Climate change: health risks mount while Nero fiddles

The IPCC's latest assessment highlights risks, ethical challenges and planning needs T he climate has long been considered beyond human control, other than through sacrifi ce and prayer. In modern times, there has been little interest in studying climatic infl uences on human health, disease and mortality. We can reduce cigarette smoking and make workplaces safer, but we cannot change the climate. Or so we thought. Now, with the advent of human-driven climate change, we need to know how climatic conditions affect health. 1 The section of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report on " impacts, adapta tion and vulnerability " was released on 31 March this year. The chapter on human health, as for other sector -specifi c chapters, comprises a comprehensive, externally peer-reviewed assessment of all relevant scientifi c liter ature by an expert international author team. 2 Many previously anticipated health impacts are now mate-rialising, making adaptation increasingly necessary in light of the dismal 20-year delay in effective international abatement (" mitigation ") action. This delay sits comfort ably with the current Australian Government's preoccupation with making the world safe — not for the wellbeing of future generations, but for economic growth today. 3 Most of the biosphere's biophysical and ecological systems that help sustain human population health are climate sensitive: plant growth; the water cycle; constraints on infectious disease spread; and forest, reef and mangrove buffers. Hence, climate-related impacts on health signify much more than mere collateral damage; they signal that nature's life-supporting system is being disrupted sufficiently to harm human populations, their cultural insulation notwithstanding. The directly harmful paths are familiar: deaths and hos-pitalisations from heatwaves; dehydration and injuries in overheated workplaces; traumatic impacts of severe fl oods, storms and fi res; and exacerbation of urban air pollution. But those are the visible tip of a much larger (ahem) iceberg. The most serious risks to health arise from disrupting nature's ecological and biophysical systems. Further, the associated economic and social consequences will often lead to job loss, impoverishment, migration and confl ict, 4,5 4,5 all of which are potential causes of illness, disease, depression and premature death. The IPCC human health chapter concludes that climate change over the next few decades will mainly act by exacerbating existing health problems. 2 The greatest impacts will occur — indeed, are occurring — in populations already burdened by climate-sensitive health problems such as child …