Geoscience Reference
In-Depth Information
injuries, poverty and mental trauma will, as ever, result from various disasters of
flood, drought and fire.
Projection of other future health risks in a
1
4°C climate then gets tougher.
A Four Degree World could seriously erode the essential foundations of human
population health - food yields, water supplies and the constraints on infectious
disease rates, population displacement, conflict and warfare. But will various
infectious diseases, especially those spread by 'vector' mosquitoes, become
resurgent and extend their geographic range in Australia? (Or might some part
of Australia become too hot and perhaps too dry to support such vectors and
the lifecycle of particular infectious agents?) An even more complex question is:
if climatic extremes coincide with very great increases in numbers of displaced
persons from the adjoining Asian and Pacific region, perhaps unavoidably housed
in emergency, poorly resourced settlements, might Australia be faced with unusual
epidemics of cholera and rampant childhood diarrhoeal diseases? Further, might
our healthcare system and public health activity become overwhelmed and
inadequate to the mounting task of risk reduction, damage repair and recovery?
These are complex multi-faceted situations in which many concurrent influ-
ences other than altered climatic conditions affect human biology, psychology
and health. Projecting the rate at which ice might melt at higher temperatures,
or how coral reefs are likely to respond to steadily increasing temperatures, is
an inherently simpler task than projecting human health outcomes within the
'noisy' setting of unknowable trends in other risk factors, including variegated
cultural practices, consumer behaviours and other external exposures.
Clearly, this chapter cannot offer a fully itemised schedule of estimated future
health impacts. The risks to human health and wellbeing from changes in
climatic conditions are wide-ranging, diverse and differ greatly in character and
complexity of causation. For most of those risks climate change will be a multi-
plier or amplifier of risk, not its initiator. Only some risks are amenable to formal
modelling, particularly when considered within such a qualitatively different
future Australia and future world. For small changes in climate, a simpler
extrapolation of impact levels in recent past experience to the postulated future
is reasonable. But for larger climatic changes and all that will flow from them,
this conventional approach is not warranted.
We should instead pay more attention to the range of human impacts of a
diverse but plausible range of future conditions and scenarios. Accordingly, we
should be readier to make policy decisions on a precautionary basis that recog-
nises the extremes of adverse human consequences that
could
result. A simple
entry point for understanding these limitations to future high-exposure risk
modelling is to review the experience of Europe in the hot summer of 2003.
Death in Paris: impacts beyond simplistic expectation
In Paris in August 2003 the great European heatwave of that summer caused a
surge in the daily death rate during and in the several days following (van den
Torren et
al., 2004). Around 1,000 additional deaths occurred. A more typical
