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China has established three rounds of low-carbon pilot city initiatives. However, a gap exists between policy making and successful implementation, and the effects on greenhouse gas (GHG) emission reduction were found to be different among pilots. This paper considers the question of how low-carbon policies in cities can be implemented effectively and how policy combinations are adopted for GHG emissions reduction. It uses a mixed research approach, including Qualitative Comparative Analysis (QCA) and field investigation in Pilot Y (situated in the southwest China). The results show that, first, financial support and monitoring systems are necessary conditions, while political leadership is a sufficient condition. This means that the absence of financial support or monitoring systems could lead to increased GHG emissions, while the presence of political leadership always promotes the reduction of GHG emissions but may not be sufficient on its own to achieve them. Second, the target responsibility system (TRS) – a system used by higher government levels to assess the policy implementation of lower government levels – and human resource mechanisms cannot effectively lead to the promotion of GHG emissions reduction. Finally, in the absence of TRS and human resource mechanisms, environmental information disclosure (EID) was found to effectively promote low-carbon urban development by encouraging public participation. This paper reveals the complexity of the implementation of low-carbon policies in cities, identifies the link between city-level and national action, and enriches the theoretical explanation of governance and low-carbon policy implementation gaps in China. Key policy insights China's low-carbon pilot city project is critical for reducing GHG emissions, however, the effects of the low-carbon pilot city programmes varied greatly. Financial support and monitoring systems are necessary conditions, while political leadership is a sufficient condition to achieve cities' GHG emissions reduction goals. Local low-carbon development is limited and not put into practice at the city level in China, in part because of the absence of financial support and limited political attention. This study highlights the key conditions of organizational behaviour at the meso-level, and enriches the theoretical explanation of environmental policy implementation gaps in China. [ABSTRACT FROM AUTHOR]

In response to the pressing global challenges around climate change and the imperative of transitioning the energy market towards sustainability, this paper presents a comprehensive review starting from the late 18th century. The study examines the pivotal role of Transmission System Operators (TSOs) and Distribution System Operators (DSOs) in shaping the evolving energy landscape, with a specific emphasis on the C+++ Framework. This framework emphasizes coordination, cooperation, and collaboration between TSOs and DSOs to achieve sustainable energy systems through the integration of renewable energy technologies, storage systems, and efficient energy demand management. In addition, the review provides a historical overview of global warming from 1800 to the present, highlighting key events and developments related to greenhouse gas emissions. Furthermore, the paper delves into the significance of international agreements such as the Paris Agreement and the importance of reducing greenhouse gas emissions for a sustainable future. Recognizing the vital role of the C+++ Framework, the paper concludes with a discussion of future hybrid sustainable technologies incorporating various storage and efficient lighting technologies that can optimize energy management and reduce carbon emissions. This research aims to contribute valuable insights to inform energy policy and decision-making processes for a reliable, efficient, and sustainable energy delivery system. [ABSTRACT FROM AUTHOR]

Assuming responsibility for emission reduction is an important part of participating in the global governance of climate change. Countries with a carbon neutrality target now cover about 75% of global greenhouse gas emissions. Carrying out fairness evaluations of their carbon neutrality targets provide a strong basis for the global carbon inventory. In this paper, the target years of carbon neutrality for major countries and regions under the global target of 2 °C and 1.5 °C are studied using the burden sharing model. On this basis, this paper simulates the possible pathways of carbon neutrality and evaluates the ambition of emission reduction targets in terms of annual emission reduction, per capita emission, and cumulative per capita emission. The results show that, from the perspective of equity, most of the developing countries cannot meet the global goal of 1.5 °C. The United States and the European Union nations could achieve carbon neutrality by 2050 by continuing their annual emission reductions under their existing NDC targets. However, to achieve carbon neutrality by 2060, China's annual emission reduction rate from 2030 to 2050 will be 6.7%, and the annual amount of emission reduction accounts for 51% of the global amount under the 1.5 °C target. Meanwhile, China would become the main force behind global cumulative emissions in the following decades. Thus, the emission reduction pathways China chooses will have an important impact on global climate mitigation progress. Based on the above research conclusions, this paper proposes that developed countries and developing countries should explore bilateral or multilateral cooperation in technology and finance in the field of climate change. Under the great pressure to achieve carbon neutrality, China needs to carry out research on the overall emission reduction pathways as soon as possible and clarify the paths at the scale of sectors, industries, provinces, and time stages. [ABSTRACT FROM AUTHOR]

Climate change is having a detrimental effect on the environment's natural equilibrium. The population that depends on agriculture is suffering from rising temperatures, sporadic droughts and famines, unpredictable dry spells, and irregular rains. Deploying Climate Smart Agriculture (CSA) is a terrific strategy to cut greenhouse gas emissions and boost crop output for food security and climate change adaptation. The primary objective of this study is to provide an organized appraisal of current advancements in the field of climate-smart agriculture. For this study, the Scopus database was used to analyze 157 papers that were published between 2013 and 2022. However, the use of climate-smart agriculture technology that considers local knowledge is still quite low in developing countries. Therefore, raising the importance of indigenous knowledge in the context of climate change could aid smallholder agricultural groups in their adaptation. Improving adaptability, developing capacity, and fusing indigenous knowledge with climate-smart agricultural practices may all be necessary to increase a community's effective resilience to climate change. [ABSTRACT FROM AUTHOR]

Combating global warming-related climate change demands prompt actions to reduce greenhouse gas emissions, particularly carbon dioxide. Biomass-based biofuels represent a promising alternative fossil energy source. To convert biomass into energy, numerous conversion processes are performed at high pressure and temperature conditions, and the design and dimensioning of such processes requires thermophysical property data, particularly thermal conductivity, which are not always available in the literature. In this paper, we proposed the application of Chemoinformatics methodologies to investigate the prediction of thermal conductivity for hydrocarbons and oxygenated compounds. A compilation of experimental data followed by a careful data curation were performed to establish a database. The support vector machine algorithm has been applied to the database leading to models with good predictive abilities. The support vector regression (SVR) model has then been applied to an external set of compounds, i.e. not considered during the training of models. It showed that our SVR model can be used for the prediction of thermal conductivity values for temperatures and/or compounds that are not covered experimentally in the literature. [ABSTRACT FROM AUTHOR]

