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In the global context, countries must reduce carbon dioxide emissions to "net zero" by 2050 to limit global warming to 1.5 °C above pre-industrial levels. China's Nationally Determined Contributions (NDCs) are to peak carbon dioxide emissions by 2030 and achieve the carbon neutrality target by 2060. To monitor the achievements of the NDCs, establishing an annual-based accounting mechanism is necessary to record the carbon stocks in China, especially for Blue Carbon. The paper aims to present China's first national-scale systematic Blue Carbon accounting for mangroves, salt marshes, and seagrasses, covering the accounting subjects of physical and monetary assets, as well as relevant indicators for investors. It focuses on the design of the accounting method and system, the selection of data categories applied to this system, and the application of China's Blue Carbon accounting based on this accounting system. Taking Blue Carbon accounting as a starting point, this paper analyses the restoration prospects of these ecosystems and their application potential for NDCs in China compared with the terrestrial ecosystems. The results indicate that mangroves are the most cost-effective type of ecosystem, even compared to terrestrial forests. Thus, the paper provides policymakers with a new perspective on the decision-making of carbon sequestration relevant decisions, aiming to promote the monitoring, restoration, and expansion of China's coastal blue carbon ecosystem through the establishment of a sound Blue Carbon accounting system, and to help achieve the carbon neutrality goal in China's NDCs through regular and systematic monitoring of its national Blue Carbon inventories. • China's coastal blue carbon ecosystems are carbon sources rather than carbon sinks. • Mangroves are the most cost-effective coastal blue carbon ecosystem compared to salt marshes and seagrass beds. • The Blue Carbon of mangroves is more cost-effective than the Green Carbon of terrestrial forests when meeting China's Nationally Determined Contributions target of increasing forest stocks. • Establishing guidelines for Blue Carbon data requirements will lay a scientific foundation for formulating strategies and policies to cope with global climate change. [ABSTRACT FROM AUTHOR]

Sub-Saharan Africa (SSA) experiences soil degradation, food and livelihood insecurity, environmental pollution and lack of access to energy. Biochar has gained international research attention, but few studies have investigated the potential of biochar to address the challenges in SSA. This paper seeks to identify and evaluate generic potential opportunities and constraints associated with biochar application in sub-Saharan Africa using Zimbabwe as case study. Specific objectives were to; (1) identify and quantify feedstocks for biochar production; (2) review literature on the biochar properties, and evaluate its potential applications in agriculture, environmental remediation and energy provision, and (3) identify research gaps, risks and constraints associated with biochar technology. Biochar feedstocks in Zimbabwe were estimated to be 9.9 Mton yr −1 , predominantly derived from manure (88%) and firewood (10%). This will yield 3.5, 1.7 and 3.1 Mton yr −1 of biochar, bio-oil and synthetic gas, respectively. Land application of the 3.5 Mton yr −1 of biochar (≈63% C) would sequester approximately 2.2 Mton yr −1 of soil carbon in Zimbabwe alone, while simultaneously minimizing the environmental and public health risks, and greenhouse gas emissions associated with solid organic wastes. Biochar potentially enhances soil and crop productivity through enhanced nutrient and soil moisture availability, amelioration of acidic soils and stimulation of microbial diversity and activity. Due to its excellent adsorption properties, biochar has potential applications in industrial and environmental applications including water and wastewater treatment, remediation and revegetation of contaminated soils and water. Biochar products have energy values comparable or higher than those of traditional biomass fuels; thereby making them ideal alternative sources of energy especially for poor households without access to electricity. Before the benefits of biochar can be realized in SSA, there is need to overcome multiple risks and constraints such as lack of finance, socio-economic constraints including negative perceptions and attitudes among both researchers and consumers, and environmental and public health risks. Therefore, there is need to conduct fundamental research to demonstrate the benefits of biochar applications, and develop policy framework and criteria for its production and subsequent adoption. [ABSTRACT FROM AUTHOR]

The present paper investigates the various features of NaOH aqueous solution when applied as an absorbent to capture carbon dioxide (CO2) emitted with relatively high concentration in the flue gas. The overall CO2 absorption reaction was carried out according to consecutive reaction steps that are generated in the order of Na2CO3 and NaHCO3. The reaction rate and capture efficiency were strongly dependent on the NaOH concentration in the Na2CO3 production range, but were constant in the NaHCO3 production step, irrespective of the NaOH concentration. The amount of CO2 absorbed in the solution was slightly less than the theoretical value, which was ascribed to the low trona production during the reaction and the consequent decrease in CO2 absorption in the NaOH solution. The mass ratio of absorbed CO2 that participated in the Na2CO3, NaHCO3, and trona production reactions was calculated to be 20:17:1, respectively. [Copyright &y& Elsevier]

Abstract: Using Cape York Peninsula, Queensland, Australia as a case study, this paper combines field sampling of woody vegetation with cost–benefit analysis to compare the social optimality of fire-assisted pastoralism with sustainable forestry. Carbon sequestration is estimated to be significantly higher in the absence of fire. Integration of carbon sequestration benefits for mitigating future costs of climate change into cost–benefit analysis demonstrates that sustainable forestry is a more socially optimal land use than fire-assisted pastoralism. Missing markets for carbon, however, imply that fire-assisted pastoralism will continue to be pursued in the absence of policy intervention. Creation of markets for carbon represents a policy solution that has the potential to drive land use away from fire-assisted pastoralism towards sustainable forestry and environmental conservation. [Copyright &y& Elsevier]

Terrestrial ecosystems have received considerable attention as a significant sink for organic carbon at regional to global scales. Previous studies were focused on assessment and quantification of carbon sinks for one ecotype, and few have worked on the interconnection of terrestrial sinks. In this paper, we synthesized the data from China's second national soil survey and direct measurements from 54 lakes. Meanwhile, we investigated the controlling factors of carbon accumulation dynamics in soils and lakes. Results showed varied spatial distribution of soil and lake organic carbon in different regions, and three storage modes were found. The storage mode of watershed collection was observed in the region of the Qinghai-Tibetan Plateau, while the northeast China and Yunnan-Guizhou Plateau revealed another storage mode of autochthonous deposition, and the mode of human activities affection was represented by the East Plain and Mongolia-Xinjiang Plateau. The spatial difference throughout China was regulated by various climate patterns, geological conditions and anthropogenic interference. Our results provide insights into carbon storage modes in various regions, and also inform strategies for enhancing global carbon sequestration and future mitigation policies towards global climate change. • Climate, topography and human activity regulate regional soil and lake carbon storage. • Three carbon storage modes based on relationship between soil and lake carbon. • Suggestions to enhance carbon sequestration through soil and lake management. [ABSTRACT FROM AUTHOR]