Role In Climate Change Mitigation Research Articles

Biomass and soil carbon stocks in different forest types, Northwestern Ethiopia

ABSTRACT Attempts to mitigate global climate change have brought forestry into focus. Forests absorb carbondioxide from the atmosphere, alleviate global warming and contribute for rural livelihoods. To realize these benefits, there is a need to conserve the existing forests and establish new forests by using different restoration techniques. Information is scarce in Ethiopia on the carbon stock efficiency of the different forest types. Therefore, this study focused on comparing biomass and soil carbon stock potential of a natural forest, exclosure and Eucalyptus plantation. Primary and secondary data were collected and analysed using allometric equations. The results of this study stated that the total mean carbon stock for exclosure was 131.6 ± 45.5 t ha−1, for plantation 160.1 ± 35.8 t ha−1 and for natural forest 195.3 ± 58.3 t ha−1. The carbon stocks in each pool exhibited distinct patterns between the forest types. The above ground, below ground and soil organic carbon stock, increased in the natural forests and plantation, while the litter carbon stock showed decreasing towards the exclosure. Generally, the total natural forests store high amount of carbon and can play an important role in climate change mitigation. The carbon pool variation between different forest types was significant at (P < .05); however, there was no significance difference between forest types by aboveground and belowground biomass. From the main findings of this study, it is possible to conclude that climate change mitigation measures should consider expanding exclosure with the same priority as conserving natural forest and increasing plantation forests.

Grain legume production and their potential for sustainable agriculture in Botswana between 2008 and 2015: a review

Pulse crops are an integral component of arable agriculture in Botswana, particularly in subsistence farming. The benefits of these crops include provision of nutrition for both human beings and livestock, as well as environmental sustainability needs. Although they have a far reaching socio-economic impact, these benefits have not been adequately characterized for inclusion in endeavors of conservation agriculture in the country. Furthermore, data on pulses are often lumped together without identifying important pulse crops grown in Botswana. The objective of this paper was to review production of pulses and their potential as components in cropping systems and conservation agriculture in Botswana. The data used in this study were obtained from reports of Ministry of Agriculture and Food Security (MOA), Statistics Botswana, FAOSTAT and other literature sources. With the ongoing changes in climate and predicted increase in incidences of drought, pulses are among crops most relevant to sustainable agriculture. They are among the most versatile because of their variability in cropping duration from early to late maturity. Their consumption ranges from fresh forms to physiologically mature grain. Pulses play an important role in climate change mitigation through their ability to fix nitrogen, thus reducing dependency on organic and synthetic fertilizers. They use less water from relatively shallow soil and allow for stratified soil water use for companion crops in intercropping or conserve soil water for subsequent crops in rotations. Thus pulses improve both water and nutrient use efficiencies when included in cropping systems. Their production also has a low footprint in both carbon and water. Currently, pulses are among the few highly priced crops in Botswana markets and together with the possibility of replacement of imported grain, investments in their production can generate income and improve livelihood of both farmers and consumers in Botswana. Crop production management technology involves judicious use of integrated nutrient, pest and disease management; appropriate integrated management packages that include pulses can be promoted to ensure sustainable crop production under the adverse impacts of climate change.

Role of Biogas in Climate Change Mitigation and Adaptation

The study was carried out to analyze the role of biogas in climate change mitigation and adaptation. The study is based on the perception of 108 households of Muralibhanjyang VDC of Dhading district, Nepal. The study showed that amount of greenhouse gas emission was reduced by 3.82 tons per household per year of carbon dioxide equivalent by reducing 65.10% of fuel wood consumption per household per year. It was found that biogas has an effective role in climate change mitigation by reducing greenhouse gases emission. On installing 352 biogas plants, the number of trees saved in VDC was estimated to be 4083 per year which helps in mitigation and adaptation too. Adaptive capacity was determined on the basis of five different assets by giving the index value for each indicator ranging from one to four, which indicates low to very high value. The indicators of adaptive capacity for human, natural and social assets were obtained with values 2, 3.2, 3 and 1.2, 2.3, 2.1 for biogas users and non-users respectively. The physical and financial assets were obtained similar for both users and non-users (i.e. 3). There was significant difference between the adaptive capacity of biogas users and non-users where the average adaptive capacity value for biogas users was found to be 3.24 (high) and that of non-users was 2.8 (medium to high). It can be said that biogas plays a significant role in climate change adaptation by increasing adaptive capacity.

