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The links between climate change and public health

Written by King's College London | Jun 20, 2024 3:01:33 PM

Uncover the concerning link between climate change and public health through recent WHO findings.

Looking at a fact sheet released by the World Health Organization (WHO) in October 2023, the figures are alarming. 37% of heat-related deaths can be linked to human-induced climate change, and heat-related deaths among people aged 65+ have risen by 70% in just two decades. Developing countries that contribute minimally to global emissions are suffering the most, with 2 billion people across the globe unable to access safe drinking water. 

As the climate crisis looms over us, researchers everywhere have noted the emergence of adverse patterns in public healthcare challenges, too. While it’s difficult to measure the true scope of its impact, one thing is certain: fundamentally, the climate crisis is also a public health crisis. 

As we explore this complex, interwoven relationship, it becomes clear that tackling one issue necessitates addressing the other. Urgent action is imperative for the wellbeing of both our planet and its inhabitants. 

Understanding the connections 

Air quality and respiratory health 

Air quality is one of the most direct, visible and widespread links between public health and climate change. The burning of fossil fuels for energy production and transportation emits a cocktail of pollutants into the air, including particulate matter, nitrogen oxides, and sulphur dioxide. These pollutants not only contribute to global warming but also have severe implications for respiratory health. 

Despite efforts to move towards cleaner energy, greener cities and greener transport, many of us are still suffering the effects of poor air quality first-hand. The UK is no stranger to this: a 2023 study published by public health journal The Lancet links human-made air pollution to the onset and exacerbation of several chronic disorders, such as cardiovascular and respiratory diseases. This leads to between 28,000 and 36,000 deaths every year. 

London earned its nickname “the Big Smoke” in the 1950’s, and even 70 years on, it proves to be relevant. A study commissioned by City Hall reported that in 2019, the equivalent of between 3,600 to 4,100 deaths were estimated to be attributable to air pollution in Greater London alone. From reduced lung function and aggravated asthma to bronchitis and heart disease, we face a wide range of short- and long-term effects directly stemming from air pollutants. 

On a global level, the WHO estimates that around 7 million deaths per year can be attributed to exposure to fine particles in polluted air, with the Eastern Mediterranean region and South-East Asia being the worst-affected regions worldwide. Regions within the African continent are also thought to be severely affected, but definitive figures are hard to obtain due to limited monitoring and measurement of air pollution in these areas. 

The impact of air pollution also reveals noticeable disparities in public health across the globe. Those who are most vulnerable to air-pollution related health issues tend to be the elderly, as well as the poorest and most marginalised. Underprivileged demographics are more likely to live in industrial urban areas with busy main roads. They are also less likely to have easy access to green spaces. 

Natural disasters and vector-borne diseases 

Rising temperatures, natural disasters and shifting weather patterns create ideal conditions for the spread of vector-borne diseases such as malaria, dengue fever, and Lyme disease. Warmer temperatures allow disease-carrying mosquitoes, ticks, and other vectors to expand their habitats into new regions that were previously unaffected. 

Communities that lack adequate resources for disease prevention and control are hit hardest by these shifts. Tropical diseases that were once confined to specific regions are now encroaching on new territories, posing a significant challenge to public health systems worldwide. 

We can see evidence of this issue in action in Nigeria, which is bracing itself for further outbreaks of Malaria and Meningitis following this year’s adverse weather conditions. In fact, focusing specifically on Malaria, the WHO’s World Malaria Report 2023 revealed that “twenty-nine countries accounted for 95% of malaria cases globally. Four countries – Nigeria (27%), the Democratic Republic of the Congo (12%), Uganda (5%) and Mozambique (4%) – accounted for almost half of all cases globally”.

Pakistan saw a major uptick in the prevalence of Malaria due to major flooding in 2022. The country remains vulnerable to the effects of climate change and vector-borne disease, with limited healthcare access, a dependence on agriculture and insufficient vector control posing as contributing factors. 

