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Date updated: 8/03/2023

What is climate change?

The United Nations Framework Convention on Climate Change defines this as a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.

Humans increased use of oil, gas and coal releases greenhouse gases (measured by units of carbon dioxide equivalent, or CO2e) into the atmosphere at an unsustainable rate. For the UK this means warmer wetter winters and hotter drier summers.

These two articles by the BBC provide an easy-to-understand overview of the processes involved in climate change and the terms used to understand them:

What is Climate change? A really simple guide

Climate change: What do all the terms mean?

What is climate action?

This refers to the efforts taken to reduce greenhouse gases and build resilience to adapt to climate change. Goal 13 of the United Nations Sustainable Development Goals is Climate Action. Goal 13 of the United Nations Sustainable Development Goals is Climate Action. Goal 13 calls for urgent action to combat climate change and its impacts. It is intrinsically linked to all 16 of the other Goals of the 2030 Agenda for Sustainable Development. To address climate change, 196 parties adopted the Paris Agreement in 2015 to limit global temperature rise to well below 2 degrees Celsius.

What is the UK Government doing?

The Climate Change Act 2008 introduced the UK’s first legally binding target for 2050 to reduce greenhouse gas emissions by at least 80% compared to 1990 levels. On 27 June 2019, the UK government amended the Climate Change Act and set a legally binding target to achieve net zero greenhouse gas emissions from across the UK economy by 2050. This world-leading target will bring to an end the UK’s contribution to climate change.

More on Government action on climate change

What is the City of London Corporation doing?

The City of London Corporation adopted its science-based Climate Action Strategy in October 2020. It aims to reduce carbon emissions, build climate resilience, and champion sustainable growth.

Through the strategy, the City Corporation commits to achieving:

  • Net zero by 2027 in the City Corporation’s operations
  • Net zero by 2040 across the City Corporation’s full value chain
  • Net zero by 2040 in the Square Mile
  • Climate resilience in our buildings, public spaces and infrastructure

What do these targets mean?

Operations refers to the 650 sites, mainly buildings, that the City Corporation owns and operates, which include offices, residential housing, open spaces, schools and markets.

Full value chain refers to the City Corporation’s investments, tenanted properties, purchased goods and services, and capital assets.

Square Mile refers to the City of London which is London’s financial district. It is the ancient core from which the rest of London developed. It has been a centre for settlement, trade, commerce and ceremony since the Roman period. In just 1.12 square miles, the City of London counts around 8,000 residents, 513,000 daily commuters and 10m annual visitors. The City of London boundaries stretch from Temple to the Tower of London, on the River Thames including, from west to east Chancery Lane and Liverpool Street.

Net zero emissions are achieved when emissions of greenhouse gases caused by human activity to the atmosphere are balanced by removals by human activity over a specified period

Climate resilience is the ability to prepare for, recover from and adapt to the impacts of climate change. For the City this will mean hotter drier summers, warmer wetter winters, more extreme weather events and sea level rise.

What is being measured?

GHGs are greenhouse gases, the emissions responsible for global warming. These include carbon dioxide, methane, nitrous oxide and fluorinated gases amongst others.

ktCO2 is the unit of measurement for GHG emissions. It standardises greenhouse gases into units of kilo-tonnes of carbon dioxide equivalent (ktCO2e).

Science-based - GHG emissions reduction targets are considered “science-based” if they are in line with what the latest climate science says is necessary to meet the goals of the Paris Agreement (2015); to limit global warming to well-below 2°C above pre-industrial levels and pursue efforts to limit warming to 1.5°C.

CDR (Carbon Dioxide Removal) According to the Intergovernmental Panel on Climate Change (IPCC), anthropogenic activities removing CO2 from the atmosphere and durably store it in geological, terrestrial, or ocean reservoirs, or in products constitutes carbon removals. The removals are either nature-based, geological or a hybrid.

How can an organisation group its emissions in order to understand and reduce them?

Grouping emissions into common types or ‘scopes’ helps an organisation such as a local authority to understand which areas result in the highest levels of emissions. Targeting these areas will result in the most effective reduction of emissions. Using scopes also ensures a common language to compare data and results across all areas of climate action.

Scope 1 means emissions from activities owned or controlled by an organisation that release emissions into the atmosphere. They are direct emissions. Examples of scope 1 emissions include emissions from combustion in owned or controlled boilers, furnaces, and vehicles emissions from chemical production in owned or controlled process equipment.

