Forest ecosystems play an important role in carbon sequestration, climate change mitigation, and achieving China's target to become carbon (C) neutral by 2060. However, changes in C storage and net primary production (NPP) in natural secondary forests stemming from tree growth and future climate change have not yet been investigated in subtropical areas in China. Here, we used data from 290 inventory plots in four secondary forests [evergreen broad-leaved forest (EBF), deciduous and evergreen broad-leaved mixed forest (DEF), deciduous broad-leaved forest (DBF), and coniferous and broad-leaved mixed forest (CDF)] at different restoration stages and run a hybrid model (TRIPLEX 1.6) to predict changes in stand carbon storage and NPP under two future climate change scenarios (RCP4.5 and RCP8.5).
Results
The runs of the hybrid model calibrated and validated by using the data from the inventory plots suggest significant increase in the carbon storage by 2060 under the current climate conditions, and even higher increase under the RCP4.5 and RCP8.5 climate change scenarios. In contrast to the carbon storage, the simulated EBF and DEF NPP declines slightly over the period from 2014 to 2060.
Conclusions
The obtained results lead to conclusion that proper management of China’s subtropical secondary forests could be considered as one of the steps towards achieving China’s target to become carbon neutral by 2060.
{"title":"Stand carbon storage and net primary production in China’s subtropical secondary forests are predicted to increase by 2060","authors":"Jia Jin, Wenhua Xiang, Yelin Zeng, Shuai Ouyang, Xiaolu Zhou, Yanting Hu, Zhonghui Zhao, Liang Chen, Pifeng Lei, Xiangwen Deng, Hui Wang, Shirong Liu, Changhui Peng","doi":"10.1186/s13021-022-00204-y","DOIUrl":"10.1186/s13021-022-00204-y","url":null,"abstract":"<div><h3>Background</h3><p>Forest ecosystems play an important role in carbon sequestration, climate change mitigation, and achieving China's target to become carbon (C) neutral by 2060. However, changes in C storage and net primary production (NPP) in natural secondary forests stemming from tree growth and future climate change have not yet been investigated in subtropical areas in China. Here, we used data from 290 inventory plots in four secondary forests [evergreen broad-leaved forest (EBF), deciduous and evergreen broad-leaved mixed forest (DEF), deciduous broad-leaved forest (DBF), and coniferous and broad-leaved mixed forest (CDF)] at different restoration stages and run a hybrid model (TRIPLEX 1.6) to predict changes in stand carbon storage and NPP under two future climate change scenarios (RCP4.5 and RCP8.5).</p><h3>Results</h3><p>The runs of the hybrid model calibrated and validated by using the data from the inventory plots suggest significant increase in the carbon storage by 2060 under the current climate conditions, and even higher increase under the RCP4.5 and RCP8.5 climate change scenarios. In contrast to the carbon storage, the simulated EBF and DEF NPP declines slightly over the period from 2014 to 2060.</p><h3>Conclusions</h3><p>The obtained results lead to conclusion that proper management of China’s subtropical secondary forests could be considered as one of the steps towards achieving China’s target to become carbon neutral by 2060.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00204-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46986822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quantifying the stock of soil organic carbon (SOC) and evaluating its potential impact factors is important to evaluating global climate change. Human disturbances and past climate are known to influence the rates of carbon fixation, soil physiochemical properties, soil microbial diversity and plant functional traits, which ultimately affect the current SOC storage. However, whether and how the paleoclimate and human disturbances affect the distribution of SOC storage on the high-altitude Tibetan Plateau remain largely unknown. Here, we took the Qinghai Plateau, the main component of the Tibetan Plateau, as our study region and applied three machine learning models (random forest, gradient boosting machine and support vector machine) to estimate the spatial and vertical distributions of the SOC stock and then evaluated the effects of the paleoclimate during the Last Glacial Maximum and the mid-Holocene periods as well as the human footprint on SOC stock at 0 to 200 cm depth by synthesizing 827 soil observations and 71 environmental factors.
Results
Our results indicate that the vegetation and modern climate are the determinant factors of SOC stocks, while paleoclimate (i.e., paleotemperature and paleoprecipitation) is more important than modern temperature, modern precipitation and the human footprint in shaping current SOC stock distributions. Specifically, the SOC stock was deeply underestimated in near natural ecosystems and overestimated in the strongly human disturbance ecosystems if the model did not consider the paleoclimate. Overall, the total SOC stock of the Qinghai Plateau was underestimated by 4.69%, 12.25% and 6.67% at depths of 0 to 100 cm, 100 to 200 cm and 0 to 200 cm, respectively. In addition, the human footprint had a weak influence on the distributions of the SOC stock. We finally estimated that the total and mean SOC stock at 200 cm depth by including the paleoclimate effects was 11.36 Pg C and 16.31 kg C m−2, respectively, and nearly 40% SOC was distributed in the top 30 cm.
Conclusion
The paleoclimate is relatively important for the accurate modeling of current SOC stocks. Overall, our study provides a benchmark for predicting SOC stock patterns at depth and emphasizes that terrestrial carbon cycle models should incorporate information on how the paleoclimate has influenced SOC stocks.
