Carbon emission trading, also known as a carbon market, emission trading scheme (ETS), or cap and trade, is a system designed to control the amount of carbon dioxide (CO₂) and other greenhouse gases (GHGs) released into the atmosphere. It is a type of carbon pricing that aims to reduce climate change by setting a limited number of permits for emissions. Many countries use this method to meet their goals under the Paris Agreement, with systems already in place in China, the European Union, and other nations.
A carbon tax is a fee charged on the carbon emissions created when making goods and services. This tax helps show the costs of carbon emissions that society often does not see. It is meant to lower greenhouse gas emissions by raising the cost of fossil fuels.
Carbon sequestration is the natural process of storing carbon in a carbon pool. It is important for managing the global carbon cycle and reducing climate change by lowering the amount of carbon dioxide in the atmosphere. There are two main types of carbon sequestration: biologic (also called biosequestration) and geologic.
A carbon credit is a certificate that can be bought and sold. It shows that one ton of carbon dioxide or an equal amount of other greenhouse gases (GHG) was prevented from entering the atmosphere or was removed from it. Carbon offsetting happens when a group or person uses carbon credits to balance out their own GHG emissions, following rules set by programs or goals.
Global net-zero emissions occur when the amount of greenhouse gases released by human activities equals the amount removed from the atmosphere. This is often called “net zero.” After global net zero is reached, the rate of global warming is expected to slow significantly. However, the warming caused by greenhouse gases already in the atmosphere will continue for some time.
A carbon footprint (or greenhouse gas footprint) is a number or measure that shows how much greenhouse gas an activity, product, company, or country adds to the atmosphere. Carbon footprints are usually reported in tonnes of emissions (CO2-equivalent) for each unit being compared. These units might include tonnes of CO2-equivalent per year, per kilogram of protein eaten, per kilometer traveled, per piece of clothing, and others.
Methane is a chemical compound with the formula CH₄, meaning one carbon atom is bonded to four hydrogen atoms. It is a type of hydride from group 14, the simplest alkane, and the main part of natural gas. Methane is common on Earth, making it a valuable fuel.
Carbon dioxide is a chemical compound with the formula CO₂. Each molecule contains one carbon atom connected to two oxygen atoms. At room temperature, it exists as a gas and has no smell.
The greenhouse effect happens when gases in a planet’s atmosphere trap heat, preventing the planet from losing heat to space. This raises the planet’s surface temperature. Surface heating can come from an internal heat source, like Jupiter, or from an external source, such as a star.
Climate change today includes global warming, which is the steady rise in Earth’s average temperature, and the larger effects this warming has on Earth’s climate. Climate change also refers to long-term changes in Earth’s climate that happened in the past. The recent increase in Earth’s temperature is mainly caused by human activities, especially the burning of fossil fuels like coal, oil, and natural gas since the Industrial Revolution.