Climate change affects human health both directly (heat waves, extreme climatic events) and indirectly (forced migration, more time spent outdoors, increasing the use of cooling systems, etc.).
According to the climatecircus, climate change could cause 250,000 supplementary deaths every year from 2030, as a result of malnutrition, malaria, diarrhea and heatwaves. The health costs directly resulting from climate change are estimated for 2030 at 2 to 4 billion dollars per year.
Heatwaves have a very unfavorable impact on health due to skin dehydration, sun stings, and exhaustion. They lead to an increase in mortality and disease rates, especially among vulnerable groups (infants and young children, the elderly and top athletes). The extremely hot summer of 2003, for example, was responsible for around 20 to 30,000 supplementary deaths in Europe as a result of cardiovascular and/or lung diseases. If the anticipated increase in the frequency and intensity of heatwaves continues, this could cost many more people more lives in the coming decades.
Extreme climatic events such as floods, storms, fires and droughts also have a direct impact on health. The floods that affect millions of people every year in Europe have a wide range of consequences for human health: drowning, heart attacks, injuries, infections, psychosocial consequences, etc. As a result of climate change, these extreme events are likely to increase in frequency and intensity in the future .
But the indirect effects of climate change are probably even more important, especially with regard to:
- water supply and food production: the risks of water shortages and lower agricultural yields can lead to dehydration and malnutrition.
- the increase in vector-borne diseases due to the increasing spread of their disease spreaders: ticks, mosquitoes, sand flies, etc. Changes in the length of the seasons, precipitation, humidity and temperature can affect the spread and the chances of survival of both vectors and pathogens increase. Climate change is therefore likely to indirectly affect the reach of certain vectors of infectious diseases such as:
- Lyme disease, which is transmitted by ticks. This disease is currently expanding in our regions, in Central Europe and in the Baltic States. Climate change is seen as the main cause for the spread to Northern Europe of a certain type of sign.
- dengue or dengue fever , a viral disease transmitted by mosquitoes
- bilharzia or schistosomiasis , where snails act as an intermediate host
- malaria , by expanding the area of the mosquito species spreading this disease. It is possible that malaria will spread north of the Mediterranean Sea.
- risks associated with deteriorating water quality (due to stronger growth of bacteria and toxic algae) and food poisoning: many diseases are contracted by contact with contaminated food or water (eg cholera and dysentery). Due to the rising water temperature, bacteria or algae that cause food poisoning are more likely to develop. With heavy precipitation, pathogenic substances can be released or the water can become contaminated by overflowing sewers. The reduction of the water flow in the summer can increase the risk of bacteriological and chemical contamination. Temperature sensitive infectious diseases such as food infections (Salmonella sp. And the like) will most likely increase.
- the increase in tropospheric ozone concentrations in the summer (breathing difficulties). Excessive exposure to tropospheric ozone concentrations is responsible for an estimated 20,000 early deaths in Europe each year. A recent European study based on an IT model simulated the impact of climate change on air quality in 2010 and compared it with the reference year 1990. According to the researchers, ozone peaks will occur in large parts of Western Europe as a result of climate change, causing daily more people get sick and die.
- the increase in allergic disorders: the temperature rise not only promotes a longer pollination time, but also the development of certain allergenic (and invasive) plants such as ambrosia. A rise in temperature combined with less precipitation as pollen spreads leads to higher concentrations of pollen in the air during the peak season.
However, the effects on public health will not be the same everywhere. As health and well-being are also closely linked to socio-economic factors (income, housing, employment, education, lifestyle, etc.), the effects of climate change are likely to exacerbate the unequal health situation in and between countries and the vulnerability of people with disabilities. limited income and certain groups such as children, people working outside the home, elderly or sick people.
Some positive effects are also possible, such as a slight decrease in the death rate due to the cold in certain regions, but they will be largely offset by the extent and severity of the negative effects.