Climate-smart soils.

Better information on greenhouse gas (GHG) emissions and mitigation potential in the agricultural sector is necessary to manage these emissions and identify responses that are consistent with the food security and economic development priorities of countries. Critical activity data (what crops or livestock are managed in what way) are poor or lacking for many agricultural systems, especially in developing countries. In addition, the currently available methods for quantifying emissions and mitigation are often too expensive or complex or not sufficiently user friendly for widespread use.The purpose of this focus issue is to capture the state of the art in quantifying greenhouse gases from agricultural systems, with the goal of better understanding our current capabilities and near-term potential for improvement, with particular attention to quantification issues relevant to smallholders in developing countries. This work is timely in light of international discussions and negotiations around how agriculture should be included in efforts to reduce and adapt to climate change impacts, and considering that significant climate financing to developing countries in post-2012 agreements may be linked to their increased ability to identify and report GHG emissions (Murphy et al 2010, CCAFS 2011, FAO 2011).

● An expert survey highlighted the most effective strategies for GHG and ammonia mitigation. ● Interventions considered to have the highest mitigation potential are discussed. ● Experts agreed that no single mitigation measure can uniquely deliver GHG and ammonia mitigation. ● Experts noted a need for further investment in research, knowledge exchange, education and to develop implementation pathways. ● There is a need for more data to better quantify mitigation potentials and implement effective management strategies. Agriculture is essential for providing food and maintaining food security while concurrently delivering multiple other ecosystem services. However, agricultural systems are generally a net source of greenhouse gases and ammonia. They, therefore, need to substantively contribute to climate change mitigation and net zero ambitions. It is widely acknowledged that there is a need to further reduce and mitigate emissions across sectors, including agriculture to address the climate emergency and emissions gap. This discussion paper outlines a collation of opinions from a range of experts within agricultural research and advisory roles following a greenhouse gas and ammonia emission mitigation workshop held in the UK in March 2022. The meeting identified the top mitigation priorities within the UK’s agricultural sector to achieve reductions in greenhouse gases and ammonia that are compatible with policy targets. In addition, experts provided an overview of what they believe are the key knowledge gaps, future opportunities and co-benefits to mitigation practices as well as indicating the potential barriers to uptake for mitigation scenarios discussed.

With the increasing attention to the environmental impact of discharging greenhouses gases, there has been a growing public pressure to reduce the carbon footprint associated with the use of fossil fuels. In this context, one of the key strategies is the substitution of fossil fuels with biofuels such as biodiesel. The design of biodiesel production facilities has traditionally been carried out based on technical and economic criteria. Greenhouse gas (GHG) policies (e.g., carbon tax, subsidy) have the potential to significantly alter the design of these facilities, the selection of the feedstocks, and the scheduling of multiple feedstocks. The objective of this article is to develop a systematic approach to the design and scheduling of biodiesel production processes while accounting for the effect of GHG policies in addition to the technical, economic, and environmental aspects. An optimization formulation is developed to maximize the profit of the process subject to flowsheet synthesis and performance modeling equations. Furthermore, the carbon footprint is accounted for with the help of a life cycle analysis (LCA). The objective function includes a term which reflects the impact of the LCA of a feedstock and its processing to biodiesel. A multiperiod approach is used to discretize the decision-making horizon into time periods. During each period, decisions are made on the type and flowrate of the feedstocks, as well as the associated design and operating variables. A case study is solved with several scenarios of feedstocks and GHG policies.