Liquid biofuels: not a long-term transport solution

Because of concerns about global climate change, possible global oil depletion, and because of potential benefits for both urban air pollution and rural employment and industry, many countries both in and out of the Organization for Economic Cooperation and Development (OECD), are promoting liquid biofuels as a replacement for oil-based transport fuels, and global output is rising steadily. In fact, bioenergy use in general is promoted, and is expected by many to play a major role in climate change mitigation. But bioenergy use in general faces competition for resources such as land, water and fertiliser from the two other general biomass uses, food production and biomaterials. Ethically, food production should take precedence over the other two uses (and at present all bioliquids are made from foodstuffs), and using biomass for biomaterials will in many situations reduce greenhouse gas emissions more than using the same amount of biomass for energy. Where a given amount of biomass is available for transport energy use, it will usually produce more greenhouse gas reductions per vehicle-km if used to produce electricity rather than liquid biofuels. Finally, there are signs that internal combustion engine vehicles could be phased out in the coming decades. If so, liquid biofuels will be phased out along with existing oil-based transport fuels. In conclusion, except for specialist uses, liquid biofuels do not appear to have a long-term future.

Preliminary estimate of carbon sequestration potential of Faidherbia albida (Delile) A.Chev in an agroforestry parkland in the Central Rift Valley of Ethiopia

ABSTRACTAgroforestry parklands are a common land-use in Ethiopia and many parts of the tropics. These systems play an important role in climate change mitigation and adaptation, through carbon (C) sequestration. However, C sequestration in both tree biomass and soil has not been extensively studied for parklands of the Central Rift Valley (CRV), Ethiopia. Therefore, here we sampled a small number of F. albida trees and soil from the Adulala watershed, CRV, to provide a preliminary estimate of the C sequestration potential of these systems. Mean above-ground total dry biomass of trees was estimated at 844 kg tree−1. Tree density was 5.80 ha−1, which corresponded to 2.45 t C ha−1 in above-ground biomass and 0.76 t C ha−1 below-ground; and 118 t C ha−1 in soil (0–80 cm depth) under trees, compared to 84 t C ha−1 in the soil of crop-only areas. We speculate that if tree density was increased to 100 trees ha−1, the rate of soil C sequestration could be estimated as 0.48 t C ha−1 year−1 for 42 years. Faidherbia albida tree density is sparse in the study area, but could be increased by encouraging farmers to protect planted seedlings or natural regeneration.

Spatio-temporal climate and agroclimate diversities over the Zagreb city area

The Zagreb city is rich in green urban infrastructure that has an important role in climate change mitigation and adaptation. Knowledge on climate change and agroclimate has an important role in planning of green areas. Therefore, the aim is to evaluate the temporal and spatial diversities of agroclimate indicators over Zagreb city. Warming and no change in mean annual precipitation, as well as prolonged vegetation periods and reduced evapotranspiration were observed at all locations in the recent 1991-2018 compared to reference 1961-1990 period. The results indicate different intensity in climate change of observed indicators and existance of diffrences in indicators between city centre, suburb and hilly slopes thatshould be considered while planning green urban infracture.

