Geoscience Reference
In-Depth Information
would require commensurate increases in the capacity of the healthcare system
to respond quickly and cope with the enormous demand, and to be able to do so
in conditions of lost, destroyed or damaged power, communications and physical
infrastructure. During the unusually severe heatwave of late January to early
February 2009 in Melbourne and Adelaide, some aspects of public infrastructure
and services failed under stress - power supplies, morgue capacity and transport
systems. In Adelaide many dozens of rail services were cancelled because of heat-
induced buckling of the railway lines and emergency commercial refrigeration
vans were hired to provide extra storage space for dead bodies.
The impacts of temperature extremes on human biology and health provide an
easy entry-point to this discussion. The full range of direct and indirect climatic
influences on human population health is much more diverse in its content.
Types of climate-related health impacts
There are three categories of health impacts from climate change (Butler and
Harley, 2010). Primary impacts result from communities and particular occupa-
tional groupings being directly exposed to extremes of weather: heat, rain (and
flooding), hail, snowstorms, wind and bushfires. On a broader front, though one
step removed, there are direct impacts on immediate post-event mental health,
jobs, livelihoods, community morale and other aspects of human wellbeing.
Secondary health impacts arise from the environmental and ecological conse-
quences of changes in climatic conditions. These include impairment of food
yields and human nutrition, changes in the range and seasonality of various
infectious diseases, and the generation and dispersal of various air pollutants
(e.g. ozone) and aeroallergens from pollens and spores. If changes in climatic
conditions reduce freshwater availability, this can compromise domestic hygiene,
drinking water safety, local food yields and personal hydration. One interesting
and unforeseen secondary health consequence in some other parts of the world
reflects the increasing salinity of coastal groundwater (well water) due to sea
level rise. Studies in low-lying coastal Bangladesh have revealed this as a likely
cause of increased blood pressure - including an increase in late-pregnancy
complications because of raised maternal blood pressure - due to the often-
substantial increase in daily salt intake (Kahn and Vineis, 2012).
Tertiary health impacts have a more complex and protracted causal chain.
They emerge more slowly and affect the fundamental supports of human
wellbeing, health and survival. These are less easy to study in a specific and
quantitative way (and are therefore of less interest to conventional epidemio-
logical research). Examples include the physical and mental health consequences
of impoverishment (especially in rural communities) due to downturns in family
income and the loss of livelihoods; emotional anxieties and behavioural distur-
bances in young children becoming apprehensive or fearful about the future; the
wide-ranging health consequences (both negative and positive) of displacement
and relocation of communities and families due to mounting climatic and
environmental adversity; and the more unsettling prospect of rising tensions
