Experts forecast an increase in world average temperature by 2100 within the range 1.4-5.8°C. In their Review Tony McMichael (The Australian National University, Canberra, Australia) and colleagues state that some health outcomes have already been affected by climate change. One manifestation of global warming over the past 50 years is an increased duration of heatwaves in Alaska, Canada, central and eastern Europe, Siberia, and central Australia. The authors estimate that approximately half the excess deaths during the severe European heatwave of 2003 were due to the warming trend induced by anthropogenic greenhouse gases. Several reports have also shown that climate change might now be affecting some infectious diseases, although the authors state that no one study is conclusive.
They add that in the future, global warming could also affect regional food yields and water supplies with knock-on effects for health. For example, modelling of climate change effects on cereal grain yields later this century indicates a 5-10% increase in the global number of underfed people.
Professor McMichael states: "The advent of changes in global climate signals that we are now living beyond Earth's capacity to absorb a major waste product: anthropogenic greenhouse gases. The resultant risks to health (and other environmental and societal outcomes) are anticipated to compound over time as climate change--along with other large-scale environmental and social changes--continues."
Contact: Professor Anthony J McMichael, National Centre of Epidemology and Population Health, The Australian National University, Canberra ACT 0200, Australia. T) 61-26-125-4578 tony.mcmichael@anu.edu.au
Journal
The Lancet