Carbon stocks and accumulation rates in Red Sea seagrass meadows

Seagrasses play an important role in climate change mitigation and adaptation, acting as natural CO2 sinks and buffering the impacts of rising sea level. However, global estimates of organic carbon (Corg) stocks, accumulation rates and seafloor elevation rates in seagrasses are limited to a few regions, thus potentially biasing global estimates. Here we assessed the extent of soil Corg stocks and accumulation rates in seagrass meadows (Thalassia hemprichii, Enhalus acoroides, Halophila stipulacea, Thalassodendrum ciliatum and Halodule uninervis) from Saudi Arabia. We estimated that seagrasses store 3.4 ± 0.3 kg Corg m−2 in 1 m-thick soil deposits, accumulated at 6.8 ± 1.7 g Corg m−2 yr−1 over the last 500 to 2,000 years. The extreme conditions in the Red Sea, such as nutrient limitation reducing seagrass growth rates and high temperature increasing soil respiration rates, may explain their relative low Corg storage compared to temperate meadows. Differences in soil Corg storage among habitats (i.e. location and species composition) are mainly related to the contribution of seagrass detritus to the soil Corg pool, fluxes of Corg from adjacent mangrove and tidal marsh ecosystems into seagrass meadows, and the amount of fine sediment particles. Seagrasses sequester annually around 0.8% of CO2 emissions from fossil-fuels by Saudi Arabia, while buffering the impacts of sea level rise. This study contributes data from understudied regions to a growing dataset on seagrass carbon stocks and sequestration rates and further evidences that even small seagrass species store Corg in coastal areas.

The implications of ignoring smallholder agriculture in climate-financed forestry projects: empirical evidence from two REDD+ pilot projects

ABSTRACTChanges in agricultural practices can play a pivotal role in climate change mitigation by reducing the need for land use change as one of the biggest sources of GHG emissions, and by enabling carbon sequestration in farmers’ fields. Expansion of smallholder and commercial agriculture is often one of the main driving forces behind deforestation and forest degradation. However, mitigation programmes such as REDD+ are geared towards conservation efforts in the forestry sector without prominently taking into account smallholder agricultural interests in project design and implementation. REDD+ projects often build on existing re- and afforestation projects without major changes in their principles, interests and assumptions. Informed by case study research and interviews with national and international experts, we illustrate with examples from Ethiopia and Indonesia how REDD+ projects are implemented, how they fail to adequately incorporate the demands of smallholder farmers and how this leads to a loss of livelihoods and diminishing interest in participating in REDD+ by local farming communities. The study shows how the conservation-based benefits and insecure funding base in REDD+ projects do not compensate for the contraction in livelihoods from agriculture. Combined with exclusive benefit-sharing mechanisms, this results in an increased pressure on forest resources, diverging from the principal objective of REDD+. We note a gap between the REDD+ narratives at international level (i.e. coupling development with a climate agenda) and the livelihood interests of farming communities on the ground. We argue that without incorporating agricultural interests and a review of financial incentives in the design of future climate finance mechanisms, objectives of both livelihood improvements and GHG emission reductions will be missed.Key policy insightsREDD+ is positioned as a promising tool to meet climate, conservation and development targets. However, these expectations are not being met in practice as the interests of smallholder farmers are poorly addressed.REDD+ policy developers and implementers need more focus on understanding the interests and dynamics of smallholder agriculturalists to enable inclusive, realistic and long-lasting projects.For REDD+ to succeed, funders need to consider how to better ensure long-term livelihood security for farming communities.

Good practices in local climate mitigation action by small and medium-sized cities; exploring meaning, implementation and linkage to actual lowering of carbon emissions in thirteen municipalities in The Netherlands

Cities around the world are gearing up to play a major role in climate change mitigation. However, concrete results – significant emissions reductions, expected from cities committed to mitigating climate change, are currently conspicuously absent. While there are several good practice guides available for large/mega cities there are little available for small and medium-sized ones (SMCs). In this paper the main research questions are, “When exploring local climate mitigation action among multiple small- and medium-sized cities, what actions are perceived as good practices?”, and “Are there any demonstrable effects linking them to achieving climate mitigation targets, and is this monitored?” A multiple case study research approach, using quali-quantitative mixed methods with multiple types of data sources, was used to analyze thirteen SMCs in the Netherlands. Results revealed twenty six good practices, with the majority exhibiting the characteristics of governing by enabling. However, no evidence was found that these good practices had been embedded in indicators or protocols, nor that they led to actual GHG emission reduction. In addition, action plans were found to be incomplete, in particular regarding implementation, and municipalities were found to work in isolation, with little inter-municipal collaboration. Moreover, whereas a monitor of local climate mitigation performance exists – using output and outcome indicators - it was found to be hardly known nor used among local policy makers. The results reveal a need to learn from good practices, to develop indicators that mirror these practices, and integrate them into local climate mitigation performance measurement tools. Currently, this is not the case, making it difficult to monitor local climate mitigation performance and progress vis-à-vis commitments made regarding the Paris Agreement.

