Climate change history reveals future threats

Tony McMichael.

The historical record foreshadows a grim picture for a future threatened by even greater climate change according to a study from The Australian National University.

Professor Tony McMichael from the ANU National Centre for Epidemiology and Population Health looked at climate changes and their impacts over the last 6,000 to 7,000 years, as documented in historical, archaeological and fossil records. Professor McMichael said that his study showed that time and time again weather extremes and climatic changes have posed a threat to human health, safety and survival.

"Currently, a lot of debate and research about climate change focuses on the short-term impacts like the effect it will have on the economy," said Professor McMichael. "Unfortunately the long-term impacts to human health, safety and wellbeing are overlooked. I wanted to go back over the historical record to see how the factors crucial to our survival were affected by climate change.

"And history tells us some very alarming things. Firstly, long-term climate changes have often destabilised civilisations through food shortages, consequent hunger, infectious disease and unrest. Medium-term climatic adversity - including, floods, drought and plague - have caused similar health, social and sometimes political consequences.

"On top of this when the world has gone through brief episodes of temperature shifts, there have been outbreaks of infectious diseases which have been compounded by food shortages, social disruption and impoverishment.

"Global climate change poses many risks to human health, safety and survival. Most environmental systems that sustain human population health, including food yields, water supply natural constraints on human disease and protection against weather extremes, are sensitive to climate change."

Professor McMichael added that it was time we examined history to help us look forward and meet the challenge of contemporary climate change.

"Throughout history the relationship between drought, famine and starvation has been the main, recurring serious threat to human health. With models forecasting an increase in the range and severity of droughts, as well as increased climatic variability, there is significant need to abate human-caused climate change.

"Modern societies, while larger, better resourced and more interconnected than past societies, are less flexible, more infrastructure-dependent, densely populated and therefore more vulnerable. Recent trends in climate change-related indicators, along with ongoing political procrastination, means a three to four degree Celsius surface warming this century is becoming more likely.

"Compared with the historical record this would be an extreme and long-term change in climate without precedent. Such a change will pose serious risks to human health and survival and will spare no population."

Professor McMichael’s study has been published online today in the journal PNAS (Proceedings of National Academy of Sciences). A copy is available from the ANU media office.

: James Giggacher, ANU Media -02 6125 7988