土壤有机碳储量的量化及其潜在影响因子的评价对全球气候变化评价具有重要意义。人类活动和过去的气候会影响固碳速率、土壤理化性质、土壤微生物多样性和植物功能性状，最终影响当前的有机碳储量。然而，古气候和人为干扰是否以及如何影响青藏高原高海拔地区有机碳储量的分布仍然是一个未知的问题。本文以青藏高原的主要组成部分——青海高原为研究区域，应用了三种机器学习模型(随机森林、综合827份土壤观测资料和71个环境因子，利用梯度增强机和支持向量机估算了末次极大冰期和全新世中期古气候以及人类足迹对0 ~ 200 cm深度土壤有机碳储量的影响。结果植被和现代气候是有机碳储量的决定因子，古气候(即古温度和古降水)比现代温度、现代降水和人类足迹对当前有机碳储量分布的影响更大。在不考虑古气候的情况下，近自然生态系统的碳储量被严重低估，而强烈人为干扰生态系统的碳储量被高估。总体而言，青海高原碳储量在0 ~ 100 cm、100 ~ 200 cm和0 ~ 200 cm深度分别被低估4.69%、12.25%和6.67%。此外，人类足迹对土壤有机碳储量分布的影响较小。结果表明，考虑古气候影响的200 cm深度有机碳总储量和平均储量分别为11.36 Pg C和16.31 kg C m−2，其中近40%的有机碳分布在表层30 cm。结论古气候对准确模拟当前有机碳储量具有重要意义。总的来说，我们的研究为预测深层有机碳储量模式提供了一个基准，并强调陆地碳循环模型应该包含古气候如何影响有机碳储量的信息。
{"title":"Uncertainties of soil organic carbon stock estimation caused by paleoclimate and human footprint on the Qinghai Plateau","authors":"Xia Liu, Tao Zhou, Peijun Shi, Yajie Zhang, Hui Luo, Peixin Yu, Yixin Xu, Peifang Zhou, Jingzhou Zhang","doi":"10.1186/s13021-022-00203-z","DOIUrl":"10.1186/s13021-022-00203-z","url":null,"abstract":"<div><h3>Background</h3><p>Quantifying the stock of soil organic carbon (SOC) and evaluating its potential impact factors is important to evaluating global climate change. Human disturbances and past climate are known to influence the rates of carbon fixation, soil physiochemical properties, soil microbial diversity and plant functional traits, which ultimately affect the current SOC storage. However, whether and how the paleoclimate and human disturbances affect the distribution of SOC storage on the high-altitude Tibetan Plateau remain largely unknown. Here, we took the Qinghai Plateau, the main component of the Tibetan Plateau, as our study region and applied three machine learning models (random forest, gradient boosting machine and support vector machine) to estimate the spatial and vertical distributions of the SOC stock and then evaluated the effects of the paleoclimate during the Last Glacial Maximum and the mid-Holocene periods as well as the human footprint on SOC stock at 0 to 200 cm depth by synthesizing 827 soil observations and 71 environmental factors.</p><h3>Results</h3><p>Our results indicate that the vegetation and modern climate are the determinant factors of SOC stocks, while paleoclimate (i.e., paleotemperature and paleoprecipitation) is more important than modern temperature, modern precipitation and the human footprint in shaping current SOC stock distributions. Specifically, the SOC stock was deeply underestimated in near natural ecosystems and overestimated in the strongly human disturbance ecosystems if the model did not consider the paleoclimate. Overall, the total SOC stock of the Qinghai Plateau was underestimated by 4.69%, 12.25% and 6.67% at depths of 0 to 100 cm, 100 to 200 cm and 0 to 200 cm, respectively. In addition, the human footprint had a weak influence on the distributions of the SOC stock. We finally estimated that the total and mean SOC stock at 200 cm depth by including the paleoclimate effects was 11.36 Pg C and 16.31 kg C m<sup>−2</sup>, respectively, and nearly 40% SOC was distributed in the top 30 cm.</p><h3>Conclusion</h3><p>The paleoclimate is relatively important for the accurate modeling of current SOC stocks. Overall, our study provides a benchmark for predicting SOC stock patterns at depth and emphasizes that terrestrial carbon cycle models should incorporate information on how the paleoclimate has influenced SOC stocks.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00203-z","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42352960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-26DOI: 10.1186/s13021-022-00207-9
Mercy N. Ndalila, Grant J. Williamson, David M. J. S. Bowman
Background
Uncontrolled wildfires in Australian temperate Eucalyptus forests produce significant smoke emissions, particularly carbon dioxide (CO2) and particulates. Emissions from fires in these ecosystems, however, have received less research attention than the fires in North American conifer forests or frequently burned Australian tropical savannas. Here, we use the 2013 Forcett–Dunalley fire that caused the first recorded pyrocumulonimbus event in Tasmania, to understand CO2 and particulate matter (PM2.5) emissions from a severe Eucalyptus forest fire. We investigate the spatial patterns of the two emissions using a fine scale mapping of vegetation and fire severity (50 m resolution), and utilising available emission factors suitable for Australian vegetation types. We compare the results with coarse-scale (28 km resolution) emissions estimates from Global Fire Emissions Database (GFED) to determine the reliability of the global model in emissions estimation.
Results
The fine scale inventory yielded total CO2 emission of 1.125 ± 0.232 Tg and PM2.5 emission of 0.022 ± 0.006 Tg, representing a loss of 56 t CO2 ha−1 and 1 t PM2.5 ha−1. The CO2 emissions were comparable to GFED estimates, but GFED PM2.5 estimates were lower by a factor of three. This study highlights the reliability of GFED for CO2 but not PM2.5 for estimating emissions from Eucalyptus forest fires. Our fine scale and GFED estimates showed that the Forcett–Dunalley fire produced 30% of 2013 fire carbon emissions in Tasmania, and 26–36% of mean annual fire emissions for the State, representing a significant single source of emissions.
Conclusions
Our analyses highlight the need for improved PM2.5 emission factors specific to Australian vegetation, and better characterisation of fuel loads, particularly coarse fuel loads, to quantify wildfire particulate and greenhouse gas emissions more accurately. Current Australian carbon accountancy approach of excluding large wildfires from final GHG accounts likely exaggerates Tasmania’s claim to carbon neutrality; we therefore recommend that planned and unplanned emissions are included in the final national and state greenhouse gas accounting to international conventions. Advancing these issues is important given the trajectory of more frequent large fires driven by anthropogenic climate change.