The current geopolitical landscape of the European Union has made it clear that the energy sector must be a top priority in EU policy, especially in light of the sudden escalation of Russian–Ukrainian conflicts. Energy efficiency has been used as the first tool of EU policy to tackle energy and climate crises, given the issues surrounding energy vulnerability and the need to limit gas emissions that contribute to climate change. The white certificate mechanism in Italy has played a pivotal role in encouraging measures to achieve the country's energy-saving goals. Given the high energy requirements of Wastewater Treatment Plants (WWTPs), especially for aeration in the biological section, this paper examines the replacement of the air distribution system for a large WWTP as a viable intervention. In order to provide economic perspective for the plant, both the discounted Payback Period (dPBP) and the Net Present Value (NPV) were calculated for the investment. When viewed through an economic lens, the dPBP metric exhibits values that span from less than 1 year to nearly 4.5 years. Additionally, the investment's cost-effectiveness was emphasized by the NPV, which, depending on the factors considered, can exceed 17.5 million euros. Finally, given the centrality of the theme of climate change, the avoided greenhouse gas emissions generated by the efficiency intervention were calculated, according to the GHG Protocol, resulting in a quantity of avoided emissions equivalent to over 57,770 tonnes of CO2e. These results highlight important achievements in terms of both the cost-effectiveness of the plant and the reduction of greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Thailand's Nationally Determined Contribution (NDC) submitted to the United Nations Framework Convention on Climate Change (UNFCCC) aims to reduce 20 to 25% of greenhouse gas (GHG) emissions with respect to the projected reference level of NDC in 2030, respectively, in its unconditional and conditional scenarios. The Intergovernmental Panel on Climate Change (IPCC) states that limiting global temperature rise to 1.5°C would require net zero carbon dioxide emissions globally by around 2050. Thailand's current energy system is highly fossil fuel dependent and requires enormous transformations to achieve more stringent GHG emission reduction targets beyond its NDC. This paper seeks to estimate the level and the intensities of Thailand's energy system and their economy-wide effects post-2030 under the business as usual and 16 GHG emission reduction scenarios ranging from 30 to 100% by 2050. A computable general equilibrium analysis using the AIM/Hub model is employed to estimate the macroeconomic impacts of meeting the unconditional and conditional emission reductions of Thailand's NDC in 2030 along with varying GHG emission reductions in 2050. Results show that renewables – constituting solar, wind, biomass and hydro and carbon capture and storage (CCS) technologies account for more than 95% in the power generation mix by 2050, if 100% GHG emission reduction from the 2010 level is to be achieved. Electricity generation based on biomass both with and without CCS will occupy a major share in the investments by 2050 in all the conditional and unconditional NDC scenarios. A rapid increase in carbon sequestration occurs from 2040 onwards through the deployment of CCS and bioenergy with CCS (BECCS) technologies in all the conditional and unconditional NDC scenarios. Carbon prices lie in the range of 3.4–266.2 US$/tCO2eq during 2025–2050 to achieve 100% GHG emission reductions in 2050. Imposition of early stringent mitigation target lowers the carbon prices in the conditional scenarios towards 2050 when compared to the unconditional scenarios. The rapid uptake of CCS, energy efficiency improvements and electrification of the end-use technologies are identified to be the key measures to transform the energy system of Thailand. By 2050, the Thai economy would face a higher fall in both the GDP and household consumption in the unconditional scenarios than those in the conditional scenarios at all levels of GHG emission reduction. Results indicate that early mitigation efforts can be less costly than the delayed ones in the long-term. The cumulative investment needed to achieve decarbonization in Thailand is estimated to exceed 355 billion US$2005 over the period 2010–2050 in the 100% GHG reduction scenarios. The transmission and distribution investments in the power sector need to increase by 30–35% to attain 100% GHG emission reductions during 2010–2050. The trade deficit improves by up to 23–29% in the various GHG mitigation scenarios in 2050. [ABSTRACT FROM AUTHOR]

Roads play a vital role in transportation systems, and their construction and maintenance expenses are high. Those reasons make crucial the examination of factors that accelerate road deterioration and those factors' negative impacts on societies. Climatic-related elements, especially temperature and precipitation, significantly affect the quality and lifespans of roads. The Intergovernmental Panel on Climate Change has reported that increasing greenhouse gas (GHG) emissions is causing changes in climate and that the rate of change has accelerated during the past several decades. To assess the impacts of changing climatic parameters on flexible-pavement performance, this study used 32 climate models to evaluate the performance of interstate, primary, and secondary roads across 11 diverse locations with varying traffic and climatic conditions. The study's findings reveal that changing climate exacerbates pavement distresses, leading to reduced pavement lifespans and increased numbers of reconstruction projects, which in turn raise demands for materials and equipment and contribute to higher GHG emissions. The effects of changing climate and changing climate's associated economic and environmental costs make the application of various engineering solutions to enhance pavement resilience essential, as described in this paper, in the absence of comprehensive emissions reduction strategies. [Display omitted] [ABSTRACT FROM AUTHOR]

There is a growing body of modelling evidence that demonstrates the potential for immediate and substantial benefits to adult health from greenhouse gas mitigation actions, but the effects on the health of younger age groups is largely unknown. We conducted a systematic review to identify the available published evidence of the modelled effects on child and adolescent health (≤18 years of age) of greenhouse gas mitigation. We searched six databases of peer-reviewed studies published between January 1, 1990 and July 27, 2022, screened 27,282 original papers and included 23 eligible papers. All included studies were set in high- and middle-income countries; and all studies modelled the effects of interventions that could mitigate greenhouse gas emissions and improve air quality. Most of the available evidence suggests positive benefits for child and adolescent respiratory health from greenhouse gas mitigation actions that simultaneously reduce air pollution (specifically PM2.5 and nitrogen dioxide). We found scant evidence on child and adolescent health from regions more vulnerable to climate change, or on mitigation interventions that could affect exposures other than air pollution. [ABSTRACT FROM AUTHOR]

As a solution to mitigate the effects of climate change, scientists have been looking for more environmentally friendly energy production alternatives, so, since the 2000s, renewable energy production has increased across Europe. Climate change has a negative impact on our planet, with increased emissions of greenhouse gases contributing to global warming. In this context, biogas has become a promising solution for reducing greenhouse gas emissions and improving environmental quality. The purpose of the study is to review the evolution of research and development in this field, identify trends and gaps in existing knowledge, and assess the impact and significance of published research. In this sense, a bibliometric analysis was carried out, based on the topics "renewable energy" and "biogas", in which VosViewer software was used to create maps. The research results show that existing policies worldwide encourage transfer and synergy between researchers from different countries, achieving important results. Practically, researches and examples of good practise show that biogas can be a viable solution to mitigate the effects of climate change, and in the coming decades, under the conditions of the population growth estimates materialization, we will most likely witness an intensification of agriculture to ensure the population's food needs. [ABSTRACT FROM AUTHOR]

In 2022, Saudi Arabia's anthropogenic greenhouse gas emissions amounted to 810 million tons of CO 2 e. The country has pledged to cut its emissions by 278 million tons of CO 2 e per year by 2030. This paper contributes a modeling view on the climate-related effects of various energy policies on the Saudi energy system. We use an energy system model designed to represent seven sectors in the Saudi economy. In addition to a baseline, which entails the continuation of current domestic policies, we look at a scenario that incorporates some of the plans announced by the Saudi government. We also examine the baseline scenario with a cap on total CO 2 emissions equal to those exhibited with the announced plans. The model then makes the necessary decisions to abate CO 2. We find that the energy system contributes 130 million tons of CO 2 e to the nationally determined contribution amount in 2030. Also, a non-prescriptive scenario that caps energy-system CO 2 emissions produces the same emissions reductions as the announced plans while lowering the present cost by 2030 by $70 billion. The corresponding implicit marginal abatement cost of CO 2 approaches 35 $/tonCO 2 by 2045. This cost would displace around half of crude and fuel oil use in the Saudi energy system. • Saudi Arabia plans to cut annual greenhouse gas emissions by 278 million tonsCO 2 e. • We use a multi-sector model built from the ground up for Saudi Arabia. • The energy system can contribute 130 million tons of CO 2 e in reductions in 2030. • We find a scenario that achieves GHG abatement at a lower cost than official plans. • The marginal value attributed to CO 2 approaches 35 $ per tonCO 2 by 2045. [ABSTRACT FROM AUTHOR]

