Prof. Dr. Levent Kurnaz
Climate Scientist at
Bogazici Univ

Dr. Elif Altuğ
Amerikan Hastanesi
(Göğüs Hastalıkları)

The increasing and frequent effects of climate crisis affect our health. The impacts of the climate crisis on public health were outlined by the Climate Clinic Science Board Members, Prof. Dr. Levent Kurnaz and Dr. Elif Altuğ.

The climate crisis continues to impact the world in every field. Global health organizations have declared the human-induced climate crisis a major threat to public health. Although the health effects of the climate crisis have already started to be observed, it is known that the frequency and severity of these unwanted and sometimes destructive health effects will increase in the coming decades. The climate crisis has many negative effects on the health of people and all living beings. These effects are observed in areas including extreme weather events, air pollution, waterborne diseases, vector-borne diseases, food insecurity, and nutritional disorders, mental health issues, among others. On the other hand, the effects of the climate crisis can also pose a threat to health services and health systems.

For all these reasons, the first Climate Clinic in Türkiye continues this summer with informative content titled as “The Climate Clinic Post” on health risk factors that have emerged and may emerge due to changing climates, stating that ‘the climate crisis is also a health crisis’.

The second season these posts by the Climate Clinic, opened in collaboration with Koç University and Hacettepe University by Yuvam Dünya Association, which aims to raise awareness about the climate crisis and collective transformation in society, began with the first informative post of this summer, prepared by Climate Clinic Science Board Members Prof. Dr. Levent Kurnaz and Dr. Elif Altuğ.

If it weren’t for El Nino and La Nina, each year could be hotter than the previous one

Yuvam Dünya Association Science Board Chair Prof. Dr. Levent Kurnaz explained the scientific cycle behind the surprising temperatures: “The Pacific Ocean covers almost half of the Earth’s surface. The warming or cooling of this ocean’s waters, accordingly, has the greatest impact on the warming or cooling of our atmosphere. We call the warmer than normal conditions of the Pacific waters El Nino and the cooler than normal conditions La Nina. The climate crisis increases the average temperature of the Earth by a certain amount each year. During times of El Nino, this increase is a bit more than expected; during La Nina, it is a bit less. 

Various regions of the world are affected differently by these events, but generally speaking, global average temperatures increase a few months after El Nino begins and return to normal a few months after it ends. Last April, El Nino was observed in the Pacific. Consequently, global temperatures began to rise in June. From the beginning of last June to this June, we experienced the hottest 12 months ever due to the effects of El Nino. If the El Nino/La Nina cycle didn’t exist, each year we experienced could be hotter than the previous year. This cycle makes some years much hotter and some years slightly less hot than the increases brought by the climate crisis. 2023 was one of the much hotter years; 2024 also started as one of the much hotter years under the effect of El Nino.”

While it is wondered whether temperatures will continue this way throughout the summer, Prof. Dr. Kurnaz clarified: “El Nino officially ended at the beginning of May. We are currently in the normal temperature period between El Nino and La Nina, and we will probably shift towards La Nina very soon. This means that we will continue to experience much hotter days than expected for a while, but we will return to the expected hot days by mid-summer. Towards the end of the summer, we might also transition to slightly less hot days than expected. If we translate this to Istanbul, it means the following: the expected average highest temperature for July is 28 degrees Celsius. Global warming has raised this expected temperature to 29.5 degrees Celsius. In years with El Nino, this average is measured at 30 degrees Celsius; in years with La Nina, it is measured at 29 degrees Celsius. Looking at the highest temperatures, El Nino brings high temperatures ranging from 35-37 degrees Celsius to Istanbul, while La Nina causes conditions in the range of 34-36 degrees Celsius. But if global warming did not exist, these high temperatures would be approximately 32-34 degrees Celsius.”