背景在澳大利亚温带桉树林中，不受控制的野火产生了大量的烟雾排放，特别是二氧化碳和颗粒物。然而，与北美针叶林或经常燃烧的澳大利亚热带稀树草原的火灾相比，这些生态系统中火灾产生的排放物受到的研究关注较少。在这里，我们使用了2013年的force - dunalley火灾，该火灾导致了塔斯马尼亚州第一次有记录的火积雨云事件，以了解严重桉树森林火灾产生的二氧化碳和颗粒物(PM2.5)排放。我们利用植被和火灾严重程度(50米分辨率)的精细比例尺制图，并利用适合澳大利亚植被类型的可用排放因子，研究了这两种排放的空间格局。我们将结果与全球火灾排放数据库(GFED)的粗尺度(28公里分辨率)排放估计值进行比较，以确定全球模型在排放估算中的可靠性。结果细尺度清查产生的CO2总排放量为1.125±0.232 Tg, PM2.5总排放量为0.022±0.006 Tg，分别损失了56 t CO2 ha - 1和1 t PM2.5 ha - 1。二氧化碳排放量与GFED的估计相当，但GFED对PM2.5的估计要低三分之一。这项研究强调了GFED在估计桉树森林火灾排放时对二氧化碳而不是PM2.5的可靠性。我们的精细尺度和GFED估算显示，福斯特-杜纳利火灾产生的碳排放量占塔斯马尼亚州2013年火灾碳排放量的30%，占该州平均年火灾排放量的26-36%，是一个重要的单一排放源。sour分析强调需要改善澳大利亚植被的PM2.5排放因子，并更好地表征燃料负荷，特别是粗燃料负荷，以更准确地量化野火颗粒和温室气体排放。目前澳大利亚的碳核算方法将大型野火排除在最终的温室气体核算之外，这可能夸大了塔斯马尼亚州对碳中和的主张;因此，我们建议将计划内和计划外的排放纳入国际公约的最终国家和州温室气体核算中。考虑到由人为气候变化引起的更频繁的大火的轨迹，推进这些问题是重要的。
{"title":"Carbon dioxide and particulate emissions from the 2013 Tasmanian firestorm: implications for Australian carbon accounting","authors":"Mercy N. Ndalila, Grant J. Williamson, David M. J. S. Bowman","doi":"10.1186/s13021-022-00207-9","DOIUrl":"10.1186/s13021-022-00207-9","url":null,"abstract":"<div><h3>Background</h3><p>Uncontrolled wildfires in Australian temperate <i>Eucalyptus</i> forests produce significant smoke emissions, particularly carbon dioxide (CO<sub>2</sub>) and particulates. Emissions from fires in these ecosystems, however, have received less research attention than the fires in North American conifer forests or frequently burned Australian tropical savannas. Here, we use the 2013 Forcett–Dunalley fire that caused the first recorded pyrocumulonimbus event in Tasmania, to understand CO<sub>2</sub> and particulate matter (PM<sub>2.5</sub>) emissions from a severe <i>Eucalyptus</i> forest fire. We investigate the spatial patterns of the two emissions using a fine scale mapping of vegetation and fire severity (50 m resolution), and utilising available emission factors suitable for Australian vegetation types. We compare the results with coarse-scale (28 km resolution) emissions estimates from Global Fire Emissions Database (GFED) to determine the reliability of the global model in emissions estimation.</p><h3>Results</h3><p>The fine scale inventory yielded total CO<sub>2</sub> emission of 1.125 ± 0.232 Tg and PM<sub>2.5</sub> emission of 0.022 ± 0.006 Tg, representing a loss of 56 t CO<sub>2</sub> ha<sup>−1</sup> and 1 t PM<sub>2.5</sub> ha<sup>−1</sup>. The CO<sub>2</sub> emissions were comparable to GFED estimates, but GFED PM<sub>2.5</sub> estimates were lower by a factor of three. This study highlights the reliability of GFED for CO<sub>2</sub> but not PM<sub>2.5</sub> for estimating emissions from <i>Eucalyptus</i> forest fires. Our fine scale and GFED estimates showed that the Forcett–Dunalley fire produced 30% of 2013 fire carbon emissions in Tasmania, and 26–36% of mean annual fire emissions for the State, representing a significant single source of emissions.</p><h3>Conclusions</h3><p>Our analyses highlight the need for improved PM<sub>2.5</sub> emission factors specific to Australian vegetation, and better characterisation of fuel loads, particularly coarse fuel loads, to quantify wildfire particulate and greenhouse gas emissions more accurately. Current Australian carbon accountancy approach of excluding large wildfires from final GHG accounts likely exaggerates Tasmania’s claim to carbon neutrality; we therefore recommend that planned and unplanned emissions are included in the final national and state greenhouse gas accounting to international conventions. Advancing these issues is important given the trajectory of more frequent large fires driven by anthropogenic climate change.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00207-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41947202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-23DOI: 10.1186/s13021-022-00208-8
Mina Hong, Cholho Song, Moonil Kim, Jiwon Kim, Sle-gee Lee, Chul-Hee Lim, Kijong Cho, Yowhan Son, Woo-Kyun Lee
Background
Forests are atmospheric carbon sinks, whose natural growth can contribute to climate change mitigation. However, they are also affected by climate change and various other phenomena, for example, the low growth of coniferous forests currently reported globally, including in the Republic of Korea. In response to the implementation of the Paris Agreement, the Korean government has proposed 2030 greenhouse gas roadmap to achieve a Nationally Determined Contribution (NDC), and the forest sector set a sequestration target of 26 million tons by 2030. In this study, the Korean forest growth model (KO-G-Dynamic model) was used to analyze various climate change and forest management scenarios and their capacity to address the NDC targets. A 2050 climate change adaptation strategy is suggested based on forest growth and CO2 sequestration.
Results
Forest growth was predicted to gradually decline, and CO2 sequestration was predicted to reach 23 million tons per year in 2050 if current climate and conditions are maintained. According to the model, sequestrations of 33 million tCO2 year−1 in 2030 and 27 million tCO2 year−1 in 2050 can be achieved if ideal forest management is implemented. It was also estimated that the current forest management budget of 317 billion KRW (264 million USD) should be twice as large at 722 billion KRW (602 million USD) in the 2030s and 618 billion KRW (516 million USD) in the 2050s to achieve NDC targets.
Conclusions
The growth trend in Korea's forests transitions from young-matured stands to over-mature forests. The presented model-based forest management plans are an appropriate response and can increase the capacity of Korea to achieve its NDC targets. Such a modeling can help the forestry sector develop plans and policies for climate change adaptation.
{"title":"Application of integrated Korean forest growth dynamics model to meet NDC target by considering forest management scenarios and budget","authors":"Mina Hong, Cholho Song, Moonil Kim, Jiwon Kim, Sle-gee Lee, Chul-Hee Lim, Kijong Cho, Yowhan Son, Woo-Kyun Lee","doi":"10.1186/s13021-022-00208-8","DOIUrl":"10.1186/s13021-022-00208-8","url":null,"abstract":"<div><h3>Background</h3><p>Forests are atmospheric carbon sinks, whose natural growth can contribute to climate change mitigation. However, they are also affected by climate change and various other phenomena, for example, the low growth of coniferous forests currently reported globally, including in the Republic of Korea. In response to the implementation of the Paris Agreement, the Korean government has proposed 2030 greenhouse gas roadmap to achieve a Nationally Determined Contribution (NDC), and the forest sector set a sequestration target of 26 million tons by 2030. In this study, the Korean forest growth model (KO-G-Dynamic model) was used to analyze various climate change and forest management scenarios and their capacity to address the NDC targets. A 2050 climate change adaptation strategy is suggested based on forest growth and CO<sub>2</sub> sequestration.</p><h3>Results</h3><p>Forest growth was predicted to gradually decline, and CO<sub>2</sub> sequestration was predicted to reach 23 million tons per year in 2050 if current climate and conditions are maintained. According to the model, sequestrations of 33 million tCO<sub>2</sub> year<sup>−1</sup> in 2030 and 27 million tCO<sub>2</sub> year<sup>−1</sup> in 2050 can be achieved if ideal forest management is implemented. It was also estimated that the current forest management budget of 317 billion KRW (264 million USD) should be twice as large at 722 billion KRW (602 million USD) in the 2030s and 618 billion KRW (516 million USD) in the 2050s to achieve NDC targets.</p><h3>Conclusions</h3><p>The growth trend in Korea's forests transitions from young-matured stands to over-mature forests. The presented model-based forest management plans are an appropriate response and can increase the capacity of Korea to achieve its NDC targets. Such a modeling can help the forestry sector develop plans and policies for climate change adaptation.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00208-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49268597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-17DOI: 10.1186/s13021-022-00205-x
Tanja Myllyviita, Elias Hurmekoski, Janni Kunttu
Background
The building and construction sectors represent a major source of greenhouse gas (GHG) emissions. Replacing concrete and steel with wood is one potential strategy to decrease emissions. On product level, the difference in fossil emissions per functional unit can be quantified with displacement factors (DFs), i.e., the amount of fossil emission reduction achieved per unit of wood use when replacing a functionally equivalent product. We developed DFs for substitution cases representative of typical wood-frame and non-wood frame multi-story buildings in the Nordic countries, considering the expected decarbonization of the energy sector and increased recycling of construction products.