Feeding the world's population while minimising the contribution of agriculture to climate change is one of the greatest challenges facing modern society. This challenge is particularly pronounced for dairy production where the carbon footprint of products and the mitigation costs are high, relative to other food stuffs. This paper reviews a number of mitigation measures that may be adopted by dairy farmers to reduce greenhouse gas emissions from their farms. A simulation model is developed to assess the cost-benefit of a range of mitigation measures. The model is applied to data from Ireland, a country with a large export-oriented dairy industry, for a range of farms including top, middle and bottom performing farms from a profitability perspective. The mitigation measures modelled included animal productivity, grass production and utilisation, better reproductive performance, early compact calving, reduced crude protein, decreased fertiliser N, protected urea, white clover, slurry tank cover and low emission slurry spreading (LESS). The results show that over half of the greenhouse gas abatement potential and most of the ammonia abatement potential were realised with cost-beneficial measures. Animal and feed-related measures that increased efficiency drove the abatement of GHG emissions. Low-emission slurry spreading was beneficial for the bottom and middle one-third of farms, while protected urea and reducing nitrogen use accounted for most of the ammonia abatement potential for the most profitable farms. Results showed that combining mitigation measures resulted in a decrease of 23%, 19%, and 12% in GHG emissions below 2020 levels for the bottom, middle, and top performing dairy farms, respectively. The findings imply that top dairy farms, that are already managed efficiently and optimally, may struggle to achieve the national and international GHG reduction targets with existing technologies and practices. • The top dairy group may struggle to achieve the 2030 and future GHG reductions targets with existing technologies and practices • 56%–86% of emissions reduction achieved through mitigation measures that were cost effective, net-zero for all three groups • Farm-level MACCs can account for variability in GHG and NH3 mitigation potentials and costs, that are often missed at the sectoral or country level. • The study found that combining mitigation measures resulted in a decrease of 23%, 19%, and 12% in GHG emissions below 2020 levels for the bottom, middle, and top dairy groups, respectively • Farm-level marginal abatement cost curve (MACC) are useful for understanding the capacity to reduce gaseous emissions from specific agricultural systems or farms [ABSTRACT FROM AUTHOR]

The myriad impacts of climate change (including environmental, social and economic outcomes) and the need to act urgently to limit these impacts is being increasingly understood by influential decision makers and the general population with significant climate change impacts such as sea level rise and migration of populations due to increasing vulnerability already occurring. Improving our understanding of climate change is critical to making swift and significant change – something which is essential in sufficiently reducing atmospheric concentrations of greenhouse gases (GHGs) and slowing climate change. Whilst these changes, including New Zealand’s commitment to net zero emissions by 2050, will greatly contribute to the significant reductions in GHG emissions required, it is important to note that significant change can also be achieved through the cumulative effect of many small, everyday changes. This paper explores the potential cumulative impact of the general population making many small, everyday changes to reduce GHG emissions to help slow climate change. [ABSTRACT FROM AUTHOR]

The current work aims to analyze the existing situation in Romania compared to other EU countries, regarding bovines herds, given that this species is one of the ones that causes the highest level of greenhouse gases, with a direct effect on the environment and global warming. This is the reason why the subject has become a priority not only at the community level, but also worldwide. Through the Common Agricultural Policy, important funds have been allocated at the level of the European Union, which will continue to be allocated, not only for the reduction of climate change, but also for the adaptation of the states of the world to these existing climate changes at the global level. Given the path in which animal husbandry influences sustainable development, through the study we have followed both the effective changes, but also the obtained productions, with a direct impact on consumption. It was found that both at the community level, as well as at the national level, there was a decrease in bovines herds in in the period 2016-2020, the reasons being primarily of an economic nature, but equally important being the social and environmental ones. The analysis was carried out starting from the data published by the National Institute of Statistics and Eurostat, data that were then processed and analyzed with the help of statistical methods. Based on these, the conclusions were formulated that show us that in Romania the number of bovines herds decreased by 11% in the period 2016-2021. At the European Union level, Romania ranks 10th in terms of bovines herds and 20th in terms of density/100 ha. Although there are advances in terms of applied technologies or more productive breeds, at the global level the objectives pursued by the reduction of greenhouse gas emissions have not been influenced by these advances, which makes the activity of raising bovines to be considered one with effects negative effects on the environment, but also high consumption of energy and water, which in turn have a negative impact on climate change. [ABSTRACT FROM AUTHOR]

The industrial sector has significantly contributed to global climate change and urban air pollution while driving economic development. This paper takes the synergistic CO2 and SO2 emission reduction in China's industrial sector as an entry point quantifies the synergistic CO2 and SO2 emission reduction effect using the Kaya extension model and analyzes the synergistic emission reduction expansion mechanism in depth. It is found that the synergistic effect of CO2 and SO2 in the industrial sector is prevalent in most provinces in China. Every 10,000 tons of CO2 emission reduction leads to 1600 tons of SO2 emission reduction. Regional heterogeneity also clarifies that there are differences in synergistic emission reduction among different provinces, with most regions having a significant positive effect of synergistic emission reduction, while a small number of regions have an inverse effect, and direct SO2 reduction measures should be considered separately. The interaction effect analysis found that energy efficiency improvement in the industrial sector is the critical path to synergistic effect enhancement. At the same time, R&D expenditure and fixed asset investment have a weak effect on synergistic emission reduction. The interaction of the three factors can synergize the emission reduction effect by more than twice. The study's findings can be used as a reference for China's industrial sector to achieve the goal of reducing pollution and carbon emissions and for the practice of regional synergistic emission reduction, as well as for the formulation of international synergistic emission reduction policies. [ABSTRACT FROM AUTHOR]

[Display omitted] • The influencing factors of MOFs for CO 2 capture and CO 2 -to-alcohols are discussed. • Strategies for improving the CO 2 capture of MOFs-based materials are introduced. • The catalytic systems used for CO 2 -to-alcohols are summarized. • The hydrogenation pathway of CO 2 -to-alcohols by MOFs-based materials are presented. • The challenges and trends of MOFs in CO 2 capture and conversion are prospected. The global climate change caused by the continuous increase of carbon dioxide (CO 2) emissions has seriously threatened the survival of human beings, so it is imperative to control its emission reduction and achieve its utilization. The adsorption of CO 2 and conversion into high-value-added chemicals can not only reduce the exhaust emission of greenhouse gas, but also help to solve the problems of excessive dependence on fossil fuels and the storage of renewable energy. As a promising carbon recycling technology, carbon capture and utilization (CCU) has attracted wide attention in the past decades. Various functional materials such as metal-organic frameworks (MOFs), metal oxides, molecular sieves and porous carbon materials have sprung up for CO 2 capture and conversion. MOFs have become a more promising candidate due to their highly tunable pore structure, easy surface functionalization and abundant active sites. This paper reviews most studies published in the last five years on MOFs used for capturing CO 2 and CO 2 -to-alcohols conversion. The main topics include 1) The influencing factors of MOFs-based materials for CO 2 capture and CO 2 -to-alcohols; 2) strategies to improve CO 2 adsorption performance and the role of high throughput computational screening (HTCS) on the development and screening of MOFs adsorbent; 3) MOFs-based materials used for CO 2 -to-alcohols conversion in photo-, electro-, thermal-catalytic and their hybrid catalytic systems, as well as the corresponding mechanistic studies. The purpose of this review is to offer a technical and theoretical direction for the creation and industrial implementation of high-performance MOFs-based materials in the field of CO 2 adsorption and conversion, highlight the associated challenges and opportunities. [ABSTRACT FROM AUTHOR]

