The interactions between climate change and human health are both numerous and complex. Scientific evidence has shown that climate change has altered the distribution of a number of vectors of infectious diseases, as well as the seasonality of certain pollen allergens, and led to a rise in the number of deaths attributed to heat waves.
In the last century, heatwaves in Sweden occurred once every 20 years (the last being in 1975). Since the start of the new millennium, four heatwaves (2003, 2007, 2010 and 2018) have been already experienced. The frequency of these events is expected to further increase due to climate change; they will occur once every three to five years towards the end of the century. Heatwaves are already leading to increased mortality. Botkyrka is a municipality in Stockholm County in east central Sweden, not far from the capital with a population of 91.925 inhabitants.
West Nile virus (WNV) is a vector-borne pathogen, which can infect humans, mammals (e.g., horses) and birds. Its transmission cycle is related to the interactions between pathogen, vector, vertebrate hosts, and the environment. Weather conditions have direct and indirect influences on this vector; changes in climatic conditions (temperature, precipitation, relative humidity, and winds) could lead to an increased spread of WNV also in areas that currently are not severely affected.
Evidence that elevated temperatures can lead to increased mortality and morbidity is well documented, with population vulnerability being location specific. The elderly are particular vulnerable to extreme heat stress. Being part of the Iberian Peninsula, Portugal has a mild Mediterranean climate. Climate change projections indicate that the number of days with extreme heat in Portugal will increase with urban areas being more sensitive.
Evidence that increasing temperatures leads to increased mortality and morbidity is well documented, with population vulnerability being location specific. Especially the 2003 heat wave in Europe raised the awareness of negative impacts of heat stress on human health in Austria. Increased incidence of heat waves leads to an increase in heat stress, especially in urban areas; the intensification of the heat-island effect is to be expected.
The city of Antwerp, in order to better understand the problem of heat stress, commissioned the research organization VITO to map the current and future temperatures and thermal comfort in the city. The research results indicate that the urban heat island of Antwerp exacerbates the impact of climate change on the urban population as the amount of heatwave days in the city raises twice as fast as in the rural surroundings. To tackle the problem of heat stress in the city, adaptation measures at three different scales (city-wide, local and the individual citizen) are put forth.
The 19th century industrialisation in Lodz heavily affected the city’s rivers, altering their ecosystems and hydrology. Many rivers in the densely built-up city were canalized. This resulted in a higher flood risk from runoff during heavy rain periods. Low water retention also implies reduction of soil moisture during dry spells, contributing to higher temperature and reduced air humidity (urban heat island). Based on climate change projections, it is expected that the intensity of heavy rain periods and higher temperatures will increase and exacerbate these problems.
Stuttgart’s location in a valley basin, its mild climate, low wind speeds, industrial activity and high volume of traffic has made the city highly susceptible to poor air quality. Development on the valley slopes has prevented air from moving through the city, worsening air quality and contributing to the urban heat island effect. A Climate Atlas was developed for the Stuttgart region, presenting the distribution of temperature and cold air flows according to the city’s topography and land use.
High temperatures and heatwaves in the summer pose increasing risks to people living in Slovakian cities. In particular older people and children, those living on top floors in poorly insulated buildings, and those relying on facilities such as nurseries, schools or care homes are prone to heat stress. The Carpathian Development Institute, in collaboration with local authorities in Trnava and Košice, carried out an assessment of vulnerability to high temperatures and heatwaves in residential environment, taking into account the social aspects.
Demographic change and climate change together place great challenges on the society. The life expectancy of the population in Germany rises and so does the share of older people. Besides chronic patients and children, the elderly are especially affected by the effects of the climate change. At the same time more and more people live in single person households (increase from 14.56 million in 2004 to 16.83 million in 2016 in Germany), which can influence their social isolation.