The consequences of temperature increases on the human body

Climate Clinic Science Board Member Dr. Elif Altuğ drew attention to the methods by which the human body responds to temperature increases: “The human body responds to temperature increases in two ways. The first is by dilating the vessels to increase blood flow towards the skin and facilitate heat transfer from the body to the environment. The second is by secreting sweat through the skin, which evaporates and naturally cools the body by maintaining the body temperature between 36.5 and 37.1 degrees Celsius. The moisture created by sweating on the skin evaporates with the heat released from the body, naturally cooling it.”

Dr. Altuğ also made statements about the short and long-term consequences of temperature increases on human health, emphasizing the importance of changes in environmental conditions; “Early-stage health-related conditions developed due to temperature increases include sunburns and burns from contact with hot surfaces, prickly heat (itchy or painful small water blisters, papules or pustules caused by clogged sweat glands), heat cramps (painful involuntary muscle contractions due to water loss and electrolyte imbalance associated with sweating), heat edema, heat syncope (fainting during prolonged standing due to partial fluid loss), heat exhaustion, and heatstroke. In heat exhaustion, symptoms such as lethargy, headache, sweating, muscle cramps, and palpitations develop, while the internal body temperature can rise partially, but the mental state remains normal. In heatstroke, however, the internal body temperature rises above 40 degrees Celsius, and disruptions in central nervous system functions can lead to multiple organ failure and potentially fatal outcomes. 

Numerous epidemiological studies report health problems that develop due to prolonged exposure to heatwaves. Cardiovascular events (acute myocardial infarction, arrhythmia, exacerbation of congestive heart failure, and stroke), respiratory conditions (asthma and chronic lung disease), and kidney-related diseases and their associated mortality risks increase parallel to temperature increases. High temperatures also increase the risk of premature birth, stillbirth, low birth weight, and congenital heart diseases during pregnancy.”

Dr. Altuğ also addressed the effects of extreme heat on human psychology: “Temperature increases are associated with an increase in anxiety and depression, a tendency towards suicide, and behaviors involving anger and violence. In this regard, compiling studies often focus on the early and direct effects of temperature increases. However, psychiatrists also draw attention to the indirect long-term effects of climate change on mental health. Particularly, eco-anxiety and climate depression, which affect children and adults, similarly, are due to the emotional struggles caused by the inability to prevent the destruction of our world, the uncertainty of the future, and the inadequacy of necessary actions... Our ability to adapt to climate change is directly linked to our emotional capacity to face this threat.”

Climate crisis and disease have shifted places

Dr. Altuğ also noted that diseases are shifting due to the climate crisis: “The climate crisis means the spread of infectious diseases to new regions. Let’s consider malaria, for example. Regions that were too dry or too cold for malaria in the past have become suitable for malaria transmission in the last 10 years. Warming in these regions also increases the spread of viral diseases such as Dengue Fever and Zika virus,” she stated, and drew attention to how this situation is perceived across different age groups: “Individual susceptibility and environmental vulnerability affect the impacts of heat on health. Being part of a marginalized ethnic group or having low socioeconomic conditions, as well as social isolation, advanced age, accompanying diseases, and medication use, also influence the outcomes. Elderly individuals (65 years old and above) with weakened body heat regulation systems and reduced ability to cool themselves are at significant risk due to potential additional diseases, the use of medications affecting the heat-regulating system, limited mobility, or inadequate home care support. Climate change poses different threats to infants and children. Today, nearly every child faces at least one climate issue. Temperature increases and rising carbon dioxide levels extend the pollen production period and increase their numbers, causing more allergy and asthma attacks in children. Children, especially infants, are sensitive to gastrointestinal infections developed by bacterial pathogens like salmonella. This situation also becomes more frequent under environmental temperatures that facilitate bacterial division.”

In addition, Dr. Elif Altuğ referred to a psychological assessment survey conducted in 10 countries: “Two out of three children report being anxious due to climate change. Deviation from usual temperature levels makes it difficult for humans to physiologically adapt to and tolerate heat. As humanity, we are approaching our physiological and sociological limits... While managing the climate crisis, many preventive and adaptive suggestions can be taken personally and societally to improve heat-related illnesses.”

See you in the next issue of The Climate Clinic Post. Remember, when it comes to health, the day to fight the climate crisis is today.