Australians are one of the world’s highest per capita emitters of greenhouse gases, yet the country’s target for emissions reductions by 2030 remains modest. This paper looks at policy options for Australian cities to deliver faster emissions reductions than the national commitment level. The main focus is on an accelerated reduction in emissions from urban road transport, through technological improvements and behaviour changes. Targets are proposed for improved emissions intensities, to bring Australia much closer to US and EU performance expectations. A range of behaviour change measures is then tested on Melbourne and Sydney, the Sydney analysis using MetroScan-TI, an integrated evaluation framework, to explore how behaviour changes might enhance emissions outcomes. The potential contribution of public transport is a particular focus. The paper concludes that, with sufficient political will, Australia could reduce its 2030 road transport emissions to 40% below 2005 levels. This is a much larger reduction than the current 26–28% Australian target but is more consistent with longer term pathways to acceptable carbon budgets. [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]

This paper investigates the potential pathways and associated requirements to meet a goal of net-zero greenhouse gas (GHG) emissions from the US commercial aviation sector by 2050 as outlined in the US 2021 Aviation Climate Action Plan. Aviation traffic (RTK) is projected to grow at an average of 2.0% per annum between 2019 and 2050, suggesting that a progressive and ultimately total decoupling of emissions from traffic growth will be required to meet the US aviation sector goal. Aircraft technology advancements, operational efficiency improvements, sustainable aviation fuels, and market-based measures (MBM) are considered as emissions reductions measures towards the goal. A parametric analysis framework is used to develop low, medium, and high emission reduction scenarios for each of these emissions reduction measures. If aircraft technology, operations, and fuels were frozen at 2019 levels, the aviation sector is projected to emit ≈430 million tonnes of CO 2 (MtCO 2) in 2050. Retirements of older aircraft, replaced by current-generation alternatives, may contribute 17% of the total 2050 emissions reduction goal. Further introduction of advanced aircraft technologies may contribute an additional system-level 11% emissions reductions towards the goal. Operational improvements may contribute ≈2% with a range from 1.5 to 4%. The remaining 70% of emissions in 2050 will be addressed through a combination of sustainable fuels and MBM, where appropriate. The level of contribution from fuels will be dependent on continued production ramp-up to meet aviation demand as well as improvements in lifecycle emissions reduction factor (ERF) for current and future fuel feedstock and production pathways, ranging from 0% for current petroleum-based fuels to 100% for sustainable aviation fuels with zero life-cycle emissions. Meeting a net-zero emissions goal by 2050 with SAF would require an increase in SAF production by 57% annually from 2022 to 2030 and 13% per year thereafter, reaching 100% emissions reductions factor by 2050. MBM may fill the gap between residual lifecycle emissions after accounting for all other in-sector improvement opportunities and the goal. [ABSTRACT FROM AUTHOR]

The present paper focuses on the European Union emissions trading system and its development. The main regulatory provisions regulating the functioning of the EU emissions trading system, the procedure for selling permits at auctions, the free allocation of permits and the use of funds from sales of permits are analyzed. The process of developing the mechanism of emission trading in Ukraine is described, and existing regulatory and draft documents in this area are analyzed. Recommendations on the introduction of the emissions trading system in Ukraine are proposed. [ABSTRACT FROM AUTHOR]

Climate change mitigation requires the reduction of greenhouse gas (GHG) emissions. The majority of the discussions on climate change policy focus exclusively on the reduction of carbon dioxide (CO 2 ) emissions but ignore other important GHGs such as methane. This paper investigates the optimal choice of policy instruments under the joint consideration of CO 2 and methane in a dynamic setting with asymmetric information and pollutant correlations. We develop a dynamic programming model with two state variables and calibrate it to the global warming case. The results show that it is optimal to levy tax on both CO 2 and methane. A mixed strategy that implements a tax on CO 2 and a quota on methane is the second-ranked choice. [ABSTRACT FROM AUTHOR]

Biomass plays a dual role as an energy source and a solution for climate change mitigation. There are complexities surrounding decentralized electricity generation, and Ghana could not achieve its 10% renewable energy target in 2020. The paper assesses the greenhouse gas mitigation potential and economic impact of electricity from major food crop residues subjected to anaerobic digestion technology in 16 regions and 88 districts in Ghana from 2017 to 2020. Buswell equation was applied to calculate the biogas and methane yield. The environmental impact assessment was expressed as global warming potential, and the economic feasibility was conducted. The results showed that crop residues' annual theoretical and technical potential was 28.92 Mt and 17.24 Mt. The top four residues with the largest share of technical potential were maize (5.41 Mt), yam (3.58 Mt), plantain (3.05 Mt) and cassava (2.39 Mt). Biogas and electricity potentials were 1,912.74 Mm3 and 3,068.34 GWh, which could offset 15.56% of electricity consumption in Ghana. The Ashanti (478.18 GWh), Eastern (430.20 GWh), Bono East (318.29 GWh) and Northern (314 GWh) regions demonstrated the highest electricity potential. Ghana could generate the highest electricity potential of 46.52 GWh in the districts and a minimum potential of 0.89 GWh annually. Power generation potential from anaerobic digestion had a diesel displacement capacity of 923.35 × 10 6 L with a GHG emissions reduction of 2,507.35 kt CO 2 eq. The largest GHG reduction potential was 38.15 kt CO 2 eq at the district level. The findings show that the project is economically viable, with an average net present value of $ 10,105,904 per region and an electricity cost of $ 0.0321/kWh. The study provides critical insights to policymakers and industry developers for decentralized biomass-based electricity generation in Ghana. • A sustainable crop residue assessment is conducted in Ghana. • The total biogas-based electricity is 3,068.34 GWh. • Ashanti region has high electricity (478.18 GWh) than Greater Accra (9.82 GWh). • The total GHG mitigation is estimated as 2507.35 kt CO 2 eq. • The project is economically viable at a cost of $ 0.0321/kWh. [ABSTRACT FROM AUTHOR]

This article builds on the premise that human consumption of goods, food and transport are the ultimate drivers of climate change. However, the nature of the climate change problem (well described as a tragedy of the commons) makes it difficult for individuals to recognise their personal duty to implement behavioural changes to reduce greenhouse gas emissions. Consequently, this article aims to analyse the climate change issue from a human-scale perspective, in which each of us has a clearly defined personal quota of CO2 emissions that limits our activity and there is a finite time during which CO2 emissions must be eliminated to achieve the “well below 2°C” warming limit set by the Paris Agreement of 2015 (COP21). Thus, this work’s primary contribution is to connect an equal per capita fairness approach to a global carbon budget, linking personal levels with planetary levels. Here, we show that a personal quota of 5.0 tons of CO2 yr-1 p-1 is a representative value for both past and future emissions; for this level of a constant per-capita emissions and without considering any mitigation, the global accumulated emissions compatible with the “well below 2°C” and 2°C targets will be exhausted by 2030 and 2050, respectively. These are references years that provide an order of magnitude of the time that is left to reverse the global warming trend. More realistic scenarios that consider a smooth transition toward a zero-emission world show that the global accumulated emissions compatible with the “well below 2°C” and 2°C targets will be exhausted by 2040 and 2080, respectively. Implications of this paper include a return to personal responsibility following equity principles among individuals, and a definition of boundaries to the personal emissions of CO2. [ABSTRACT FROM AUTHOR]

