Scotland Greenpathway 

In 2021, Scottish agriculture sector produced 7.8 MtCO2e (million tonnes of carbon dioxide equivalent), which accounted for 19% of total Scottish emissions. ( The Scottish Government, 2022). According to ClimateXChange (2023), livestock farming in Scotland generates significant methane emissions, a potent greenhouse gas. Manure and slurry from these operations account for a substantial portion of the agriculture sector's contribution to climate change, roughly 24% of the country's total emissions, with methane emissions accounting for approximately 44%. 

The Scottish Government sees farmyard slurry as a key resource for meeting renewable energy goals. Manure is a particularly interesting bioresource owing to the greenhouse gas impact. When manure and slurry are left unmanaged, they naturally release methane - a potent greenhouse gas - into the atmosphere, when used for anaerobic digestion, this methane can be captured and valorised to fully utilize this potential, the 2021 Bioenergy Update highlighted the need to develop a market for digestate. Additionally, Changes in farming techniques, as well as the use of new technology and inventive instruments, can result in large carbon reductions ( The Scottish Government, 2022).

 

Benefits of Anaerobic Digestion for  Scotland

Anaerobic digestion has been recommended as a technology that has multifaceted applicability for two major byproducts: biogas and biofertilizer, which are highly rich in nitrogen, phosphorus, potassium, calcium manganese. All these nutrients are essential to enhance soil fertility and grow better crops ( Isha et al,2020).

According to the Scottish government (2024), bioenergy has many applications across heating needs, power, industry, and transport, with a diversified range of mature and emergent technologies, reducing reliance on fossil fuels and supporting the country's grid stability.

 
“We expect the use of biomass to increasingly be prioritised for emissions removals”

The government highlights that the bioenergy sector should prioritise the use of available feedstocks and this use must support emissions reduction and the pathway to Net zero in 2045. The use of by-products of whiskey distillery was highlighted as an important energy source. To achieve this ambitious goal is necessary major efforts and increase substantially the share of renewable energy in the country's energy matrix. 

This nutrient-rich fertilizer is a byproduct of anaerobic digestion, and establishing a market for it would encourage increased biomethane production. Digestate contributes to a circular economy by nourishing soils, lessening the demand for chemical fertilizers, and enhancing crop productivity (Xiao et al., 2022).

Additionally, Subbarao ,et al (2023) claim that this technology recovers the volatile matter from waste biomass as much as possible to produce biogas, therefore reducing carbon emission as compared to open dumping or burning.Methane and carbon dioxide are the main carbon-based greenhouse gases gathered in the atmosphere. CH4 emissions are part of fossil fuel withdrawal, excessive agricultural activities, animal husbandry, and accumulated unprocessed biomass. The residence time of CO2 in the atmosphere is beyond a thousand years, creating chaos in the carbon cycle. Even though the atmospheric residence time of CH4 is shorter (12 years) and present at lower concentrations the radiation trapping capacity is higher, making it 28 times more fatal than CO2 (US EPA, 2023, Isha et al,2020).

Therefore, anaerobic digestion diverts organic waste from landfills, preventing the release of potent greenhouse gases and creating valuable by-products.