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.

A collection of tiny solid or liquid particles in the atmosphere that can come from natural sources (such as wildfires, dust storms, and volcanoes) or people’s activities (such as burning fossil fuels). Some aerosols make the atmosphere warmer because they absorb energy. Others have a cooling effect because they reflect sunlight back to space. Aerosols also influence cloud formation.

A disease that affects a person’s lungs and can make it difficult to breathe. Many factors can trigger an asthma attack. For some people, these triggers may include air pollution, allergens, heavy exercise, or certain weather conditions

The basic building block of all the matter in the universe. Every element (for example, carbon or oxygen) represents a unique type of atom. Atoms combine together to make molecules such as carbon dioxide.

A substance, such as pollen, mold, and dust mites, that causes allergies.

A mixture of nitrogen, oxygen, carbon dioxide, and other gases that surrounds the Earth. The atmosphere is critical to supporting life on Earth.

The amount of a particular substance that exists within a certain volume or weight of air, water, soil, or other medium. For example, scientists measure the concentration of a particular gas (such as carbon dioxide) in the atmosphere in units of parts per million.

The process that takes place when corals lose the microscopic organisms called algae that live within their tissues. These algae provide the coral with nutrients, and they’re responsible for the color of the coral. If a disturbance such as rising water temperature causes the algae to leave, corals will appear white (or bleached) and could eventually die.

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.

A dark-colored solid fossil fuel that can be mined from the Earth. Coal is the most abundant fossil fuel produced in the United States.

The average weather conditions in a particular location or region at a particular time of the year. Climate is usually measured over a period of 30 years or more.

A significant change in the Earth’s climate. The Earth is currently getting warmer because people are adding heat-trapping greenhouse gases to the atmosphere. The term “global warming” refers to warmer temperatures, while “climate change” refers to the broader set of changes that go along with warmer temperatures, including changes in weather patterns, the oceans, ice and snow, and ecosystems around the world.

The movement and exchange of carbon through living organisms, the ocean, the atmosphere, rocks and minerals, and other parts of the Earth. Carbon moves from one place to another through various chemical, physical, geological, and biological processes

A type of fuel produced from plants or other forms of biomass. Examples of biofuels include ethanol, biodiesel, and biogas.

 A chemical element that is essential to all living things. Carbon combines with other elements to form a variety of different compounds. Plants and animals are made up of carbon compounds, and so are certain minerals. Carbon combines with oxygen to make a gas called carbon dioxide.

Material that comes from living things, including trees, crops, grasses, and animals and animal waste. Some kinds of biomass, such as wood and biofuels, can be burned to produce energy.

An instrument that measures the air pressure of the atmosphere. Differences in air pressure are responsible for wind and weather patterns, and low pressure is generally associated with storms.

A type of biofuel typically made from soybean, canola, or other vegetable oils; animal fats; or recycled grease. Biodiesel can be blended with regular diesel fuel and used in most diesel engines. Some engines can also be modified to run on pure biodiesel.

 The breakdown of matter by bacteria and fungi. Decomposition changes the chemical makeup and physical appearance of materials.

The total amount of greenhouse gases that are emitted into the atmosphere each year by a person, family, building, organization, or company. A person’s carbon footprint includes greenhouse gas emissions from fuel that he or she burns directly, such as by heating a home or riding in a car. It also includes greenhouse gases that come from producing the goods or services that the person uses, including emissions from power plants that make electricity, factories that make products, and landfills where trash gets sent.

The release of a gas (such as carbon dioxide) or other substance into the air.

A type of alcohol that can be produced from different forms of biomass, such as agricultural crops. Ethanol can be burned as a fuel, often by blending it with gasoline.

A type of fuel that forms deep within the Earth. Examples of fossil fuels include coal, oil, and natural gas. Fossil fuels are created over millions of years as dead plant and animal material becomes trapped and buried in layers of rock, and heat and pressure transform this material into a fuel. All fossil fuels contain carbon, and when people burn these fuels to produce energy, they create carbon dioxide.

Heat from inside the Earth. People can use geothermal energy to heat buildings or produce electricity.

The average climate around the world.

An increase in temperature near the surface of the Earth. Global warming has occurred in the distant past as the result of natural causes. However, the term is most often used to refer to recent and ongoing warming caused by people’s activities. Global warming leads to a bigger set of changes referred to as global climate change.

A period of unusually dry weather lasting long enough to cause serious shortages of water for ecosystems and human use (such as drinking water and agriculture) in the affected area.