In the years since being unceremoniously dumped from his country’s top job, former Prime Minister of Australia Tony Abbott has not shied away from controversy. Last month he addressed the United Kingdom’s Global Warming Policy Foundation in a speech entitled Daring to Doubt, an attack on climate science and the widely held beliefs about the harm climate change is causing to our planet. During this address, he disputed the potential health impacts of global warming, even going so far as to say that global warming may be doing more good than harm for the health of our population. In an era where climate change has been variously described as “the great moral challenge of our generation” to “absolute crap,” it seems pertinent as future health professionals to have a look at the evidence and ask ourselves how this issue might come to affect the health of our prospective patients.
A Controversial Issue
Mr. Abbott is certainly not alone in his disdain for climate science and the impact it has had on global policy and debate. US president Donald Trump has been quoted as describing climate change as “a myth,” while Russian president Vladimir Putin has questioned the extent of human impact on climate patterns. Add to this the countless debates at dinner tables across the globe, and you have potentially the most controversial issue of our time. It is rare in the modern day for an issue based in science to generate such heated debate around its factuality across the full spectrum of society, but it is equally rare for one issue to so greatly impact our health, economic and political future.
A Matter of Life and Death
In his speech, Mr. Abbott made the point that more people die from cold exposure than from the effects of heat waves globally. While this is not necessarily false, he is missing the point of the major health effects of climate change. Acutely, climate change has been linked to an increased frequency and intensity of natural disasters such as the recent Hurricane Irma. However, it is the long-term effects on social and environmental determinants of health that are often overlooked. A research collaboration titled The Lancet Countdown: tracking progress on health and climate change appeared in the Lancet earlier this year and outlined a number of areas in which global health is impacted by climate change, and suggested ways in which these areas can be monitored.
The most immediately obvious impact on health from climate change comes in the form of extreme weather events. It has been widely reported (and disputed from some corners) that ongoing climate change will result in an increased frequency of disasters such as hurricanes, floods, fires and droughts. The impact of these events is wide-reaching and can include short-term effects such as injury and death, as well as longer-term impacts like population displacement and destruction of food sources. These factors can lead to significant mental health, food security and infectious disease issues further down the line.
Impact on Existing Illness
It is easy to focus on the extreme events and the health impacts these entail, but this is not the end of the story. While the disproportionate impact of climate change on health in developing nations is well known, it was surprising to find the effect climate change has on many common conditions in the developed world. A key area is respiratory illness, and one of the major culprits is the gas ozone. Better known for its role in the upper atmosphere as chief protector against the sun’s harsh rays, ozone is also an increasingly common pollutant at ground level. Rising temperatures result in increased biogenic emissions, while increasing frequency of blocked weather patterns results in more prolonged episodes of air stagnation. These increasing levels of ozone, along with a general increase in dust and particulate matter, have been associated with an increased frequency of respiratory symptoms, decreased lung function, worsening of asthma and the development of chronic bronchitis. While there is insufficient data on climate change’s impact on COPD incidence, it certainly appears to contribute to worsening of symptoms. Similarly, allergic rhinitis is a disease that looks to be increasing in frequency with ongoing climate change. Increasing levels of pollen mean this is a disease that we will be seeing more of, and possibly for a longer period of the year.
Existing illnesses are not the only diseases affected by the rise of climate change. Across the globe, climate change has been reported as having significant impacts on infectious disease frequency and geographic distribution. As the weather warms, certain water and vector-borne diseases are becoming more common in regions where they were previously unheard of. This phenomenon boils down to alterations in the physiology of the organisms, pathogen-host interactions, and changes in ecosystem composition. Essentially this means that warming weather allows vectors such as mosquitoes to successfully breed in new areas, while also altering the transmission and life cycle of these vectors and pathogens. It is important to note, however, that there are a number of factors at play in these scenarios. When it comes to human disease, societal responses such as vector-control, antimicrobial treatments, and infrastructural changes can help disguise the effects that climate change creates. As such, a review article published in Science Magazine in 2013 looked at the plethora of factors impacting the complex relationship between climate and infectious disease, specifically focusing on plant-based diseases which are less likely to be impacted by human controls. What they found was that climate change limits the potential for transmission of some pathogens, but allows improved transmission of others. In a practical sense, this means that we will likely be dealing with a changing landscape of infectious diseases as clinicians.
Recent research from the University of Colorado addressed this issue from a different perspective, looking at the impact of single catastrophic events on infectious disease outbreaks. Researchers focussed on a recent earthquake in Ecuador which occurred during a significant El Niño weather event, meaning warmer temperatures and increased rainfall. They found that the effects of the El Niño predisposed the region to increased prevalence of mosquitoes, while the earthquake resulted in a severe interruption to social infrastructure. The combined effect of this was a significant increase in cases of Zika virus diagnosed in the region during this period. While it is unlikely that the earthquake itself was related to climate change, the coinciding El Niño event made its impact far more significant than it otherwise might have been.
As we know, the realm of health stretches far beyond disease, and also includes critical public health issues such as nutrition. An often bandied but rarely explained term is the concept of food security. In his speech, Mr. Abbott discussed how climate change had been beneficial for primary producers because certain regions have become more fertile thanks to warmer temperatures. What he neglected to mention was the vast number of negative impacts climate change is likely to have in this area. Food security is a term that describes stable access to and utilization of nutritious, affordable food in sufficient quantities. Climate change affects not only average temperatures but also rainfall patterns across the globe. Mr. Abbott is right when he says that certain regions will become more fertile due to this phenomenon, however by the same token, many existing agricultural regions will become less so. This means regions which are built around food production, with all the required infrastructure and equipment already established, will have a reduced capacity to produce the required raw produce for their community. This affects access, not only through availability but also through rising cost and falling wages. Adequate nutrition is a crucial pillar of population health, and the cycle of hunger will not be broken if the issue of food security is not adequately addressed.
An area of continually increasing interest and awareness, mental health impacts of climate change can be seen across the board. The most obvious effect comes in the form of psychological distress caused by severe weather events and the destruction that accompanies them. The personal and material loss is often significant, and the effect on psychological welfare is vast. In a longer-term setting, these changing weather patterns can affect the viability of careers and livelihoods. In developing nations, areas that were once fertile may become arid, forcing people to relocate. The psychological stress associated with this must not be underestimated. In developed nations, the agricultural industry is severely affected by worsening drought and the insecurity this brings. In Australia, suicide risk is greater in young men living in rural and remote areas when compared with their urban counterparts. While the factors responsible for this are myriad, the psychosocial stress of financial insecurity brought about by changing climate is certainly a significant consideration.
Despite the assertions of Tony Abbott and others, there is little doubt that climate change will have an impact on the health of our future patients. During the lifespan of our medical careers, we will likely see noticeable changes in many of the areas above. It will be up to us to not only recognize this but to do what we can to prevent it.