We all need to urgently recognise that climate change is not merely a distant socioeconomic issue – that it is a current, unfolding health crisis affecting tens of millions globally, Professor Ashraf Hassen Coovadia reminds us in Daily Maverick.
He writes:
The link between climate change and human health is well established, though perhaps not widely recognised by the public. This may be due to the issue being overshadowed by its economic and social implications, or insufficient emphasis in public discourse.
This week, the second G20 Health Working Group meeting is taking place in KwaZulu-Natal. While South Africa’s G20 health agenda looks at important issues such as stemming the tide of non-communicable diseases and pandemic prevention, preparedness and response, there is a lack of focus on the impact of climate change on public health.
Human health is already being affected by climate change. To better understand these effects, it’s helpful to think in terms of direct and indirect pathways: those that are immediately visible and those with more delayed but substantial consequences.
Extreme weather
Direct impacts include the devastation caused by extreme weather events – storms, hurricanes and wildfires – which pose acute threats to survival.
While these events often cause significant loss of life, many more are injured or displaced. Health systems are frequently overwhelmed, unable to manage the burden, and critical services like immunisation programmes are disrupted.
Infrastructure damage leads to economic hardship, exacerbating poverty and malnutrition, particularly among displaced populations.
Heatwaves, occurring with increasing frequency and severity, directly affect health by causing dehydration, kidney dysfunction, heatstroke and even death. The number of such incidents is rising as these events become more common and prolonged.
Some regions are now facing conditions that render them uninhabitable, due to persistent extreme heat.
Indirect consequences
While direct effects have an impact on millions, most health consequences arise through slower, indirect pathways. These result from the disruption of ecosystems caused by rising temperatures and other human activities.
One notable example is the changing distribution of disease vectors. Mosquitoes that transmit diseases like malaria and dengue are now thriving in new regions, with longer breeding seasons. This means that disease patterns across the globe are changing and healthcare systems need to adapt to this.
Air quality is another critical area of concern. The link between pollution and respiratory health is well documented. Wildfires that occur more often due to climate change produce fine particulate matter that can enter the lungs, worsening conditions such as asthma and chronic lung ailments.
Rising temperatures also increase ground-level ozone concentrations, further aggravating these conditions. Additionally, climate change has led to longer and more intense pollen seasons, contributing to the rise in allergic conditions like hay fever and asthma.
Diarrhoeal diseases are associated with climate change as we see a higher risk of infections that appear to have an increased prevalence in warmer temperatures, such as with Escherichia coli, Cryptosporidium, rotaviruses, and parasites (eg Giardia and toxoplasmosis gondii).
Diarrhoeal rates are also affected by the availability of safe drinking water, which in turn is affected by both droughts and flooding.
Climate change has also been shown to affect the rates of interpersonal violence through heat-driven aggression and resource conflicts. Studies have linked higher temperatures and extreme weather to increased homicide, intimate partner violence and conflict.
Mental health impacts of climate change range from direct trauma that can cause post-traumatic stress disorder (PTSD) after an extreme weather disaster, to climate anxiety, especially in the youth, to displacement and loss of livelihood resulting from extreme weather events.
The 2023 Lancet Countdown names several vulnerable populations that are especially vulnerable to climate health risks:
• Children are at higher risk due to their developing bodies and greater exposure;
• The elderly, particularly those with pre-existing heart or lung conditions, are also at increased risk, especially during heatwaves;
• Pregnant women represent another sensitive group, with growing evidence linking heat exposure to poor pregnancy outcomes such as low birth weight, preterm births and stillbirths; and
• Those who are socioeconomically disadvantaged, as they often live in areas more exposed to environmental hazards, have limited access to healthcare and fewer resources to adapt or recover from climate-related events.
We all need to urgently recognise that climate change is not merely a distant socioeconomic issue; it is a current, unfolding health crisis affecting tens of millions globally.
Avoiding this crisis requires changing our individual habits, but more importantly, it requires advocating and working in our own communities towards a systemic change.
Professor Ashraf Hassen Coovadia is the academic head of the Department of Paediatrics and Child Health at the University of the Witwatersrand, Johannesburg.
Daily Maverick article – Human health is already being affected by climate change (Open access)
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