Search

The reliance on petroleum derivatives and the increasing trend of fuel consumption in the transport sector have brought attention to biofuels as a measure to reduce greenhouse gas (GHG) emissions, enhance energy security and boost economic development. The incentive for utilizing biofuels is their potential to reduce carbon dioxide (CO2) emissions compared to fossil fuels. Biofuels are considered to be carbon-neutral, regarding the direct CO2 emissions associated with their combustion, on the grounds that the carbon dioxide absorbed by the plants through photosynthesis is equivalent to the CO2 released during their combustion. However, a part of the carbon of biofuels may have a fossil origin and therefore, it is responsible for "non-neutral" CO2 emissions. This was recognized by the Intergovernmental Panel on Climate Change (IPCC) in its guidelines for greenhouse gas inventories. Nevertheless, specific guidance of how to estimate fossil CO2 emissions per each type of biofuel, in order to facilitate the work of emission inventory compilers and practitioners, is neither available in the IPCC guidelines nor in the scientific literature. The purpose of this paper is to define a higher tier method to estimate the associated CO2 emissions with the fossil carbon content of biofuels, aiming to cover all possible biofuel types that are mainly used nowadays to replace diesel and gasoline. [ABSTRACT FROM AUTHOR]

Improving soil management to enhance soil carbon sequestration (SCS)—a cost-efficient carbon dioxide (CO2) removal approach—can result in co-benefits or trade-offs. Here we address this issue by setting up a modeling framework for Switzerland that combines soil carbon (C) storage, food production and agricultural greenhouse gas (GHG) emissions. The link to food production is crucial because crop types and livestock numbers influence soil organic C (SOC) stocks, through soil C inputs from plants and manure. We estimated SCS rates for the years 2020–2050 for three scenarios, each with two variants for biochar: cover cropping (0.30 t CO2 equivalents [CO2-eq] ha−1 yr−1), biochar addition (0.36–1.8 t CO2-eq ha−1 yr−1) and agroforestry-biochar addition (2.2–2.3 t CO2-eq ha−1 yr−1). Different limiting factors (land and biomass availability, population growth) affected SCS rates and indicated that they cannot be sustained until 2100 under all scenarios (cover cropping: 0.10 t CO2-eq ha−1 yr−1 [2051–2100]; biochar addition: 0.35–1.8 t CO2-eq ha−1 yr−1; agroforestry-biochar addition: 1.0–1.7 t CO2-eq ha−1 yr−1). This information together with the associated GHG emissions is critical for planning net zero strategies and highlights the importance of integrated assessments that capture links between SCS and the food system. [ABSTRACT FROM AUTHOR]

Partitioning the contributions of climate, economic growth, and policy to a region's carbon flows is an important process for the Chinese government seeking to optimize their regional development policies to achieve carbon neutrality by 2060. A combination of the carbon emission analysis and human appropriation of net primary production (HANPP) framework was applied to a village in the Lhasa river valley, Tibet, to quantify the contributions of these different factors to carbon flows and neutrality. From 2010 to 2019, the average annual net sequestration of CO2 was 374.9 g CO2 m−2 a−1. Changes in climate conditions and the regional policy of Grassland Ecological Protection Subsidy and Reward increased carbon sequestrations by 409.5 and 25.7 g CO2 m−2 a−1, respectively. Socioeconomic development, policies for reducing poverty, and promotion of forage production led to the increase in CO2 emissions by 103.5, 88.8, and 4.3 g CO2 m−2 a−1, respectively. The cumulative CO2 emissions (including HANPP) caused by land use were 298.92 Tg CO2 (2479.63 g CO2 m−2; 1 Tg = 1012 g), while the cumulative CO2 emissions due to energy use were only 11.22 Tg CO2 (93.07 g CO2 m−2), equal to 3.75% of the CO2 emissions driven by land use. Livestock grazing and cropland cultivation were the two main land use factors affecting the carbon balance. We argue that unhooking economic growth from traditional nomadic animal husbandry and lifestyles through policy optimizations would highly contribute the carbon neutrality in Tibet. [ABSTRACT FROM AUTHOR]

