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Under the Paris Agreement, countries must articulate their most ambitious mitigation targets in their Nationally Determined Contributions (NDCs) every five years and regularly submit interconnected information on greenhouse gas (GHG) aspects, including national GHG inventories, NDC progress tracking, mitigation policies and measures (PAMs), and GHG projections in various mitigation scenarios. Research highlights significant gaps in the definition of mitigation targets and the reporting on GHG-related elements, such as inconsistencies between national GHG inventories, projections, and mitigation targets, a disconnect between PAMs and mitigation scenarios, as well as varied methodological approaches across sectors. To address these challenges, the Mitigation-Inventory Tool for Integrated Climate Action (MITICA) provides a methodological framework that links national GHG inventories, PAMs and GHG projections, applying a hybrid decomposition approach that integrates machine learning regression techniques with classical forecasting methods for developing GHG emission projections. MITICA enables mitigation scenario generation until 2050, incorporating over 60 PAMs across Intergovernmental Panel on Climate Change (IPCC) sectors. It is the first modelling approach that ensures consistency between reporting elements, aligning NDC progress tracking and target setting with IPCC best practices while linking climate change with sustainable economic development. MITICA's results include projections that align with observed trends, validated through cross-validation against test data, and employ robust methods for evaluating PAMs, thereby establishing its reliability. [ABSTRACT FROM AUTHOR]

Nitrogen (N) lost during beef cattle production accompanies various environmental risks and has become a rising concern among agricultural stakeholders. The objective of this study was to quantify the N footprint of producing Hanwoo beef cattle, which is a Korean indigenous breed of cattle, in Korea at the farm gate through a life cycle assessment approach. Field surveys were conducted on 106 farms across 9 provinces to identify regional distinctions in farming systems and evaluate total N losses from beef production. N losses were calculated using emission factors from the refined IPCC guidelines, which were then expressed as N footprint (g N/kg of live body weight (LBW)). Uncertainty and sensitivity analyses were deployed to evaluate the precision of the results and identify factors that contributed to the output. The N footprint averaged 132.7(± 61.8) g N/kg LBW and varied between provinces according to animal categories, manure management systems, land use and fertilizer application rates. Volatilization was the highest contributing factor, followed by leaching and denitrification, each representing 68.5, 21.4, and 10.1 percent of the N footprint, respectively. The uncertainty of the result was found to be 46.6 percent and was highly associated with emission factor uncertainties. We devised five mitigation scenarios that are cost effective and do not penalize productivity and evaluated their capacity for reducing N footprint: (i) dietary modifications to decrease animal N excretion rate; (ii) microorganism additives to reduce volatilization from housing; (iii) manure storages recycling manure within the farm to replace synthetic fertilizers; (iv) distributing biochar to the field after fertilizer application to curtail losses from crop production; (v) combination of i, ii, iii, and iv. Combining these scenarios demonstrated the potential to reduce 12.1 percent of the total N footprint. The extents of mitigation scenarios varied across provinces (ranging from 5.2 to 21.7 percent) and were shown to be contingent on feeding practices and type of crop cultivated. Overall, our study provides a national metric that can be utilized to communicate the environmental impacts of Korean beef production. The analyses indicate that more precise results could be achieved with future endeavors towards developing country-specific emission factors. The mitigation potentials of the presented scenarios propose possibilities for feasible and sustainable beef production in Korea. [ABSTRACT FROM AUTHOR]

Summary: Pledges at recent climate summits fall short for 1.5°C warming. Here, we calculate the CO2 emissions reduction required to stay below 1.5°C, considering available data on current emissions up to 2022, extending the time horizon to 2300, and using an approach different from the carbon budget to offer another perspective on what is required to stay below 1.5°C. For a 50% chance of staying below 1.5°C during this century, fossil fuel and industry CO2 emissions need to decrease linearly by about 5% per year, in line with other recent studies. However, extending the time horizon to 2300 leads to chances dropping to 30% for the same decarbonization scenario without sustained carbon dioxide removal beyond levels needed for offsetting residual CO2 emissions. We further show that the chances of staying below 1.5°C of global warming critically hinge on the assumed future land-use CO2 emissions and mitigation of non-CO2 forcers. Science for society: We used an observation-informed numerical model that differs from the traditional “carbon budget” approach to estimate fossil CO2 emissions cuts in line with limiting global warming, considering the latest data on emissions up to 2022. We showed that to have a 50% chance of staying below 1.5°C this century, emissions from fossil fuel burning and industrial processes must drop by about 5% each year (or equivalently, reach zero in 20 years). If we extend the timeframe to 2300, the chances drop to 30% even with this level of emissions reduction. The success of limiting warming also depends heavily on future land use (especially deforestation) and reducing other greenhouse gases besides CO2. This research highlights the importance of taking stronger action now to reduce emissions and finding ways to remove CO2 from the atmosphere. It also emphasizes the need for smart land-use practices and tackling other greenhouse gases to achieve our climate goals.

How the implementation of the European Commission's landing obligation (LO) would affect French vessels of the mixed demersal fishery in the Eastern English Channel was hardly foreseen because of the diversity of vessel characteristics and strategies in the area. Assessing whether the vessels would be able to mitigate the bio-economic impacts of LO and avoid choke situations through exemptions, by changing their fishing patterns or by avoiding areas, required fine scale spatio-temporal modelling of fish and fleet dynamics and of resulting technical interactions. We conducted a bio-economic impact assessment for seven scenarios of mitigation focussing on the differences across fleets and the impact of fleet spatial behavioural flexibility. We found that netters rapidly benefited from the LO as opposed to trawlers and that exemptions helped mitigate the economic loss with limited biomass loss. The avoidance strategies proved to be efficient in reducing unwanted catch of whiting and enabled unexpected protection of juvenile sole. Sensitivity analysis on the drivers of fishing behaviour indicated that the ability and efficiency of adapting fishing patterns depended on main gear and vessel size. Results evidenced the difficult trade-offs LO implies among stocks, fish stages, fleets, and even sub-regions, beyond the usual biological vs. economic contrasts. [ABSTRACT FROM AUTHOR]

