Meeting GHG reduction targets requires accounting for all forest sector emissions
Meeting GHG reduction targets requires accounting for all forest sector emissions
复制标题
DOI：
10.1088/1748-9326/ab28bb
复制
发表时间：
2019-09-01
影响因子：
6.7
通讯作者：
Stenzel, Jeffrey E.
中科院分区：
文献类型：
--
作者：
Hudiburg, Tara W.;Law, Beverly E.;Stenzel, Jeffrey E.
必须减少大气温室气体，以避免不可持续的气候。由于二氧化碳被从大气中清除并被森林和木材产品吸收，因此正在制定维持和增加森林碳吸收的缓解战略。这些战略要求充分核算森林部门的温室气体预算。在这里，我们描述了一个严格的方法，使用超过一百万个观测森林清查数据和区域校准的生命周期评估计算摇篮到坟墓的森林部门的排放和封存。我们发现，美国西部的森林是净汇，因为有一个积极的森林碳吸收超过损失的净平衡，由于采伐，木材产品的使用，和野火燃烧。然而，100多年的木材产品使用使潜在的年吸收汇平均减少了21%，这表明森林碳储存可以通过减少采伐、延长轮伐期或更有效地使用木材产品来更有效地减缓气候变化。自1900年以来，从西海岸森林中清除的二氧化碳当量约为107亿公吨，其中81%已返回大气或沉积在垃圾填埋场。此外，州和联邦报告错误地排除了一些与产品相关的排放，导致州二氧化碳排放总量被低估了25%-55%。对于寻求到2030年实现温室气体减排任务的州来说，重要的是要有效地确定州二氧化碳预算，否则声称的减排量将不足以减缓气候变化。
Atmospheric greenhouse gases (GHGs) must be reduced to avoid an unsustainable climate. Because carbon dioxide is removed from the atmosphere and sequestered in forests and wood products, mitigation strategies to sustain and increase forest carbon sequestration are being developed. These strategies require full accounting of forest sector GHG budgets. Here, we describe a rigorous approach using over one million observations from forest inventory data and a regionally calibrated life-cycle assessment for calculating cradle-to-grave forest sector emissions and sequestration. We find that Western US forests are net sinks because there is a positive net balance of forest carbon uptake exceeding losses due to harvesting, wood product use, and combustion by wildfire. However, over 100 years of wood product usage is reducing the potential annual sink by an average of 21%, suggesting forest carbon storage can become more effective in climate mitigation through reduction in harvest, longer rotations, or more efficient wood product usage. Of the similar to 10 700 million metric tonnes of carbon dioxide equivalents removed from west coast forests since 1900, 81% of it has been returned to the atmosphere or deposited in landfills. Moreover, state and federal reporting have erroneously excluded some product-related emissions, resulting in 25%-55% underestimation of state total CO2 emissions. For states seeking to reach GHG reduction mandates by 2030, it is important that state CO2 budgets are effectively determined or claimed reductions will be insufficient to mitigate climate change.