Urbanisation is truly a global phenomenon. Starting at 39% in 1980, the urbanisation level rose to 52% in 2011. Ongoing rapid urbanisation has led to increase in urban greenhouse gas (GHG) emissions. Urban climate change risks have also increased with increase in climate-induced extreme weather events and more low-income urban dwellers living in climate sensitive locations. Despite increased emissions, including GHGs and heightened climate change vulnerability, climate mitigation and adaptation actions are rare in the cities of developing countries. Cities are overwhelmed with worsening congestion, air pollution, crime, waste management, and unemployment problems. Lack of resources and capacity constraints are other factors that discourage cities from embarking on climate change mitigation and adaptation pathways. Given the multitude of problems faced, there is simply no appetite for stand-alone urban climate change mitigation and adaptation policies and programmes. Urban mitigation and adaptation goals will have to be achieved as co-benefits of interventions targeted at solving pressing urban problems and challenges. The paper identifies administratively simple urban interventions that can help cities solve some of their pressing service delivery and urban environmental problems, while simultaneously mitigating rising urban GHG emissions and vulnerability to climate change. [ABSTRACT FROM PUBLISHER]

The United Nations Framework Convention on Climate Change (UNFCCC) sets an overall framework for intergovernmental efforts to tackle the challenge posed by climate change. Besides the “flexibility mechanisms” defined by the Kyoto Protocol to lower the overall costs of achieving their emissions targets, The Voluntary Green House Gases (GHG) reduction projects can have a lead role in GHG reduction in “non Emissions Trading System ETS sectors”. Nowadays, the voluntary market is characterised by critical aspects, such as fragmentation, lack of accounting, monitoring and validation rules that have led to the low spread of voluntary emission reduction projects developed by local authorities in the European Union despite their high potentiality. The aim of this paper is to test the applicability of voluntary emission reduction projects in the public sector following a homogeneous and consistent pattern. A research has been performed at local level on 143 voluntary emission reduction projects implemented by Public Administrations in Northern and Central Italy in renewable energy, energy efficiency and transport sectors. The applicable standards and methodologies have been checked and the case studies have been analysed though a three-step process: Preliminary additionality assessment; Projects selection; Validation of the selected project. The assessment shows that energy efficiency projects, once overcoming additionality issues, are the most promising for public entities while renewable energy and transport projects resulted to be mainly affected by double counting problems and lack of reliable methodologies. [ABSTRACT FROM AUTHOR]

Abstract: Low carbon cities. What, exactly, are we talking about? Are we talking about lifestyles, activities, or enterprises? Are we talking about individual or group voluntary behavior change or a policy framework that seeks to encourage behavior change by regulatory force? Faced with an enormous literature that mixes related topics like sustainable development/climate change/energy conservation/low carbon, it is not surprising to hear about local governments’ or planners’ “climate change initiatives”. This paper describes/reflects on how officials in Broward County, Florida, are dealing with issues of awareness, governance, measurement, and instruments for challenges arising from the combined threats of energy depletion and climate change. The overriding objective of this paper is to provide some pith for the discussion of planning for low carbon cities. To this end, we describe and reflect on the planning management responses of Broward County, Florida, USA – as an illustrative local government – in dealing with climate change challenges (CCC), energy conservation (EC) and greenhouse gas reduction (GHG). Both description and reflection are important as it is primarily the latter that provides the critical perspective necessary for assessing both potential and effect. The paper is organized into five sections. The first two sections address the “contextual” questions raised above: what is the level of knowledge and/or awareness among the collection of planners and/or local governments; and, what are/is appropriate responses of different levels of government. In the next section, we review overall levels of knowledge and awareness of basic science and policy dimensions, with particular attention paid to (a version of the) US planning profession. This is followed by a discussion of “theoretical” prescriptions for actions at different levels of government. The third and fourth sections focus on Broward County. The third section describes the county and presents a current measurement of its carbon footprint (at least at the level to which it can be measured). The fourth section describes the operational response of Broward County government. The final section returns to the original questions of knowledge and appropriate types of responses and argues that while the Broward response is generally effective in certain aspects, the current policy paradigm contains both strengths and weaknesses, which are generally outlined and discussed. [Copyright &y& Elsevier]

It is now accepted that tourism is a significant contributor to global climate change, especially through air travel's high greenhouse gas emissions. This paper analyses the dilemmas facing tourism planning in many small island developing states and presents a model approach toward overcoming those dilemmas by adapting carbon neutral tourism policies. It researches the implementation issues facing carbon neutral tourism policies on the Seychelles Islands: tourism to the islands is energy-intensive, and current plans to increase tourist numbers will entail growing emissions of greenhouse gases. This paper analyses tourism's current levels of energy use and emissions, and explores ways to reduce them. Based on a survey of tourists and industry representatives in the Seychelles, it discusses options for tourism-dependent small island developing states to implement and finance carbon neutrality, while outlining the complexities and limitations of such an objective. [ABSTRACT FROM AUTHOR]

Germany is the leader among countries belonging to the Organisation for Economic Co-operation and Development (OECD) in reducing its emissions of the Kyoto basket of greenhouse gases (GHGs), having accomplished an emissions reduction of 18.9 percent from 1990 to 2000. This paper aims to explain the reasons for this success and to examine the impacts of the adoption of the Kyoto Protocol on the development of Germany's climate policy. In order to identify the factors that determined this outcome, we divide our examination of the policy process in Germany since 1987 into five periods and will evaluate it with a focus on policy measures implemented and actors as well as the institutions involved. It concludes that domestic factors, including the participation of the Greens in the coalition government, mainly determined Germany's success in developing advanced climate policies and measures to reduce its GHG emissions. The paper also highlights the importance of the linkage of climate policy with other policies, which provided incentives to those who would otherwise have opposed or remained neutral on the development of climate policy. As such, the adoption of the Kyoto Protocol did not have a direct impact on climate policy development in Germany, but it did have an indirect impact in that it triggered the development of common and coordinated policies and measures at the European Union (EU) level in order to achieve its quantified GHG reduction target of 8 percent committed to under the Kyoto Protocol, as seen in the introduction of an EU-wide emissions trading scheme. [ABSTRACT FROM AUTHOR]

Climate change will have potentially significant effects on freshwater quality due to increases in river and lake temperatures, changes in the magnitude and seasonality of river runoff, and more frequent and severe extreme events. These physical impacts will in turn have economic consequences through effects on riparian development, river and reservoir recreation, water treatment, harmful aquatic blooms, and a range of other sectors. In this paper, we analyze the physical and economic effects of changes in freshwater quality across the contiguous U.S. in futures with and without global-scale greenhouse gas mitigation. Using a water allocation and quality model of 2119 river basins, we estimate the impacts of various projected emissions outcomes on several key water quality indicators, and monetize these impacts with a water quality index approach. Under mitigation, we find that water temperatures decrease considerably and that dissolved oxygen levels rise in response. We find that the annual economic impacts on water quality of a high emissions scenario rise from $1.4 billion in 2050 to $4 billion in 2100, leading to present value mitigation benefits, discounted at 3%, of approximately $17.5 billion over the 2015-2100 period. [ABSTRACT FROM AUTHOR]

