Health and climate change

Food supply and risk of hunger

This paper explores the value of using community risk assessments (CRAs) for climate change adaptation. CRA refers to participatory methods to assess hazards, vulnerabilities and capacities in support of community-based disaster risk reduction, used by many NGOs, community-based organizations, and the Red Cross/Red Crescent. We review the evolution of climate change adaptation and community-based disaster risk reduction, and highlight the challenges of integrating global climate change into a bottom-up and place-based approach. Our analysis of CRAs carried out by various national Red Cross societies shows that CRAs can help address those challenges by fostering community engagement in climate risk reduction, particularly given that many strategies to deal with current climate risks also help to reduce vulnerability to climate change. Climate change can also be explicitly incorporated in CRAs by making better use of CRA tools to assess trends, and by addressing the notion of changing risks. However, a key challenge is to keep CRAs simple enough for wide application. This demands special attention in the modification of CRA tools; in the background materials and trainings for CRA facilitators; and in the guidance for interpretation of CRA outcomes. A second challenge is the application of a limited set of CRA results to guide risk reduction in other communities and to inform national and international adaptation policy. This requires specific attention for sampling and care in scaling up qualitative findings. Finally, stronger linkages are needed between organizations facilitating CRAs and suppliers of climate information, particularly addressing the translation of climate information to the community level.

Global warming has serious implications for all aspects of human life, including infectious diseases. The effect of global warming depends on the complex interaction between the human host population and the causative infectious agent. From the human standpoint, changes in the environment may trigger human migration, causing disease patterns to shift. Crop failures and famine may reduce host resistance to infections. Disease transmission may be enhanced through the scarcity and contamination of potable water sources. Importantly, significant economic and political stresses may damage the existing public health infrastructure, leaving mankind poorly prepared for unexpected epidemics. Global warming will certainly affect the abundance and distribution of disease vectors. Altitudes that are currently too cool to sustain vectors will become more conducive to them. Some vector populations may expand into new geographic areas, whereas others may disappear. Malaria, dengue, plague, and viruses causing encephalitic syndromes are among the many vector-borne diseases likely to be affected. Some models suggest that vector-borne diseases will become more common as the earth warms, although caution is needed in interpreting these predictions. Clearly, global warming will cause changes in the epidemiology of infectious diseases. The ability of mankind to react or adapt is dependent upon the magnitude and speed of the change. The outcome will also depend on our ability to recognize epidemics early, to contain them effectively, to provide appropriate treatment, and to commit resources to prevention and research.

Human activity has contributed to climate change. The relationship between climate and child health has not been well investigated. This review discusses the role of climate change on child health and suggests 3 ways in which this relationship may manifest. First, environmental changes associated with anthropogenic greenhouse gases can lead to respiratory diseases, sunburn, melanoma, and immunosuppression. Second, climate change may directly cause heat stroke, drowning, gastrointestinal diseases, and psychosocial maldevelopment. Third, ecologic alterations triggered by climate change can increase rates of malnutrition, allergies and exposure to mycotoxins, vector-borne diseases (malaria, dengue, encephalitides, Lyme disease), and emerging infectious diseases. Further climate change is likely, given global industrial and political realities. Proactive and preventive physician action, research focused on the differential effects of climate change on subpopulations including children, and policy advocacy on the individual and federal levels could contain climate change and inform appropriate prevention and response.

The impacts of greenhouse warming have been described by Working Group 2 of the 1995 IPCC assessment. They include the impacts of changing vegetation zones on agriculture and silviculture, changes in the occurrence of crop pests and disease-carrying insects, as well as estimates of the effects of increased frequencies of extreme events such as heat waves, dry spells and floods. The present study attempts to quantify and valuate each of these impacts, integrated over the 21st century, under the assumption of continued injection of greenhouse gases into the atmosphere, leading to a doubling of atmospheric content around the middle of the 21st century. The result is a greenhouse warming externality constituting a sizable fraction of the global gross national product, provided that impacts are valued in the way normally done in externality studies for the industrialized world. As the greenhouse gas emissions are chiefly from industrialized countries, while the largest impacts are in those regions of the world least likely to reach stages of high development during the 21st century, the results pose a difficult geo-political problem. The implications for estimating externalities of particular energy conversion activities are briefly discussed.