Climate Change and Public Health

Climate change in the context of environmental sustainability

The climate is only one part of the environment and ecosystem, and health impacts of climate change should be seen in that context. The figure below, from the Millennium Ecosystem Assessment published by WHO in 2005.

The figure above is quoted in https://www.eird.org/isdr-biblio/PDF/Ecosystems%20and%20human%20well-being.pdf

"Large-scale and global environmental hazards to human health include climate change, stratospheric ozone depletion, changes in ecosystems due to loss of biodiversity, changes in hydrological systems and the supplies of freshwater, land degradation, urbanization, and stresses on food-producing systems.

Appreciation of this scale and type of influence on human health requires a new perspective which focuses on ecosystems and on the recognition that the foundations of long-term good health in populations rely in great part on the continued stability and functioning of the biosphere's life-supporting systems. It also brings an appreciation of the complexity of the systems upon which we depend."

The page Climate change 2014: impacts, adaptation, and vulnerability from WHO states:

"The IPCC constitutes arguably the largest scientific assessment exercise in human history. The five assessment reports it has released since 1988 have been assembled by several thousand authors, and document the now overwhelming evidence that human activities have been the major driver of recent warming of the earth's surface, and that both climate change, and its consequences, will continue into the future. This latest report covers evidence on the impacts of climate change and adaptation measures for different regions, natural and human systems - including health.

Health problems exacerbated

Additional health risks: heat exposure
Investment in preventative health
Improving health while cutting carbon emissions

The health assessment, firstly, confirms and expands the evidence base on the health risks presented in the previous assessment report, in 2007.

This includes the much stronger evidence that negative health impacts will outweigh positive effects. It concludes that climate change will act mainly, at least until the middle of this century, by exacerbating health problems that already exist, and the largest risks will apply in populations that are currently most affected by climate-related diseases.

It supports the case that under-nutrition resulting from reductions in food production, injury and disease due to intense heat waves and fires, and shifts in the timing and spatial distribution of infectious diseases are likely to present the greatest risks.

Secondly, the report documents evidence on an additional set of risks. Notably, the report reflects recent research on the significant possibility of "high end” climate scenarios, with some projecting warming of 4-7 degrees over much of the globe.

Under these conditions, human capacity to deal with heat will be exceeded in the hottest parts of the year in some regions, and it will no longer be possible to undertake unprotected outdoor labour or recreational activity.

Thirdly, the latest report presents evidence that can guide the response to this challenge. It drew on studies that modelled for the first time the potential consequences of changes in climate alongside projected social and economic changes.

This research illustrates how climate change opposes the health gains achieved by social development, and may hold back progress in the poorest countries - but also shows how investment in preventive health programmes, in the context of strong and equitable socioeconomic development can also greatly decrease vulnerability, and potentially over-ride at least some of the health risks, in the short- to medium-term.

Perhaps the largest advance is in documenting the rapidly growing evidence that well-planned actions to reduce greenhouse gas emissions can also bring very large health gains. The most obvious gains would come through reductions in air pollution, recently identified as the cause of approximately seven million deaths a year, or one in every eight deaths in the world.

The report documents the evidence that reducing emissions of short-lived climate pollutants such as methane and black carbon would not only slow warming, but could avoid 2-2.5 million deaths per year, globally. If converted into economic terms, the health gains associated with mitigation could offset much of the early cost of greenhouse gas mitigation.

This supports the conclusion that both climate-sensitive health risks, and the health benefits of cutting greenhouse gas emissions, should be central to any discussion on climate change."

Another way of looking at this is again shown in a picture from WHO in Ecosystems goods and services for health:

The site goes on to say:

"The term ecosystem refers to the combined physical and biological components of an environment. These organisms form complex sets of relationships and function as a unit as they interact with their physical environment. The causal links between environmental change and human health are complex because they are often indirect, displaced in space and time, and dependent on a number of modifying forces. Human health ultimately depends upon ecosystem products and services (such as availability of fresh water, food and fuel sources) which are requisite for good human health and productive livelihoods. Significant direct human health impacts can occur if ecosystem services are no longer adequate to meet social needs. Indirectly, changes in ecosystem services affect livelihoods, income, local migration and, on occasion, may even cause political conflict. The resultant impacts on economic and physical security, freedom, choice and social relations have wide-ranging impacts on well-being and health, and the availability and access to health services and medicines.""

