Seeing (Climate) Change

In 1938, steam engineer and amateur scientist Guy Callendar made a historic discovery. After meticulously collecting records from 147 weather stations around the world, and then performing calculations by hand, Callendar came to a startling conclusion: the global temperature had risen by 0.3 ^oC over the preceding 50 years (1). Hypothesizing that carbon dioxide emissions from industry were the underlying cause behind this increase, both Callendar’s calculations and conclusion line up remarkably with modern scientific consensus. Despite this initial warning 85 years ago, the issue of global warming is one that is more pertinent than ever – with its effect on the planet (and those calling it home) only getting more severe.

When we think of the effects of climate change, those that tend to immediately come to mind are those of an environmental nature – rising sea levels, increased droughts, the extinction of species, to name a few. And though these are crucial issues that are deserving of humanity’s focus, they are not the only challenges. In 2015, the Lancet Commission on Health and Climate Change named “addressing climate change” as the greatest public health opportunity of the 21st century, with failure to adequately do so having the potential to undo the majority of global health progress over the past century (2). This caution was echoed by the World Health Organization (WHO) in 2021. Additionally, recent surveys by the Medical Society Consortium on Climate & Health – which brings together associations representing over 700,000 clinicians – indicate that the majority of practitioners are observing health harms from climate change among their own patient populations (3). Based on our current trajectory, it seems that climate change will play an increasingly large role in shaping the eye health of the global population.

So what should those in the eye care field expect in the years to come? As David F. Chang, co-creator of Eyesustain – a global coalition of eye societies, organizations, and ophthalmologists working to make the field more sustainable – explained to us last year, “The International Agency for the Prevention of Blindness predicts that global warming will increase trachoma, onchocerciasis, cataract, and other age-related disorders causing visual disability and blindness.” A recent global review of the literature on the impact of air pollution and climate change confirmed this prediction, demonstrating that climate change adversely affected different ocular conditions, with ocular surface diseases, including conjunctivitis and dry eye, being particularly affected (4). Exacerbating these problems is the disruptive effect that climate change is having on the delivery of eyecare. On their website, Eyesustain warns that increasingly frequent and extreme weather events have the potential to prevent local operations and block supply chains – things that may disproportionately affect less developed areas (5).

Although the challenge facing humanity is a steep one, clinicians may be perfectly positioned to drive forward the solutions needed to appropriately respond to the climate crisis. Practitioners will be on the front lines when it comes to helping the increased number of patients developing ocular conditions as a result of climate change, but they also work within an industry that has historically played a large part in the development of the problem. Did you know that America’s healthcare sector makes up approximately 10 percent of the country’s entire carbon footprint? I recently spoke to Netan Choudhry and Omar Salem Taboun, two authors of a paper that investigated the factors contributing to the carbon footprint of cataract surgery, to find out what exactly can be done to reduce the carbon footprint of, not just this procedure, but the field at large (6). Their answer: a concerted effort by everybody in the field to do their part. “It is important for ophthalmologists to be more aware of their carbon footprint and environmental impact. Increasing awareness within the ophthalmology community can be achieved through various means. One effective approach is to promote research on the carbon footprint [of cataract surgery] among ophthalmologists. Encouraging them to conduct studies in their own practices will generate more data and enhance understanding of the emissions produced [associated with this procedure]. As more ophthalmologists engage in research, their colleagues will be influenced to become more aware as well.”

What do you think can be done to reduce the carbon footprint of ophthalmology as a field? Have you done anything to reduce the carbon footprint of your practice? Are there any other comments or perspectives that you would like to share? Please let us know: [email protected].