Results
Most of the DFs were positive, implying lower fossil emissions, if wood construction is favored. However, variation in the DFs was substantial and negative DFs implying higher emissions were also detected. All DFs showed a decreasing trend, i.e., the GHG mitigation potential of wood construction significantly decreases under future decarbonization and increased recycling assumptions. If only the decarbonization of the energy sector was considered, the decrease was less dramatic compared to the isolated impact of the recycling of construction materials. The mitigation potential of wood construction appears to be the most sensitive to the GHG emissions of concrete, whereas the emissions of steel seem less influential, and the emissions of wood have only minor influence.
Conclusions
The emission reduction due to the decarbonization of the energy sector and the recycling of construction materials is a favorable outcome but one that reduces the relative environmental benefit of wood construction, which ought to be considered in forest-based mitigation strategies. Broadening the system boundary is required to assess the overall substitution impacts of increased use of wood in construction, including biogenic carbon stock changes in forest ecosystems and in wood products over time, as well as price-mediated market responses.
{"title":"Substitution impacts of Nordic wood-based multi-story building types: influence of the decarbonization of the energy sector and increased recycling of construction materials","authors":"Tanja Myllyviita, Elias Hurmekoski, Janni Kunttu","doi":"10.1186/s13021-022-00205-x","DOIUrl":"10.1186/s13021-022-00205-x","url":null,"abstract":"<div><h3>Background</h3><p>The building and construction sectors represent a major source of greenhouse gas (GHG) emissions. Replacing concrete and steel with wood is one potential strategy to decrease emissions. On product level, the difference in fossil emissions per functional unit can be quantified with displacement factors (DFs), i.e., the amount of fossil emission reduction achieved per unit of wood use when replacing a functionally equivalent product. We developed DFs for substitution cases representative of typical wood-frame and non-wood frame multi-story buildings in the Nordic countries, considering the expected decarbonization of the energy sector and increased recycling of construction products.</p><h3>Results</h3><p>Most of the DFs were positive, implying lower fossil emissions, if wood construction is favored. However, variation in the DFs was substantial and negative DFs implying higher emissions were also detected. All DFs showed a decreasing trend, i.e., the GHG mitigation potential of wood construction significantly decreases under future decarbonization and increased recycling assumptions. If only the decarbonization of the energy sector was considered, the decrease was less dramatic compared to the isolated impact of the recycling of construction materials. The mitigation potential of wood construction appears to be the most sensitive to the GHG emissions of concrete, whereas the emissions of steel seem less influential, and the emissions of wood have only minor influence.</p><h3>Conclusions</h3><p>The emission reduction due to the decarbonization of the energy sector and the recycling of construction materials is a favorable outcome but one that reduces the relative environmental benefit of wood construction, which ought to be considered in forest-based mitigation strategies. Broadening the system boundary is required to assess the overall substitution impacts of increased use of wood in construction, including biogenic carbon stock changes in forest ecosystems and in wood products over time, as well as price-mediated market responses.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00205-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43365814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-03DOI: 10.1186/s13021-022-00206-w
Chaerin Park, Sujong Jeong, Moon-Soo Park, Hoonyoung Park, Jeongmin Yun, Sang-Sam Lee, Sung-Hwa Park
Background
Cities are a major source of atmospheric CO2; however, understanding the surface CO2 exchange processes that determine the net CO2 flux emitted from each city is challenging owing to the high heterogeneity of urban land use. Therefore, this study investigates the spatiotemporal variations of urban CO2 flux over the Seoul Capital Area, South Korea from 2017 to 2018, using CO2 flux measurements at nine sites with different urban land-use types (baseline, residential, old town residential, commercial, and vegetation areas).
Results
Annual CO2 flux significantly varied from 1.09 kg C m− 2 year− 1 at the baseline site to 16.28 kg C m− 2 year− 1 at the old town residential site in the Seoul Capital Area. Monthly CO2 flux variations were closely correlated with the vegetation activity (r = − 0.61) at all sites; however, its correlation with building energy usage differed for each land-use type (r = 0.72 at residential sites and r = 0.34 at commercial sites). Diurnal CO2 flux variations were mostly correlated with traffic volume at all sites (r = 0.8); however, its correlation with the floating population was the opposite at residential (r = − 0.44) and commercial (r = 0.80) sites. Additionally, the hourly CO2 flux was highly related to temperature. At the vegetation site, as the temperature exceeded 24 ℃, the sensitivity of CO2 absorption to temperature increased 7.44-fold than that at the previous temperature. Conversely, the CO2 flux of non-vegetation sites increased when the temperature was less than or exceeded the 18 ℃ baseline, being three-times more sensitive to cold temperatures than hot ones. On average, non-vegetation urban sites emitted 0.45 g C m− 2 h− 1 of CO2 throughout the year, regardless of the temperature.
Conclusions
Our results demonstrated that most urban areas acted as CO2 emission sources in all time zones; however, the CO2 flux characteristics varied extensively based on urban land-use types, even within cities. Therefore, multiple observations from various land-use types are essential for identifying the comprehensive CO2 cycle of each city to develop effective urban CO2 reduction policies.
