Climate change does not create new diseases, but rather amplifies and redistributes existing diseases and this influences the health characteristics and conditions of a given population. We refer to the increases in mortality and disease that are directly caused by the increase in extreme weather events, heat and cold waves, droughts, floods, wildfires and worsening air pollution.
But we must also take into account the indirect effects of the climate emergency, which leads to changes in ecosystems - spread of vector-borne diseases such as mosquitoes/ ticks or reduced water availability and quality - and in social systems - reduced food production and food insecurity, reduced labour capacity, deterioration of mental health, climatic migrations, increased pressure on health systems and infrastructures. The climate emergency is therefore a public health crisis.
If we look at inequalities, all populations are exposed to the negative health impacts of climate change, but there are circumstances that increase vulnerability, such as geographic location and socio-economic inequalities, which also increase health inequities. The impact differs totally depending on the socio-economic level of the affected geographical area and, therefore, on the pre-existing health conditions of its population, contributing significantly to a worsening of general health conditions and to the chronification of certain diseases, so we should modify the way in which we should consider the protection of vulnerable populations.
All populations are exposed to the negative health impacts of climate change, but circumstances such as geographic location and socio-economic inequalities increase vulnerability
The different incidence in different regions, in people with different socio-economic levels and the possibility of adapting to the changes produced will be essential for populations to minimise the health impacts of global warming. Particularly susceptible groups are the elderly, women and children, people with low income levels, people with chronic diseases (cardiovascular and pulmonary, mental, obesity, neurological) or outdoor workers, for example. In Spain, it is highly likely that increasingly intense heat waves, increased effects attributable to atmospheric pollution, more frequent forest fires and droughts will have the greatest impact on health.
Adapting epidemiological surveillance to climate change
In cities, these health effects can be exacerbated especially by greater socio-economic differences, inadequate housing conditions and increased exposure to air pollutants. Low-income populations generally live in poorer housing in city centres, increasing their vulnerability to high temperatures. We should be able to identify the target population through home help services, telecare and social centres.
The main problem we face is that our epidemiological surveillance systems are not yet specialised in quantifying these causes associated with climate change impacts and attributing them correctly. It is necessary to implement alert and surveillance systems that integrate all the impacts of climate change that affect the same place simultaneously. For example, this summer in our country records have been broken in terms of burned surface area and no epidemiological system is quantifying the associated health effects, not only short-term aggravation of respiratory problems but, in the long term, the worsening of cardiovascular disease or associated mental illnesses such as post-traumatic stress, anxiety, depression, adherence to treatment, etc.
It is the responsibility of governments to articulate the necessary mitigation and adaptation measures to prevent the impact of climate risks on vulnerable populations from increasing
It is the responsibility of the competent administrations to articulate the necessary mitigation and adaptation measures to prevent the impact of climate risks on the vulnerable population from increasing. In addition, these risks must be managed appropriately to minimise the effects on health. Adaptation measures include the design and implementation of local prevention plans adapted to each geographical area based on its socio-demographic characteristics. With regard to the impacts of heat waves, for example, adaptation involves investing in the creation of public climate shelters and redesigning cities to reduce the heat island effect, which can be achieved through different strategies such as increasing the albedo (the percentage of radiation that any surface reflects with respect to the radiation that falls on it) of buildings and the ground; including green roofs; increasing green areas such as parks or trees, and creating "blue zones" such as lakes, fountains or ponds.
National and local plans for critical times
From the point of view of health, it would be necessary to draw up, develop and implement integrated national plans for adaptation to climate change in health. This implies the geographical detection of vulnerabilities according to their degree of impact. Going down to the local level is essential in order to adapt to the heterogeneous socio-demographic characteristics of the population and to carry out risk assessments of the effects of climate change at the local level in relation to population health factors. It is about designing and developing integrated plans that address the synergistic health impacts of different environmental factors that enhance the impacts of climate change (air pollution, dust intrusions, droughts, forest fires, etc.), rather than being addressed individually, strengthening the health system and health infrastructures to be resilient to the impacts of the climate crisis. We need to learn how to manage these risks through specific programmes so that health services can continue to protect the population even in critical times.
If one thing has become clear in adapting to extreme temperatures, it is the key role that environmental education plays in the development of the so-called "heat culture". Spending on environmental education and health education programmes and activities related to the adaptation of the population to climate risks should be increased, explaining not only what is happening, but why this climate crisis has occurred and informing of the many co-benefits of climate action on the well-being of populations.
It is a reality that the IPCC reports are increasingly discouraging that the limits of no return have already been exceeded, even earlier than predicted, but every tenth of a degree that we manage to reduce the increase in temperatures is relevant to minimise all the impacts of climate change. It is important to convey to society that climate action, through adaptation, mitigation and risk management, has very important direct and indirect benefits on the health of individuals and communities, and can prevent and avoid climate change-related illnesses and deaths, saving the lives of millions of people. Perhaps this is how we will respond.
