Group 1. Temperature and extreme weather events

Many of the health impacts of climate act through societal or economic factors, or through various biological agents. There are some health impacts, however, that can be directly attributed to the climate itself. These include heat-related and cold-related mortality and morbidity, death and injury from river, flash, and coastal floods, and death and injury from wildfires. The Intergovernmental Panel on Climate Change (IPCC 2012) concluded:

  • It is virtually certain that increases in the frequency and magnitude of warm daily temperature extremes and decreases in cold extremes will occur in the 21st century at the global scale
  • It is likely that the frequency of heavy precipitation or the proportion of total rainfall from heavy falls will increase in the 21st century over many areas of the globe
  • Projected precipitation and temperature changes imply possible changes in floods, although overall there is low confidence in projections of changes in fluvial floods. There is medium confidence that projected increases in heavy rainfall would contribute to increases in local flooding in some catchments or regions. It is very likely that mean sea-level rise will contribute to upward trends in extreme coastal high water levels in the future.

In addition, the strong relationship between bushfire activity and rainfall and temperature, especially in southern Australia, suggests the possibility of an increase in bushfire risk.

These projected changes imply an intensification of the underlying risk of mortality and morbidity. However, actual changes in the health impact will depend on changes in exposure or vulnerability of populations exposed to the various threats, in addition to the threats themselves. Actions to reduce either the vulnerability or exposure of populations to these threats have included developing of early warning systems including heat alert systems, flood forecasts, and bushfire alerts, as well as increased precautionary burns, improved fire-fighting capacity, and more rigorous building codes in threatened areas. Some of these actions can have unintended consequences for health, e.g. precautionary burns leading to respiratory illness. Some climate change mitigation strategies (e.g. reducing dependence on fossil fuels) may increase vulnerability to climate extremes (if energy reliability decreases).

Questions to get you thinking

  • What new approaches, methodologies and research could lead to policy initiatives to reduce the risks of adverse direct health impacts from climate change, while avoiding unintended consequences?
  • How do we act to reduce future climate threats, while avoiding actions that enhance vulnerability or exposure?
  • How do we mitigate climate change while avoiding the unintended health impacts of such mitigation? 
  • What is the appropriate balance between mitigation and adaptation? What ethical issues arise in this context?


IPCC, 2012. Managing the risks of extreme events and disasters to advance climate change adaptation. Cambridge University Press, 582pp.




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