[Display omitted] Dynamic modeling of building performance is essential for understanding how current buildings will respond to projected changes in environmental conditions, and how these responses will in turn affect building occupants. Additionally, expected shifts in background energy systems will change the carbon intensity of energy delivered to buildings, while shifts in atmospheric composition will alter the global warming potential of each greenhouse gas. This paper models these three dynamic systems simultaneously to determine which projected shifts will have the largest influence on global warming impacts and occupant satisfaction metrics throughout the use phase of an office building prototype model in different climate zones of the United States. The median of RCP8.5 and RCP4.5 climate scenarios were used to morph local weather files to simulate the electricity and natural gas needed to meet heating and cooling loads in each location, as well as thermal comfort and daylighting metrics. These RCPs were also used to estimate shifts in the global warming potential factors for CO 2 , CH 4 , and N 2 O. Projected shifts in the electricity generation mix and upgrades to transmissions and distribution infrastructure in each region were used to estimate future carbon intensity factors for building site energy use. Compared to the baseline results, decarbonization of the electricity grid results in the largest shift in building operational GHG emissions, far outweighing emissions increases due to higher cooling loads. Shifts in ambient temperatures and direct and diffuse radiation had heterogeneous effects on occupant comfort, particularly in Boston across different seasons and orientations. Understanding how building performance is expected to respond to complex future trends will assist in designing adaptive buildings that take advantage of projected changes. [ABSTRACT FROM AUTHOR]

Climate change due to anthropogenic greenhouse gas emissions is expected to increase the frequency and intensity of precipitation events, which is likely to affect the probability of flooding into the future. In this paper we use river flow simulations from nine global hydrology and land surface models to explore uncertainties in the potential impacts of climate change on flood hazard at global scale. As an indicator of flood hazard we looked at changes in the 30-y return level of 5-d average peak flows under representative concentration pathway RCP8.5 at the end of this century. Not everywhere does climate change result in an increase in flood hazard: decreases in the magnitude and frequency of the 30-y return level of river flow occur at roughly one-third (20-45%) of the global land grid points, particularly in areas where the hydrograph is dominated by the snowmelt flood peak in spring. In most model experiments, however, an increase in flooding frequency was found in more than half of the grid points. The current 30-y flood peak is projected to occur in more than 1 in 5 y across 5-30% of land grid points. The large-scale patterns of change are remarkably consistent among impact models and even the driving climate models, but at local scale and in individual river basins there can be disagreement even on the sign of change, indicating large modeling uncertainty which needs to be taken into account in local adaptation studies. [ABSTRACT FROM AUTHOR]

Scientific evidence indicates that greenhouse gases emissions related to human activity are a significant contributor to global climate change. This paper investigates the impact of policy prescriptions and technologies for reducing U.S. greenhouse gas emissions. The analysis uses NERA's NewERA integrated model, which combines a top-down general equilibrium macro model of the U.S. economy with a detailed bottom-up model of the North American electricity sector. It examines the cost of cutting emissions by 0% to 80% of 2005 levels by 2050 under several scenarios, which consider different assumptions about policy choices ranging from purely market-based policy such as a cap-and-trade program to purely command-and-control policies and technology involving availability and efficacy of nuclear, Carbon Capture and Storage, renewables, and end-use efficiency technology. Our analysis shows a distinct efficiency advantage for market-based mechanisms and interaction of command-and-control mandates with market-based policies increase market distortions leading to higher welfare loss. We show that under such a mixed policy regime, carbon price is an unsuitable indicator of economic costs. [ABSTRACT FROM AUTHOR]

This paper uses decomposition analysis to investigate the key contributions to changes in greenhouse gas emissions in different scenarios. We derive decomposition formulas for the three highest-emitting sectors: power generation, industry, and transportation (both passenger and freight). These formulas were applied to recently developed 1.5 °C emission scenarios by the Integrated Model to Assess the Global Environment (IMAGE), emphasising the role of renewables and lifestyle changes. The decomposition analysis shows that carbon capture and storage (CCS), both from fossil fuel and bioenergy burning, renewables and reducing carbon intensity provide the largest contributions to emission reduction in the scenarios. Efficiency improvement is also critical, but part of the potential is already achieved in the Baseline scenario. The relative importance of different emission reduction drivers is similar in the OECD (characterised by relatively high per capita income levels and emissions) and non-OECD (characterised by relatively high carbon intensities of the economy) region, but there are some noteworthy differences. In the non-OECD region, improving efficiency in industry and transport and increasing the share of renewables in power generation are more important in reducing emissions than in the OECD region, while CCS in power generation and electrification of passenger transport are more important drivers in the OECD region. [ABSTRACT FROM AUTHOR]

Abstract: This paper examines potential changes in solid waste policies for the reduction in GHG for the country of Brazil and one of its major states and cities, Rio de Janeiro, from 2005 to 2030. To examine these policy options, trends in solid waste quantities and associated GHG emissions are derived. Three alternative policy scenarios are evaluated in terms of effectiveness, technology, and economics and conclusions posited regarding optimal strategies for Brazil to implement. These scenarios are been building on the guidelines for national inventories of GHG emissions (IPCC, 2006) and adapted to Brazilian states and municipalities’ boundaries. Based on the results, it is possible to say that the potential revenue from products of solid waste management is more than sufficient to transform the current scenario in this country into one of financial and environmental gains, where the negative impacts of climate change have created a huge opportunity to expand infrastructure for waste management. [Copyright &y& Elsevier]

To mitigate greenhouse gas and comply with cap-and-trade systems, the carbon capture and storage (CCS) is presently unviable for industrials dealing with low concentration of CO2 emissions. Alternatively, a new offset opportunity is being analysed in Canada: the afforestation of open woodlands (OWs) in the boreal territory. The results obtained from model simulations (with CBM-CFS3) showed that afforestation of boreal OWs can be a low C-intensive mitigation activity, in particular when understory planting is the chosen silvicultural approach, so that only 8-12 years are needed to reach a net positive C balance with the afforestation of OWs. A large-scale afforestation of boreal OWs - scheduled at 20kha per year during 20 years for a maximum of 400 kha - could provide capped industrials with a significant offset potential, for instance up to nearly 8% offset of all Quebec industrial process emissions (2009 data) after 45 years. In spite of a certain number of issues that can contribute to the uncertainty of the real environmental and economical benefits from the afforestation of OWs as a mitigation activity - most of which issues are discussed in this paper - this study presented a first glimpse at the extent to which the afforestation of boreal OWs in Quebec can provide large emitters with eventually substantial and efficient GHG offset potential, especially those emitters tied up with incompressible GHG emissions. [ABSTRACT FROM AUTHOR]

