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The atmospheric concentration of CO2 is steadily increasing and causing climate change. To achieve the Paris 1.5 or 2°C target, negative emission technologies must be deployed in addition to reducing carbon emissions. The ocean is a large carbon sink but the potential of marine primary producers to contribute to carbon neutrality remains unclear.Here we review the alterations to carbon capture and sequestration of marine primary producers (including traditional 'blue carbon' plants, microalgae and macroalgae) in the Anthropocene, and, for the first time, assess and compare the potential of various marine primary producers to carbon neutrality and climate change mitigation via biogeoengineering approaches.The contributions of marine primary producers to carbon sequestration have been decreasing in the Anthropocene due to the decrease in biomass driven by direct anthropogenic activities and climate change. The potential of blue carbon plants (mangroves, saltmarshes and seagrasses) is limited by the available areas for their revegetation. Microalgae appear to have a large potential due to their ubiquity but how to enhance their carbon sequestration efficiency is very complex and uncertain. On the other hand, macroalgae can play an essential role in mitigating climate change through extensive offshore cultivation due to higher carbon sequestration capacity and substantial available areas. This approach seems both technically and economically feasible due to the development of offshore aquaculture and a well‐established market for macroalgal products.Synthesis and applications. This paper provides new insights and suggests promising directions for utilizing marine primary producers to achieve the Paris temperature target. We propose that macroalgae cultivation can play an essential role in attaining carbon neutrality and climate change mitigation, although its ecological impacts need to be assessed further. [ABSTRACT FROM AUTHOR]

The continued rise in anthropogenic carbon dioxide (CO2) emissions and increase in atmospheric CO2 concentration has led to calls from experts, including the Intergovernmental Panel on Climate Change that has estimated that global warming needs to be limited to 1.5 °C above preindustrial levels to avoid the worst effects of climate change, and that carbon neutrality would need to be achieved globally by 2050 to meet this target. Achieving carbon neutrality by mid‐century will rely on successful implementation and widespread adoption of technologies for reducing emissions from large point sources of CO2, direct CO2 capture from the air, as well as storage and utilization technologies that would convert CO2 to a form that would ensure safety and permanency of storage. In this paper, engineering solutions for CO2 capture, utilization, and storage are reviewed with a focus on technology readiness level, and cost. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Human-induced climate change has become a prominent political issue, at both national and international levels, leading to the search for regulatory 'solutions'. Emissions trading has risen in popularity to become the most broadly favoured government strategy. Carbon permits have then quickly been developed as a serious financial instrument in markets turning over billions of dollars a year. In this article, I show how the reality of permit market operation is far removed from the assumptions of economic theory and the promise of saving resources by efficiently allocating emission reductions. The pervasiveness of Greenhouse Gas emissions, strong uncertainty and complexity combine to prevent economists from substantiating their theoretical claims of cost-effectiveness. Corporate power is shown to be a major force affecting emissions market operation and design. The potential for manipulation to achieve financial gain, while showing little regard for environmental or social consequences, is evident as markets have extended internationally and via trading offsets. At the individual level, there is the potential for emissions trading to have undesirable ethical and psychological impacts and to crowd out voluntary actions. I conclude that the focus on such markets is creating a distraction from the need for changing human behaviour, institutions and infrastructure. [ABSTRACT FROM AUTHOR]

The small but stubbornly unyielding possibility of a very large long-term response of global temperature to increases in atmospheric carbon dioxide can be termed the fat tail of high climate sensitivity. Recent economic analyses suggest that the fat tail should dominate a rational policy strategy if the damages associated with such high temperatures are large enough. The conclusions of such analyses, however, depend on how economic growth, temperature changes, and climate damages unfold and interact over time. In this paper we focus on the role of two robust physical properties of the climate system: the enormous thermal inertia of the ocean, and the long timescales associated with high climate sensitivity. Economic models that include a climate component, and particularly those that focus on the tails of the probability distributions, should properly represent the physics of this slow response to high climate sensitivity, including the correlated uncertainty between present forcing and climate sensitivity, and the global energetics of the present climate state. If climate sensitivity in fact proves to be high, these considerations prevent the high temperatures in the fat tail from being reached for many centuries. A failure to include these factors risks distorting the resulting economic analyses. For example, we conclude that fat-tail considerations will not strongly influence economic analyses when these analyses follow the common-albeit controversial-practices of assigning large damages only to outcomes with very high temperature changes and of assuming a significant baseline level of economic growth. [ABSTRACT FROM AUTHOR]

