A report released by The U.N. Intergovernmental Panel on Climate Change (IPCC) detailed the dire consequences that climate change can have on worldwide global health.

Access to medicine, cutting-edge health technology, improved sanitation and vaccination, and the growing affordability of health care means that global health has improved drastically over the past century. However, the looming threat of global warming may change this very soon.

Brian O’Neill, chief scientist at the Pacific Northwest National Laboratory and a contributor to the report explained that ‘for many aspects of human well-being, we are actually in a period of decades of progress. Climate impacts slow that progress or put it at risk.’

The report explains many different aspects in-depth, though perhaps the most surprising discussion lies in the health and wellbeing chapter.

Observed unpredictable temperature and cataclysmic natural phenomena have made it extremely evident that ecosystems have been negatively and directly impacted by global warming. However, this has created a domino effect and has seeped into human physical and mental health.

Climate change and disease

Mosquito-borne diseases such as dengue fever and malaria have become more prevalent due to increased global average temperatures – the report holds that 12 areas have become more suitable for transmission. As an example, highland areas of Colombia and Ethiopia that were previously untouched by the illness have become susceptible to malaria cases due to the warming climate. More cases have shifted to higher altitudes, meaning that cases could increase and spread geographically without intervention.

This is also true of Japanese encephalitis in Nepal and southwest China.

As global temperatures increase, hotter climates have been experiencing drought. The Zika outbreak in South America was directly influenced by this. The use of household water storage increased, exposing a greater population to the Zika vector.

In Canada, climate warming has increased tick populations, many of which are the vectors for Lyme disease – leading to a huge uptick in cases in the area.

Warming temperatures have also tampered with food storage, leading to food-borne diseases such as Salmonella, which thrive in hotter climates.

Heat is not the only problem, but extreme weather conditions as a whole.

Extended periods of precipitation increase the spread of water-borne diseases – environmental pathogens from pastures and fields to groundwater, rivers, and lakes, can infiltrate water treatment and distribution plants.

Cases of respiratory tract infections, such as pneumonia and influenza are heavily affected by temperature, precipitation and humidity extremes, dust storms, as well as climate variability. In Australia, emergency visits for childhood pneumonia have been associated with sharp temperature drops, respiratory disease incidences in China are related to large inter-daily temperature changes, and rapidly changing and extreme temperatures during pregnancy can be linked to childhood pneumonia. Pneumonia incidence also increases in tropical areas of Africa and Asia during the rainy season, showing the association between pneumonia, temperature, and precipitation.

Most visibly, the severity and spread of COVID-19 has been further proliferated by climate change, as disease reproduction and transmission are linked with ecosystem degradation. Emerging infectious diseases are affected by climate change through movements of species, spurring vectors and reservoirs of diseases into human populations and vice versa. This spillover from wildlife to humans is through live animal-human markets, intensified livestock production, and ‘climate-related movements of humans and animals into new areas that alter human-animal interactions’. However, the report asserts that human-to-human interaction is the main driver of transmission, as opposed to climatic ones.

Non-communicable diseases – those that are not directly transferable from one human to another – are also climate change-related. Flare-ups of cardiovascular and respiratory diseases are affected by air pollutants and wildfires, whilst the emergence of several types of cancer is influenced by the mobility of carcinogens through environmental media such as precipitation and flooding.

Most directly, extreme cold or heat can cause temperature-related illnesses such as hypothermia or heatstroke, which can be deadly when left untreated.

Mental health

Interestingly, the report acknowledges the mental burden of global warming on individuals on top of their physical health section.

The report explains that children and adolescents, people with existing mental and physical problems, and elderly people are the most at risk from climate-related stressors. These include ‘exposure to high temperatures, extreme weather events, displacement [due to unlivable climate], malnutrition, conflict, climate-related economic and social losses, and anxiety and distress associated with worry about climate change’.

Susan Clayton, professor at the University of Ohio and contributor to the report explained:

‘There’s increasing evidence that high temperatures, themselves, are associated with decreased mental health, increased rates of suicide, psychiatric hospitalizations […] Mental health affects physical health. It’s very hard to separate the two. People experiencing mental health threats might engage in more risky behaviour. They might not take care of their physical health or put themselves more at risk.’

Adaptation is key

The report warns that adaptation to create resilience is necessary for lessening the effects of climate change on human wellbeing.

Hoesung Lee, the Chair of the IPCC explained:

‘This report is a dire warning about the consequences of inaction. It shows that climate change is a grave and mounting threat to our wellbeing and a healthy planet. Our actions today will shape how people adapt and nature responds to increasing climate risks’.

The report outlines that it is already difficult to carry out many climate change mitigation actions, but if global temperatures increase by 1.5°C, options will become more limited. More alarmingly, it will be impossible in some regions if warming reaches 2°C.

In order to reduce climate-related detriment to global health, careful planning and adaptation are needed. Climate-resilient and environmentally sustainable health systems should be developed at a national or local level, as the climate effects vary in each region. Most important, however, is understanding that climate change as a whole affects not only wildlife and arctic regions but all populations on earth. As such, the disadvantages humans will suffer will be both direct (extreme temperatures, forced migration, etc.) and indirect (poor mental and physical health, monetary losses). With every day that passes without action, the dire consequences of climate change become even more irreversible.

IPCC Working Group II Co-Chair Hans-Otto Pörtner said:

‘Healthy ecosystems are more resilient to climate change and provide life-critical services such as food and clean water. By restoring degraded ecosystems and effectively and equitably conserving 30 to 50 percent of Earth’s land, freshwater and ocean habitats, society can benefit from nature’s capacity to absorb and store carbon, and we can accelerate progress towards sustainable development, but adequate finance and political support are essential’.

Governments need to invest in more clean energy, transportation, and waste management and place sanctions on the mass agricultural and manufacturing industries. Citizens must also make an effort to choose cleaner, greener options when possible.

Pörtner concluded:

‘The scientific evidence is unequivocal: climate change is a threat to human wellbeing and the health of the planet. Any further delay in concerted global action will miss a brief and rapidly closing window to secure a liveable future’.

About the Author: Shadine Taufik

Shadine Taufik is a contributing Features writer with expertise in digital sociology and culture, philosophy of technology, and computational creativity.