城市是大气中二氧化碳的主要来源;然而，由于城市土地利用的高度异质性，了解决定每个城市排放的二氧化碳净通量的地表二氧化碳交换过程具有挑战性。基于此，本研究利用不同城市土地利用类型(基线、住宅、老城区住宅、商业和植被区)的9个地点的二氧化碳通量测量数据，对2017 - 2018年韩国首尔首都圈城市二氧化碳通量的时空变化进行了研究。结果CO2年通量从基线站点的1.09 kg C m−2 year−1显著变化到首都圈老城区住区站点的16.28 kg C m−2 year−1。月CO2通量变化与植被活动密切相关(r = - 0.61);然而，其与建筑能源使用的相关性在不同的土地利用类型中有所不同(住宅用地的r = 0.72，商业用地的r = 0.34)。各站点CO2日通量变化与交通流量的相关性最大(r = 0.8);然而，在居住(r = - 0.44)和商业(r = 0.80)地点，其与流动人口的相关性相反。此外，每小时CO2通量与温度高度相关。在植被点，当温度超过24℃时，CO2吸收对温度的敏感性比前温度提高了7.44倍。相反，当温度低于或超过18℃基线时，非植被样地的CO2通量增加，对低温的敏感性是高温的3倍。平均而言，无论温度如何，非植被城市站点全年排放的二氧化碳为0.45 g C m−2 h−1。结论研究结果表明，在所有时区，大部分城市地区都是CO2排放源;然而，二氧化碳通量特征因城市土地利用类型而有很大差异，甚至在城市内部也是如此。因此，不同土地利用类型的多重观测对于确定每个城市的综合二氧化碳循环，制定有效的城市二氧化碳减排政策至关重要。
{"title":"Spatiotemporal variations in urban CO2 flux with land-use types in Seoul","authors":"Chaerin Park, Sujong Jeong, Moon-Soo Park, Hoonyoung Park, Jeongmin Yun, Sang-Sam Lee, Sung-Hwa Park","doi":"10.1186/s13021-022-00206-w","DOIUrl":"10.1186/s13021-022-00206-w","url":null,"abstract":"<div><h3>Background</h3><p>Cities are a major source of atmospheric CO<sub>2</sub>; however, understanding the surface CO<sub>2</sub> exchange processes that determine the net CO<sub>2</sub> flux emitted from each city is challenging owing to the high heterogeneity of urban land use. Therefore, this study investigates the spatiotemporal variations of urban CO<sub>2</sub> flux over the Seoul Capital Area, South Korea from 2017 to 2018, using CO<sub>2</sub> flux measurements at nine sites with different urban land-use types (baseline, residential, old town residential, commercial, and vegetation areas).</p><h3>Results</h3><p>Annual CO<sub>2</sub> flux significantly varied from 1.09 kg C m<sup>− 2</sup> year<sup>− 1</sup> at the baseline site to 16.28 kg C m<sup>− 2</sup> year<sup>− 1</sup> at the old town residential site in the Seoul Capital Area. Monthly CO<sub>2</sub> flux variations were closely correlated with the vegetation activity (r = − 0.61) at all sites; however, its correlation with building energy usage differed for each land-use type (r = 0.72 at residential sites and r = 0.34 at commercial sites). Diurnal CO<sub>2</sub> flux variations were mostly correlated with traffic volume at all sites (r = 0.8); however, its correlation with the floating population was the opposite at residential (r = − 0.44) and commercial (r = 0.80) sites. Additionally, the hourly CO<sub>2</sub> flux was highly related to temperature. At the vegetation site, as the temperature exceeded 24 ℃, the sensitivity of CO<sub>2</sub> absorption to temperature increased 7.44-fold than that at the previous temperature. Conversely, the CO<sub>2</sub> flux of non-vegetation sites increased when the temperature was less than or exceeded the 18 ℃ baseline, being three-times more sensitive to cold temperatures than hot ones. On average, non-vegetation urban sites emitted 0.45 g C m<sup>− 2</sup> h<sup>− 1</sup> of CO<sub>2</sub> throughout the year, regardless of the temperature.</p><h3>Conclusions</h3><p>Our results demonstrated that most urban areas acted as CO<sub>2</sub> emission sources in all time zones; however, the CO<sub>2</sub> flux characteristics varied extensively based on urban land-use types, even within cities. Therefore, multiple observations from various land-use types are essential for identifying the comprehensive CO<sub>2</sub> cycle of each city to develop effective urban CO<sub>2</sub> reduction policies.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00206-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41753963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-01DOI: 10.1186/s13021-022-00202-0
Ning Zeng, Henry Hausmann
<div><h3>Background</h3><p>Wood harvesting and storage (WHS) is a hybrid Nature-Engineering combination method to combat climate change by harvesting wood sustainably and storing it semi-permanently for carbon sequestration. To date, the technology has only been purposefully tested in small-scale demonstration projects. This study aims to develop a concrete way to carry out WHS at large-scale.</p><h3>Results</h3><p>We describe a method of constructing a wood storage facility, named Wood Vault, that can bury woody biomass on a mega-tonne scale in specially engineered enclosures to ensure anaerobic environments, thus preventing wood decay. The buried wood enters a quasi-geological reservoir that is expected to stay intact semi-permanently. Storing wood in many environments is possible, leading to seven versions of Wood Vault: (1) Burial Mound (Tumulus or Barrow), (2) Underground (Pit, Quarry, or Mine), (3) Super Vault, (4) Shelter, (5) AquaOpen or AquaVault with wood submerged under water, (6) DesertOpen or DesertVault in dry regions, (7) FreezeVault in cold regions such as Antarctica. Smaller sizes are also possible, named Baby Vault. A prototype Wood Vault Unit (WVU) occupies 1 hectare (ha, 100 m by 100 m) of surface land, 20 m tall, stores up to 100,000 m<sup>3</sup> of wood, sequestering 0.1 MtCO<sub>2</sub>. A 1 MtCO<sub>2</sub> y<sup>−1</sup> sequestration rate can be achieved by collecting currently unused wood residuals (WR) on an area of 25,000 km<sup>2</sup>, the size of 10 typical counties in the eastern US, corresponding to an average transportation distance of less than 100 km. After 30 years of operation, such a Wood Vault facility would have sequestered 30 MtCO<sub>2</sub>, stored in 300 WVUs, occupying a land surface of 300 ha. The cost is estimated at $10–50/tCO<sub>2</sub> with a mid-point price of $30/tCO<sub>2</sub>. To sequester 1 GtCO<sub>2</sub> y<sup>−1</sup>, wood can be sourced from currently unexploited wood residuals on an area of 9 Mkm<sup>2</sup> forested land (9 million square kilometers, size of the US), corresponding to a low areal harvesting intensity of 1.1 tCO<sub>2</sub> ha<sup>−1</sup> y<sup>−1</sup>. Alternatively, giga-tonne scale carbon removal can be achieved by harvesting wood at a medium harvesting intensity of 4 tCO<sub>2</sub> ha<sup>−1</sup> y<sup>−1</sup> on 3 Mkm<sup>2</sup> of forest (equivalent to increasing current world wood harvest rate by 25%), or harvest on 0.8 Mkm<sup>2</sup> forest restored from past Amazon deforestation at high harvest intensity, or many combinations of these and other possibilities. It takes 1000 facilities as discussed above to store 1 GtCO<sub>2</sub> y<sup>−1</sup>, compared to more than 6000 landfills currently in operation in the US. After full closure of a Wood Vault, the land can be utilized for recreation, agriculture, solar farm, or agrivoltaics. A more distributed small operator model (Baby Vault) has somewhat different operation and economic constraints. A 10 gi