In Time to Regenerate: Ecosystems and Health Promotion, Butler and Friel define a term 'ecohealth' :

"Ecohealth extends traditional environmental health by studying the relationship between health and explicitly ecological factors such as biodiversity and ecosystem "services” . There are four kinds of services: "provisioning” (e.g., food), "regulating” (e.g., climate), "cultural” (e.g., sacred groves), and "supporting” (e.g., the maintenance of soil fertility by worms). More subtly, ecohealth borrows insights developed by human ecology to understand and predict health through consideration of the relationships between human populations and between human and non-human species. At the largest scale, ecohealth differs conceptually from traditional environmental health in considering humans as a part of the global biosphere--the systemic, interacting forces which regulate life and its inorganic substrate. Falling within this scope are topics such as health and the global atmosphere, including climate change, stratospheric ozone depletion, and the movement of transcontinental air pollution and dust clouds. Even more broadly, ecohealth grapples with the sustainability of civilisation, and therefore of human health."

They go on to outline the need for a new approach: "The knowledge and methods developed by health promoters to advance social change to improve health can and should be used to promote the social changes needed to promote ecohealth. Such promotion will have symbiotic benefits for the health of human populations and the state of the physical environment. The challenge is to ensure government commitment to health-promoting policies, whatever they are called, and to advance partnerships between the new and old health players. Health promotion cannot abandon its pursuit of social justice. Without sustainability, neither health nor social justice can be attained."

Climate change and food security

You might like to explore this paper Reducing risks to food security from climate change. which outlines the far reaching effects of climate change on food security.

Planetary Health

A new concept - Planetary health is defined in The Rockefeller Foundation–Lancet Commission on Planetary Health

as “the achievement of the highest attainable standard of health, wellbeing, and equity worldwide through judicious attention to the human systems—political, economic, and social—that shape the future of humanity and the Earth's natural systems that define the safe environmental limits within which humanity can flourish. Put simply, planetary health is the health of human civilisation and the state of the natural systems on which it depends”.

Please take a look at the range of papers from the Lancet discussing the issue of Planetary Health. The executive summary includes the statement:  "A growing body of evidence shows that the health of humanity is intrinsically linked to the health of the environment, but by its actions humanity now threatens to destabilise the Earth’s key life-support systems. As a Commission, we conclude that the continuing degradation of natural systems threatens to reverse the health gains seen over the last century. In short, we have mortgaged the health of future generations to realise economic and development gains in the present".

Equity. Climate change may affect various population groups differently, both between and within countries. One paper focuses on urban health Climate change, equity and the Sustainable Development Goals: an urban perspective and suggests "Climate change is acknowledged as the largest threat to our societies in the coming decades, potentially affecting large and diverse groups of urban residents in this century of urbanization. As urban areas house highly diverse people with differing vulnerabilities, intensifying climate change is likely to shift the focus of discussions from a general urban perspective to who in cities will be affected by climate change, and how. This brings the urban equity question to the forefront. Here we assess how climate change events may amplify urban inequity. We find that heatwaves, but also flooding, landslides, and even mitigation and adaptation measures, affect specific population groups more than others."

Cultural factors. As Linda Connor states in Anthropogenic Climate Change and Cultural Crisis: An Anthropological Perspective  "The peoples and communities long studied by anthropologists – many of whom are Indigenous and/or living in postcolonial, neo-colonial and socioeconomically marginal conditions – are particularly vulnerable. As ACC threatens all aspects of human-ecosystem relationships, Indigenous and small-scale food producer livelihoods and cultural practices become less viable. Anthropological studies in societies of the global North also reveal the vulnerabilities and inequities for many social groups and local communities at risk from ACC effects."

Connor quotes Crate and Nuttall "…climate change is a threat multiplier. It magnifies and exacerbates existing social, economic, political, and environmental trends, problems, issues, tensions, and challenges". In addition Connor states: 

"...climate change scepticism and denial are considered as significant cultural phenomena requiring anthropological analysis. Anthropology also provides the methods to understand the broader field of climate change concern and action in specific local contexts..."