By Ben Griffiths — Community Engagement Project Manager
Understanding the links between climate change and public health is paramount to comprehending the potential devastation that communities could face and building a foundation for tangible action. Various aspects of climate change have been observed to produce deleterious effects on public health. This article will examine the effects of climate change on public health, the impact of public health interventions on climate change, and the co-benefits to health observed in responses to climate change.
The impacts of climate change on health are truly plethoric, with dramatic current and projected effects from a variety of climatic and human factors. Below are a few factors that contribute to negative health outcomes:
Air pollution
As one of the leading causes of death and health risk globally, air pollution is a major silent killer. Ambient particulate matter in the atmosphere from fossil fuels and coal has been linked to heart attacks, asthma, stroke, hypertension, lung cancer, and miscarriage amongst other ailments. These millions of annual deaths are inexorably linked to climate change through fossil fuel use, which will continue to escalate and result in further deaths unless full decarbonisation is achieved. Moreover, household air pollution both exacerbates climate change through burning solid fuels and causes millions of deaths annually. Burning solid fuels such as coal, wood, and dung for household use is disproportionately employed in low-income communities that are reliant on this energy source, thus leading to disproportionate negative health implications as well.
Natural disasters
Climate change is causing an increase in the frequency and intensity of natural disasters globally, with dramatic consequences for sentient wellbeing and human health. Natural disasters can have wide-ranging health consequences through disrupting supply chains of medical supplies, death and bodily injury, displacement, infectious diseases, damages to clean water systems, and consequently mental health challenges.
The Asia-Pacific region is particularly subject to risk, with countries such as Vietnam, the Philippines, and Japan facing significant disaster risk, as well as small island developing states like Kiribati facing dramatic sea-level rise. While the Asia-Pacific region faces risk due to being in the tropics and along major fault lines, most regions of the world have begun to experience significant and escalating risks. Dramatic sea-level rise is projected to affect coastal communities globally and different combinations of increasingly regular and severe natural disasters create unique challenges for each region.
The stark reality of the damages caused by natural disasters was brought to where many of us live, work, and study when the devastating bushfires arrived in Australia early in 2020. The fires resulted in at least 33 direct deaths, hundreds of deaths in indirect excess mortality, trauma to firefighters and those directly impacted, biodiversity loss, and reduced air quality. These all present challenges to healthcare systems that will be magnified in future years when Australia faces concurrent disasters that occur more regularly and severely. A recent report from the Grattan Institute outlines the effects of climate change on public health, with particular focus drawn to the recent bushfires and future steps to be taken.

Heat
Global warming is causing sustained increases in temperatures, which are projected to result in 75% of the world’s population experiencing deadly heat waves by 2100 and some areas of the world becoming uninhabitable for human life. This has the potential to cause global disruption and additional strain on healthcare systems during hotter periods, with potentially existential consequences for sentient life in the long-term.
Sustained heat exposure can result in heat exhaustion, heat stroke, and the exacerbation of existing health problems such as heart failure.
MALNUTRITION
Through increased drought, natural disasters, ocean acidification, soil degradation, pollution, and the spread of infectious diseases, climate change will have a substantial negative effect on agricultural yields and the nutritional value of crops. This leads to malnutrition both from a lack of food availability and decreased quality of the food that does exist.
Once again, low-income nations will be affected disproportionately by food and nutrient scarcity, thus necessitating justice-based approaches to climate change that are cognisant of this inequity.
Co-benefits
These substantial negative health implications of climate change should act as an impetus for action so that they can be avoided through a combination of adaptation and mitigation measures. However, it is also worth noting that many of these climate change interventions result in considerable public health co-benefits that reach communities immediately. This is a much more compelling motivator relative to simply avoiding the damages of climate change, which are often perceived to be conceptually abstract and long-term. It is worth noting that while this article has a health focus, co-benefits of climate action can extend to “increased energy security, job creation, and reductions in poverty and inequality”. Moreover, adaptation efforts that build community resilience for future disasters also improve adaptability to current disasters and health issues.
Policies and initiatives that deliver health co-benefits are wide-ranging, with opportunities emerging across the spectrum of decarbonisation possibilities and industries. Given the plethoric range of policy possibilities that couldn’t easily be summarised in a single article, only a few of these initiatives will be outlined.
Renewable energy transition
Fossil fuel use is the primary means through which climate change manifests, and a transition towards alternative sources of energy is fundamental to mitigating future harm. Beyond merely averting harm, such a transition has the potential to improve human lives and avert needless deaths through resultant improvements in air quality. For example, three million premature deaths by 2040 could be averted with a 7% increase in investment in a “Clean Air Scenario”. Reducing the amount of ambient particulate matter and ozone in the air would result in significant quality of life improvements as the aforementioned negative effects of air pollution are minimised and outdoor spaces become less polluted.
There are also simpler shifts of energy use that can make a profound impact on climate change, public health, and economic development. For example, national programs that transition solid fuel cooking utensils to low-emissions stove technology could save millions of lives and avoid millions of tonnes of greenhouse gas emissions.
Increased use of active and low emissions transport
Transport represents 21% of overall CO2 emissions, which both necessitates decarbonisation of this sector while presenting opportunities to improve public health. For example, the electrification of transport in addition to increasing public transport use can decrease emissions while increasing air quality. Encouraging increases in active transport methods such as walking and cycling results in greater cardiovascular health, lower overall morbidity, and greater mental health outcomes in addition to the previously mentioned benefits to health and the climate.
Dietary choices
Agriculture represents 26% of overall CO2 emissions, a substantial portion of which is animal agriculture. Industrialised animal agriculture is currently unsustainable, using inefficient levels of water and land, while resulting in substantial methane and CO2 emissions and a number of other negative environmental impacts. Moreover, the greatest sources of environmental degradation—red meat and processed meat—are also the sources of animal agriculture with the most negative health implications. Diets with large amounts of animal agriculture—in particular red and processed meat—are associated with health risks including heart disease, stroke, and higher overall morbidity relative to plant-based diets. This dual benefit to health and the environment merits a shift towards diets with more fruits, vegetables, nuts, seeds, and beans, with the greatest positive impacts associated with an exclusively plant-based diet.
Greening cities
Creating more urban green spaces doesn’t only provide an aesthetic benefit. Increased numbers of trees in cities are a valuable source of carbon sequestration and a shared space that allows a city’s denizens to connect with nature. Beyond these benefits, green spaces also reduce the “urban heat island effect”, provide psychological benefits, and reduce water runoff that is associated with disease spreading, land degradation, and polluted waterways.
Final remarks
Climate change advocacy often takes the form of justifiably warning about impending devastation and framing climate action through the lens of avoiding or mitigating harm. Reframing the issue through co-benefits discourse may prove to be more effective as it shifts the conversation from advocating sacrifice for the greater good to improving the planet through corresponding improvements to society that we should all want to pursue, irrespective of the looming spectre of climate change.