Carbon offsets

A reduction of carbon dioxide emissions or other greenhouse gases made to compensate for emissions created elsewhere.

Offsets are quantified in tonnes of carbon dioxide equivalent.

Parts per million

 A unit of measurement that can be used to describe the concentration of a particular substance within air, water, soil, or some other medium. For example, the concentration of carbon dioxide in the Earth’s atmosphere is almost 400 parts per million, which means 1 million liters of air would contain about 400 liters of carbon dioxide.

Biogas

A type of biofuel that contains methane from landfills, animal waste, sewage, or other decomposing waste materials. Biogas can be burned to produce heat or electricity.

Adaptation

Taking actions to avoid, benefit from, or deal with current and future climate change. Adaptation can take place in advance (by planning before an impact occurs) or in response to changes that are already occurring. Taking actions to avoid, benefit from, or deal with current and future climate change. Adaptation can take place in advance (by planning before an impact occurs) or in response to changes that are already occurring.

Wind turbine

Wind turbine: A machine that converts energy from the wind into electricity. The wind spins a set of blades connected to a generator.

Wetland

Wetland: An area of land that is periodically saturated with water, which influences the types of plants and animals that can live there. Wetlands include swamps, marshes, bogs, and other similar areas.

Weather

Weather: The condition of the atmosphere at a particular place and time. Some familiar characteristics of the weather include wind, temperature, humidity, atmospheric pressure, cloudiness, and precipitation. Weather can change from hour to hour, day to day, and season to season.

Watt

Watt: A measurement of power, usually used when talking about electricity. A watt measures the rate at which energy is used.

Water vapor

Water vapor: Water that is present in the atmosphere as a gas. Water vapor is a greenhouse gas and plays an important role in the natural greenhouse effect. Clouds form when extra water vapor in the atmosphere condenses to form ice, water droplets, and precipitation.

Waterborne disease

Waterborne disease: A disease caused by bacteria or other organisms that live in water. A person can get a waterborne disease if they drink or come in contact with contaminated water. Cholera and E. coli are examples of waterborne diseases.

Uranium

Uranium: A heavy, naturally radioactive, metallic element that is used to produce nuclear power.

Ultraviolet (UV) radiation

Ultraviolet (UV) radiation: A type of electromagnetic radiation that is produced by the sun. UV radiation is not visible to the naked eye. Most UV radiation is blocked by ozone high in the Earth's atmosphere, but some of it reaches the Earth’s surface. Being exposed to too much UV radiation can cause a sunburn, and over time it can lead to skin cancer and eye damage. Too much UV radiation can also harm plants.

Turbine

Turbine: A device with blades that can be turned by a force such as wind, water, or high pressure steam. The energy of a spinning turbine is converted into electricity by a generator.

Tropics

Tropics: The parts of the Earth near the Equator, which are very warm all year long because they receive a lot of direct sunlight.

Tides

Tides: A variation in the surface level of the oceans caused by the gravitational pull of the moon and sun. Tides fluctuate between high and low twice a day.

Tidal power

Tidal power: A form of renewable energy generated from the natural rise and fall of the ocean.

Sunspot

Sunspot: A dark area that forms and disappears on the surface of the sun over periods of days or weeks. The amount of sunspot activity varies over time, but it tends to follow a roughly 11-year cycle. This sunspot cycle causes slight differences in the amount of energy that the sun gives off.

Subtropics

Subtropics: The parts of the Earth immediately north and south of the tropics. The southern part of the United States is considered subtropical.

Solar thermal technology

Solar thermal technology: A system that uses sunlight to heat water or create steam, which can then be used to generate electricity.

Positive feedback loop

Positive feedback loop: A process in which one change leads to another, which then causes even more of the original change. In climate change, a positive feedback loop occurs when warming causes changes that lead to even more warming. For example, as the Earth gets warmer, the amount of ice that covers the Arctic Ocean is shrinking, which leaves more open water. Ice reflects a lot of sunlight back into space, while the open ocean is dark and absorbs more of the sun’s energy, making the Earth warmer. Thus, melting ice causes the Earth to absorb more energy from the sun and become even warmer.