The food chain is a large contributor to environmental pollution, especially greenhouse gas emissions, strongly associated with the consumption of animal-based proteins. The understanding of the negative environmental impacts of dietary habits by the population is of the utmost importance to provide the means to effect change to more sustainable eating patterns. The main purpose of this study was to assess the carbon footprint of animal protein consumption in Portugal, while also evaluating six mitigation scenarios aiming to lower greenhouse gas emissions through strategic changes to the animal protein consumption of current dietary habits. Overall, the carbon footprint associated with animal protein consumption is 2.63 kg CO2 eq/(cap⋅day) nationally and 28.4 t CO2 eq/month for the faculty canteen. Meat is by far the largest contributor to the carbon footprint in both cases, with beef being its "hotspot". All scenarios showed significant reduction potentials, with values ranging from 16% (lower value for both the national case and the faculty canteen) to 71% (faculty canteen). In sum, substantial carbon footprint reductions can be attained if policymakers support the implementation of effective measures to promote a shift in the current animal protein consumption towards more sustainable eating habits. [ABSTRACT FROM AUTHOR]

The main objective of the present study is the development of a comprehensive methodology for the estimation of the Carbon Footprint (CF) of research project activities and the identification of the best practices that can be followed by project partners within the project implementation to reduce its carbon footprint. The CF methodology is based on the GHG Protocol Guidance and the emissions factors of the Department for Environment Food & Rural Affairs (DEFRA). The emissions sources related to project activities are the following: heating (from fuels combustion), electricity, water, work-commuting, materials, printable deliverables, IT equipment and events. An application study is performed for a research project focusing on the Mediterranean area and it is found that on-site events represent a 41% share of the total CF of the project. The use of public transport and soft mobility by employees can result in a −37% reduction in the CF of work-commuting. The most significant best practices for more sustainable organization of project events, leading to a reduction of −62% and −50% in the CF of the events, are (1) public transportation and soft mobility of the events' participants to reach the event location within the host city, and (2) the promotion of the use of buses and railway for the international/national travels of participants to/from the event's host city, respectively. Τhe organization of hybrid events may also reduce the project event's CF by −50%. The cumulative reduction in the total CF of the project examined from all the CF mitigation scenarios studied, relevant to the energy-efficient target of the EU, the origin of materials used, work-commuting and events (materials used, transportation, hybrid events), is estimated to be −45%. [ABSTRACT FROM AUTHOR]

The water energy environment (WEE) nexus models have become indispensable for the integrated natural resources management under the growing regional and global risks and insecurities in pursuit of sustainable development. A new framework has been developed based on bottom-up energy system model and the related greenhouse gas emissions which aimed to predict and depict an apparent WEE nexus outlook for residential, electric power, industry, and agriculture sectors under various scenarios. Bottom-up nexus modeling has been done by Long Energy Alternative Planning software tool for the mentioned sectors from 2016 to 2040. The Urmia Lake basin covering 52,000 Km2 as a vulnerable region to climate change located in the northwest of Iran is selected as a case study in this paper. The UL basin's demographic and economic data were used as energy demand drivers. Discussion of the results based on the detailed energy and emission analysis under different scenarios showed the most energy saving and environmental pollutants abatement potential equal to 27.76 million barrels of oil equivalent and 11.3 million metric tons of carbon dioxide equivalents under the Integrated Policy (IP) scenario up to 2040. Sensitivity analysis of total energy demand to socioeconomic changes shows mean increases of 3% and 2% to each unit increase in the population and gross domestic product. The cost–benefit analysis for the IP scenario indicates more net present values if the interest rate remains less than 8%. [ABSTRACT FROM AUTHOR]

China is currently in the process of the middle and late stage of industrialization, and energy-related CO2 emissions have reached 10 Gt. This paper models energy consumption and related CO2 emissions and analyzes the development trends of various driving factors of CO2 emissions, explicitly considering China's economic and social development goals in the medium- and long-term. Different scenarios for 2020–2060 are projected based on the Kaya identity. Energy consumption will peak at 6,200 Mtce in 2035 in the BAU scenario with the energy-related CO2 emissions peaking at 11.1 Gt in 2026–2027 advanced by the rising non-fossil energy share, while energy consumption and CO2 emissions in the accelerated transition scenario would be potentially reduced by 300 Mtce and 300–400 Mt respectively. In the BAU scenario, the net CO2 emissions will remain around 2,000 Mt in 2060, after removing 1,800 Mt by CCS/CCUS, indicating that China needs to enhance its post-2030 policy to deliver the carbon neutrality pledge. Steady energy efficiency improvement, radical industrial and energy restructuring are three key driving forces for carbon neutrality. [ABSTRACT FROM AUTHOR]

We analyze a set of simulations to assess the impact of climate change on global forests where MC2 dynamic global vegetation model (DGVM) was run with climate simulations from the MIT Integrated Global System Model-Community Atmosphere Model (IGSM-CAM) modeling framework. The core study relies on an ensemble of climate simulations under two emissions scenarios: a business-as-usual reference scenario (REF) analogous to the IPCC RCP8.5 scenario, and a greenhouse gas mitigation scenario, called POL3.7, which is in between the IPCC RCP2.6 and RCP4.5 scenarios, and is consistent with a 2 °C global mean warming from pre-industrial by 2100. Evaluating the outcomes of both climate change scenarios in the MC2 model shows that the carbon stocks of most forests around the world increased, with the greatest gains in tropical forest regions. Temperate forest regions are projected to see strong increases in productivity offset by carbon loss to fire. The greatest cost of mitigation in terms of effects on forest carbon stocks are projected to be borne by regions in the southern hemisphere. We compare three sources of uncertainty in climate change impacts on the world's forests: emissions scenarios, the global system climate response (i.e. climate sensitivity), and natural variability. The role of natural variability on changes in forest carbon and net primary productivity (NPP) is small, but it is substantial for impacts of wildfire. Forest productivity under the REF scenario benefits substantially from the CO2 fertilization effect and that higher warming alone does not necessarily increase global forest carbon levels. Our analysis underlines why using an ensemble of climate simulations is necessary to derive robust estimates of the benefits of greenhouse gas mitigation. It also demonstrates that constraining estimates of climate sensitivity and advancing our understanding of CO2 fertilization effects may considerably reduce the range of projections.