This article develops a formal model for comparing the cost structure of the two main transport options for natural gas: liquefied natural gas (LNG) and pipelines. In particular, it evaluates how variations in the prices of natural gas and greenhouse gas emissions affect the relative cost-efficiency of these two options. Natural gas is often promoted as the most environmentally friendly of all fossil fuels, and LNG as a modern and efficient way of transporting it. Some research has been carried out into the local environmental impact of LNG facilities, but almost none into aspects related to climate change. This paper concludes that at current price levels for natural gas and CO2 emissions the distance from field to consumer and the volume of natural gas transported are the main determinants of transport costs. The pricing of natural gas and greenhouse emissions influence the relative cost-efficiency of LNG and pipeline transport, but only to a limited degree at current price levels. Because more energy is required for the LNG process (especially for fuelling the liquefaction process) than for pipelines at distances below 9100 km, LNG is more exposed to variability in the price of natural gas and greenhouse gas emissions up to this distance. If the prices of natural gas and/or greenhouse gas emission rise dramatically in the future, this will affect the choice between pipelines and LNG. Such a price increase will be favourable for pipelines relative to LNG. [ABSTRACT FROM AUTHOR]

The increase of greenhouse gases (GHG) in the atmosphere and the resulting climatic change will have important effects in the 21st century. Agricultural activity is a source for three primary GHG: carbon dioxide (CO2 ), methane 2 (CH4 ) and nitrous oxide (N2O). Agricultural soils can also be a sink for CO2 through C sequestration into biomass products and soil organic matter. In this paper; it was summarized the literature on GHG emissions and C sequestration, provided a perspective on how agriculture can reduce its GHG burden and how it can help to mitigate GHG emissions through conservation measures. Impacts of agricultural practices and systems on GHG emission were reviewed. The potential of agricultural lands for CO2 , N2O and CH4 mitigation is not well recognized. Besides, there are a number of shortcomings that need to be emphasized. These include the uncertainties related to future shifts in global climate, land-use and plant cover, the poor yields of trees and crops on low fertile soils and under arid climate conditions, mineral fertilizers efficiency. In addition, more efforts are needed to improve methods for estimating C stocks and gas balances such as nitrous oxide (N2O) and methane (CH4) to determine net benefits of agriculture on the atmosphere. [ABSTRACT FROM AUTHOR]

In addition to reducing greenhouse gas emissions, societies worldwide have to cope with the potential impacts of climate change. The central question of this paper is to what extent our historically grown institutions enable actors to cope with the new challenges of climate adaptation. We present six qualities of governance institutions that are crucial to allow for, and encourage adaptation, and apply them to the National Adaptation Strategies of the Netherlands, the United Kingdom, Finland and Sweden. We conclude that although the governance institutions involved seem to have the basic qualities required, they face five institutional weaknesses, causing tensions on the long term: (1) lack of openness towards learning and variety; (2) strong one-sided reliance on scientific experts; (3) tension between top-down policy development and bottom-up implementation; (4) distrust in the problem-solving capacity of civil society; and (5) wickedness of reserving funding for long-term action. [ABSTRACT FROM AUTHOR]

Increased public awareness of climate change and shifting political attitudes within the United States may lead to federal regulations on the emissions of greenhouse gases. The transportation sector represents 27% of the total U.S. GHG emissions, with passenger cars and light-duty trucks accounting for 17% of the total. This paper examines international, national, state, and local level policies that may reduce transportation related GHG emissions. Emission reduction targets and atmospheric concentration stabilization goals will be decided upon at the international and national levels; however, implementation of emission reduction strategies will be delegated to the state and local governments and given flexibility to choose their specific approaches. Emission reduction strategies most likely to be implemented by states and local municipalities are examined for their effectiveness. The results are intended to be used by municipal public works managers and state level administrators for making GHG reduction policy decisions. At the local level, the climate action plans of four cities with varying populations were examined to calculate the annual reduction in tons of CO2 equivalents. At the state level, the climate action plans of Arizona, Colorado, Montana, North Carolina, New Mexico, and Vermont were examined for percent reduction in greenhouse gas emissions from transportation related initiatives. Results from GHG reduction initiatives in Miami, FL; Brookline, MA; Austin, TX; and Brattleboro, VT show that most effective local strategies are increased public transit ridership, increased bicycle use, and increased carpooling, with annual per capita reductions in CO2 of 279 lbs, 645 lbs, and 75 lbs, respectively. Effective state level policies are emission reductions for light-duty vehicles and smart growth measures with average reduction percentages of 9.2% and 7.1%, respectively. Economic cost-benefit analyses should be performed for each initiative before being implemented to ensure effective emission reduction measures are also cost effective. [ABSTRACT FROM AUTHOR]

The climatic effects of air-traffic pollutants, such as carbon dioxide (CO2) and mononitrogen oxides (NOx), aerosols, contrails, and aviation induced cirrus clouds, are repeatedly stressed in assessment reports. It is therefore desired to reduce all aviation emissions simultaneously. In this paper, a novel propulsion concept, which has the potential to reduce all pollutants, is assessed regarding its performance. It is based on gas turbine technology, derived from the intercooled and recuperated engine cycle. Exhaust water condensation is facilitated inside the engine to avoid the formation of contrails. Particles and aerosols are scavenged from the exhaust gases during condensation. The condensed water is partially redirected into the combustion chamber to mitigate NOx emissions via water injection technique. Calculations suggest that this new concept allows higher thermal efficiencies than conventional designs, yielding in better fuel economy and hence reduces greenhouse gas emissions. The corresponding design parameters for bypass ratio and fan pressure ratio suggest that this concept might be well suited for propfans or remotely driven fans. [ABSTRACT FROM AUTHOR]

Climate change is a long-term issue due to the long lifespan of greenhouse gases (GHG) and the delayed response of the climate system. This paper investigates the long-term economic consequences of both climate change impacts and mitigation efforts by applying the multi-regional, multi-sectoral integrated assessment model WIAGEM based on GTAP-EL coupled with the reduced-form multi-gas climate model ICM. We investigate emissions reduction paths to reach a radiative forcing target of 4.5 W/m². Economic impacts are studied and compared with and without the inclusion of all GHG gases. We find that multi-gas emissions reduction causes less economic losses compared with a case where only CO2 emissions reductions would be considered. [ABSTRACT FROM AUTHOR]

The non-CO2 greenhouse gases have so far jointly contributed around 40 percent to overall global warming. In this paper we examine the role of non-CO2 greenhouse gases in meeting long-term climate change targets. For this purpose, we develop climate mitigation scenarios aimed at achieving long-term stabilization of global radiative forcing. We use the MESSAGE model for a thorough bottom-up representation of the six Kyoto greenhouse gases and corresponding mitigation technologies. This approach endogenizes energy feedback effects from mitigation of non-CO2 gases and takes into account the interplay and side benefits that exist across GHGs. We analyze two mitigation scenarios that stabilize global radiative forcing at 4.5 W/m² as compared to pre-industrial times-one allowing only for CO2 mitigation and another with multigas mitigation. In addition, we also investigate a lower stabilization level of 3 W/m² and look into the implications this has for abatement strategies. Our approach helps us to identify a portfolio of measures in the energy, industry and agricultural sectors for achieving a proposed climate target. We find that considering the full basket of GHGs improves the effectiveness of the mitigation portfolio resulting in significantly lower costs, especially in the short term. In the long run, the bulk of the emissions reductions are still found to come from CO2 and this effect becomes more pronounced under the more stringent climate target. This emphasizes the importance of a diverse mitigation portfolio that includes both CO2 and non-CO2 related abatement options in meeting long-term climate targets. [ABSTRACT FROM AUTHOR]