How relevant is the role of CO2 from harvested wood products (HWPs) for the Brazilian GHG emission balance? The C stocks and CO2 emissions and removals from the HWPs in Brazil during 1900–2016 were evaluated using three methodological approaches: stock-change approach (SCA), production approach (PA), and stock-change of domestic origin (SCDOA). Data from the FAO’s FAOSTAT system on production, import and export of semi-finished products (sawnwood, wood-based panels and paper/paperboard) were analyzed, considering distinct land-use activities: deforestation (D), forest management (FM) and afforestation/reforestation (A/R). Two scenarios to evaluate the effect of HWPs from D were evaluated. The C stock in HWPs in 2016 reached 252 Mt C, by SCA. Contributions to C storage historically were higher from sawnwood, but wood-based panels and paper/paperboard have recently outperformed it. A/R is the major activity responsible for C storage in HWPs. The CO2 removal by HWPs was 521 Mt during 1990–2016, which corresponds to 1.1% of the country’s emissions in the same period. It was concluded that Brazil has become a major producer and wood consumer and that HWPs are allies for a positive C balance and fulfillment of the commitments assumed by the country regarding climate change. Abbreviations AFOLUAgriculture, forestry and other land uses A/RAfforestation/reforestation DDeforestation FAOUnited Nations Food and Agriculture Organization FMForest management HWPsHarvested wood products IBGEBrazilian Institute of Geography and Statistics PAProduction approach PEVSPlant extraction and forestry SCAStock-change approach SCDOAStock-change of domestic origin approach

Based on provincial panel data from 2000 to 2014, this paper measured the total factor energy efficiency by adopting the dynamic slacks-based measure model, and then employed the spatial econometric model to analyze the impact of regional mitigation of carbon dioxide on energy efficiency from both intra-regional and inter-regional perspectives in China. The results show the following: first, the average of total factor energy efficiency presents a rising trend from 2000 to 2014, and it shows a significant difference among regions. Second, the direct effect of carbon productivity on energy efficiency is positive, but the indirect effect is negative. The share ratio of direct and indirect effects is 1: −0.96; the total effect is positive but insignificant. Based on this conclusion, the paper provides some relevant policy suggestions and measures for regionally saving energy resources and relieving environmental constraints.

By storing carbon (C), soil provide natural solutions to climate change. However, implementing C sequestration practices on a large scale is complex because sequestration rates vary with climatic conditions, soil types and agricultural management. Researchers face challenges identifying effective C sequestration practices in arid and semi-arid regions because precipitation limits plant biomass production. We discuss the "more carbon per drop" approach to enhance C sequestration in a water-limited environment. This approach emphasizes increasing soil organic carbon (SOC) sequestration and reducing greenhouse gas emissions by enhancing water use efficiency and soil water storage. Agricultural strategies that increase the amount and diversity of C inputs, improve nutrient availability for crops, and minimize soil disturbance can simultaneously sequester soil C and enhance soil water storage. Strategies for enhancing SOC sequestration while increasing soil water storage could benefit farmers in arid and semi-arid regions because they can maintain a net-zero or net-negative C footprint. Therefore, implementing policies that promote SOC sequestration and soil water storage could provide natural climate solutions to the vast areas of the world facing water limitations. SOC sequestration in a water-limited environment is challenging; more carbon per drop simultaneously increases SOC and soil water storage The social, economic, and cultural challenges of changing management practices for C sequestration could be addressed through a diverse set of incentives Incentivizing conventional SOC sequestration practices while investing in research and development of new frontier technologies could provide a win–win solution [ABSTRACT FROM AUTHOR]

Soil carbon (C) plays a key role in mitigating and adapting to global climate change. In-situ soil C measurement has faced many challenges including those related to aerial coverage, economics, accuracy, and availability. The concept of paying for C credits to farmers and ranchers who sequester C has necessitated availability of improved methods for in-situ measurement of soil C at large scale. The objective of this review is to i) synthesize the existing knowledge on methods of soil C measurement, (ii) discuss their pros and cons (iii) review key factors affecting soil C measurement, and (iv) propose integrated data driven method of soil C measurement using Machine Learning (ML)/Artificial Intelligence (AI) approach. Lab and in-situ techniques of soil C determination are expensive, time consuming and lack scale. Although, remote sensing (RS) technique is used to predict soil C maps at large scale, it also lacks accuracy and requires high technical knowledge of image processing. Soil C measurements are affected by key soil physical properties such as color, texture, moisture content, bulk density etc. Thus, these factors must be considered while developing innovative methods for soil C determination. A prototype handheld device is proposed to measure these four properties along with Near Infrared (NIR) reflectance of soil that store data in cloud using Wi-Fi signals. A data driven model is proposed that can use the data from handheld devices and integrate with drone imagery to create soil C map of the entire field and satellite imagery for the entire region. This model uses data from in-situ soil C measurement technique in integrated form and soil C map can be updated every time the handheld device is used at different locations of the field. [ABSTRACT FROM AUTHOR]

