Greenhouse gas emission effect of suspending slash pile burning in Ontario's managed forests

Abstract

Ontario has made a commitment to reduce its greenhouse gas (GHG) emissions by 15, 37, and 80% below 1990 levels by 2020, 2030, and 2050, respectively. Ontario's forest managers can contribute to meeting these targets by implementing changes to forestry practices that either reduce emissions from operations or increase carbon sequestration in forest ecosystems and harvested wood products. We present an analysis of the effects on GHG emissions resulting from suspending the current management practice of slash pile burning (burning harvest residue in the forest without energy recovery). The analysis was performed for each of Ontario's forest management units (FMU) with assumed suspension of slash pile burning for four different

Climate impact of diverting residual biomass to cement production

“…Residual biomass diverted from slash burning had the lowest atmospheric CO 2 load (3.5 kg CO 2 e/Mg clk, Table 5, Item 30) because this biomass was destined to be burnt (Figure 2). The and atmospheric CO 2 load of this scenario would have been zero (Miner et al, 2014) had we not accounted for the formation and deposition of biochar (0.031 Mg biochar C/Mg biomass C) on the forest floor with slash burning (Lehmann et al, 2006; Ter‐Mikaelian et al, 2016).…”

“…Similar to number 3 except fossil fuel recovery and refining emissions are only 10% due to improved methane management. 5. Biomass CO 2 emissions (Column A) from (Nhuchhen et al, 2021), CH 4 (Column C) and N 2 O (Column E) emissions from Ter‐Mikaelian et al (2016). Upstream emissions are set to zero since this is residual biomass. 6.…”

“…5. Biomass CO 2 emissions (Column A) from (Nhuchhen et al, 2021), CH 4 (Column C) and N 2 O (Column E) emissions from Ter‐Mikaelian et al (2016). Upstream emissions are set to zero since this is residual biomass.…”

“…This methodology requires an understanding of the fate of biomass C under BAU conditions so it can be compared with the destiny of biomass C if diverted to use as a bioenergy resource. Figure 2 summarizes the range (shaded area) and assumed average (lines) profiles for biomass C remaining in the biosphere for 100 years following a decision regarding how that biomass will be used: Combustion for industrial heat and power generation leaves little biochar (Lehmann et al, 2006), thus we assumed all the biomass C was converted to CO 2 (Figure 2, Orange line). Slash burning of residual forest biomass leaves behind 1.2%–5.1% of the biomass C as biochar (Finkral et al, 2012; Ter‐Mikaelian et al, 2016), which is resistant to subsequent degradation (Lehmann et al, 2006). Only 3% (Wang et al, 2016) to 25% (Hammes et al, 2008) of the biochar C is lost within 100 years of the formation while the remainder of the C contributes to long‐term soil C storage (Hammes et al, 2008; Wang et al, 2016).…”

“…Furthermore, the study did not account for biogenic CH 4 and N 2 O emissions associated with the bioenergy systems (Cherubini et al, 2009). Although diverting residual biomass from slash burning into bioenergy avoids GHG emissions by preventing open‐air combustion of biomass (Pingoud et al, 2012; Ter‐Mikaelian et al, 2016), industrial combustion of biomass also releases GHGs into the atmosphere (Ministry of Environment British Columbia, 2014).…”