Sydney: Long-term climate change has often destabilized civilizations through food shortages, hunger, infectious disease and unrest, a study reveals.
Historical records foreshadow a grim picture for a future threatened by even greater climate change, says the study by the Australian National University (ANU).
Tony McMichael, professor at the ANU National Centre for Epidemiology and population Health, examined climate change and its impact over the last 6,000 to 7,000 years, as documented in historical, fossil and archaeological records.
"And history tells us some very alarming things. Firstly, long-term climate changes have often destabilized civilizations through food shortages, consequent hunger, infectious disease and unrest," the journal Proceedings of National Academy of Sciences reported.
Medium-term climatic adversity -- including, floods, drought and plague -- have caused similar health, social and sometimes political consequences, a university statement said.
"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," said 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," he said.
"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," said McMichael.
"Modern societies, while larger, are better resourced and more interconnected than past societies, and are less flexible, more infrastructure-dependent, densely populated and therefore more vulnerable," added McMichael.