While uncertainty persists about the pace of climate change, there is scientifi c consensus that the build-up 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.