Table 1:

Summary of the health impacts of climate change, based on the Intergovernmental Panel on Climate Change Assessment Report Four (16).

Existing impacts	Level of uncertainty*
Alter the distribution of some infectious disease vectors	Medium confidence
Alter the seasonal distribution of some allergenic pollen species	High confidence
Increase heatwave-related deaths	Medium confidence
Projected impacts
Increase in malnutrition and consequent disorders, including child growth and development	High confidence
Increase in morbidity and mortality related to heatwaves, floods, storms, fires, and droughts	High confidence
Continued changes in the ranges of some infectious disease vectors	High confidence
Mixed effects on malaria incidence and distribution (expansion in some areas, contraction in others)	Very high confidence
Increase in the burden of diarrhoeal diseases	Medium confidence
Increase in cardio-respiratory morbidity and morality associated with ground-level ozone	High confidence
Increase in the number of people at risk of dengue	Low confidence
Health benefits include fewer deaths due to cold	High confidence

^*Degree of confidence in being correct: Very high confidence >9 out of 10 chance; High confidence ~8 out of 10 chance; Medium confidence ~ 5 out of 10 chance; Low confidence ~ 2 out of 10 chance (16).