Curbing GHG emissions while preserving economic growth is one of the main challenges that developing countries are facing to meet the Paris Agreement commitments. Brazil's NDC target aims to reduce economy-wide absolute levels of GHG emissions by 37% in 2025 and 43% in 2030, compared to 2005 emissions. In this paper, we compare command-and-control and carbon pricing policies to induce the Brazilian economy to meet its NDC targets. We focus on analysing synergies and trade-offs in macroeconomic and social development, captured by economic growth and income distribution while reducing GHG emissions. By integrating a series of sectoral models and a computable general equilibrium (CGE) model, we develop and run different policy scenarios that simulate a set of carbon pricing schemes in Brazil. Our analysis shows that NDC implementation in Brazil under carbon pricing policies allows the country to meet its targets and improve economic and social indicators compared to a command-and-control policy. With about the same GHG emissions up to 2030, important macroeconomic and social co-benefits can be achieved under a carbon pricing policy in Brazil, allowing for reduced welfare losses against business-as-usual trends. Carbon pricing policies are more cost-effective to meet NDC targets in Brazil up to 2030, resulting in higher GDP and household income, in comparison to other individual policy instruments, including command-and-control and subsidies to investments. A carbon price of about 10 USD/tCO2e, combined importantly with deforestation rates under control, would allow Brazil to meet its NDC targets. Recycling carbon pricing revenues can help soften the burden on the labour market and protect low-income households from welfare losses. [ABSTRACT FROM AUTHOR]

Given the prospects of low short‐term emissions reduction, carbon removals (CDRs) are expected to play an important role in achieving ambitious mitigation targets in future scenarios of integrated assessment models (IAMs), particularly Bioenergy with Carbon Capture and Storage (BECCS). In this paper, we explore the IAMC 1.5℃ database to depict the characteristics of the two main CDR options present in mitigation scenarios: BECCS and afforestation/reforestation. We apply a linear mixed‐effect model to capture the specific regional and cross‐IAM effects. Results reveal that the distribution of BECCS and afforestation deployment differs across IAMs and regions and, to a second extent, time. BECCS is preferred in the scenarios not for its ability to expand energy use but actually because it appears as an alternative to afforestation, which is associated with a decrease in energy use. However, the regional distribution of CDR deployment does not show a common pattern across scenarios and IAMs. Therefore, a more comprehensive investigation is needed before it can support policy proposals. [ABSTRACT FROM AUTHOR]

This paper explores how climate change and the transition to a low-carbon economy pose new systemic financial risks (so-called Green Swans), and the role of central banks in addressing them within their financial stability mandate. It does so by developing a three-layered analytical framework that central banks could use to shape their climate-related monetary and financial policies. First, central banks have already started to revisit their backward-looking risk models for the purpose of integrating forward-looking climate-related risks. Second, given the limitations of existing climate-economy models in a context of radical uncertainty, we argue that future climate scenario analysis should rely on systems-based approaches such as non-equilibrium models and more qualitative tools such as those provided by a socio-technical perspective. However, even these new approaches will not suffice from the perspective of financial stability: climate-related risks will remain largely unhedgeable as long as a system-wide and structural transformation is not undertaken, including an unprecedented level of cooperation between central banks, fiscal authorities, the private and public sectors at large, civil society, and the international community. Third, and as a result of the first two points, embracing climate-related uncertainty means that central banks play a new role: helping to coordinate the policies needed to fight climate change, so as to fulfil their own mandate of financial stability. To this end, we make a few specific policy proposals. Key policy insights Central banks' traditional risk models do not enable them to identify climate-related systemic risks (Green Swans). Adopting new forward-looking and non-equilibrium modelling approaches is necessary to better appreciate the nature of climate-related risks, but it is not sufficient. To continue fulfilling their mandate of financial stability over longer time horizons than those traditionally considered, central banks must also get involved in policy coordination to mitigate climate change. This includes exploring which policy mixes (fiscal-monetary-prudential) can better address the climate imperatives ahead; considering climate stability as a global public good to be supported through reforms of the international monetary and financial system; and systematizing the integration of long-term sustainability criteria in both private and public sectors. [ABSTRACT FROM AUTHOR]

This article quantifies the aggregate potential of greenhouse gas (GHG) emissions reductions in 2030 from the assumed full implementation of major international cooperative initiatives (ICIs). To this end, a methodology is proposed to aggregate emission reduction goals of the most significant and potentially impactful global initiatives. We identified the extent to which reductions are additional to national policies, assuming these actions do not displace climate actions elsewhere, and accounted for overlap ranges between the ICIs. The analysis was conducted for 17 initiatives, selected from an original list of over 300 with a series of testing criteria, across eight sectors and ten major emitting economies. These initiatives include cities, regions, businesses, and other subnational and non-state actors, cooperating with each other and sometimes working in partnership with national governments or other international organizations. Our analysis shows that the combined achievement of initiatives' reduction goals could reduce global emissions in 2030 by 18–21 GtCO2e/year in addition to current national policies (total of 60–63 GtCO2e/year), down to 39–44 GtCO2e/year. If delivered fully, reductions from these 17 initiatives would help move the global emissions trajectory within the range of a 2°C-consistent emission pathway by 2030, although a significant gap would remain to reduce emissions to a 1.5°C-consistent pathway. Key policy insights We propose a transparent and robust methodology to aggregate GHG mitigation potential of ICIs, accounting for overlaps between ICIs. If major initiatives meet their goals and do not change the course of other existing climate actions, they could make large contributions by 2030 towards global efforts to stay within the range of a below 2°C-consistent emission pathway by 2030. The full suite of existing initiatives beyond those in this analysis could further increase ambition towards achieving the Paris Agreement's temperature goals. Cities and regions, businesses and forestry initiatives account for significantly more than half of all possible emission reductions from ICIs; implementation of their goals should be a key policy focus. [ABSTRACT FROM AUTHOR]

The Nationally Determined Contributions (NDCs) to the Paris Agreement (PA) submitted so far do not put the world on track to meet the targets of the Agreement and by 2020 countries should ratchet up ambition in the new round of NDCs. Brazil's NDC to the PA received mixed reviews and has been rated as "medium" ambition. We use the Brazil Land Use and Energy System (BLUES) model to explore low-emission scenarios for Brazil for the 2010–2050 period that cost-effectively raise ambition to levels consistent with PA targets. Our results reinforce the fundamental role of the agriculture, forest, and land use (AFOLU) sectors and explore inter-sectoral linkages to power generation and transportation. We identify transportation as a prime candidate for decarbonization, leveraging Brazil's already low-carbon electricity production and its high bioenergy production. Results indicate the most important mitigation measures are electrification of the light-duty vehicle (LDV) fleet for passenger transportation, biodiesel and biokerosene production via Fischer-Tropsch synthesis from lignocellulosic feedstock, and intensification of agricultural production. The use of carbon capture and storage (CCS) as well as netzero deforestation make significant contributions. We identify opportunities for Brazil, but synergies and trade-offs across sectors should be minded when designing climate policies. [ABSTRACT FROM AUTHOR]

