Climate change has the potential to affect the environment in a number of ways that place increased stress on everyone, but disproportionately on the most vulnerable populations, including the young, the old, those with chronic illness, and the poor. Older people are among the most at risk because of decreased mobility resulting from age, changes in physiology, and more restricted access to resources, all of which may limit adaptive capacity. The challenges older people will face adapting to climate change have potentially far-reaching implications for the health of individuals and the population as a whole. A number of societal strategies to cope will be required. Habitability, health, and environmental justice will be challenged as the adverse effects of climate change interact with factors that are characteristic of older people.