The combustion of fossil fuels drive the steady increase in greenhouse gases (GHG) and global temperatures observed in recent decades. The realization of adverse effects of increase in GHG emissions on the environment, the desire to limit atmospheric CO2 concentration at 450 ppm or lower and limit global temperature increase to ≤2 °C, combined with increasing energy needs have made the quest for sustainable and environmentally benign sources of energy for industrial economies and consumer societies a high priority since 1980s. To limit atmospheric CO2 concentration at 450 ppm, a total CO2 emission reduction of 50–85% is required by 2050. As a result, there are a renewed interests in carbon-neutral or carbon-negative renewable energy sources. Among the renewable energy sources, biofuels are considered as an attractive fuel sources for replacing fossil fuels. Bioenergy is important for many sectors and mitigation perspectives as well as from the perspective of developmental goals such as energy security and rural development. It is argued that increasing the contribution of biofuels will reduce the GHG emission by reducing the carbon intensity of the transport sector and addressing energy security concerns. In addition to global climate change threat, interests in biofuels are enhanced by growing global energy demand and diminishing crude oil supply. However, there is concern about the existing interlink between biomass , bioenergy, land use, food supply, water use, and biodiversity. The first generation biofuels primarily produced from food crops feedstock are unsustainable due to the potential stress their production places on food, feed and fiber production. The second and third generation biofuels produced from abundant biomass and algae respectively are seen as the attractive solution to limitations of the first generation biofuels and also have higher potential for GHG emission mitigation. Yet, the practicalities of deployment of bioenergy at a large scale are mired in controversies over the potential resource conflicts that might occur, particularly over land, water and biodiversity. Additionally, a number of technical huddles must be overcome before their true potential can fully be realized and evaluated. This chapter summarizes the current knowledge of biofuels , the potential role in mitigating GHG emission, societal dilemma in large scale biofuel production, current assumptions on which global bioenergy resource estimates are predicted and future directions of biofuels research with the emphasis on assessments informed by empirical studies.

For many developing countries, the land use sector, particularly agriculture and forestry, represents a large proportion of their greenhouse gas (GHG) emissions, making this sector a priority for GHG mitigation activities. Previous global surveys (e.g., IPCC 2000) as well as the most recent IPCC assessment report clearly indicate that the greatest technical potential for carbon sequestration and reductions of non-CO2 GHG emissions from the land use sector is in developing countries. Estimates that consider economic feasibility suggest that agriculture and forestry together provide among the greatest opportunities for short-term and low-cost mitigation measures across all sectors of the global economy1 (IPCC 2007). In addition, it is widely recognized that the ecosystem changes entailed by most mitigation practices, i.e., building soil organic matter, reducing losses and tightening nutrient cycles, more efficient production systems and preserving native vegetation, are well aligned with goals of increasing food security and rural development as well as buffering land use systems against climate change (Lal 2004). Hence, there is growing interest in jump-starting the capacity for broad-based engagement in agriculturally-based GHG mitigation projects in developing countries.

Fiscal Soundness and Economic Growth: An Economic Program for Ontario

Biofuel mandates are being widely used by countries to achieve multiple objectives of energy security and climate change mitigation. The Renewable Fuel Standard (RFS) in the US specifies arbitrarily chosen volumetric targets for different types of biofuels in the US based on their greenhouse gas intensity only. Cellulosic biofuels from high yielding energy crops like miscanthus have the potential to co-generate multiple environmental impacts, including reducing nitrate runoff, being a sink for Greenhouse Gas (GHG) emissions and providing a given volume of biofuel with less diversion of land from food crop production than corn ethanol, but at a significantly higher cost. This paper quantifies the tradeoffs between profitability, food and fuel production, GHG emissions and nitrate runoff reduction with different types of biofuels in the Sangamon watershed in Illinois and analyzes the optimal mix of biofuels as well as the policies that should supplement the mandate to achieve multiple environmental outcomes. We find that a two-thirds share of cellulosic biofuel in the mandated level could reduce nitrate run-off by 20% while reducing GHG emissions by 88–100% but would reduce profits by 15–27% depending on whether a GHG policy or a Nitrate policy is used relative to the case where the mandate is met by corn ethanol alone. Additionally, the ratio of corn stover to miscanthus used to produce cellulosic biofuels is higher under a GHG policy compared to a Nitrate policy that achieves the same level of nitrate reduction. Our results show that the optimal mix of different types of biofuels and the policy to induce it depend on the environmental objectives and the tradeoffs that society is willing to make between low cost energy security, food production and various environmental benefits.

Spatially explicit database on crop-livestock management, soil, climate, greenhouse gas emissions and mitigation potential for all of Bangladesh