This article quantifies the net aggregate impact in 2030 of commitments by individual non-state and subnational actors (e.g. regions, cities and businesses, collectively referred to as 'NSAs') to reduce greenhouse gas (GHG) emissions. The analysis was conducted for NSAs operating within ten major emitting economies that together accounted for roughly two-thirds of global GHG emissions in 2016. Our assessment includes 79 regions (e.g. subnational states and provinces), approximately 6,000 cities, and nearly 1,600 companies with a net emissions coverage of 8.1 GtCO2e/year, or a quarter of the ten economies' total GHG emissions in 2016. The analysis reflects a proposed methodology to aggregate commitments from different subnational (i.e. regional and city government) and non-state (i.e. business) actors, accounting for overlaps. If individual commitments by NSAs in the ten high-emitting economies studied are fully implemented and do not change the pace of action elsewhere, projected GHG emissions in 2030 for the ten economies would be 1.2–2.0 GtCO2e/year or 3.8%–5.5% lower compared to scenario projections for current national policies (31.6–36.8 GtCO2e/year). On a country level, we find that the full implementation of these individual commitments alone could result in the European Union and Japan overachieving their nationally determined contributions (NDCs), while India could further overachieve its unconditional NDC target. In the United States, where the national government has rolled back climate policies, NSAs could become a potential driving force for climate action. Key policy insights Full implementation of reported and quantifiable individual commitments by regions, cities and businesses (NSAs) in ten major economies could reduce emissions by 3.8%–5.5% in 2030 below current national policies scenario projections. National governments' mitigation targets could be more ambitious if they would take NSA commitments into account. With full implementation of such action, the European Union and Japan would overachieve their NDC targets. For the United States such action could help meeting its original 2025 NDC target in spite of rollbacks in national climate policies. The full universe of NSA climate action expands far beyond the subset of commitments analysed in this study; NSAs could become a strong driving force for enhanced action towards the Paris climate goals. [ABSTRACT FROM AUTHOR]

A study from Bjørn et al (2021) suggests that methods to allocate emissions to companies proportionally to their economic growth are consistent with equity-related principles and are effective at conserving a global emissions budget while the science based targets initiative’s (SBTi’s) absolute contraction approach (ACA) fulfills neither qualification. Here we identify four areas of concern with the study and propose a more comprehensive approach to science based targets (SBT) method evaluation. We respond that first, the authors’ method characterization does not differentiate between the emissions allocation that occurs in mitigation scenarios and that which is normatively caused by method formulae, and it misinterprets the drivers of emissions allocation in scenarios. Second, we note that the authors evaluate a method formula for ACA that does not match its use by the SBTi. Third, we acknowledge that allocating emissions based on economic growth can yield incoherent results by comparison to published climate change mitigation scenarios and suggest the authors also evaluate whether methods are effective at conserving sub-global emissions budgets. Fourth, we observe that although the study is framed as an evaluation of SBT methods, it relies almost entirely on assessments of one characteristic. We conclude by proposing a set of principles that should be met by effective SBT methods and a high-level assessment of SBT methods against these principles.

This is the first comprehensive study to examine how urbanization affects the microclimate of Istanbul using the urban climate model MUKLIMO_3 with a 200 m horizontal resolution. In this study, the parameters in the land use table were estimated for Istanbul by combining different land use data sets and creating a high-resolution land use distribution. A specified heat wave episode was simulated via MUKLIMO_3 by using defined land use, meteorological sounding, and surface measurements. The findings suggest that MUKLIMO_3 can reasonably capture the 24-h daily temperature variation in both rural and urban locations, but it has a negative bias compared to station observations. We also employ eight mitigation scenarios by changing the albedo of roofs and implementing green-roofs and walls. All scenarios reduced air temperatures to varying degrees in urbanized areas along the northern Marmara coastline on both sides of Istanbul during daylight hours. The white and hybrid scenarios resulted in a temperature drop of up to 2 K at 12:00 UTC, with the most significant cooling effect observed in hybrid 4. Increasing the albedo of roofs from 0.5 to 0.7 resulted in the spatial expansion of cooled areas towards the north of the city along the Bosphorus. However, green roof scenarios are not found to be as effective as high-albedo scenarios. [Display omitted] • High-resolution land use data were created for Istanbul. • Urban climate model MUKLIMO_3 is evaluated for the first time for UHI in Istanbul. • Heat reduction effects of the eight UHI mitigation scenarios were tested. • Hybrid scenarios have the most effective cooling potential for UHI intensity. [ABSTRACT FROM AUTHOR]

This article identifies and quantifies the 10 most important benchmarks for climate action to be taken by 2020–2025 to keep the window open for a 1.5°C-consistent GHG emission pathway. We conducted a comprehensive review of existing emissions scenarios, scanned all sectors and the respective necessary transitions, and distilled the most important short-term benchmarks for action in line with the long-term perspective of the required global low-carbon transition. Owing to the limited carbon budget, combined with the inertia of existing systems, global energy economic models find only limited pathways to stay on track for a 1.5°C world consistent with the long-term temperature goal of the Paris Agreement. The identified benchmarks include:Sustain the current growth rate of renewables and other zero and low-carbon power generation until 2025 to reach 100% share by 2050;No new coal power plants, reduce emissions from existing coal fleet by 30% by 2025;Last fossil fuel passenger car sold by 2035–2050;Develop and agree on a 1.5°C-consistent vision for aviation and shipping;All new buildings fossil-free and near-zero energy by 2020;Increase building renovation rates from less than 1% in 2015 to 5% by 2020;All new installations in emissions-intensive sectors low-carbon after 2020, maximize material efficiency;Reduce emissions from forestry and other land use to 95% below 2010 levels by 2030, stop net deforestation by 2025;Keep agriculture emissions at or below current levels, establish and disseminate regional best practice, ramp up research;Accelerate research and planning for negative emission technology deployment. Key policy insightsThese benchmarks can be used when designing policy options that are 1.5°C, Paris Agreement consistent.They require technology diffusion and sector transformations at a large scale and high speed, in many cases immediate introduction of zero-carbon technologies, not marginal efficiency improvements.For most benchmarks we show that there are signs that the identified needed transitions are possible: in some specific cases it is already happening. [ABSTRACT FROM PUBLISHER]

