively on human health. So, what can we do about it? What can we, as an Extreme Medicine community, do about it? Well, at least three things.

  1. Reduce Harm: We need to consider how our individual, institutional, and collective actions contribute to the problem of climate change, including causing those countless avoidable deaths. Reducing our carbon emissions is absolutely crucial. Even the COP28 President, Sultan Al Jaber, who is also the UAE’s Minister of Industry, concedes that phasing out fossil fuels is ‘inevitable and essential’[9].
  2. Bear Witness: All of us in the World Extreme Medicine community – whether we’re in humanitarian, wilderness, expedition, military, environmental, dive, space, or whatever-else medicine – are uniquely positioned to observe and describe what’s happening to our patients, their environments and how they interconnect, across the myriad contexts where we work.
  3. Share Knowledge: We are among the most trusted professions. We are credible and reliable sources of information. We need to use that power wisely and raise awareness of how climate change affects health, and why it’s vital that we act with urgency to slow, halt and reverse climate change to protect the health of people and the planet we share.

Dr. Lachlan McIver recently delivered an impassioned speech at the 2023 World Extreme Medicine Conference, where his message resonated with urgency about the imperative to recognise the intrinsic links between our planet’s health and that of its inhabitants.

The Ultimate Emergency – Dr. Lachlan McIver at WEM23


[1] https://www.theguardian.com/environment/2023/jul/11/uncharted-territory-un-declares-first-week-of-july-worlds-hottest-ever-recorded
[2] https://public.wmo.int/en/media/press-release/past-eight-years-confirmed-be-eight-warmest-record#:~:text=The%20warmest%20eight%20years%20have,contributed%20to%20record%20global%20temperatures.
[3] https://www.theguardian.com/politics/2021/nov/01/boris-johnson-will-travel-home-from-cop26-by-private-plane
[4] https://www.who.int/news-room/fact-sheets/detail/climate-change-and-health
[5] https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(22)00090-0/fulltext
[6] https://www.ipcc.ch/report/ar6/wg2/chapter/chapter-7/
[7] https://www.who.int/news/item/06-10-2015-who-calls-for-urgent-action-to-protect-health-from-climate-change-sign-the-call
[8] https://www.nature.com/articles/s41586-022-04788-w
[9] https://www.theguardian.com/environment/2023/jul/13/phase-down-of-fossil-fuel-inevitable-and-essential-says-cop28-president

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