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Sustainability jargon in plain English

Sustainability has more than its share of jargon. Here are the terms you are most likely to meet, each explained in a sentence or two.

By Richard Harvie · Updated November 2026

A

Adaptation

Preparing for the effects of climate change that are already happening or on their way, such as heatwaves and flooding. Cutting emissions is the other half of the job. More

B

Baseline

Your emissions (or energy use) in a chosen starting year. Targets and progress are measured against it, so it needs to be solid. More

C

Capital goods

Things you buy that last for years, such as vehicles, buildings and IT equipment. Under the GHG Protocol, the emissions from making them all count in the year you buy them.

Carbon dioxide equivalent (CO2e)

One unit for all greenhouse gases. Each gas is converted into the amount of carbon dioxide that would warm the climate by the same amount, so they can be added together.

Carbon offset

A credit for a tonne of CO2e cut or removed somewhere else, bought to balance your own emissions. Quality varies widely, and offsets are no substitute for cutting your own emissions.

Carbon Reduction Plan

A short public document setting out a supplier's emissions and its commitment to net zero. Central government and the NHS ask for one on many contracts. More

Carbon removal

Taking carbon dioxide out of the atmosphere and storing it, for example in trees, soils or underground. Used to balance the emissions that cannot be cut.

Circular economy

Keeping products and materials in use for as long as possible through reuse, repair and recycling, instead of make, use and throw away.

Conversion factor

A number that turns an activity, such as litres of diesel or kWh of electricity, into kilograms of CO2e. Also called an emission factor. The UK Government publishes a new set each June. More

CSRD

The Corporate Sustainability Reporting Directive: the EU law that makes large companies publish sustainability reports. It mostly reaches UK firms through EU customers asking for data. More

D

Decarbonisation

Reducing the greenhouse gas emissions caused by an activity, an organisation or the whole economy.

DESNZ

The Department for Energy Security and Net Zero, the government department that publishes the official conversion factors and national emissions figures.

Display Energy Certificate (DEC)

A certificate showing how much energy a public building actually uses. In England and Wales, large public buildings that the public often visit must display one.

Double counting

Counting the same emissions twice, for example once in your energy bills and again in your spending data. More

E

Energy Performance Certificate (EPC)

A rating from A (most efficient) to G of how energy efficient a building is, needed when it is built, sold or let.

Environmental management system (EMS)

A structured way of managing an organisation's environmental impacts, with policies, targets, checks and regular review. ISO 14001 is the best-known standard.

ESG

Environmental, social and governance: a way of judging an organisation on its environmental impact, how it treats people and how well it is run.

ESOS

The Energy Savings Opportunity Scheme: large businesses must assess their energy use and look for savings every four years. More

F

F gases

Man-made gases, mainly the refrigerants in air conditioning, fridges and heat pumps. Most are powerful greenhouse gases if they leak, so larger systems must be checked for leaks.

G

GHG Protocol

The Greenhouse Gas Protocol: the rules most organisations around the world follow to measure their emissions. It is where Scopes 1, 2 and 3 come from. More

Greenhouse gas

A gas that traps heat in the atmosphere, such as carbon dioxide, methane and nitrous oxide.

Greenwashing

Making an organisation or product seem greener than it really is. The Competition and Markets Authority's Green Claims Code sets out how to keep claims honest.

Grey fleet

Staff's own cars used for work journeys and paid through mileage claims. Their emissions count in your Scope 3.

Gross calorific value (gross CV)

The basis most UK gas bills use to measure gas. Use the gas conversion factor on the same basis; picking the other one (net CV) by mistake is a common slip. More

H

Heat pump

Electric heating that moves heat from the air, ground or water into a building, using much less energy than a boiler. Many can also cool.

I

Intensity ratio

Emissions divided by a measure of size, such as tonnes per member of staff or per square metre. It shows whether you are getting more efficient as you grow or shrink.

K

kWh (kilowatt hour)

The unit of energy on gas and electricity bills: one kilowatt used for one hour.

L

Location-based and market-based

Two ways of counting electricity emissions. Location-based uses the average for the grid; market-based uses what your contract says you bought, such as a renewable tariff. The GHG Protocol asks you to report both where you can.

M

Method note

A short record of how you measured your footprint: what you included, the period, where the data came from, the factors and any estimates, so someone else could repeat it.

Minimum energy efficiency standards (MEES)

The lowest EPC rating at which a landlord may let a property. In England and Wales, let commercial buildings must currently be rated E or better unless an exemption is registered.

Mitigation

Reducing greenhouse gas emissions to limit climate change. In plain English: cutting emissions.

N

Net zero

Cutting emissions as far as possible, then removing from the atmosphere the same amount as you still release. It is not the same as buying offsets to cover business as usual.

O

Operational control

A simple way to decide what your footprint covers: if your organisation runs it, you count it.

Outside of scopes

Carbon dioxide from burning biofuels such as wood or HVO. It is reported separately and not added to your total, because the plants absorbed the carbon recently.

P

PPN 006

The government procurement rule that asks suppliers bidding for central government contracts worth more than £5 million a year for a Carbon Reduction Plan. More

R

REGO

A Renewable Energy Guarantee of Origin: a certificate for each megawatt hour of renewable electricity generated in the UK. Suppliers use them to show how much of what they sell is renewable.

Resilience

The ability of an organisation to keep working through, and recover from, disruption such as extreme weather. More

Restating

Recalculating past figures, usually the baseline, after a significant mistake or a change of method, so that years can still be compared fairly.

Risk matrix

A grid that plots risks by how likely they are and how bad they would be, so the biggest stand out. More

S

Science-based target

An emissions target in line with what climate science says is needed to limit warming, often checked by the Science Based Targets initiative (SBTi).

Scope 1

Direct emissions from things you own or control, such as gas boilers and your own vehicles. In short: what you burn. More

Scope 2

Emissions from producing the electricity, heat or cooling you buy. In short: the electricity you use. More

Scope 3

Everything else in your value chain, such as what you buy, business travel, staff commuting and waste. Usually the largest part of a footprint. More

SECR

Streamlined Energy and Carbon Reporting: rules that make quoted companies and larger unquoted companies and LLPs report their energy use and emissions in their annual reports. More

Simpler Recycling

The rules in England that make workplaces separate their recycling and food waste. Workplaces with fewer than ten full-time equivalent staff must comply from 31 March 2027. More

Spend-based emissions factor

An average figure for the emissions caused by each pound spent on a type of product or service. Used for a first, rough estimate of your supply chain. More

Surface water flooding

Flooding caused when heavy rain cannot drain away fast enough. It can happen a long way from any river or the sea. More

T

Transmission and distribution losses

Electricity lost on its way from the power station to your building. Counted in your Scope 3, using a small extra conversion factor.

U

UK Sustainability Reporting Standards (UK SRS)

UK versions of international standards for reporting sustainability and climate information, published in 2026. Listed companies use them from 2027; anyone else can by choice. More

Upstream and downstream

In Scope 3, upstream emissions come from what you buy and how it reaches you; downstream emissions come from what happens to your products or services after they leave you.

V

Value chain

Everything that happens before and after your own activities, from your suppliers to the people who use what you provide.

Verification

An independent check of your emissions figures and method, sometimes called assurance.

W

Waste hierarchy

The order of preference for dealing with waste: prevent it, reuse it, recycle it, recover energy from it and, last of all, dispose of it.

Well-to-tank

The emissions from producing and transporting fuels before you use them. An optional part of Scope 3 in UK reporting; say whether you included them.