A significant reduction in global greenhouse gas emissions will require development of new technologies if such reductions are to be achieved without excessive costs. An important question is whether an agreement of the Kyoto type, which does not include elements related to research and development of new technologies, will give sufficient incentives to develop such new technologies. On the one hand, since greenhouse gas emissions will become costly for countries and private producers, there will then be incentives to undertake the effort and costs to develop new technologies. On the other hand, research and development in one country is not only advantageous for this country, but usually also for other countries. The reason for this is that producers in these countries will learn from the project in many cases; for example, through (informal) networks, journals, and, in some cases, through the import of goods from the country where the new technology is developed. The purpose of this paper is to discuss properties of an international climate agreement of the Kyoto type, when research and development investments undertaken in one country are also beneficial for other countries. We examine whether a Kyoto type of agreement can provide the correct social amount of aggregate emissions, and research and development investments in new technologies. We argue that the outcome of a Kyoto type agreement will differ from the social optimum. In particular, for a given level of abatement a Kyoto type agreement provides too few investments relative to the social optimum. [ABSTRACT FROM AUTHOR]

This paper examines different concepts of a 'warming commitment' which is often used in various ways to describe or imply that a certain level of warming is irrevocably committed to over time frames such as the next 50 to 100 years, or longer. We review and quantify four different concepts, namely (1) a 'constant emission warming commitment', (2) a 'present forcing warming commitment', (3) a 'zero emission (geophysical) warming commitment' and (4) a 'feasible scenario warming commitment'. While a 'feasible scenario warming commitment' is probably the most relevant one for policy making, it depends centrally on key assumptions as to the technical, economic and political feasibility of future greenhouse gas emission reductions. This issue is of direct policy relevance when one considers that the 2002 global mean temperatures were 0.8 ± 0.2°C above the pre-industrial (1861-1890) mean and the European Union has a stated goal of limiting warming to 2°C above the pre-industrial mean: What is the risk that we are committed to overshoot 2°C? Using a simple climate model (MAGICC) for probabilistic computations based on the conventional IPCC uncertainty range for climate sensitivity (1.5 to 4.5 °C), we found that (1) a constant emission scenario is virtually certain to overshoot 2°C with a central estimate of 2.0°C by 2100 (4.2°C by 2400). (2) For the present radiative forcing levels it seems unlikely that 2°C are overshoot. (central warming estimate 1.1 °C by 2100 and 1.2°C by 2400 with ∼10% probability of overshooting 2°C). However, the risk of overshooting is increasing rapidly if radiative forcing is stabilized much above 400 ppm CO2 equivalence (1.95 W/m²) in the long-term. (3) From a geophysical point of view, if all human-induced emissions were ceased tomorrow, it seems 'exceptionally unlikely' that 2°C will be overshoot (central estimate: 0.7°C by 2100; 0.4°C by 2400). (4) Assuming future emissions according to the lower end of published mitigation scenarios (350 ppm CO2eq to 450 ppm CO2eq) provides the central temperature projections are 1.5 to 2.1 °C by 2100 (1.5 to 2.0°C by 2400) with a risk of overshooting 2°C between 10 and 50% by 2100 and 1-32% in equilibrium. Furthermore, we quantify the 'avoidable warming' to be 0.16-0.26°C for every 100 GtC of avoided CO2 emissions - based on a range of published mitigation scenarios. [ABSTRACT FROM AUTHOR]

Long-living wood products contribute to the mitigation of climate change in many ways. They act as a carbon pool during their service life, as they withdraw CO2 from its natural cycle. After their service life, they can substitute for fossil fuels if they are incinerated in adequate furnaces. Furthermore, wood products can substitute for more energy-intense products made of 'conventional' materials. This paper quantifies the substitution and pool effects of an increased use of wood in the building sector in Switzerland for the years 2000-2130. Life cycle data on greenhouse gas (GHG) emissions of 12 wood products and their substitutes are used as proxies for relevant building products; this data is linked to the forecasted wood flows for each group of building products in a cohort-model. For the political assessment, GHG effects occurring abroad and in Switzerland are distinguished. The results show that the pool effect of an increased use of long-living wood products is of minor importance, whereas the energetic and material substitution effects are much more relevant, especially on a long-term. For construction products, the Swiss share of the GHG effect related to the material substitution is relatively high, as mainly nationally produced materials are substituted for. For interior products, the Swiss share of the GHG effect related to the material substitution is rather small because mainly imports are substituted for. The results must be considered as rough estimates. Nonetheless, these calculations show that an increased use of wood in the building sector is a valid and valuable option for the mitigation of greenhouse gas emissions and for reaching GHG emission targets in a mid- to long-term. Still, the pool and substitution capacity of an increased use of wood is relatively small compared to the overall GHG emissions of Switzerland. [ABSTRACT FROM AUTHOR]

To what extent should States curb current and future greenhouse gas emissions? Integrated assessment models are commonly used to build or at least legitimize policy making. Although these models should not be viewed automatically as black boxes, they are particularly complex and are built on restrictive assumptions. Hence results derived from such models need to be taken with caution and on no account as "scientific truth". The aim of this paper is to provide a deeper insight into some of the key methods and assumptions these models are based on. We focused our work on climate change response functions. Assumptions and methods selected to evaluate the influence of climate change impacts will indeed strongly orientate the results derived from integrated assessment models based on cost-benefit concepts. It is therefore essential to point out their chief characteristics and limitations. [ABSTRACT FROM AUTHOR]

It is widely agreed that the Clean Development Mechanism (CDM) is a useful international instrument that encourages and reinforces the reduction of greenhouse gas emissions (GHGs), and also that it should be further promoted as a way to fill the gap in energy and GHG efficiency between industrialized and developing countries. A number of problematic issues have become apparent, however, during the past two and a half years of experience with the CDM. This paper identifies some of these and provides possible insights into their nature and possible resolution. While some technical aspects such as baseline setting are crucial and are being resolved gradually through accumulated experience, other political aspects such as the utilization of public funding need more discussion (rather than formal negotiations). [ABSTRACT FROM AUTHOR]

Under the United Nations Framework Convention on Climate Change, the international community has sought to find a policy framework to address the threat of human-induced climate change. The most significant action to date has been the adoption of the Kyoto Protocol in December 1997. Given Russia's recent decision to ratify the protocol it is now likely to enter into force early in 2005 despite its repudiation by the United States. The protocol includes legally-binding emission reductions for some countries over the period 2008 to 2012. It has not yet been possible, however, to find an approach that is truly global and that is aligned with the long-term environmental goal of reducing global greenhouse gas emissions to a "safe" level. A framework for action that addresses these shortcomings is developed in this paper. The underlying tenets are environmental effectiveness, economic efficiency, and equity. The importance of an appropriate timeframe for action is acknowledged, and involvement by all major emitting countries is facilitated. Importantly, this last point includes participation by developing countries in a way that accommodates their aspirations for economic growth. The crucial role of technology is recognized and is drawn into the solution. Together these elements allow a response that minimizes costs and maximizes the environmental outcome while at the same time enhancing the growth prospects of developing countries. [ABSTRACT FROM AUTHOR]