Estimating carbon loss due to internal decay in living trees using tomography: implications for forest carbon budgets

The world’s forests sequester and store vast amounts of atmospheric carbon, playing a crucial role in climate change mitigation. Internal stem decay in living trees results in the release of stored carbon back into the atmosphere, constituting an important, but poorly understood, countervailing force to carbon sequestration. The contribution of internal decay to estimates of forest carbon stocks, though likely significant, has yet to be quantified, given that an accurate method for the non-destructive quantification of internal decay has been lacking. To that end, we present here a novel and potentially transformative methodology, using sonic and electrical resistance tomography, for non-destructively quantifying the mass of stored carbon lost to internal decay in the boles of living trees. The methodology was developed using 72 northern hardwood trees (Fagus grandifolia, Acer saccharum and Betula alleghaniensis) from a late-successional forest in northwestern Connecticut, USA. Using 105 stem disks corresponding to tomographic scans and excised from 39 of the study’s trees, we demonstrate the accuracy with which tomography predicts the incidence and severity of internal decay and distinguishes active decay from cavities. Carbon mass fractions and densities, measured and calculated from 508 stem disk wood samples corresponding to density categories, as predicted by sonic tomography, were used with stem disk volumes to generate indirect estimates of stem disk carbon mass accounting for decay, CSD, or assuming no decay, CND; these indirect estimates were compared with direct estimates calculated using stem disk mass, Cmass, and carbon mass fraction data. A comparison of three linear regression models with Cmass as the response variable and CSD or CND as the predictor variable ( R2 = 0.9733, Model 1; Cmass ∼ CND, ) demonstrates the accuracy with which CSD predicts Cmass. Forcing the regression through the origin resulted in improved metrics ( Model 2) for which a null hypothesis that y = x (Model 3) could not be rejected (). For each of the study’s 72 trees, two estimates of lower bole carbon mass—Cbole, accounting for decay, and assuming no decay—were obtained using all three models, with the difference between Cbole and used to estimate the proportion of the lower bole’s carbon lost to decay, Overall, tomography identified decay in 47 of the 72 trees, with values ranging from 0.13% to 36.7%. No decay was detected by tomography in the remaining 25 trees. The combined uncertainty due to both measurement error and model prediction error was ±2.1% for all three models. These results demonstrate the efficacy of the proposed methodology in non-destructively quantifying the carbon loss associated with internal decay in the boles of living trees, and its applicability to studies aimed at measuring internal decay rates, and more accurately quantifying forest carbon stocks.

Climate change impacts in Missouri State Parks: Perceptions from engaged park users

Frequent visitors to natural areas may be more receptive to climate change messages and more likely to act on their environmental values. To aid in developing targeted communication strategies, this exploratory study assessed how engaged state park users perceive climate change impacts and what they view as the agency role in climate change mitigation, education, and communication. Photo elicitation and semi-structured interviews were conducted with 18 members of the Missouri Parks Association (MPA), an advocacy group. While participants expressed concern about the threat of climate change to state parks, some doubted their ability to identify impacts. Despite this, participants accurately identified most of the regional threats predicted by experts, including increased flooding and drought, early blooming, invasive species, and extreme weather. Some reported that participation in the study inspired them to observe climate impacts more closely. Participants affirmed that state parks should lead climate change education and mitigation efforts, while acknowledging the challenges of addressing a politically charged subject. Regarding communication, MPA members recommend focusing on the science behind climate change and ecological mitigation. Although this study focused on Missouri state parks, results may be applicable to visitors in other Midwestern states. Management implications●Study participants supported managerial action on climate change adaptation through education and ecological management.●They acknowledged the political challenges managers face. This study supports presenting scientific evidence to the public and framing climate-change communication around specific, resource-related impacts, especially vegetation, wildlife, and landscape themes that visitors identify as locally salient.●Alternatively, park management could focus natural resource-based climate change education on the broader ecological benefits of environmental behavior.●Staff can also highlighting environmental efforts underway in parks, such as adoption of energy efficient technology and landscape management practices aimed at increasing ecological resilience.●Staff should be educated, empowered and encouraged to deliver locally-relevant climate change interpretation.