Despite recent voluntary climate change reporting (VCCR) initiatives, such as the Carbon Disclosure Project (CDP), Chinese companies continue to lag behind their global counterparts. This research contributes to the existing literature examining the effects of CEO background (specifically academic, foreign and political background) on corporate decisions to engage in VCCR. The data sample consists of Chinese listed companies that participated in CDP surveys during 2010–2017 (1041 final firm-year observations). The study's descriptive findings reveal that most Chinese companies are reluctant to report their climate change information to the CDP as only 12% of Chinese companies participated in the CDP annual survey during the study period. However, using a logistic regression model, we find that CEOs with academic experience, foreign exposure and political connections positively affect firms' decisions to engage in VCCR. The results remain robust when we use the propensity score matching technique to account for sample selection problems. Overall, the results are interpreted within the theoretical insights of the upper echelons perspective. [ABSTRACT FROM AUTHOR]

The inventory of the carbon (C) pools in Africa's ecosystems is not well documented, although it is crucial to support climate mitigation policies. We quantified the C stocks in plant biomass, woody necromass, litter and soil (0–30 and 30–100 cm) for the five main land uses – forest, tree plantation, young and adult palm groves, croplands – of Ferralsols on the Allada plateau in southeast Benin. Forests have the highest total C stocks (389 ± 54 Mg C ha−1) compared with other land uses (222 ± 33, 154 ± 6, 105 ± 2, 77 ± 3 Mg C ha−1 in tree plantations, adult palm groves, young palm groves and croplands, respectively). The C stocks are higher in the biomass than in the soil (0–100 cm), e.g. in the forest, stocks were 279 ± 54 Mg C ha−1 in the biomass versus 83 ± 2 Mg C ha−1 in the soil. Differences of soil C stocks between land uses are low (≈ 28 Mg C ha−1) and concentrated in topsoils. The structure and species diversity of the forest partly explained the variability and the high C biomass compared to tree plantations. Type of forest and plantations is important to consider in conserving C stocks in landscapes. [ABSTRACT FROM AUTHOR]

Comparing forest and harvested wood product carbon (C) stocks and accumulation among forest management treatments commonly applied in managed forests is needed to inform planning and policy decisions for C objectives. Therefore, pre- and post-harvest C stocks were quantified and C accumulation was projected over a 31-year period (to ∼2050) among forest management treatments that were applied on a subset (n = 3) of the Maine Adaptive Silviculture Network installations in northern Maine, USA. These installations included mature, second-growth forests composed of northern hardwood and hardwood-dominated mixedwood stands. Before treatments were initiated, average aboveground live tree C stocks ranged from 67.1 to 99.7 Mg ha−1. For the aboveground portions of live trees, dead wood and harvested wood products, the projected average annual net change in C (AAC) was 0.232 ± 1.164 Mg ha−1 year−1 (mean ± standard deviation). Models of projected AAC indicated that less biomass removal during harvests and greater representation of tree species with low tolerance of shade were associated with positive AAC values. The results emphasize the importance of leveraging multiple harvesting strategies to achieve C objectives, including consideration of forest reserves and using targeted yet operationally feasible silvicultural treatments that promote forest resilience relative to climate change. [ABSTRACT FROM AUTHOR]

Wildfires have been an important process affecting forests and rangelands worldwide. In the Mediterranean region, wildfires burn about half a million hectares of forest and scrubland every year. Fuel loads are the main factor controlling fire risk and its propagation. The reduction of fuel loads by grazing could help to decrease the spread and intensity of wildfires in this region. This study aims to assess the contribution of sheep grazing on fuel load management and their role to the mitigation of wildfire greenhouse gas (GHG) emissions. The methodological approach is based on a simulation of the grazing pressure required to reduce a given quantity of fuel, under the assumption that if it is not consumed, it becomes fuel. Following, a simulation model was designed to estimate the total GHG emissions prevented through grazing, by reducing the risk of fire. These emissions were estimated based on the Intergovernmental Panel on Climate Change (IPCC) framework. The accumulated fuels were estimated to be 3126.65 kg dry matter (DM) ha−1 and the biomass potentially consumed by sheep was 1416.03 kg DM ha−1 yr−1, corresponding to 45.29% of accumulated fuel loads. Our findings suggest a value of 3.88 sheep ha−1 day−1 as the ideal to reduce 4833.63 kg CO2eq ha−1 yr−1 of emissions, distributed between CO2 (−2221.76 kg CO2eq ha−1 yr−1; 45.96%), NOx (−1873.41 kg CO2eq ha−1 yr−1; 38.76%), CO (−454.55 kg CO2eq ha−1 yr−1; 9.40%), CH4 (−186.35 kg CO2eq ha−1 yr−1; 3.86%) and N2O (−97.56 kg CO2eq ha−1 yr−1; 2%). The results of this study also underline that livestock can help to mitigate climate change in areas prone to wildfires. [ABSTRACT FROM AUTHOR]

