All definitions from Wikipedia unless noted

Carbon footprint: the total set of greenhouse gas (GHG) emissions caused by an organization, event, product or person. An individual's, nation's, or organization's carbon footprint can be measured by undertaking a GHG emissions assessment. Once the size of a carbon footprint is known, a strategy can be devised to reduce it by technological developments, better process and product management, green purchasing, carbon capture, consumption strategies, and others.

Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions, or in the distribution of weather around the average conditions (i.e., more or fewer extreme weather events). Climate change is caused by factors that include oceanic processes, variations in solar radiation received by Earth, plate tectonics and volcanic eruptions, and human-induced alterations of the natural world; these latter effects are currently causing global warming, and "climate change" is often used to describe human-specific impacts.

An ecological foot print is a measure of human demand on the Earth's ecosystems. It is a standardized measure of demand for natural capital that may be contrasted with the planet's ecological capacity to regenerate.[1] It represents the amount of biologically productive land and sea area necessary to supply the resources a human population consumes, and to assimilate associated waste.

An ecosystem is a biological system consisting of all the living organisms or biotic components in a particular area and the nonliving or abiotic components with which the organisms interact, such as air, mineral soil, water, and sunlight.[1] Key processes in ecosystems include the capture of light energy and carbon through photosynthesis, the transfer of carbon and energy through food webs, and the release of nutrients and carbon through decomposition. Biodiversity affects ecosystem functioning, as do the processes of disturbance and succession. Ecosystems provide a variety of goods and services upon which people depend; the principles of ecosystem management suggest that rather than managing individual species, natural resources should be managed at the level of the ecosystem itself.

Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years.[1] Fossil fuels contain high percentages of carbon and include coal, petroleum, and natural gas. They range from volatile materials with low carbon: hydrogen ratios like methane, to liquid petroleum to nonvolatile materials composed of almost pure carbon, like anthracite coal.

Gray water is wastewater generated from domestic activities such as laundry, dishwashing, and bathing, which can be recycled on-site for uses such as landscape irrigation and constructed wetlands. Gray water differs from water from the toilets which is designated sewage or blackwater to indicate it contains human waste.

The Greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases.

Hazardous waste facility: a facility that stores, recycles, or disposes of hazardous waste according to strict guidelines for environmental safety. The closest Hazardous Waste Facilities to Union City are in Fremont and Hayward.

A nonrenewable resources is a natural resource which cannot be produced, grown, generated, or used on a scale which can sustain its consumption rate, once depleted there is no more available for future needs. Also considered non-renewable are resources that are consumed much faster than nature can create them.

Occupancy sensorsindoor lighting controls—detect activity within a certain area. They provide convenience by turning lights on automatically when someone enters a room. They reduce lighting energy use by turning lights off soon after the last occupant has left the room. (from USDoE)

Post-consumer waste is a waste type produced by the end consumer of a material stream; that is, where the waste-producing use did not involve the production of another product. Quite commonly, it is simply the garbage that individuals routinely discard, either in a waste receptacle or a dump, or by littering, incinerating, pouring down the drain, or washing into the gutter. Post-consumer waste is distinguished from pre-consumer waste, which is the reintroduction of manufacturing scrap (such as trimmings from paper production, defective aluminum cans, etc.) back into the manufacturing process. Pre-consumer waste is commonly used in manufacturing industries, and is often not considered recycling in the traditional sense.

Single-stream recycling (also known as “fully commingled” or "single-sort") recycling refers to a system in which all paper fibers, plastics, metals, and other containers are mixed in a collection truck, instead of being sorted into separate commodities (newspaper, paperboard, Corrugated fiberboard, plastic, glass, etc.) by the resident and handled separately throughout the collection process. In single stream, both the collection and processing systems are designed to handle this fully commingled mixture of recyclables, with materials being separated for reuse at a materials recovery facility.