China's energy transition strategy at the city level: The role of renewable energy

Renewable energy plays a significant role in climate change mitigation and energy transition. China has established demonstration cities for energy transition and renewable energy development. However, the assessment system for these implementations is relatively blank. This study develops an index system to guide the construction of energy transition demonstration project and optimize energy transition development at the city level. The genetic algorithm-based analytic hierarchy process is employed to form energy transition strategies in the cities of Guiyang, Tongren, Zhangjiakou, and Nanning. The priority values of different renewable energy technologies are given for the cities. The results show that resource endowment is not the only driver for the priority due to the unique combination of influence factors in decision. The assessment system can help avoid the problems of single operating mode and over-investment in the process of energy transition so as to find the benchmark for energy structure adjustment. Finally, some policy recommendations are made for city-scale energy transition.

Critical sectors and paths for climate change mitigation within supply chain networks

Certain sectors and paths along supply chains play a critical role in climate change mitigation. We develope a consumption-based framework, which combines input–output analysis, a power-of-pull approach and structural path analysis, and applied it to supply chain networks derived from 2010 and 2012 Jing-Jin-Ji interregional input–output tables. The aim of this study is to identify (1) the key economic sectors for controlling carbon emissions and their changes, (2) the critical directions from a carbon-pulling sector to the emissions of key economic sectors, and (3) the paths with the largest carbon emissions flux in these critical directions. Our results show that the key sectors are from Hebei and Tianjin, more concentrated in Hebei. Most sectors have the largest pulling power over their own carbon emissions, and within-region connections dominated in the emission network, with a stronger tie between Beijing and the other two regions. Critical paths along carbon-pulling directions are located in tiers 0 and 1. Our framework can provide new insight into the creation of carbon emissions control policies.

Determinants of Above-Ground Biomass and Its Spatial Variability in a Temperate Forest Managed for Timber Production

The proper estimation of above-ground biomass (AGB) stocks of managed forests is a prerequisite to quantifying their role in climate change mitigation. The aim of this study was to analyze the spatial variability of AGB and its uncertainty between actively managed pine and unmanaged pine-oak reference forests in central Mexico. To investigate the determinants of AGB, we analyzed variables related to forest management, stand structure, topography, and climate. We developed linear (LM), generalized additive (GAM), and Random Forest (RF) empirical models to derive spatially explicit estimates and their uncertainty, and compared them. AGB was strongly influenced by forest management, as LiDAR-derived stand structure and stand age explained 80.9% to 89.8% of its spatial variability. The spatial heterogeneity of AGB varied positively with stand structural complexity and age in the managed forests. The type of predictive model had an impact on estimates of total AGB in our study site, which varied by as much as 19%. AGB densities varied from 0 to 492 ± 17 Mg ha−1 and the highest values were predicted by GAM. Uncertainty was not spatially homogeneously distributed and was higher with higher AGB values. Spatially explicit AGB estimates and their association with management and other variables in the study site can assist forest managers in planning thinning and harvesting schedules that would maximize carbon stocks on the landscape while continuing to provide timber and other ecosystem services. Our study represents an advancement toward the development of efficient strategies to spatially estimate AGB stocks and their uncertainty, as the GAM approach was used for the first time with improved results for such a purpose.

Capturing complexity: Forests, decision-making and climate change mitigation action

Managed forests can play an important role in climate change mitigation due to their capacity to sequester carbon. However, it has proven difficult to harness their full potential for climate change ...

