A medicine student reflects on the effects that climate change will have on our health
In 2018 the World Health Organization (WHO) stated that “Between 2030 and 2050, climate change is expected to cause approximately 250,000 additional deaths per year.” According to their calculations the direct costs that result from effects of climate change on our health are estimated to be between two to four billion US dollar a year by 2030. But how do we explain these numbers? How can a few degrees more have such a big effect on our well-being? In this article, I will summarize the most important risks the change of temperature will have on the very roots of our lives – our health.
Text and illustration: Merle Sauer, Medicine.
Vector-borne infectious diseases
Until the middle of the 20th century malaria was common in South and Central Europe. Thousands of people were dying from this mosquito-borne disease that causes recurrent fever, headache and vomiting and in severe cases seizures and coma. The disease affected all classes of society and did not miss out on prominent people for example Oliver Cromwell and Friedrich Schiller. It was only through the systematic drainage of marshlands and use of insecticides that malaria could be eradicated in Europe in the 1960s. Hard to believe? But imagine having malaria in central Europe again. Imagine having to think about malaria-prophylaxis not only when travelling to Southeast Asia or Central Africa, but also during city trips to Rome or Paris. Even harder to believe? Well, we are actually not so far away from this scenario. With rising temperatures and move of climate zones the Anopheles mosquitoes that transmit malaria will find their way back to Europe and Northern America. Many other infectious diseases transmitted by mostly insects, so called “vector-borne diseases”, will also spread, for example Lyme disease that is transmitted by ticks and West Nile virus transmitted by mosquitoes. This is because of earlier seasonal activity and a northward expansion of these vectors in response to increasing temperatures. Together with a longer seasonal activity this will increase the risk of human exposure to these vectors.
Extreme temperature-related death and illness
But these vector-borne diseases are probably not the first thing that comes into mind when thinking about the effect of climate change on our health. First, we should reflect about the direct effect of an increase of both average and extreme temperatures. The heat wave of summer 2003 in Europe for example has led to more than 70,000 excess deaths due to extreme heat. It can result in numerous severe illnesses, like heat cramps, heat exhaustion, heat strokes and hyperthermia. It is also associated with increased rates of cardiovascular and kidney disorders, typically as a result of dehydration. Increased admissions to hospital because of respiratory diseases can also be due to higher levels of pollen and other aeroallergens in the air in extreme heat. But climate change will also bring colder days in the winter with the risk of hypothermia and frostbite. In general, temperature extremes can also worsen chronic conditions such as cardiovascular or respiratory diseases and diabetes-related conditions.
Imagine having to think about malaria-prophylaxis not only when travelling to Southeast Asia or Central Africa, but also during city trips to Rome or Paris.
Mental health and well-being
From these extreme seasonal temperatures, the weakest will suffer the most, very young, very old and very sick people. However former completely healthy people might also be at risk. Take heat stress at the workplace as an example. This is something that could affect all of us. Did you ever try to work in an office that was 40 °C? Probably not, because you will likely be allowed to be dismissed early or your office might have an air-conditioner. But what about people who work outdoors? The heat-stress will of course have a huge effect on our mental health and general well-being. The consequences range from minimal stress and distress symptoms to clinical disorders, such as anxiety, depression and post-traumatic stress, for instance after having experienced climate-related disasters.
Violent and unpredictable weather
These climate-related disasters will come or are already happening. Climate change increases the rate of violent and unpredictable weather, resulting in tornados, floods or droughts that have severe consequences. Take the Bushfires in Australia as a recent example. Of course, Bushfires are part of the natural ecological system in Australia, but the extent of fires we have seen this season go beyond that and they have evolved out of the increasing droughts due to global warming. Such extreme events can of course have direct impacts on our health, if people get injured or even die. But there are a lot more consequences to take into account. In the case of the Australian Bushfires many people reported that they had struggle breathing because of smoke and debris. The effects from smoke inhalation range from eye and respiratory tract irritation to more serious disorders, including reduced lung function, bronchitis and triggering of asthma symptoms, like wheezing, breathlessness, coughing or chest tightness. Health impacts can also occur long after such weather catastrophes, because of damage to property or loss of infrastructure that might result in financial ruin of individuals or even homelessness.
Food safety, nutrition, and distribution
Lastly, but probably most importantly, climate change also has an effect on the security and availability of food and drinking water. Like many of the other points, this will affect developing countries the most. Rising temperatures and increasingly variable and unpredictable rainfall patterns will decrease the production of staple foods in many of the poorest regions. This leads to rising numbers in malnutrition and starvation. According to the WHO assessment the biggest part, namely 95,000 of the additional 250,000 deaths per year caused by climate change will be due to childhood malnutrition. The variable rainfall patterns will also affect the supply of fresh water. People, especially in developing countries, will be exposed to water contaminated with pathogens, such as bacteria, viruses or protozoa, that cause mainly diarrheal diseases. Even if these infections seem easy to treat and harmless in developed countries, in children in poorer regions they can be very dangerous. In fact, over 500,000 children aged under 5 years die every year from diarrheal diseases.
To conclude, there are several fields in which climate change affects our health and the whole extent of the consequences can probably not even be grasped completely at this time. But all the effects of climate change have one thing in common: the weakest will suffer the most, old people, people with chronic diseases and children. Also, areas with weak health infrastructure, mostly in developing countries, will be the least able to cope without assistance to prepare and respond. Not only do we therefore have to put all our effort into decelerating climate change, we should also make sure that the populations of concern are protected and that our health systems are fit for the consequences of climate change. This is not only a matter of billions of dollars that could be spared, but more importantly of human lives that must be protected.