木材采伐和储存(WHS)是一种自然与工程相结合的混合方法，通过可持续地采伐木材并将其半永久性地储存以封存碳来应对气候变化。迄今为止，这项技术只在小规模示范项目中进行了有目的的测试。本研究旨在探索大规模开展WHS的具体途径。我们描述了一种建造木材储存设施的方法，名为wood Vault，它可以在特殊设计的外壳中掩埋数百万吨的木质生物质，以确保厌氧环境，从而防止木材腐烂。埋藏的木材进入一个准地质储层，预计将半永久保持完整。在许多环境中储存木材是可能的，导致七个版本的木库:(1)土墩(土坟或Barrow)，(2)地下(坑，采石场或矿山)，(3)超级库，(4)避难所，(5)水下淹没木材的AquaOpen或AquaVault，(6)干旱地区的DesertOpen或DesertVault，(7)南极洲等寒冷地区的FreezeVault。更小的尺寸也可以，命名为婴儿保险库。一个原型木库单元(WVU)占地1公顷(公顷，100米乘100米)的地表，高20米，储存高达10万立方米的木材，封存了10万吨二氧化碳。通过在25,000平方公里的面积上收集目前未使用的木材残留物(WR)，可以实现100万吨co2 y - 1的固存率，这相当于美国东部10个典型县的面积，对应的平均运输距离不到100公里。经过30年的运行，这样的Wood Vault设施将封存3000万吨二氧化碳，储存在300个wvu中，占地300公顷。成本估计为每吨二氧化碳10-50美元，中间价格为每吨二氧化碳30美元。为了吸收1 GtCO2 y - 1，木材可以来自9 Mkm2林地(900万平方公里，相当于美国的大小)目前未开发的木材残留物，对应于1.1 tCO2 ha - 1 y - 1的低面积采伐强度。另外，千兆吨规模的碳去除可以通过以下方式实现:在3 Mkm2的森林上以4 tCO2 ha - 1 y - 1的中等采伐强度采伐木材(相当于将目前的世界木材采伐率提高25%)，或在高采伐强度下从过去的亚马逊森林砍伐中恢复的0.8 Mkm2的森林采伐，或这些和其他可能性的多种组合。如上所述，需要1000个设施才能储存1亿吨二氧化碳，而美国目前有6000多个垃圾填埋场在运行。在木库完全关闭后，土地可以用于娱乐，农业，太阳能农场或农业发电。一个更分散的小运营商模式(Baby Vault)有一些不同的操作和经济约束。100千兆吨的固存率只吸收了陆地净初级生产量的5%，因此使用WHS是可能的，但需要非常谨慎，以确保可持续的木材采购。结论我们的技术和经济分析表明，利用多种木材资源，木库可以成为可靠固碳的有力工具。该技术的大部分部分已经存在，但它们需要在实践中有效地组合在一起。一些不确定因素需要解决，包括埋藏木材的耐久性如何取决于详细的储存方法和埋葬环境，但科学技术已经足够成熟，可以相信这种方法的实用性。高耐久性、可验证性和低成本使其在当前的全球碳市场上已经成为一个有吸引力的选择。储存在木库中的木质生物质不仅是应对当前气候危机的碳汇，而且是未来可用作生物质/生物能源和碳供应的宝贵资源。这种木材的使用量可以被仔细控制，以保持大气中所需的二氧化碳量，防止地球气候进入下一个冰河期，起到气候恒温器的作用。二氧化碳减少的时间大约是100年，而增加的时间是10年。由于二氧化碳的去除率受到生物圈生产力的限制，因此延迟行动意味着失去机会，因此有必要产生紧迫感。总之，WHS为管理我们的地球系统提供了一个工具，这个系统可能会永远存在于人类世。
{"title":"Wood Vault: remove atmospheric CO2 with trees, store wood for carbon sequestration for now and as biomass, bioenergy and carbon reserve for the future","authors":"Ning Zeng, Henry Hausmann","doi":"10.1186/s13021-022-00202-0","DOIUrl":"10.1186/s13021-022-00202-0","url":null,"abstract":"<div><h3>Background</h3><p>Wood harvesting and storage (WHS) is a hybrid Nature-Engineering combination method to combat climate change by harvesting wood sustainably and storing it semi-permanently for carbon sequestration. To date, the technology has only been purposefully tested in small-scale demonstration projects. This study aims to develop a concrete way to carry out WHS at large-scale.</p><h3>Results</h3><p>We describe a method of constructing a wood storage facility, named Wood Vault, that can bury woody biomass on a mega-tonne scale in specially engineered enclosures to ensure anaerobic environments, thus preventing wood decay. The buried wood enters a quasi-geological reservoir that is expected to stay intact semi-permanently. Storing wood in many environments is possible, leading to seven versions of Wood Vault: (1) Burial Mound (Tumulus or Barrow), (2) Underground (Pit, Quarry, or Mine), (3) Super Vault, (4) Shelter, (5) AquaOpen or AquaVault with wood submerged under water, (6) DesertOpen or DesertVault in dry regions, (7) FreezeVault in cold regions such as Antarctica. Smaller sizes are also possible, named Baby Vault. A prototype Wood Vault Unit (WVU) occupies 1 hectare (ha, 100 m by 100 m) of surface land, 20 m tall, stores up to 100,000 m<sup>3</sup> of wood, sequestering 0.1 MtCO<sub>2</sub>. A 1 MtCO<sub>2</sub> y<sup>−1</sup> sequestration rate can be achieved by collecting currently unused wood residuals (WR) on an area of 25,000 km<sup>2</sup>, the size of 10 typical counties in the eastern US, corresponding to an average transportation distance of less than 100 km. After 30 years of operation, such a Wood Vault facility would have sequestered 30 MtCO<sub>2</sub>, stored in 300 WVUs, occupying a land surface of 300 ha. The cost is estimated at $10–50/tCO<sub>2</sub> with a mid-point price of $30/tCO<sub>2</sub>. To sequester 1 GtCO<sub>2</sub> y<sup>−1</sup>, wood can be sourced from currently unexploited wood residuals on an area of 9 Mkm<sup>2</sup> forested land (9 million square kilometers, size of the US), corresponding to a low areal harvesting intensity of 1.1 tCO<sub>2</sub> ha<sup>−1</sup> y<sup>−1</sup>. Alternatively, giga-tonne scale carbon removal can be achieved by harvesting wood at a medium harvesting intensity of 4 tCO<sub>2</sub> ha<sup>−1</sup> y<sup>−1</sup> on 3 Mkm<sup>2</sup> of forest (equivalent to increasing current world wood harvest rate by 25%), or harvest on 0.8 Mkm<sup>2</sup> forest restored from past Amazon deforestation at high harvest intensity, or many combinations of these and other possibilities. It takes 1000 facilities as discussed above to store 1 GtCO<sub>2</sub> y<sup>−1</sup>, compared to more than 6000 landfills currently in operation in the US. After full closure of a Wood Vault, the land can be utilized for recreation, agriculture, solar farm, or agrivoltaics. A more distributed small operator model (Baby Vault) has somewhat different operation and economic constraints. A 10 gi","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00202-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4002423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-02DOI: 10.1186/s13021-022-00201-1
Benjamin M. Sleeter, Leonardo Frid, Bronwyn Rayfield, Colin Daniel, Zhiliang Zhu, David C. Marvin
Background
Quantifying the carbon balance of forested ecosystems has been the subject of intense study involving the development of numerous methodological approaches. Forest inventories, processes-based biogeochemical models, and inversion methods have all been used to estimate the contribution of U.S. forests to the global terrestrial carbon sink. However, estimates have ranged widely, largely based on the approach used, and no single system is appropriate for operational carbon quantification and forecasting. We present estimates obtained using a new spatially explicit modeling framework utilizing a “gain–loss” approach, by linking the LUCAS model of land-use and land-cover change with the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3).
