The sectors treated in the preceding seven chapters refer to technology options
for mitigating climate change and for adapting to the impacts of climate change.
The consideration of human health is largely limited to health impacts and benefits
that arise from: (i) climate change, (ii) mitigation, and (iii) adaptation.
The formal health sector is not substantively involved in the reduction of greenhouse
gas emissions - other than incidentally via participation in society-wide improved
energy efficiency (hospital building design, institutional energy-use policies,
etc.), and by promoting alternative energy-saving systems of transport and mobility
to increase physical activity levels. Nevertheless, by providing reproductive
health and family planning services (in concert with education and social liberalisation),
the health sector contributes to climate change mitigation via reductions in
birth rates. Human population size is one of the prime determinants of total
greenhouse gas emissions (Engelman, 1998).
Long-term changes in world climate would affect the foundations of public health
- sufficient food, safe and adequate drinking water, secure community settlement
and family shelter, and the environmental and social control of various infectious
diseases. Currently, malnutrition is a major factor in 11.7% of deaths worldwide
(i.e., 5.8 million deaths every year) and accounts for an estimated 15.9% of
total DALYs lost (Disability-Adjusted Life Years - a composite measure of the
burden of ill health) (Murray and Lopez, 1996). Climate change is likely to
make food and water supplies more uncertain in various regions, thereby increasing
the risk to health for hundreds of millions of vulnerable persons, particularly
in sub-Saharan Africa.
Despite the fundamental long-term dependence of human health upon the sustainability
of physical and ecological systems, this dependency is not yet well appreciated
by the general public and policymakers. Ecosystem services (i.e., processes
maintained by the natural ecosystems) are essential for the support of human
health and well-being. Natural processes that are maintained at levels adequate
for human health include: the chemical composition of the atmosphere; decontamination
of rivers and oceans; fertility of soils; and the availability of genetic resources.
Climate change, by contributing either directly or indirectly to the impairment
of natural unmanaged ecosystems can affect human health. This damage can occur
via changes in species composition occurring in response to new climatic conditions.
Climate change may also cause an increase in forest fires due to drought; salinisation
of water sources; increased soil erosion due to heavy rainfall; and the reduction
of GHG sinks due to reductions in vegetation cover.
Climate change, by stretching limited social resources across a broad range
of additional health and other problems, could also impair existing public health
programmes. Enhancement of the public health and nutrition interventions that
are cornerstones of development (e.g., food and nutrition policies, environmental
management, disease surveillance, and access to high quality health services)
is an important way to reduce vulnerability to the health impacts of climate
change. Whatever the economic or developmental level of the population in question,
adaptations that also meet more general policy needs and specific existing local
needs should generally be favoured, for reasons of cost-effectiveness, equity
(especially between present and future generations), and political acceptability
(McMichael and Hales, 1997).