Food security and malnutrition 

Climate change disrupts agricultural systems, leading to crop failures, reduced yields, and compromised food security. In recent years, the UK and most other countries in Western Europe have seen periodic shortages in vegetable produce because of this issue – but once again, developing countries are bearing the brunt of the impact. Extreme weather events, such as droughts and floods, can wipe out entire harvests, leaving communities vulnerable to hunger and malnutrition. 

The World Bank Group estimates that around 80% of the population most at risk of crop failures and hunger resulting from climate change are in Africa (particularly sub-Saharan regions), South Asia, and South-East Asia. In these regions, farming families are ‘disproportionately poor and vulnerable’, and their geographical proximity to the equator often makes these regions more susceptible to drought and flooding. 

Efforts are being made to mitigate this issue, including the cultivation of less thirsty crops and more efficient water usage, but these solutions can only go so far. Children are especially susceptible to the devastating long-term consequences of inadequate nutrition, with effects that can last a lifetime. 

Mental health and climate anxiety 

The toll of climate change on mental health cannot be overlooked. The relentless onslaught of natural disasters, loss of livelihoods, and uncertainty about the future contribute to a growing sense of anxiety and despair. Those who have experienced natural disasters first-hand are especially prone to conditions such as post-traumatic stress disorder (PTSD), and experience issues with social cohesion due to sudden displacement. 

It’s important to note that the impact of the climate crisis on mental health is not at all limited to those who have survived environmental catastrophes. Researchers have coined the term "eco-anxiety" to describe the overwhelming fear and helplessness that many individuals experience in the face of environmental degradation. Addressing the mental health impacts of climate change is an integral part of promoting overall wellbeing and resilience within communities. Scientists at Imperial College London’s Grantham Institute have conducted extensive research on this subject, and published a briefing with key recommendations on how to tackle this pressing issue. 

The path forward: A call to action 

Recognising the interplay between public health and climate change is the first step towards effective action. Governments, policymakers, healthcare professionals, and individuals alike have a role to play in mitigating these challenges. 

Transition to renewable energy 

A decisive shift away from fossil fuels towards renewable energy sources is crucial for both curbing climate change and improving air quality. Investments in solar, wind, and hydroelectric power not only reduce greenhouse gas emissions but also create cleaner, healthier environments for all. 

Build resilient healthcare systems 

Healthcare systems must adapt to the changing landscape of public health challenges brought about by climate change. This includes bolstering disease monitoring and response strategies, improving access to healthcare in vulnerable communities, and incorporating climate resilience into healthcare infrastructure. 

Promote sustainable agriculture 

Supporting sustainable farming practices, such as regenerative agriculture and agroforestry, can enhance food security while mitigating the impacts of climate change. Encouraging local, organic and less resource-intensive food production reduces reliance on fossil fuel-intensive transportation and supports healthier diets. In the same vein, local authorities must ensure that farmers are paid a fair salary that eliminates wealth disparity (and thus, better access to healthcare). 

Education and advocacy 

Empowering individuals with knowledge about the links between public health and climate change is key to fostering informed decision-making and advocacy. From grassroots initiatives to global movements, collective action can drive meaningful change at all levels of society. The overall goal is to ensure that everyone’s voices are heard, everyone’s concerns are addressed, and everyone has access to the services they need, regardless of their socioeconomic status. 

Seizing the power to make a difference 

At first glance, the prospect of tackling the issues we’ve delved into above can be overwhelming – especially with exacerbating factors like warfare, political instability and medical staff shortages to contend with. Yes, tackling them is much easier said than done, but with the right leadership and expertise, there is always hope.  

The complex interplay between public health and climate change demands a holistic, collaborative approach to solutions. As we navigate the challenges ahead, we must heed the warnings of science and prioritise the wellbeing of both people and the planet. 

Are you a healthcare professional seeking to advance your career? Our Public Health MSc offers an opportunity to further develop your expertise and make a meaningful impact in the world of public health.

With modules covering areas ranging from epidemiology and statistics to health psychology, you can tailor your studies to suit your own areas of interest. Best of all, since our course is 100% online and part-time, you can do all this without putting your career on hold.