Scope 2 means emissions released into the atmosphere associated with your consumption of purchased electricity, heat, steam and cooling. These are indirect emissions that are a consequence of the local authority’s activities, but which occur at sources which we do not own or control.

Scope 3 means emissions that are a consequence of our actions, which occur at sources which we do not own or control and which are not classed as scope 2 emissions. These are also indirect emissions. Examples of scope 3 emissions are purchased materials and financial investments; business travel not owned or controlled by our organisation, waste disposal not owned or controlled by our organization.

How can emissions for a city be grouped in order to understand and reduce them?

A similar approach can be taken to grouping a city’s emissions to those within an organisation, recognising that the sources of emissions and their control may belong to multiple owners and operators.

Scope 1 means GHG emissions from sources located within the city boundary

Scope 2 means GHG emissions occurring because of the use of grid- supplied electricity, heat, steam and/or cooling within the city boundary

Scope 3 means all other GHG emissions that occur outside the city boundary because of activities taking place within the city boundary.

BASIC+ definition emissions include those from within the Square Mile from stationary energy, transportation and waste, as well as transboundary transportation, industrial processes and product use and the agriculture, forestry and land use sectors. It does not include emissions from investments.

What actions are planned to reach these goals?

The City Corporation’s Climate Action Strategy sets out the actions that will have the biggest positive impact in reducing carbon emissions and ensuring climate resilience. Listed here are some technical terms linked to those projects in alphabetical order:

Biodiversity refers to the variety of plants and animals and other living things in a particular area or region. It encompasses habitat diversity, species diversity and genetic diversity. Biodiversity has its own value and has social and economic value for human society.

BREEAM (Building Research Establishment Environmental Assessment Method) is a sustainability assessment method for planning projects, infrastructure and buildings. It assesses an asset’s environmental, social and economic sustainability performance.

Carbon sequestration is the process by which a carbon sink, such as forestry, reduces the amount of greenhouse gases in the atmosphere. The City Corporation is increasing the carbon removal potential of land at Epping Forest, using meadow and woodland management techniques.

Circular economy refers to an economy which keeps resources in use for as long as possible, extracting the maximum value from them whilst in use, then recovering and regenerating products and materials at the end of each service life.

Ecosystem services are benefits to humans from the natural environment and from healthy ecosystems.

Embodied carbon is the carbon footprint of a material. It considers how many greenhouse gases (GHGs) are released throughout the supply chain and is often measured from cradle to (factory) gate, or cradle to site (of use).

EPC (Energy Performance Certificate) is a certificate that shows how energy-efficient a property is. The document includes estimated energy costs, as well as a summary of energy performance-related features.

Green corridors are almost continuous areas of open space which are linked. They can act as wildlife corridors and serve amenity, landscape and access routes.

Green infrastructure is a strategically planned, designed and managed network of green spaces and other features vital to the sustainability of any urban area. This includes trees, green roofs, green walls and green corridors.

Hard FM refers to Hard Facilities Management. These are the physical materials of a building such as lighting and heating.

KPIs (Key Performance Indicators) are measures used in project and contract management. KPIs are usually quantifiable giving an indication that something is or is not going well.

NABERS (National Australian Built Environment Rating System) is an approach used to measure a building's energy efficiency, carbon emissions, the water consumed and the waste produced and compare it to similar buildings.

Urban greening is a process for delivering additional green infrastructure in the City of London. Due to the morphology and density of the built environment in the City, green roofs, green or living walls, street trees, and techniques such as soft landscaping, are the most appropriate elements of green infrastructure.

Urban Greening Factor refers to a model to assist boroughs and developers in determining the appropriate provision of urban greening for new developments.

SUDS (Sustainable Drainage Systems) are a range of sustainable measures for surface water management which reduce the amount, flow or rate of surface water discharge into sewers.

Soft market testing refers to supplier engagement before a procurement process. This is often used by contracting authorities to see what might be possible or prohibitive as part of the tender or contract.

SMEs (Small and Medium-sized enterprises). The City Corporation has partnered with Heart of the City to provide tailored support for SMEs to develop Climate plans

WLC (Whole Life Costing) means measuring the cost of an asset over its entire life including maintenance, repair, operational cost and potential disposal cost.

Wood pasture and parkland refers to land that has been managed through grazing.


This glossary of key climate words aims to help you understand the City of London Corporation’s approach to reducing carbon emissions and developing climate resilience in its own properties and operations across the Square Mile.

Climate Action Strategy Guide and Glossary (2MB) PDF
Date submitted: 7/09/21