The potential contributions from forest-based greenhouse gas (GHG) mitigation actions need to be quantified to develop pathways towards net negative emissions. Here we present results from a comparative analysis that examined mitigation options for British Columbia’s forest sector. Mitigation scenarios were evaluated using a systems perspective that takes into account the changes in emissions and removals in forest ecosystems, in harvested wood product (HWP) carbon stocks, and in other sectors where wood products substitute for emission-intensive materials and fossil fuels. All mitigation activities were assessed relative to a forward-looking ‘business as usual’ baseline for three implementation levels. In addition to quantifying net GHG emission reductions, we assessed economic, and socio-economic impacts as well as other environmental indicators relating to forest species, age class, deadwood availability and future timber supply. We further considered risks of reversal for land-based scenarios, by assessing impacts of increasing future wildfires on stands that were not harvested. Our spatially explicit analyses of forest sector mitigation options demonstrated a cost-effective portfolio of regionally differentiated scenarios that directed more of the harvested wood to longer-lived wood products, stopped burning of harvest residues and instead produced bioenergy to displace fossil fuel burning, and reduced harvest levels in regions with low disturbance rates. Domestically, net GHG emissions were reduced by an average of -9 MtCO2e year−1 over 2020–2050 for a portfolio of mitigation activities at a default implementation level, with about 85% of the GHG emission reductions achieved below a cost of $50/tCO2e. Normalizing the net GHG reduction by changes in harvested wood levels permitted comparisons of the scenarios with different ambition levels, and showed that a 1 MtCO2 increase in cumulative harvested stemwood results in a 1 MtCO2e reduction in cumulative emissions, relative to the baseline, for the Higher Recovery scenario in 2070. The analyses conducted in this study contribute to the global understanding of forest sector mitigation options by providing an integrated framework to synthesize the methods, assumptions, datasets and models needed to quantify mitigation activities using a systems approach. An understanding of economically feasible and socio-economically attractive mitigation scenarios along with trade offs for environmental indicators relating to species composition and age, helps decision makers with long-term planning for land sector contributions to GHG emission reduction efforts, and provides valuable information for stakeholder consultations.

中文翻译：

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不列颠哥伦比亚省林业部门的减缓气候变化：温室气体减少，成本和环境影响

需要量化森林基温室气体（GHG）缓解行动的潜在贡献，以开发实现净负排放的途径。在这里，我们提供了一项比较分析的结果，该分析检查了不列颠哥伦比亚省林业部门的缓解方案。使用系统观点评估了缓解方案，该观点考虑了森林生态系统，伐木产品（HWP）的碳储量以及木制品替代排放密集型材料和化石燃料的其他部门的排放量和清除量的变化。相对于三个实施级别的前瞻性“一切照旧”基准评估了所有缓解活动。除了量化温室气体净排放量，我们还评估了经济，以及社会经济影响以及与森林物种，年龄等级，枯木供应量和未来木材供应有关的其他环境指标。通过评估未来野火对未收获林分的影响，我们进一步考虑了陆上情景逆转的风险。我们对森林部门减缓方案进行的空间明确分析表明，该方案具有成本效益，可用于不同地区的情景，将更多的采伐木材用于寿命更长的木材产品，停止燃烧采伐残余物，并产生生物能来替代化石燃料的燃烧，并减少了低干扰率地区的收成水平。在国内 2020-2050年，在默认实施水平下，一系列减排活动的平均净温室气体排放量在-1年内平均减少了-9 MtCO2e，其中约有85％的温室气体减排量低于50美元/ tCO2e的成本。通过采伐木材水平变化对净温室气体减少量进行归一化，可以比较具有不同雄心水平的情景，并表明，相对于基准线，较高采伐量的木材累积采伐量增加1 MtCO2e，相对于基准线，累积排放量减少1 MtCO2e。 2070年的恢复情景。本研究进行的分析通过提供一个综合框架来综合使用系统方法量化缓解活动所需的方法，假设，数据集和模型，从而有助于对森林部门缓解方案的全球理解。