Carbon storage dynamics of temperate freshwater wetlands in Pennsylvania

Healthy wetlands play a significant role in climate change mitigation by storing carbon that would otherwise contribute to global warming, leading to the reduction of water and food resources as well as more extreme weather phenomena. Investigating the magnitude of carbon storage potential of different freshwater wetland systems using multiple ecological indicators at varying spatial scales provides insight and justification for selective wetland restoration and conservation initiatives. We provide a holistic accounting of total carbon values for 193 wetland sites, integrating existing carbon algorithms to rapidly assess each of the following carbon pools: above-ground, below-ground, soil, woody debris, shrub cover, and herbaceous cover. Aspects of soil, vegetation, and ecosystem characteristics and stressors were measured to obtain an overall understanding of the ecosystems ability to store carbon (long-term) along a gradient of human disturbance. Based on a review of the literature, methods were prioritized based on the initial data available from field measurements as well as their practicality and ease in replicating the process in the future. Lacustrine human impounded (88.7 ± 18.0 tC/ha), riverine beaver impounded (116.2 ± 29.4 tC/ha), riverine upper perennial (163.3 ± 11.8 tC/ha), riverine lower perennial (199.2 ± 24.7 tC/ha), riverine headwater complex (159.5 ± 22.2 tC/ha), perennial/seasonal depression (269.6 ± 42.4 tC/ha), and slope (162.2 ± 14.6 tC/ha) wetland types were compared. Overall results showed moderate variability (9.33–835.95 tC/ha) for total carbon storage values across the wetland types, with an average total carbon storage of 174.6 ± 8.8 tC/ha for all wetlands. Results show that carbon storage was significantly higher (p = 0.002) in least disturbed wetland sites. Apart from perennial/seasonal depression wetlands, all reference standard wetlands had greater carbon storage, less disturbance impact, and a greater extent of forest cover than non-reference wetlands. Carbon storage values calculated were comparable to published literature.

Low blue carbon storage in eelgrass (Zostera marina) meadows on the Pacific Coast of Canada.

Seagrass habitats provide important ecosystem services, including their ability to take up and store substantial amounts of organic carbon, known as ‘blue carbon.’ However, the paucity of geospatial and carbon storage information along the Pacific Coast of Canada hinders the inclusion of blue carbon storage data in conservation planning and policy development in coastal habitats. We assessed the carbon storage and accumulation rates in three eelgrass (Zostera marina) meadows in southern Clayoquot Sound on the Pacific Coast of British Columbia. The intertidal and subtidal portions of each meadow were mapped and sampled to estimate eelgrass density, biomass, and carbon, and sediment cores were analyzed to estimate sediment carbon storage and accumulation rates. Aboveground biomass measurements were consistent with estimates for Z. marina in other regions, with average aboveground carbon biomass estimates of 16.78 g C m-2 and 16.25 g C m-2 in the intertidal and subtidal areas, respectively. However, the estimated aboveground to belowground biomass ratio was an order of magnitude higher than for seagrass species in temperate/tropical areas, largely because belowground biomass was up to 10 times lower than for other Z. marina meadows, averaging 6.17 g C m-2 and 5.03 g C m-2 in the intertidal and subtidal zones, respectively. Sediment carbon concentrations did not exceed 1.30%Corg, and carbon accumulation rates ranged from 2.90–39.61 g Corg m-2 yr-1, decreasing with depth and averaging 10.8 ± 5.2 g Corg m-2 yr-1. While sediment carbon stocks were generally higher in the eelgrass meadows relative to non-vegetated reference sites, carbons stocks averaged 1343 ± 482 g Corg m-2, substantially less than global averages. These carbon results confirm that eelgrass does contribute to carbon storage in Clayoquot Sound but at lower rates than identified for more tropical seagrasses. By improving the quantification of site-specific carbon dynamics, eelgrass’ role in climate change mitigation and conservation planning can be assessed.