China's rapid urbanization, large population, and increasing consumption of calorie-and meat-intensive diets, have resulted in China becoming the world's largest source of ammonia (NH 3 ) emissions from livestock production. This is the first study to use provincial, condition-specific emission factors based on most recently available studies on Chinese manure management and environmental conditions. The estimated NH 3 emission temporal trends and spatial patterns are interpreted in relation to government policies affecting livestock production. Scenario analysis is used to project emissions and estimate mitigation potential of NH 3 emissions, to year 2030. We produce a 1 km × 1 km gridded NH 3 emission inventory for 2008 based on county-level activity data, which can help identify locations of highest NH 3 emissions. The total NH 3 emissions from manure generated by livestock production in 2008 were 7.3 Tg NH 3 ·yr − 1 (interquartile range from 6.1 to 8.6 Tg NH 3 ·yr − 1 ), and the major sources were poultry (29.9%), pigs (28.4%), other cattle (27.9%), and dairy cattle (7.0%), while sheep and goats (3.6%), donkeys (1.3%), horses (1.2%), and mules (0.7%) had smaller contributions. From 1978 to 2008, annual NH 3 emissions fluctuated with two peaks (1996 and 2006), and total emissions increased from 2.2 to 7.3 Tg·yr − 1 increasing on average 4.4%·yr − 1 . Under a business-as-usual (BAU) scenario, NH 3 emissions in 2030 are expected to be 13.9 Tg NH 3 ·yr − 1 (11.5–16.3 Tg NH 3 ·yr − 1 ). Under mitigation scenarios, the projected emissions could be reduced by 18.9–37.3% compared to 2030 BAU emissions. This study improves our understanding of NH 3 emissions from livestock production, which is needed to guide stakeholders and policymakers to make well informed mitigation decisions for NH 3 emissions from livestock production at the country and regional levels. [ABSTRACT FROM AUTHOR]

The Paris Agreement adopted in December 2015 puts the world on a new footing for global solutions to the issue of mitigation of climate change. In the formulation of climate policy, the issues of trade in cleantech goods, and the promotion of cleantech industries through industrial policy measures such as local content requirements, now loom large. The case for reconciliation between the United Nations Framework Convention on Climate Change (UNFCCC) and World Trade Organization (WTO) is now becoming stronger, and calls for specific steps to enable trade to accommodate green industry promotion strategies. Specifically, it is proposed that the next Conference of the Parties under the UNFCCC, to be staged in Morocco late in 2016, adopt a resolution calling on the WTO to recognize the authority of the UNFCCC in recognizing climate change mitigation as a ‘public good’, whose pursuit might allow for temporary use of industrial development policies such as local content requirements, if countries wished to follow such a strategy. Policy relevance Countries’ trade policies are currently formulated without reference to climate change, while climate change strategies are formulated without reference to principles of fair trade. The article proposes means through which the two regimes, governing trade and climate change, and the two principal bodies involved, the WTO and UNFCCC, can be brought to a state of mutual recognition and (prospective) harmony. The implications for climate policy are traced. [ABSTRACT FROM PUBLISHER]

There is much optimism that the 2015 Conference of the Parties of the United Nations Framework Convention will yield an agreement on mitigation of climate change, to become effective in 2020. In this context, Bahrain represents a developing country with insufficient data to assess mitigation opportunities: its per capita carbon emissions rank among the world's highest, yet there has been no research on the reduction potential of its rapidly growing transport sector. We examine this reduction potential and the costs of various mitigation measures and, further, explore barriers and the view of policymakers and experts. Potential benefits of combined mitigation scenarios are also identified based on their acceptability. We adopt a modified participatory method to develop the scenarios, using the long-range energy alternative planning (LEAP) modelling system, and find that an integrated policy approach can deliver a 23 % reduction in carbon dioxide emissions, costing 108 United States dollars per avoided metric tonne, with politically acceptable scenarios. Better performance, however, would require less acceptable approaches. These findings are significant for decision-making in Bahrain and other Gulf Cooperation Council countries; national target preparation and the setting of fuel economy standards should be begun promptly. We offer lessons to other developing countries on the timely regulation of technical specifications and numbers of passenger vehicles. Participatory approaches to the assessment of mitigation measures can advance environmentally effective, economically feasible and politically acceptable scenarios. The global community can use these results to provide necessary technical and financial assistance to developing countries. [ABSTRACT FROM AUTHOR]

This article assesses Japan's carbon budgets up to 2100 in the global efforts to achieve the 2 °C target under different effort-sharing approaches based on long-term GHG mitigation scenarios published in 13 studies. The article also presents exemplary emission trajectories for Japan to stay within the calculated budget. The literature data allow for an in-depth analysis of four effort-sharing categories. For a 450 ppm CO2e stabilization level, the remaining carbon budgets for 2014–2100 were negative for the effort-sharing category that emphasizes historical responsibility and capability. For the other three, including the reference ‘Cost-effectiveness’ category, which showed the highest budget range among all categories, the calculated remaining budgets (20th and 80th percentile ranges) would run out in 21–29 years if the current emission levels were to continue. A 550 ppm CO2e stabilization level increases the budgets by 6–17 years-equivalent of the current emissions, depending on the effort-sharing category. Exemplary emissions trajectories staying within the calculated budgets were also analysed for ‘Equality’, ‘Staged’ and ‘Cost-effectiveness’ categories. For a 450 ppm CO2e stabilization level, Japan's GHG emissions would need to phase out sometime between 2045 and 2080, and the emission reductions in 2030 would be at least 16–29% below 1990 levels even for the most lenient ‘Cost-effectiveness’ category, and 29–36% for the ‘Equality’ category. The start year for accelerated emissions reductions and the emissions convergence level in the long term have major impact on the emissions reduction rates that need to be achieved, particularly in the case of smaller budgets. Policy relevance In previous climate mitigation target formulation processes for 2020 and 2030 in Japan, neither equity principles nor long-term management of cumulative GHG emissions was at the centre of discussion. This article quantitatively assesses how much more GHGs Japan can emit by 2100 to achieve the 2 °C target in light of different effort-sharing approaches, and how Japan's GHG emissions can be managed up to 2100. The long-term implications of recent energy policy developments following the Fukushima nuclear disaster for the calculated carbon budgets are also discussed. [ABSTRACT FROM AUTHOR]

There is now a wealth of model-based evidence on the technology choices, costs and other impacts (such as fossil fuel demand) associated with mitigation towards stringent climate targets. Results from over 900 hundred scenarios have been reviewed in the latest Intergovernmental Panel on Climate Change Assessment Report (IPCC AR5) including baseline scenarios under which no mitigation action is taken, as well as those under which different limits to global warming are targeted. A number of additional studies have been undertaken in order to assess the implications of global mitigation action. The objective of the paper is to provide a concise overview and comparison of major input assumptions and outputs of recent studies focused on mitigating to the most stringent targets explored, which means around the 2 °C level of global average temperature increase by 2100. The paper extracts key messages grouped into four pillars: mitigation costs, technology uncertainty, policy constraints, and co-benefits. The principal findings from this comparison are that, according to the models, mitigation to 2 °C is feasible, but delayed action, the absence or limited deployment of any of a number of key technologies (including nuclear, CCS, wind and solar), and limited progress on energy efficiency, all make mitigation more costly and in many models infeasible. Further, rapid mitigation following delayed action leads to potentially thousands of idle fossil fuel plants globally, posing distributional and political economy challenges. [ABSTRACT FROM AUTHOR]