Results
We estimated forest ecosystems in the conterminous United States stored 52.0 Pg C across all pools. Between 2001 and 2020, carbon storage increased by 2.4 Pg C at an annualized rate of 126 Tg C year−1. Our results broadly agree with other studies using a variety of other methods to estimate the forest carbon sink. Climate variability and change was the primary driver of annual variability in the size of the net carbon sink, while land-use and land-cover change and disturbance were the primary drivers of the magnitude, reducing annual sink strength by 39%. Projections of carbon change under climate scenarios for the western U.S. find diverging estimates of carbon balance depending on the scenario. Under a moderate emissions scenario we estimated a 38% increase in the net sink of carbon, while under a high emissions scenario we estimated a reversal from a net sink to net source.
Conclusions
The new approach provides a fully coupled modeling framework capable of producing spatially explicit estimates of carbon stocks and fluxes under a range of historical and/or future socioeconomic, climate, and land management futures.
{"title":"Operational assessment tool for forest carbon dynamics for the United States: a new spatially explicit approach linking the LUCAS and CBM-CFS3 models","authors":"Benjamin M. Sleeter, Leonardo Frid, Bronwyn Rayfield, Colin Daniel, Zhiliang Zhu, David C. Marvin","doi":"10.1186/s13021-022-00201-1","DOIUrl":"10.1186/s13021-022-00201-1","url":null,"abstract":"<div><h3>Background</h3><p>Quantifying the carbon balance of forested ecosystems has been the subject of intense study involving the development of numerous methodological approaches. Forest inventories, processes-based biogeochemical models, and inversion methods have all been used to estimate the contribution of U.S. forests to the global terrestrial carbon sink. However, estimates have ranged widely, largely based on the approach used, and no single system is appropriate for operational carbon quantification and forecasting. We present estimates obtained using a new spatially explicit modeling framework utilizing a “gain–loss” approach, by linking the LUCAS model of land-use and land-cover change with the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3).</p><h3>Results</h3><p>We estimated forest ecosystems in the conterminous United States stored 52.0 Pg C across all pools. Between 2001 and 2020, carbon storage increased by 2.4 Pg C at an annualized rate of 126 Tg C year<sup>−1</sup>. Our results broadly agree with other studies using a variety of other methods to estimate the forest carbon sink. Climate variability and change was the primary driver of annual variability in the size of the net carbon sink, while land-use and land-cover change and disturbance were the primary drivers of the magnitude, reducing annual sink strength by 39%. Projections of carbon change under climate scenarios for the western U.S. find diverging estimates of carbon balance depending on the scenario. Under a moderate emissions scenario we estimated a 38% increase in the net sink of carbon, while under a high emissions scenario we estimated a reversal from a net sink to net source.</p><h3>Conclusions</h3><p>The new approach provides a fully coupled modeling framework capable of producing spatially explicit estimates of carbon stocks and fluxes under a range of historical and/or future socioeconomic, climate, and land management futures.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00201-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4424936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The stock dynamics of harvested wood products (HWPs) are a relevant component of anthropogenic carbon cycles. Generally, HWP stock increases are treated as carbon removals from the atmosphere, while stock decreases are considered emissions. Among the different approaches suggested by the Intergovernmental Panel on Climate Change (IPCC) for accounting HWPs in national greenhouse gas inventories, the production approach has been established as the common approach under the Kyoto Protocol and Paris Agreement. However, the 24th session of the Conference of the Parties to the United Nations Framework Convention on Climate Change decided that alternative approaches can also be used. The IPCC has published guidelines for estimating HWP carbon stocks and default parameters for the various approaches in the 2006 Guidelines, 2013 Guidance, and 2019 Refinement. Although there are significant differences among the default methods in the three IPCC guidelines, no studies have systematically quantified or compared the results from the different guidelines on a global scale. This study quantifies the HWP stock dynamics and corresponding carbon removals/emissions under each approach based on the default methods presented in each guideline for 235 individual countries/regions.
Results
We identified relatively good consistency in carbon stocks/removals between the stock-change and the atmospheric flow approaches at a global level. Under both approaches, the methodological and parameter updates in the 2019 Refinement (e.g., considered HWPs, starting year for carbon stocks, and conversion factors) resulted in one-third reduction in carbon removals compared to the 2006 Guidelines. The production approach leads to a systematic underestimation of global carbon stocks and removals because it confines accounting to products derived from domestic harvests and uses the share of domestic feedstock for accounting. The 2013 Guidance and the 2019 Refinement reduce the estimated global carbon removals under the production approach by 15% and 45% (2018), respectively, compared to the 2006 Guidelines.
