Climate change and healthcare: we must set the example by facing our gray rhinos

“Gray Rhinos?” readers may wonder. “I thought they only write about human beings in the The BMJ.”

We can explain. 

In 1697, a group of Dutch explorers led by William De Vlamingh made an unexpected discovery in Australia—a black swan. Up till then, all historical accounts only described swans as white. The 2nd century Roman Poet, Juvenal, popularised the concept of “black swan” as a metaphor for a completely impossible scenario: “rara avis in terris nigroque simillima cygno” roughly translates to a “rare bird in these lands, much like a black swan.” Although we shouldn’t overlook that the metaphor he used was to refer to a perfect wife.

This concept was employed centuries later by the economist Nassim Nicholas Taleb, using the term to refer to extremely rare financial events, those which outlie the expectation of human reality and carry an extreme impact—such as 9/11, the 2008 financial crisis, and Brexit. 

Many commentators have conceptualised covid-19 as another example of a “black swan;” this is erroneous, however. Covid-19 is a very different conceptual beast: a Gray Rhino. A Gray Rhino event is one which is highly probable, but a neglected threat that will have high impact. The term was coined by Michele Wucker, a policy analyst, in 2012, in the aftermath of the Greek Financial Crisis. In these situations, there is a slow build up to the event—often lasting many years—with multiple warning signals that are ignored, akin to a rhino stomping its ground whilst those nearby are wilfully oblivious. Ultimately, however, we are left with no choice but to face up to it—when the two-ton animal is charging directly towards you.

Why is covid-19 not a black swan? Firstly, covid-19 is not an outlier: pandemics and infectious outbreaks have occurred frequently throughout human history. Second, warnings of a looming global pandemic have been raised frequently; from many public health experts, as well as Bill Gates and Barack Obama. We only have to look back to 2016, when the British government was modelling pandemics in Exercise Cygnus, to know we were all too aware of the potential for a large-scale public health concern to wreak havoc. All in all, this was not an improbable event; we were just improbably ill-prepared for it. The remarkable part about coronavirus is that world leaders continued to downplay its significant impact.

Yet, on the horizon, another rhino looms. This one has a spikier horn and is a few tonnes heavier.  

Coronavirus has been described as climate change on steroids—the rapidity of events in the last few months has given us a flavour of what lies ahead. And, we have been warned for decades of this possibility. In the 1960s, artist Alan Sonfist started a collection of “Time Landscapes”, which contained seeds of endangered trees in Northern Europe. Thirty years later, he donated these seeds to 100 museums, as he became concerned about the inevitable extinction of the world’s forests due to human activity. Of course, he wasn’t the only one concerned. Similar to covid-19 a multitude of voices—scientists, public health experts, prominent political figures such as Al Gore, and even the World Health Organisation have urged us to pay attention to the stomping on the horizon—but this time, school children and activists are also pleading for people in power to act.

There is a collective recognition that we must act on climate change and medics have an important role central to this.

Why? First, the health impacts of climate change will be dramatic. Alongside the direct threat to health from increasingly frequent extreme weather events, water shortages, poverty and heat-related crop failures will also become more common. This will lead to mass migration of human populations; which will inevitably pose socio-political challenges. [1] And, it will be Latin America, South Asia, and Sub-Saharan Africa that will face the majority of the consequences of the actions taken by you and me, the privileged residents of a high income country. 

Unfortunately, this is a double-edged sword. If healthcare was a country, it would be the fifth largest emitter of greenhouse gas emissions in the world. [2] Healthcare supply chains are the biggest contributor and our inefficient energy systems in hospitals are another. 

Although it sounds like a doom and gloom story, some significant progress has been made. In the UK, we have reduced emissions by 30% between 2008 and 2019; NHS England announced a “Greener NHS” campaign in January; and numerous national health organisations are divesting from fossil fuel investment. [3,4]

Michele Wucker, author of “The Gray Rhino”, reminds us at the end of her book that we should not waste the opportunity of a crisis. At this moment, we are in a state of accepting new changes and “a new normal.” We readily accept online conferences; we challenge unnecessary travel; we see that things cannot operate the way they used to—for the sake of our future. We have seen the power of political will. We have seen that work can be conducted differently. So at this time, we again call doctors to action. 

On Wednesday 15th July, we are excited to be joined by an experienced and diverse panel of speakers at all stages of their medical careers, who have been working in the intersection between climate and health. 

The BMJ, a partner for this event alongside The FMLM, have been advocating for greater awareness to climate change for many years. Originally, they were told to “stick to their knitting”—climate change is not possibly anything to do with patients. [5] We now know, this was wrong. Human health doesn’t exist in isolation—it is impacted by everything else around them—therefore climate change is the responsibility of every health professional. We cannot hope to offer holistic care in the present without looking to the future. 

What will Sustainable Healthcare look like in the aftermath of covid-19 and how can you influence the changes? The time to stop this Gray Rhino’s path is now.

“Building Back Better: Sustainable Healthcare in the aftermath of Covid-19” is a free webinar, jointly hosted by The FMLM and The BMJ. It will start at 6pm on 15 July 2020. You can sign up at 

Shivali Fulchand is a junior doctor and the 2019-20 Editorial Registrar at The BMJ. 

Twitter: @shivalifulchand

Laura May Davis is an ST2 Radiology/ST4 Nuclear Medicine at University College London Hospitals NHS Foundation Trust.


Declaration of Interests: No conflicts of interest to declare.


  1. Schiermeier, Q. Eat less meat: UN climate-change report calls for change to human diet. 2019 12th August 2019 [cited 2020 23rd February].