Agricultural diffuse water pollution remains a notable global pressure on water quality, posing risks to aquatic ecosystems, human health and water resources and as a result legislation has been introduced in many parts of the world to protect water bodies. Due to their efficiency and cost-effectiveness, water quality models have been increasingly applied to catchments as Decision Support Tools (DSTs) to identify mitigation options that can be introduced to reduce agricultural diffuse water pollution and improve water quality. In this study, the Soil and Water Assessment Tool (SWAT) was applied to the River Wensum catchment in eastern England with the aim of quantifying the long-term impacts of potential changes to agricultural management practices on river water quality. Calibration and validation were successfully performed at a daily time-step against observations of discharge, nitrate and total phosphorus obtained from high-frequency water quality monitoring within the Blackwater sub-catchment, covering an area of 19.6 km 2 . A variety of mitigation options were identified and modelled, both singly and in combination, and their long-term effects on nitrate and total phosphorus losses were quantified together with the 95% uncertainty range of model predictions. Results showed that introducing a red clover cover crop to the crop rotation scheme applied within the catchment reduced nitrate losses by 19.6%. Buffer strips of 2 m and 6 m width represented the most effective options to reduce total phosphorus losses, achieving reductions of 12.2% and 16.9%, respectively. This is one of the first studies to quantify the impacts of agricultural mitigation options on long-term water quality for nitrate and total phosphorus at a daily resolution, in addition to providing an estimate of the uncertainties of those impacts. The results highlighted the need to consider multiple pollutants, the degree of uncertainty associated with model predictions and the risk of unintended pollutant impacts when evaluating the effectiveness of mitigation options, and showed that high-frequency water quality datasets can be applied to robustly calibrate water quality models, creating DSTs that are more effective and reliable. [ABSTRACT FROM AUTHOR]

Agriculture is responsible for approximately 25% of anthropogenic global GHG emissions. This significant share highlights the fundamental importance of the agricultural sector in the global GHG emissions reduction challenge. This article develops and tests a methodology for the integration of agricultural and energy systems modelling. The goal of the research is to extend an energy systems modelling approach to agriculture in order to provide richer insights into the dynamics and interactions between the two (e.g. in competition for land-use). We build Agri-TIMES, an agricultural systems module using the TIMES energy systems modelling framework, to model the effect of livestock emissions and explore emissions reduction options. The research focuses on Ireland, which is an interesting test case for two reasons: first, agriculture currently accounts for about 30% of Ireland's GHG emissions, significantly higher than other industrialized countries yet comparable with global levels (here including emissions associated with other land-use change and forestation); second, Ireland is both a complete and reasonably sized agricultural system to act as a test case for this new approach. This article describes the methodology used, the data requirements, and technical assumptions made to facilitate the modelling. It also presents results to illustrate the approach and provide associated initial insights. Policy relevance Most of the policy focus with regard to climate mitigation targets has been on reducing energy-related CO2emissions, which is understandable as they represent by far the largest source of emissions. Non-energy-related GHG emissions – largely from agriculture, industrial processes, and waste – have received significantly less attention in policy discourse. Going forward, however, if significant cuts are made in energy-related CO2emissions, the role of non-energy-related GHG emissions will grow in importance. It is therefore crucial that climate mitigation analyses and strategies are not limited to the energy system. This article shows the value of using integrated energy and agriculture techno-economic modelling techniques to draw evidence for new comprehensive climate policy strategies able to discern between the full range of technical solutions available. It enables the production of economy-wide least-cost climate mitigation pathways. [ABSTRACT FROM AUTHOR]

This paper proposes an integrative approach to assessing the impact of several highway developments on the connectivity of high-elevation coniferous forests in Yunnan (China). These forests are the optimal habitat of the black and white snub-nosed monkey ( Rhinopithecus bieti ), an endemic endangered primate species. A graph-based approach is used for modeling the ecological network of this species and analyzing connectivity across several spatio-temporal scales, from daily movements to dispersal events. The aims of this paper are (1) to assess the impact of an existing highway by comparing connectivity with and without the infrastructure; (2) to assess the potential improvement of connectivity induced by diverting traffic from the highway to a tunnels/viaducts section under construction; (3) to compare several mitigation scenarios with potential reforestation measures. The analysis is carried out both at the global level to quantify changes in the overall connectivity at several distances and, at the local level to identify which parts of the network are the most vulnerable. The results show that the highway has a low effect (− 3.3%) on connectivity at the daily scale, but that increased gradually with distance (up to − 21.5% for the largest), however habitat loss is only − 0.1%. Some of the affected habitat patches are located 30 km north of the highway. The three mitigation scenarios have a different impact on connectivity. The third scenario leading to the creation of new habitat patches is the only one that strongly increases connectivity at several scales. This kind of graph approach can improve assessment of the impact of constructing a given infrastructure by taking into account the different scales of ecological processes and so can better target conservation measures for impacted species, here the emblematic, endangered, Yunnan snub-nosed monkey. [ABSTRACT FROM AUTHOR]

Most studies that explore deep GHG emission reduction scenarios assume that climate goals are reached by implementing least-cost emission mitigation options, typically by implementing a global carbon tax. Although such a method provides insight into total mitigation costs, it does not provide much information about how to achieve a transition towards a low-carbon energy system, which is of critical importance to achieving ambitious climate targets. To enable sensible deep emission reduction strategies, this study analysed the effectiveness of 16 specific mitigation measures on a global level up to 2050, by using an energy-system simulation model called TIMER. The measures range from specific energy efficiency measures, like banning traditional light bulbs and subsidizing electric vehicles, to broader policies like introducing a carbon tax in the electricity sector. All measures combined lead to global CO2emission reductions ranging between 39% and 73% compared to baseline by 2050, depending on the inclusion of sectoral carbon taxes and the availability of carbon capture and storage (CCS) and nuclear power. Although the effectiveness of the measures differs largely across regions, this study indicates that measures aimed at stimulating low-carbon electricity production result in the highest reductions in all regions.Policy relevanceThe results of the calculations can be used to evaluate the effects of individual climate change mitigation measures and identify priorities in discussions on global and regional policies. The type of fragmented policy scenarios presented here could provide a relevant bottom-up alternative to cost-optimal implementation of policies driven by a carbon tax. We identify overlapping and even counter-productive climate policy measures through an analysis that presents the policy effectiveness by region, and by sector. The set of 16 policy measures addresses the largest emitting sectors and represents options that are often discussed as part of planned policies. [ABSTRACT FROM PUBLISHER]