Food for Hope: The Role of Personal Resources in Farmers’ Adoption of Green Technology

Innovative technologies are expected to play a significant role in climate change mitigation and adaptation within the agriculture sector and in global food security. Clearly, however, the value of technological innovations in the agriculture sector is premised on their adoption. Therefore, understanding why farmers differ in their adoption of innovative green technologies is important. In the following paper, we review current literature and set the theoretical framework for suggesting that three important personal resources correlate with agricultural technology adoption: positive emotions, character strengths (including specific ones), and cognitive goal-oriented hope. This study constitutes an important theoretical basis for future practical recommendations for environmental policy, positive psychology, and innovation adoption that may help narrow some of the gaps in technology adoption rates. In addition to its theoretical innovation, the importance of this study lies in its practical value: we focus on variables that are influenced through policy, education, and communication. The theoretical connections between positive psychology and environmental studies emerging from this study should be developed and explored. We hope that this new perspective will motivate future research on these factors within diverse farming communities across different nations.

Life-cycle carbon budget of China's harvested wood products in 1900–2015

Harvested wood products (HWP) are essential carbon pool of the forestry sector and can play an important role in climate change mitigation. Since the 10th Conference of Parties to the United Nations Framework Conversion on Climate Change in 2009, HWP have been required to be included in forest management as an additional carbon pool in national greenhouse gas (GHG) inventory reports. China is the largest consumer of end-use HWP and the largest importer of primary HWP in the world. Thus, the carbon stocks and emissions of China's HWP must be accurately assessed for evaluating their contribution to the climate change mitigation potential of global HWP. We developed an analysis framework by using Stock-Change Approach to estimate China's HWP carbon stocks/emissions from a life-cycle perspective, which covers three HWP life-cycle stages, namely, manufacture, end use, and end-of-life disposal. Using this framework, we produced the first-ever life-cycle carbon budget for HWP consumed by China in the period 1900–2015, based on a comprehensive analysis of China-specific data. From 1900 to 2015, total wood fiber input to the HWP carbon system in China was estimated to be 8049 teragrams of carbon dioxide-equivalent (Tg CO2-eq). Of the total wood fiber input, discarded mill residue, in-use HWP, and HWP disposed of at solid waste disposal sites retained 513, 3284, and 659 Tg CO2-eq of carbon, respectively, with the remaining 3591 Tg CO2-eq of wood carbon released back to the atmosphere. Of the total emission, combustion and decomposition of mill residue, burning of fuelwood, and combustion and decomposition of retired HWP accounted for 36.5%, 24.6%, and 38.9%, respectively. Landfill methane emissions were estimated to be 780 Tg CO2-eq after considering the global warming potential of this greenhouse gas. The net HWP carbon stocks, the sum of the carbon retained by discarded mill residue and the carbon stocks of HWP in use and in landfills, minus landfill methane emissions, increased from 297 Tg CO2-eq in 1950 to 4456 Tg CO2-eq in 2015.

Geospatial analysis of near-term potential for carbon-negative bioenergy in the United States

Bioenergy with carbon capture and storage (BECCS) is a negative-emissions technology that may play a crucial role in climate change mitigation. BECCS relies on the capture and sequestration of carbon dioxide (CO2) following bioenergy production to remove and reliably sequester atmospheric CO2 Previous BECCS deployment assessments have largely overlooked the potential lack of spatial colocation of suitable storage basins and biomass availability, in the absence of long-distance biomass and CO2 transport. These conditions could constrain the near-term technical deployment potential of BECCS due to social and economic barriers that exist for biomass and CO2 transport. This study leverages biomass production data and site-specific injection and storage capacity estimates at high spatial resolution to assess the near-term deployment opportunities for BECCS in the United States. If the total biomass resource available in the United States was mobilized for BECCS, an estimated 370 Mt CO2⋅y-1 of negative emissions could be supplied in 2020. However, the absence of long-distance biomass and CO2 transport, as well as limitations imposed by unsuitable regional storage and injection capacities, collectively decrease the technical potential of negative emissions to 100 Mt CO2⋅y-1 Meeting this technical potential may require large-scale deployment of BECCS technology in more than 1,000 counties, as well as widespread deployment of dedicated energy crops. Specifically, the Illinois basin, Gulf region, and western North Dakota have the greatest potential for near-term BECCS deployment. High-resolution spatial assessment as conducted in this study can inform near-term opportunities that minimize social and economic barriers to BECCS deployment.