As the world moves towards cleaner forms of energy worldwide, gas will have an increasingly important role to play in the future energy mix. From this perspective, there has been growing interest in the relative greenhouse gas (GHG) intensities of a range of fossil fuels, and how various forms of LNG compare to not only coal, but also to renewables and nuclear across their life cycles. These issues are important for energy and GHG policy, especially with developments in carbon pricing. However, until recently there has been little information on the life cycle GHG emissions from Australian fossil fuel exports. This paper helps to complete the picture. Using a wide range of available data from government submissions by industry and the authors’ own project experience, life cycle GHG emissions estimates were developed for LNG derived from conventional natural gas sourced from Western Australia's North West Shelf and Queensland coal seam gas (CSG). A comprehensive assessment of GHG emissions was made for upstream operations, LNG production, transport, regasification, and end-user combustion for electricity generation (assumed to be in China). These life cycle emission estimates were compared to life cycle emissions for Australian black coal exported to China and used to generate electricity. Comparisons were also made with renewables and nuclear. The results show that the life cycle GHG intensity (tCO2-e/MWh) of electricity sent out is highly sensitive to the thermal efficiency of the end-use combustion technology. For most comparison scenarios, natural gas-fired power generation is less GHG intensive than black coal-fired power generation. The differences range from 17% to 56% less intensive for a variety of plant efficiencies. In some cases, coal was marginally less GHG intensive when comparing open-cycle gas technology with ultra-supercritical coal combustion. LNG derived from CSG was also found to be more GHG intensive than conventional gas. Modelling of upstream methane fugitive emission scenarios from CSG (using 100-year and 20-year methane Global Warming Potentials) had little impact on the life cycle GHG intensity rankings, such is the dominance of end-use combustion. When exported to China for electricity production, LNG was found to be 22–36 more GHG intensive than wind and concentrated solar thermal (CST) power and 13–21 times more GHG intensive than nuclear power

Taking Stock of Strategies on Climate Change and the Way Forward: A Strategic Climate Change Framework for Australia

Migrating Most US Fiber Production From Forests to Farms

Major US electric utility climate pledges have the potential to collectively reduce power sector emissions by one-third

The Korean Energy and GHG Target Management System: An Alternative to Kyoto-Protocol Emissions Trading Systems?

In the United States, agricultural production is both a significant source of greenhouse gases (GHGs) (Environmental Protection Agency (EPA), 2022) and uniquely susceptible to climate change impacts (Vermeulen et al., 2012). Decarbonization solutions have been proposed for addressing agricultural GHGs; however, research has been limited in synthesizing qualitative and quantitative analysis of potential GHG mitigation solutions in the United States. In this report, we review U.S. agricultural GHG sources by activity and quantify potential mitigation solutions based on a comprehensive data and literature analysis. We also discuss agricultural carbon sequestration options to offset GHG emissions. In our analysis, we identified two significant and hard-to-abate GHG sources (N2O from soil management, and CH4 from enteric fermentation from livestock) as well as high-impact GHG mitigation solutions (e.g. agroforestry, reforestation, and biochar application) and cross-cutting GHG mitigation solutions (renewable energy production, precision agriculture, no-till, integrated nutrient management, and biochar). This report is meant to provide initial analysis and establish a foundation for future agricultural decarbonization research - it is not an exhaustive analysis of all available studies. However, to our knowledge this report is the most comprehensive assessment of agricultural GHG emissions and associated mitigation opportunities in the United States to date. Future empirical research is recommended to close research gaps in different climates, soils, and agricultural systems. Meta-analyses for all mitigation solutions would increase confidence in the estimated GHG mitigation potentials. To conclude this report, we discuss short-term and long-term pathways for agricultural decarbonization in the United States, the importance of accounting for total GHG fluxes, potential co-benefits of agricultural decarbonization, analysis of study data confidence, and research gaps.

Canadian agriculture is a source of greenhouse gases (GHG) and agroforestry has the potential to sequester carbon (C), and mitigate agricultural GHG emissions. Agroforestry systems are common features in Canada’s agricultural landscape; however, there are limited empirical data to support implementation of agroforestry practices for GHG mitigation. This shortfall of data may be a contributing factor to the lack of policy that supports the use of agroforestry for GHG mitigation in the Canadian agricultural landscape. We reviewed published studies that compared C stocks in vegetation and soils, and/or GHG emissions in agroforestry systems to traditional agriculture across Canada, with the aims of assessing the benefit of adopting agroforestry for GHG reduction. We then identified data gaps and obstacles that could direct future research. We found that most studies reported increases in vegetation and soil organic C storage in areas with woody species compared to herbaceous crops. Agroforestry systems also reduced the emission of CH4and N2O, and increased CO2respiration from soil, but few studies have examined these gases. The small set of studies we reviewed demonstrated the potential of agroforestry to store terrestrial C and mitigate GHG emissions. However, additional research is required to verify this pattern across geographic regions, determine the regional potential for development of agroforestry systems, and assess the potential atmospheric GHG reduction at regional and national scales.