Under the United Nations Framework Convention on Climate Change, industrialized countries have agreed to cover the incremental costs of climate change mitigation in developing countries and recent climate negotiations have reaffirmed the central role of climate finance for global mitigation efforts. We use an integrated energy–economy–climate model to assess the potential magnitude of financial transfers to developing countries that can be expected under non-market transfer mechanisms as well as international emission trading with several allocation schemes. Our results indicate that for the latter, depending on international permit allocation rules financial transfers to developing countries could reach almost USD bln 400 per year in 2020, with Sub-Saharan Africa receiving financial inflows of as much as 14.5% of its GDP. Reviewing the literature on natural resource revenues, official development assistance and foreign direct investment, we identify three major channels through which such sizable financial inflows may induce harmful effects for recipients: volatility, Dutch disease, and rent-seeking and corruption. We discuss the relevance of these mechanisms for climate finance and identify institutional arrangements which could help to avoid a ‘climate finance curse’. We conclude that there is no deterministic relationship between financial inflows and adverse consequences, as the most serious problems could be prevented or at least alleviated by appropriately designed policies and governance provisions. [ABSTRACT FROM PUBLISHER]

We analyze a set of simulations to assess the impact of climate change on global forests where MC2 dynamic global vegetation model (DGVM) was run with climate simulations from the MIT Integrated Global System Model-Community Atmosphere Model (IGSM-CAM) modeling framework. The core study relies on an ensemble of climate simulations under two emissions scenarios: a business-as-usual reference scenario (REF) analogous to the IPCC RCP8.5 scenario, and a greenhouse gas mitigation scenario, called POL3.7, which is in between the IPCC RCP2.6 and RCP4.5 scenarios, and is consistent with a 2 °C global mean warming from pre-industrial by 2100. Evaluating the outcomes of both climate change scenarios in the MC2 model shows that the carbon stocks of most forests around the world increased, with the greatest gains in tropical forest regions. Temperate forest regions are projected to see strong increases in productivity offset by carbon loss to fire. The greatest cost of mitigation in terms of effects on forest carbon stocks are projected to be borne by regions in the southern hemisphere. We compare three sources of uncertainty in climate change impacts on the world’s forests: emissions scenarios, the global system climate response (i.e. climate sensitivity), and natural variability. The role of natural variability on changes in forest carbon and net primary productivity (NPP) is small, but it is substantial for impacts of wildfire. Forest productivity under the REF scenario benefits substantially from the CO _2 fertilization effect and that higher warming alone does not necessarily increase global forest carbon levels. Our analysis underlines why using an ensemble of climate simulations is necessary to derive robust estimates of the benefits of greenhouse gas mitigation. It also demonstrates that constraining estimates of climate sensitivity and advancing our understanding of CO _2 fertilization effects may considerably reduce the range of projections.

This article presents and discusses the main findings of a study focusing on climate change mitigation actions (MAs) in Brazil. Brazilian government presented to the 15th Conference of the Parties of the Climate Change Convention held in Copenhagen in 2009 (UNFCCC COP15) voluntary mitigation goals: a reduction in between 36.1 and 38.9% of the country's green house gases (GHG) emissions projected to 2020. If Brazil meets its voluntary goals, its GHG emissions in 2020 will be 6–10% lower than in 2005. The main research question addressed in this study is what conditions should Brazil meet to achieve its pledge? It discusses how MAs are approached, conceptualized and planned in Brazil. It describes how the country identifies MAs and the contextual framework used to define them. It also maps the initiatives underway in the country, and analyses the issues faced for its successful implementation, as well as for future approaches. The main conclusion is that Brazil seems to be in a good position to meet its voluntary mitigation goals up to 2020, as avoiding deforestation will take up the bulk of the emission reduction. After 2020, Brazil will face a new challenge: combine economic development with low GHG energy-related emissions. [ABSTRACT FROM AUTHOR]

Context: The effective ways of using wood production with a view to mitigating climate change are still disputed. Currently, there are two major opposing conceptions. One proposes to increase the carbon stock in forests, in wood products or in some kind of long-term wood storage, thus giving primacy to carbon sequestration. The other invokes the concept of biomass carbon neutrality to assert that the substitution of wood for fossil fuels avoids carbon emissions. Aim and method: This paper contributes to this debate by comparing carbon footprints of heat generation when choosing wood or other fuels as alternatives. Result: On condition that wood can be preserved with sufficient durability to meet the time frame of the necessary transition towards carbon-free energy resources (decadal to centennial time scales), one can demonstrate that the use of fossil fuels, with the exception of coal, is still preferable. The reasons are that the intrinsic carbon emission factor for wood has the highest value among all fuels in common use and that reference to the concept of wood carbon neutrality neglects the possibility of storing carbon positively in wood for a long time. Conclusion: The conclusion is that to mitigate climate change it is better to store wood than use it as a fuel. [ABSTRACT FROM AUTHOR]

Natural carbon sinks currently absorb approximately half of the anthropogenic CO _2 emitted by fossil fuel burning, cement production and land-use change. However, this airborne fraction may change in the future depending on the emissions scenario. An important issue in developing carbon budgets to achieve climate stabilisation targets is the behaviour of natural carbon sinks, particularly under low emissions mitigation scenarios as required to meet the goals of the Paris Agreement. A key requirement for low carbon pathways is to quantify the effectiveness of negative emissions technologies which will be strongly affected by carbon cycle feedbacks. Here we find that Earth system models suggest significant weakening, even potential reversal, of the ocean and land sinks under future low emission scenarios. For the RCP2.6 concentration pathway, models project land and ocean sinks to weaken to 0.8 ± 0.9 and 1.1 ± 0.3 GtC yr ^−1 respectively for the second half of the 21st century and to −0.4 ± 0.4 and 0.1 ± 0.2 GtC yr ^−1 respectively for the second half of the 23rd century. Weakening of natural carbon sinks will hinder the effectiveness of negative emissions technologies and therefore increase their required deployment to achieve a given climate stabilisation target. We introduce a new metric, the perturbation airborne fraction, to measure and assess the effectiveness of negative emissions.