Development of carbon polygons for monitoring the emission and deposition of carbon compounds in terrestrial ecosystems is one of the priority tasks in the case of climate and biosphere conservation. Significant is the role of soils, which are not only the main source of greenhouse gas emissions into the Earth's atmosphere but also a long-term reservoir that stores significant amounts of organic carbon in the form of soil humus. The article discusses the organization of monitoring of greenhouse gases at carbon polygons, the methods of sampling soil horizons, and methodological approaches to determine the content and stocks of organic carbon in soils. The importance of information on the qualitative and quantitative composition of soil organic matter and humic substances, which is necessary for the operation of modern simulation models and calculation of carbon units for the economic assessment of the direct and reverse carbon footprint have been revealed. Russia faces a number of challenges related to carbon offset and a low-carbon economy. The necessary volumes of monitoring data, which must be obtained at carbon polygons for the use of the ROMUL and Efimod models are considered. The necessity for an adequate spatial coverage of the territory of Russia with a network of carbon polygons is emphasized. Particular attention should be paid to the arctic territories that contain significant amounts of organic matter in permafrost and can become precursors of the formation and emission of significant amounts of carbon dioxide and methane into the atmosphere. [ABSTRACT FROM AUTHOR]

Climate change research is currently a topic of great interest for economic researchers. In particular, environmental input–output analysis increasingly plays an important role in measuring the economic and environmental effects of sustainable development policies in Europe. Other approaches also exist, such as econometric modelling, in which impacts are quantified on statistical grounds and with certain desirable properties (efficient estimates, confidence intervals, hypothesis testing, etc.) that are not found in the input–output approach. Consequently, this paper merges the two approaches to address the calculation of unbiased and consistent carbon dioxide emission multipliers for Denmark and their respective confidence intervals. The use of the supply and use system instead of the symmetric input–output table also presents the opportunity to avoid the common problems associated with the construction of technical coefficients (technology assumptions, negatives, etc.). Moreover, a new policy-relevant application of these multipliers is introduced: the quantification of the performance of the carbon dioxide emission reductions carried out by industries via external trading. [Copyright &y& Elsevier]

Agricultural systems models are essential tools to assess potential climate change (CC) impacts on crop production and help guide policy decisions. In this study, impacts of projected CC on dryland crop rotations of wheat-fallow (WF), wheat-corn-fallow (WCF), and wheat-corn-millet (WCM) in the U.S. Central Great Plains (Akron, Colorado) were simulated using the CERES V4.0 crop modules in RZWQM2. The CC scenarios for CO, temperature and precipitation were based on a synthesis of Intergovernmental Panel on Climate Change (IPCC ) projections for Colorado. The CC for years 2025, 2050, 2075, and 2100 (CC projection years) were super-imposed on measured baseline climate data for 15-17 years collected during the long-term WF and WCF (1992-2008), and WCM (1994-2008) experiments at the location to provide inter-annual variability. For all the CC projection years, a decline in simulated wheat yield and an increase in actual transpiration were observed, but compared to the baseline these changes were not significant ( p > 0.05) in all cases but one. However, corn and proso millet yields in all rotations and projection years declined significantly ( p < 0.05), which resulted in decreased transpiration. Overall, the projected negative effects of rising temperatures on crop production dominated over any positive impacts of atmospheric CO increases in these dryland cropping systems. Simulated adaptation via changes in planting dates did not mitigate the yield losses of the crops significantly. However, the no-tillage maintained higher wheat yields than the conventional tillage in the WF rotation to year 2075. Possible effects of historical CO increases during the past century (from 300 to 380 ppm) on crop yields were also simulated using 96 years of measured climate data (1912-2008) at the location. On average the CO increase enhanced wheat yields by about 30%, and millet yields by about 17%, with no significant changes in corn yields. [ABSTRACT FROM AUTHOR]

In this article we unpack the 'black box' of carbon offsetting through a critical examination of the technologies and techniques that create carbon credits. Drawing on empirical research of compliance (Clean Development Mechanism) and voluntary carbon offset markets, we highlight the diversity of technologies, techniques and devices involved in carbon offsetting, ranging from refrigerant plants to systems of calculation and audit. We suggest that polarised debates for and against offsetting do not adequately reflect the considerable variations between types of offset project and governance practices in the compliance and voluntary offset markets. Using conceptual insights from governmentality theory and science and technology studies we assess the tensions in making standard, fungible carbon credits. In conclusion, we suggest attention to the technologies and materiality of carbon offsetting allows a fresh perspective on somewhat entrenched debates about the advantages and disadvantages of offsetting. [ABSTRACT FROM AUTHOR]

The threats posed by climate change to the global environment have fostered heightened scientific and commercial interest in marine geo-engineering schemes designed to boost the capacity of the oceans to absorb atmospheric carbon dioxide. This is the primary goal of a process known as ocean fertilization, which seeks to increase the production of organic material in the surface ocean in order to promote further draw down of photosynthesised carbon to the deep ocean. This article describes the process of ocean fertilization, its objectives and potential impacts on the marine environment, and some examples of ocean fertilization experiments. It analyses the applicability of international law principles on marine environmental protection to this process and the regulatory gaps and ambiguities in the existing international law framework for such activities. Finally it examines the emerging regulatory framework for legitimate scientific experiments involving ocean fertilization being developed by the London Convention and London Protocol Scientific Groups and its potential implications for the proponents of ocean fertilization trials. [ABSTRACT FROM AUTHOR]