Glossary accessory dwelling unit (ADU): A smaller dwelling unit on the property of a primary house; also called in-law or granny unit. active intervention: An intervention that requires an action by the host to be effective, such as fastening a seat belt. active recreation: Physical activity that is done for recreation, enjoyment, sports, hobbies, health, or exercise during leisure time. active transportation: Physical activity that is done primarily for the purpose of moving from one destination to another, usually by walking or bicycling; also called humanpowered transportation or active travel. adaptation: In the context of climate change, the process of adjustment to current or expected climate and its effects so as to reduce harm or exploit beneficial opportunities. adaptive behavior: Behavior or response toward new environments, tasks, objects, and people that is beneficial to the individual’s well-being and allows them to apply new skills to those new situations. adaptive capacity: The ability of systems, institutions, humans, and other organisms to adjust to potential damage, to take advantage of opportunities, or to respond to consequences. affordable housing: Housing that a household can pay for while retaining enough money to pay for other necessities such as food, transportation, and health care; affordable is sometimes defined as not exceeding 30 percent of a household’s income. age-friendly (world, community, city): Places that foster healthy and active aging for all ages, with an emphasis on the needs of older populations. agency: An individual’s or community’s ability to find solutions to the issues it faces.
aging in community: Being able to remain and live independently in one’s community as one grows older and as one’s needs change because of city- or community-level initiatives; community-centric focus. aging in place: Being able to remain and live independently in one’s home and thus community because of building-level retrofits as one grows older and as one’s needs change; dwelling-centric focus. air pollution: Contamination of air by physical, chemical, or biological agents, including solids (particulates), gases (ozone, oxides of nitrogen, and others), and toxins (for example, formaldehyde). May be indoors (“household air pollution”) or outdoors (“ambient air pollution”). air quality index (AQI): The US Environmental Protection Agency tool for communicating air pollution levels for each of five individual pollutants—ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide—and the associated health risks. AQI ranges from 0 to 500, with values below 50 designated “good” and values above 100 increasingly unhealthy. all-hazards approach: In emergency preparedness, an approach that focuses on building critical capacities for preparing for and managing a full spectrum of natural and humancaused disasters; also called multihazards approach. American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE): An American professional association of engineers who work on heating, cooling, and ventilation systems. Anthropocene: A proposed new geological epoch named for the significant humandriven changes to the structure and functioning of planetary systems.
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