Health is one of the basic human needs. According to the World Health Organization (WMO), climate change may bring certain benefits to temperate climates, such as less deaths related to cold temperatures in winter, but the net effect is likely to be very negative. Climate change affects the social and environmental determinants of health which are clean air, safe drinking water, sufficient food and secure shelter.
Extreme heat: Very high temperatures are related to a increased mortality by cardiovascular and respiratory diseases, especially among vulnerable population like elderly people. A well known example are the 70000 excess deaths recorded during the 2003 heatwave in Europe. Urban heat islands are a factor in many urban settlements: temperatures measured in- and outside urban areas can vary by several degrees. This effect is highest during the nights. Extreme high temperatures also affect the air quality by increasing the levels of ozone and other pollutants. Pollen and other aeroallergen effects tend also to be higher in extreme heat conditions, and can trigger asthma. Furthermore, variability of temperature is itself a risk factor since it is harder to adapt to a highly variable climate than in a stable one.
Natural disasters and variations in rainfall patterns: Though the future changes of rainfall patters are uncertain, they are very likely to affect the supply of fresh water in several regions. The lack of water security does favor the risk of diarrhoeal disease, and in extreme cases leads to drought and famine. Sea level rise poses also threats to the population living close to the sea. In several regions, flood intensity and/or frequency may also increase, threatening freshwater supplies and increasing the risk of spreading of infectious diseases.
Infectious diseases: As the world warms, the transmission seasons of several diseases transmitted through insects are likely to lengthen, and also their geographic range. This includes Anopheles and Aedes mosquitoes transmitting malaria and dengue. Waterborne diseases are also a threat in areas where water security is to be affected by eventual drought.
Climate impacts on human health are closely related to the occurrence of extreme events such as heat waves, droughts, floods, and change of rainfall patterns. However, the representation of these phenomena in currently available climate model simulations is affected by several important uncertainties, some of them related to the coarse resolution. Higher resolution models used in PRIMAVERA will help to gain a better understanding of how rainfall patterns and heat waves will change over the next decades, providing new, more accurate information to the stakeholders and the population, in order to improve adaptation measures.
Policy makers at the national, European or international level may be interested in the relation between climate change and health. They could ask questions such as: Which regions are affected more or less by climate change? What is the potential impact of climate change on outdoor activities for leisure or employment? Which existing diseases will extend their range to areas that are currently unaffected? What is the adaptive capacity of certain regions under high levels of warming?
Specific organizations, such as health agencies or companies, may be interested more specifically in questions such as: What changes in housing and infrastructure should be made to adapt to climate change? What are the risks of extremes and will they change substantially in the near future? Where and when will temperature exceed citizen’s comfort? Which temperature thresholds are likely to change human behaviour?
Within PRIMAVERA, we aim to reach smaller and medium enterprises, such as local health agencies, by collaborating with research groups that work on the impacts of climate change on health. Research groups typically have experience with the type of information that is of interest to users. In this way, we expect that our understanding of the impacts of future climate change on health can be improved, which would make the health sector more resilient to climate change.