Climate change and health

Abstract

While uncertainty persists about the pace of climate change, there is scientifi c consensus that the buildup of greenhouse gases has resulted in global warming and climate change. The Intergovernmental Panel on Climate Change (IPCC), an effort of a global collective of scientists, projects that the Earth’s temperature could rise by as much as 4°C by the year 2100 depending on future trends of greenhouse gas emissions [1, 2]. The magnitude of the health consequences resulting from climate change will refl ect the actual increase in temperature. The consequences of greenhouse gas emissions for climate are not simply a warming uniformly across the globe, but rather the warming is anticipated to be variable by place and over time, and extremes of weather will be enhanced. The direct weather con sequences of climate change include warmer temperatures and more extreme conditions, and an associated sealevel rise, whereas the indirect consequences are broad with implications for human health (see Table 20.1 ). Beyond the adverse consequences listed in Table 20.1 , some regions may benefi t from warming through expanded agriculture and less need for heating. The health implications of climate change refl ect both direct and indirect pathways (see Figure 20.1 ). Climate change will not lead to new causes of morbidity and mortality, but will change the distributions of some causal factors that affect the occurrence of morbidity and mortality. For vectorborne infectious diseases (e.g. malaria), changes in the geographic distributions of vectors may lead to the emergence of diseases in places that have been previously free from the particular diseases. There is concern, for example, about the potential for malaria to reenter places where it has long been eliminated if the range of its vector, the Anopheles mosquito, expands. Changes in fl ora may bring new allergens and crop yields may drop. Air pollution may worsen from fossil fuel combustion for power generation to meet increasing cooling needs due to warming and other energy demands to adapt to climate change. Rising sea levels and weather changes with consequences for agriculture and availability of water may displace people and lead to social and economic disruption with diverse potential implications for health. The consequences of climate change for human health will be manifested differentially across broad regions of the world. The extent of change is projected to be variable, at least on 20 Climate change and health