One future premature death is caused every time 1,000 tonnes of carbon is burned.

Climate change is a public health issue as it directly impacts social and environmental determinants of health, these include: cleaner, safe drinking water, sufficient food and secure shelter. A new study has suggested that 5 million deaths a year can be attributed to abnormally hot or cold temperatures caused by climate change. These temperature changes will affect both the global north and the global south – but not alike. Countries in the global south, with weaker infrastructure, will be least able to prepare, cope and respond to climatic and environmental changes without assistance.

Increasing carbon dioxide levels, rising sea and temperatures levels and more extreme weather will adversely impact: air pollution, allergens, diseases carried by vectors, food and water-borne diarrheal disease, food security, mental health related disorders and wildfires. Some existing health threats will intensify and other new health threats will emerge. Not everyone is equally at risk – age, location and economic resources all play a role in determining the severity of the health threat.

What I will mention is just a glimpse of the magnitude of problem we are set to face. Rising seal levels pose threat to coastal cities and homes and salination of soil will ruin land used for farming. Drier and longer droughts will also affect agriculture. Tropical storms will become more frequent and dangerous, causing further harm to crops but also destroy buildings, cause floods and epidemics. Heat waves will also become more frequent and intensive which can be fatal when body temperature can no longer be regulated through perspiration. The rate of species extinction (which is already up to 1,000 times faster than without humans) will continue to rise, decreasing biodiversity. The full depth and breadth of  the health impacts caused by climate change consists of far too much information and evidence to summarise on a single blog post. Nonetheless, this blog post will explore how vector borne disease and food security will impact health.

Patterns of infection are strongly affected by climatic conditions. A warmer climate, with increased rainfall and humidity, can cause a proliferation of vectors, lengthen transmission seasons of vector-borne diseases and can also alter their geographic range to higher altitudes. Malaria, transmitted by Anopheles mosquitoes, and dengue fever, transmitted by Aedes mosquitoes, are both sensitive to climatic conditions. Studies suggest climate change is likely to increase exposure to many diseases, including both of these. Malaria alone is responsible for around 230 million people suffering, particularly children under 5, and over 400,000 deaths a year, particularly in Africa and South-East Asia; hence why possible change in the dynamics of a number of infectious diseases is a worrying concept.

Food security will be compromised for many, as climate change is expected to threaten: food production, food quality, food prices and distribution systems. Combined effects of changes in rainfall, severe weather events and increasing competition from weeds and pests on plants, put crop yields at risk. Consequently, food prices are also expected to rise in response to the declining food production. With rising food prices, people may cope by turning to nutrient poor/calorie rich foods or, on the contrary, endure hunger –  consequences ranging from obesity to malnutrition. Food quality can be impacted by elevated atmospheric CO2. High levels of CO2 in the atmosphere is associated with decreased nitrogen concentration and subsequently decreased plant protein. Currently, 1 in 4 people around the world are moderately (struggle to access or afford a healthy, nutritious, balanced diet) to severely (not able to meet their energy needs) food insecure – the proportion of those living in such unjust and difficult situations is already shocking and unacceptable – and, alarmingly,climate change is only set to increase this.

Climate change may bring localised benefits to some regions of the world, such as fewer deaths, in winter, in temperate climates.However, for the most part, health impacts are overwhelmingly negative. Cost benefit estimates suggest health benefits from atmospheric pollution mitigation policies far outweigh any of the costs of meeting climate-change goals. Hence why it remains so important that governments take responsibility and individuals take action to make appropriate changes to combat climate change where they can, as soon as they can. 

Written by, Riddhi Patel