Conclusions
Gradual refinements in the IPCC default methods have a considerably higher impact on global estimates of HWP carbon stocks and removals than the differences in accounting approaches. The methodological improvements in the 2019 Refinement halve the global HWP carbon removals estimated in the former version, the 2006 Guidelines.
{"title":"The default methods in the 2019 Refinement drastically reduce estimates of global carbon sinks of harvested wood products","authors":"Chihiro Kayo, Gerald Kalt, Yuko Tsunetsugu, Seiji Hashimoto, Hirotaka Komata, Ryu Noda, Hiroyasu Oka","doi":"10.1186/s13021-021-00200-8","DOIUrl":"10.1186/s13021-021-00200-8","url":null,"abstract":"<div><h3>Background</h3><p>The stock dynamics of harvested wood products (HWPs) are a relevant component of anthropogenic carbon cycles. Generally, HWP stock increases are treated as carbon removals from the atmosphere, while stock decreases are considered emissions. Among the different approaches suggested by the Intergovernmental Panel on Climate Change (IPCC) for accounting HWPs in national greenhouse gas inventories, the production approach has been established as the common approach under the Kyoto Protocol and Paris Agreement. However, the 24th session of the Conference of the Parties to the United Nations Framework Convention on Climate Change decided that alternative approaches can also be used. The IPCC has published guidelines for estimating HWP carbon stocks and default parameters for the various approaches in the 2006 Guidelines, 2013 Guidance, and 2019 Refinement. Although there are significant differences among the default methods in the three IPCC guidelines, no studies have systematically quantified or compared the results from the different guidelines on a global scale. This study quantifies the HWP stock dynamics and corresponding carbon removals/emissions under each approach based on the default methods presented in each guideline for 235 individual countries/regions.</p><h3>Results</h3><p>We identified relatively good consistency in carbon stocks/removals between the stock-change and the atmospheric flow approaches at a global level. Under both approaches, the methodological and parameter updates in the 2019 Refinement (e.g., considered HWPs, starting year for carbon stocks, and conversion factors) resulted in one-third reduction in carbon removals compared to the 2006 Guidelines. The production approach leads to a systematic underestimation of global carbon stocks and removals because it confines accounting to products derived from domestic harvests and uses the share of domestic feedstock for accounting. The 2013 Guidance and the 2019 Refinement reduce the estimated global carbon removals under the production approach by 15% and 45% (2018), respectively, compared to the 2006 Guidelines.</p><h3>Conclusions</h3><p>Gradual refinements in the IPCC default methods have a considerably higher impact on global estimates of HWP carbon stocks and removals than the differences in accounting approaches. The methodological improvements in the 2019 Refinement halve the global HWP carbon removals estimated in the former version, the 2006 Guidelines.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8666044/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39717313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-07DOI: 10.1186/s13021-021-00199-y
Matthew J. Pringle, Steven G. Bray, John O. Carter
Background
Land clearing generates coarse woody debris (CWD), much of which ultimately becomes atmospheric CO2. Schemes for greenhouse gas accounting must consider the contribution from land clearing, but the timing of the contribution will have large uncertainty, due to a paucity of knowledge about the rate of CWD disappearance. To better understand above-ground CWD disappearance following a land clearing event—through the actions of microorganisms, invertebrates, wildfire, or deliberate burning—we combined statistical modelling with an archive of semi-quantitative observations (units of CWD %), made within Queensland, Australia.
Results
Using a generalised additive mixed-effects model (median absolute error = 14.7%), we found that CWD disappearance was strongly influenced by the: (i) number of years elapsed since clearing; (ii) clearing method; (iii) bioregion (effectively a climate-by-tree species interaction); and (iv) the number of times burned. Years-since-clearing had a strongly non-linear effect on the rate of CWD disappearance. The data suggested that disappearance was reverse-sigmoidal, with little change in CWD apparent for the first three years after clearing. In typical conditions for Queensland, the model predicted that it will take 38 years for 95% of CWD to disappear, following a land clearing event; however, accounting for uncertainty in the data and model, this value could be as few as 5 years, or > 100 years. In contrast, due to an assumption about the propensity of land managers to burn CWD, the official method used to assess Australia’s greenhouse gas emissions predicted that 95% of CWD will disappear in < 1 year.
Conclusions
In Queensland, the CWD generated by land clearing typically takes 38 years to disappear. This ultimately implies that a key assumption of Australia’s official greenhouse gas reporting—i.e. that 98% of CWD is burned soon after a clearing event—does not adequately account for delayed CO2 emissions.
{"title":"Modelling the disappearance of coarse woody debris, following a land clearing event","authors":"Matthew J. Pringle, Steven G. Bray, John O. Carter","doi":"10.1186/s13021-021-00199-y","DOIUrl":"10.1186/s13021-021-00199-y","url":null,"abstract":"<div><h3>Background</h3><p>Land clearing generates coarse woody debris (CWD), much of which ultimately becomes atmospheric CO<sub>2</sub>. Schemes for greenhouse gas accounting must consider the contribution from land clearing, but the timing of the contribution will have large uncertainty, due to a paucity of knowledge about the rate of CWD disappearance. To better understand above-ground CWD disappearance following a land clearing event—through the actions of microorganisms, invertebrates, wildfire, or deliberate burning—we combined statistical modelling with an archive of semi-quantitative observations (units of CWD %), made within Queensland, Australia.</p><h3>Results</h3><p>Using a generalised additive mixed-effects model (median absolute error = 14.7%), we found that CWD disappearance was strongly influenced by the: (i) number of years elapsed since clearing; (ii) clearing method; (iii) bioregion (effectively a climate-by-tree species interaction); and (iv) the number of times burned. Years-since-clearing had a strongly non-linear effect on the rate of CWD disappearance. The data suggested that disappearance was reverse-sigmoidal, with little change in CWD apparent for the first three years after clearing. In typical conditions for Queensland, the model predicted that it will take 38 years for 95% of CWD to disappear, following a land clearing event; however, accounting for uncertainty in the data and model, this value could be as few as 5 years, or > 100 years. In contrast, due to an assumption about the propensity of land managers to burn CWD, the official method used to assess Australia’s greenhouse gas emissions predicted that 95% of CWD will disappear in < 1 year.</p><h3>Conclusions</h3><p>In Queensland, the CWD generated by land clearing typically takes 38 years to disappear. This ultimately implies that a key assumption of Australia’s official greenhouse gas reporting—i.e. that 98% of CWD is burned soon after a clearing event—does not adequately account for delayed CO<sub>2</sub> emissions.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8650528/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39576737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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