Current status: Answered by Lorna Slater on 24 January 2022
To ask the Scottish Government what changes in emissions are modelled in its Climate Change Plan that are based on the introduction of the biodegradable municipal landfill ban, and whether these changes are attributed to the waste sector.
Greenhouse gas (GHG) emissions attributed to the waste sector in the Climate Change Plan (CCP) include emissions arising from landfill sites, waste water treatment, composting and other waste treatments, including incineration of sewage sludges and clinical wastes (without energy recovery). This is consistent with the international reporting requirements determined by the Intergovernmental Panel for Climate Change (IPCC).
The biodegradable municipal waste (BMW) landfill ban, which comes into effect in December 2025, will direct BMW to alternative treatment options, including anaerobic digestion (AD), mechanical-biological treatment (MBT) and Energy from Waste (EfW) plants or future Combined Heat and Power (CHP) facilities.
The resulting reduction in biodegradable waste sent to landfill will lead to a decline in GHG emissions, principally methane, from landfill sites; these changes are currently accounted for in the CCP waste sector emissions estimates.
Diversion of BMW from landfill will lead to a rise in GHG emissions from other treatment options, including AD, MBT and EfW plants. Changes in emissions arising from waste treatments without energy recovery (e.g. AD, MBT) are attributed to the waste sector, whilst waste treatment options with energy recovery are attributed to the energy supply sector (e.g. EfW). Overall, there is a net decline in GHG emissions when diverting waste from landfill to other treatment options, principally as a result of the conversion of potential methane release (a highly potent greenhouse gas) to carbon dioxide, which has a lower global warming potential. For example, Zero Waste Scotland estimates that on a per tonne of waste basis the carbon impacts of EfW are on average 27% lower than landfilling waste ( The climate change impacts of burning municipal waste in Scotland ) .