Most research on the impacts of climate change has focused on environmental impacts rather than health impacts. Models are currently available which measure the potential impacts of climate change on water resources, agriculture, coastal zones and other sectors, but there is no well-developed tool for health.
In the year 2000, climate change was estimated to have caused the loss of 150,000 lives - at a time when exposures to climate change were fairly limited. The Intergovernmental Panel on Climate Change (IPCC) projects that climate change is very likely to increase threats to human health, both directly through extreme temperatures or weather events, and indirectly as warmer temperatures and changes in the hydrologic cycle will alter the incidence and geographic range of a variety of infectious diseases, including malaria and some diarrhoeal diseases.
Other indirect health impacts of climate change include diseases associated with exposure to ozone and aeroallergens, such as asthma. Malnutrition is another important indirect impact of climate change.
Modelling the health impacts of diseases such as malaria is complex because a wide range of factors can influence its incidence and geographic range, such as drug resistance and economic and technological development. Current projections of the impacts of climate change on malaria take limited account of these drivers, with some projections identifying populations at risk instead of the number and location of people likely to be affected. Future models should calculate the full health burden so that proposed polices can be weighed against their consequences.
According to this latest assessment, future models will also need to be regionally differentiated and aim for country-specific projections wherever possible. Mitigation and adaptation strategies are equally important to address the health risks of climate change. Shorter term coping mechanisms could be put in place if health effects were properly understood. One example is the early heat-wave warning systems, already employed in some countries in Southern Europe.
The author writes that one of the main factors limiting the development of a model of the effects of climate change on health is the priorities of healthcare funders, who have shown little interest in interdisciplinary approaches that seek to explore, for example, the interactions of climate change and the impact of land use change on health.