Scottish Greenhouse Gas Statistics 2023

Purpose of this Publication

The “Scottish Greenhouse Gas Emissions 2023” Official Statistics publication contains the results of the Scottish Greenhouse Gas Inventory for 1990-2023.  The Scottish Greenhouse Gas Inventory is the key data source for understanding the origins and magnitudes of the emissions. The inventory is compiled in line with international guidance from the Intergovernmental Panel on Climate Change (IPCC). Data are reported by source sector (such as energy supply) and by greenhouse gas (such as carbon dioxide). 

Which greenhouse gases are reported on and how do they contribute to global warming?

The basket of greenhouse gases consists of carbon dioxide, methane, nitrous oxide, and the four F-gases (hydrofluorocarbons- HFCs, perfluorocarbons – PFCs, sulphur hexafluoride- SF6 and nitrogen trifluoride- NF3).  These gases are weighted by Global Warming Potential (GWP), so that total greenhouse gas emissions can be reported on a consistent basis. The GWP for each gas is defined as its warming influence relative to that of carbon dioxide over a 100 year period.  Greenhouse gas emissions are then presented in carbon dioxide equivalent (CO2e) units.  In the case of some of the F-gases, the global warming potential is listed as being within a range of values, due to the gases existing as a variety of isotopes with differing GWPs.

Table 1.  List of Greenhouse Gases and their contribution to Scotland's net greenhouse gas emissions, 2023

The Global Warming Potentials (GWPs) are based on international reporting standards, as set by the Intergovernmental Panel on Climate Change (IPCC)[1]. 

Reporting of the Baseline Period and 1990

In this publication, a single 1990 Base Year is used for all estimated source emissions (Section B).  This year is referred to as “1990” in charts, tables and text.

A different baseline has traditionally been used for the reporting progress against Scotland’s Climate Change Targets, using the GHG account. This is referred to as “Baseline Period” when referring to changes over time in the charts, tables and text.

The Baseline Period for reporting against Climate Change Targets is:

• 1990 for carbon dioxide carbon dioxide (CO2),  methane (CH4), nitrous oxide (N2O)
• 1995 for Fluorinated gases (F gases)[2]:  hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF6), nitrogen trifluoride (NF3)

The difference between these definitions of baseline year tend to be small as F gases are a minority contribution to the total emissions in terms of carbon dioxide equivalent.

Within this publication, data are estimated for the Baseline Period; and the years 1990, 1995 and 1998 to 2023.

What are net emissions and carbon sinks?

The emissions reported are the combination of emissions minus removals from the atmosphere by carbon sinks.  Carbon sinks are present in the ‘Land Use, Land Use Change and Forestry’ (LULUCF) category, they are mostly associated with the effects of grasslands and forestry to sequester carbon, as well as the carbon stored in wood products.  These are known as “removals” as they offset emissions.

Emissions sectors

This publication provides the latest estimates of Scotland’s greenhouse gas emissions by source from 1990-2023. It uses the ‘Territorial Emissions Statistics’ sectors, which are the same categories now used for the UK report.  For the purposes of reporting, greenhouse gas emissions are allocated into categories as follows:

• Electricity Supply – Includes emissions from power stations.
• Fuel Supply – Includes emissions from fuel production and fuel supply activities such as mining, refining, manufacturing, and distributing fuels.
• Domestic Transport – Includes all emissions from domestic vehicles, including domestic air and marine travel.
• Buildings and Product Uses – Includes emissions from combustion on residential, public sector and commercial sites. Also includes emissions from product uses such as nitrous oxide (N2O) use as an anaesthetic; and F-gas emissions from aerosols, and metered dose inhalers or residential refrigeration and air conditioning.
• Industry –These comprise of emissions from manufacturing, industrial processes and construction, as well as industrial refrigeration and air conditioning.
• Waste – Includes all emissions in the Waste Management sector. Additionally; Includes emissions from accidental fires and includes emissions from household composting, and small-scale waste burning.
• Agriculture – Covers all agricultural practices, excluding the land on which agriculture is conducted.
• Land Use, Land Use Change and Forestry (LULUCF) – Includes emissions and removals of CO2 from changes in the carbon stock in forestland, cropland, grassland, wetlands, settlements and harvested wood products, and emissions of other greenhouse gases from drainage (excl. croplands and intensive grasslands) and rewetting of soils, nitrogen mineralisation associated  with loss and gain of soil organic matter, and fires. As impacts of carbon stock  changes are included in this sector, CO2 emissions of biogenic origin (e.g. burning biomass for energy) are excluded from other sectors to avoid double counting.
• International Aviation and Shipping (IA&S) – includes emissions associated with out-bound journeys to avoid double counting.

When emissions are reported by source, emissions are attributed to the sector that emits them directly. These high-level sectors are made up of a number of more detailed sectors, which follow the definitions set out by the Intergovernmental Panel on Climate Change (IPCC), and which are used in international reporting tables which are submitted to the United Nations Framework Convention on Climate Change (UNFCCC) every year.