Climate terms explained

empty bench on a hill overlooking Cheltenham. The sky is blue and full of fluffy white clouds

Greenhouse gases (GHG)

Greenhouse gases are gases in Earth’s atmosphere that trap heat.

They let sunlight pass  through the atmosphere, but they prevent the heat that the sunlight brings from leaving the atmosphere. This warms and creates the ‘greenhouse effect’. The main greenhouse gases are water vapour, carbon dioxide, methane, ozone, nitrous oxide. When we measure GHG, we usually refer to them as carbon dioxide equivalents (CO2e) to allow us to easily compare their impact on global warming. Read more about the terms used to talk about greenhouse gases by Ecometrica, experts in climate monitoring and reporting.

Carbon neutral

Carbon neutral means that any carbon dioxide (CO2) released into the atmosphere from an organisation’s activities is balanced by an equivalent amount being removed. Typically, this would be achieved by determining the organisation’s carbon footprint and deciding how best to counteract these emissions via renewable energy generation or carbon offsetting, and sometimes carbon emissions reductions. An organisation can demonstrate carbon neutrality, whilst still increasing its own carbon emissions.

Net zero

Net zero emissions means not adding any greenhouse gases to the atmosphere through an organisation’s activities. Becoming net zero starts with a plan to rapidly reduce GHG emissions to zero by a specified date. However, most organisations find that some emissions can’t be reduced to zero. These are expected to be small and are usually then offset by initiatives aimed at removing an equivalent amount of GHG from the atmosphere. The UK became the world’s first major economy to set a target of being net zero by 2050. Cheltenham has set a more ambitious target of being net zero by 2030.

In October 2021, the government stated that to reach their net zero target, the task is to “reduce emissions to as close to zero as possible, with the small amount of remaining emissions absorbed through natural carbon sinks like forests, and new technologies like carbon capture.” Read the government's Net Zero Strategy.

Carbon footprint

Carbon footprint is the calculated amount of CO2 released into the atmosphere as a result of the activities of a particular individual, organisation, or community.

Carbon offsetting

Carbon offsetting is the action or process of compensating for the CO2 emissions arising from an organisation’s or individual’s activity by participating in schemes designed to make equivalent reductions of CO2 in the atmosphere. It is suggested that CO2 has the same impact on the climate no matter where it is emitted and, therefore, it is considered that a tonne of CO2 absorbed from the atmosphere in one part of the world, through carbon capture or tree planting, for example, can cancel out a tonne of CO2 emitted in another.

Scope 1 emissions

Scope 1 emissions cover an organisation’s GHG emissions which are produced directly by their activities. This is usually through the burning of fossil fuels, whilst running gas boilers or diesel vehicles, for instance.

Scope 2 emissions

Scope 2 emissions cover GHG emissions produced  indirectly by an organisation, for example the electricity used to heat a building which has been produced by burning fossil fuels elsewhere.

Scope 3 emissions

Scope 3 emissions include all other indirect emissions that are produced by an organisation’s activities, such as the disposal of waste, employee commuting and the supply chain.