National Assembly for Wales

The Welsh Government does not directly collect data on methane emissions. However, the National Atmospheric Emission Inventory is published annually and contains details on estimated methane emissions in Wales by sector and is used to track and monitor our emissions.

On the excel you can find two tabs for Wales:

• End-user emissions - these calculations allocate emissions from the production and processing of fuels (including the production electricity) to the consumers of these fuels to reflect the total emissions relating to that fuel use. This is in contrast to:
• 'By source' emissions - reporting which emissions are attributed to the sector that emits them directly.

You may want to focus on ‘by-source’ if you are interested in the methane emissions a sector is responsible for emitting. To extract the methane data, you will need to adjust the pivot table options. When the pivot table is selected there is a menu option at the top of excel for “PivotTable Analyse”. Once selected, on the far right select “Field List”. From the new window that opens you can drag and drop the “pollutant” tix box into the filters list below. A new drop-down list will appear at the top of the data table from which you can then select methane (CH₄) emissions. The table is now converted to show the quantity (KtCO₂ equivalent) of methane emissions for each sector.

Because you are particularly interested in methane emissions, bear in mind that in this publication, emissions estimates are primarily based on 100-year AR4 (IPCC 4^th Assessment Report) Global Warming Potential (GWP), consistent with international reporting and carbon trading protocols up to 2020. However, in November 2021 it was agreed by the international community at COP26 that greenhouse gas emissions shall be reported under the Paris Agreement transparency framework using 100-year AR5 (IPCC 5^th Assessment Report) GWP. Therefore, an additional tab is provided in the spreadsheet to show the AR5 emissions (Wales by Source AR5).