The reliance on petroleum derivatives and the increasing trend of fuel consumption in the transport sector have brought attention to biofuels as a measure to reduce greenhouse gas (GHG) emissions, enhance energy security and boost economic development. The incentive for utilizing biofuels is their potential to reduce carbon dioxide (CO2) emissions compared to fossil fuels. Biofuels are considered to be carbon-neutral, regarding the direct CO2 emissions associated with their combustion, on the grounds that the carbon dioxide absorbed by the plants through photosynthesis is equivalent to the CO2 released during their combustion. However, a part of the carbon of biofuels may have a fossil origin and therefore, it is responsible for “non-neutral” CO2 emissions. This was recognized by the Intergovernmental Panel on Climate Change (IPCC) in its guidelines for greenhouse gas inventories. Nevertheless, specific guidance of how to estimate fossil CO2 emissions per each type of biofuel, in order to facilitate the work of emission inventory compilers and practitioners, is neither available in the IPCC guidelines nor in the scientific literature. The purpose of this paper is to define a higher tier method to estimate the associated CO2 emissions with the fossil carbon content of biofuels, aiming to cover all possible biofuel types that are mainly used nowadays to replace diesel and gasoline.

The Cuajimalpa campus of the Autonomous Metropolitan University (UAM) is located in the western region of Mexico City. In 2016, its global average population (students, faculty and staff) was around 2750 people. Campus policies include sustainability as one of its main aims. To evaluate and eventually reduce the environmental impact of the campus, its greenhouse gas (GHG) inventory was assessed and the carbon footprint was calculated, using the GHG protocol (GHGP): Scope 1: direct GHG emissions; Scope 2: indirect GHG emissions; and Scope 3: other indirect GHG emissions, on a calendar year basis. Scope 1 includes mobile and stationary sources and leakage of refrigerants; Scope 2 includes electrical energy usage; Scope 3 includes consumption of paper, food, water, gases, cleaning products, solvents, wastewater treatment, municipal and hazardous wastes and academic travel. In 2016, the campus produced around 3000 tons of CO2 equivalent, with Scope 1, 2 and 3 accounting for 4%, 24% and 72%, respectively. Emissions analysis by activity indicated 51% for commuting; 24% for electricity usage; 14% for academic travel; 11% for other activities. The inventory will aid the establishment of policies for reduction and mitigation of GHG, resulting in environmental and potential economic benefits.

A reduction in the CO2 emission intensity (ton per gross domestic product) from a base year to a target year with different rates of reduction in each individual year can yield different cumulative CO2 emissions over time, which could have different effects on the climate. In this paper, an indicator is proposed to measure the extent to which the cumulative CO2 emissions are generated by a specific reduction trajectory of CO2 emission intensity, especially for emerging economies with a relatively higher economic growth rate. The proposed indicator is important for less-developed countries and regions in which economic growth is heavily reliant on energy and in which significant potential exists for improvement of energy efficiency. The indicator is applied to evaluate the CO2 emission reduction performance in China’s 12th Five-Year Plan period, and the result is not encouraging, especially when the likely gap between the energy conservation goals and temperature goals is further examined. Mitigation goals should be set by considering not only the performance in the final year, but also the reduction in cumulative emissions over the evaluation period.

This study analyzes the effect of the penalty system in an emission trading scheme (ETS) on pricing and abatement activities. No previous studies have shown that the ways of penalizing for unretired permits specifically might have a crucial role in permit pricing. Most studies show that the penalty rate is fixed, as in the EU-ETS, but this paper focuses on the mechanism that price affects penalty and this again affects price. The Korea ETS case is examined as an example in which the per-unit penalty for unretired permits is determined by the average market price. Based on simple analytical modeling, this study derives policy implications that differ from the pre-determined penalty rate system: that the penalty system linked with market prices causes downward pressure on market prices, that the maximum rate is not very meaningful in pricing, that the multiplication level of the penalty rate affects market prices, and that this price-linked penalizing system can affect the overall level of abatement.

Climate change poses one of the greatest challenges of any kind facing human society today. It is a threat to the availability of land, air, food and water – all of which are key constituents of the Sustainable Development Goals. Much of the observed change in climate is anthropogenic in nature. Hence, it is imperative for all human societies to make a positive contribution in spreading greater public awareness and engagement for creating a more sustainable world. Due to the lack of a reliable carbon footprint measurement system specific to Indian conditions, a robust multimedia application has been developed and designed in the form of India's first certified Carbon Footprint Calculator. Titled the ‘Yo!Green’ Carbon Calculator, it allows individuals and households to measure their greenhouse gas emissions, and recommends simple mitigation measures based on their emission profile. This paper presents the methodologies, assumptions and processes which have been adopted to develop the Yo!Green Carbon Calculator.