Abstract: The farm is the most influential stage of agricultural production because farming practices affect both pre-farm and on-farm environmental impacts. Since farm diversity is not usually taken into consideration, it is legitimate to question the interest of including it in Life Cycle Assessment (LCA) studies. This work explores several approaches to modelling the farm stage when assessing the environmental impact of an agricultural supply chain in a context with variable farm performances. A LCA of a poultry supply chain was applied from cradle-to-slaughterhouse gate. The first approach is a classical one in which farm diversity is not taken into account and an average farm is constructed on the basis of weighted average farm characteristics. The second approach distinguishes four farm types identified by cluster analysis, and four LCA were performed according to these farm types. Farm types were distinguished based on their consumption of inputs and the type of ventilation of the farm buildings. Results indicate that the classical approach is sufficient to highlight problem hotspots and to identify promising mitigation measures. Reducing the transport distance of imported maize, improving feed conversion efficiency and anaerobic digestion of slaughterhouse animal wastes were identified as appropriate mitigation measures. As feed production and poultry rearing are the stages with the most impact, distinguishing farm types provides i) insight into farm functioning to better explain the variability of environmental impacts and understand how to reduce them, ii) reduce the uncertainty of results, and iii) provide appropriate recommendations for mitigation measures. Coupling a farm typology with the LCA is particularly useful when farming systems are very diverse like in Reunion Island where the climate varies considerably across the island. [Copyright &y& Elsevier]

The main assumptions and findings are presented on a comparative analysis of three GHG long-term emissions scenarios for Brazil. Since 1990, land-use change has been the most important source of GHG emissions in the country. The voluntary goals to limit Brazilian GHG emissions pledged a reduction in between 36.1% and 38.9% of GHG emissions projected to 2020, to be 6–10% lower than in 2005. Brazil is in a good position to meet the voluntary mitigation goals pledged to the United Nations Framework Convention on Climate Change (UNFCCC) up to 2020: recent efforts to reduce deforestation have been successful and avoided deforestation will form the bulk of the emissions reduction commitment. In 2020, if governmental mitigation goals are met, then GHG emissions from the energy system would become the largest in the country. After 2020, if no additional mitigation actions are implemented, GHG emissions will increase again in the period 2020–2030, due to population and economic growth driving energy demand, supply and GHG emissions. However, Brazil is in a strong position to take a lead in low-carbon economic and social development due to its huge endowment of renewable energy resources allowing for additional mitigation actions to be adopted after 2020. Policy relevance The period beyond 2020 is now relevant in climate policy due to the Durban Platform agreeing a ‘protocol, legal instrument or agreed outcome with legal force’ that will have effect from 2020. After 2020, Brazil will be in a situation more similar to other industrialized countries, faced with a new challenge of economic development with low GHG energy-related emissions, requiring the adoption of mitigation policies and measures targeted at the energy system. Unlike the mitigation actions in the land-use change sector, where most of the funding will come from the national budgets due to sovereignty concerns, the huge financial resources needed to develop low-carbon transport and energy infrastructure could benefit from soft loans channelled to the country through nationally appropriate mitigation actions (NAMAs). [ABSTRACT FROM PUBLISHER]

The main assumptions and findings are presented on a comparative analysis of three GHG long-term emissions scenarios for Brazil. Since 1990, land-use change has been the most important source of GHG emissions in the country. The voluntary goals to limit Brazilian GHG emissions pledged a reduction in between 36.1% and 38.9% of GHG emissions projected to 2020, to be 6-10% lower than in 2005. Brazil is in a good position to meet the voluntary mitigation goals pledged to the United Nations Framework Convention on Climate Change (UNFCCC) up to 2020: recent efforts to reduce deforestation have been successful and avoided deforestation will form the bulk of the emissions reduction commitment. In 2020, if governmental mitigation goals are met, then GHG emissions from the energy system would become the largest in the country. After 2020, if no additional mitigation actions are implemented, GHG emissions will increase again in the period 2020-2030, due to population and economic growth driving energy demand, supply and GHG emissions. However, Brazil is in a strong position to take a lead in low-carbon economic and social development due to its huge endowment of renewable energy resources allowing for additional mitigation actions to be adopted after 2020. Policy relevance The period beyond 2020 is now relevant in climate policy due to the Durban Platform agreeing a 'protocol, legal instrument or agreed outcome with legal force' that will have effect from 2020. After 2020, Brazil will be in a situation more similar to other industrialized countries, faced with a new challenge of economic development with low GHG energy-related emissions, requiring the adoption of mitigation policies and measures targeted at the energy system. Unlike the mitigation actions in the land-use change sector, where most of the funding will come from the national budgets due to sovereignty concerns, the huge financial resources needed to develop low-carbon transport and energy infrastructure could benefit from soft loans channelled to the country through nationally appropriate mitigation actions (NAMAs). [ABSTRACT FROM AUTHOR]

The events of March 2011 at the nuclear power complex in Fukushima, Japan, raised questions about the safe operation of nuclear power plants, with early retirement of existing nuclear power plants being debated in the policy arena and considered by regulators. Also, the future of building new nuclear power plants is highly uncertain. Should nuclear power policies become more restrictive, one potential option for climate change mitigation will be less available. However, a systematic analysis of nuclear power policies, including early retirement, has been missing in the climate change mitigation literature. We apply an energy economy model framework to derive scenarios and analyze the interactions and tradeoffs between these two policy fields. Our results indicate that early retirement of nuclear power plants leads to discounted cumulative global GDP losses of 0.07% by 2020. If, in addition, new nuclear investments are excluded, total losses will double. The effect of climate policies imposed by an intertemporal carbon budget on incremental costs of policies restricting nuclear power use is small. However, climate policies have much larger impacts than policies restricting the use of nuclear power. The carbon budget leads to cumulative discounted near term reductions of global GDP of 0.64% until 2020. Intertemporal flexibility of the carbon budget approach enables higher near-term emissions as a result of increased power generation from natural gas to fill the emerging gap in electricity supply, while still remaining within the overall carbon budget. Demand reductions and efficiency improvements are the second major response strategy. [ABSTRACT FROM AUTHOR]

Abstract: In this paper the GHG mitigation potential of a power system with prevailing use of lignite is assessed through the example of the Macedonian power system. The analysis is conducted using the WASP model in order to develop three different scenarios (business as usual – BAU and two mitigation scenarios) for the power system expansion over the period 2008–2025. In the first mitigation scenario two gas power plants with combined cycle are planned to replace some of the lignite-based capacities. The second mitigation scenario, besides the gas power plants, assumes electricity consumption reduction related to the large industrial consumers and an increased share of new renewable energy sources. Detailed calculations of the GHG emissions are made for all scenarios. The comparison of emissions in 2025 and in 2008 shows that the increase of 78% in the case of predominantly lignite BAU scenario is reduced to 41% by the first mitigation scenario, and to 14% by the second mitigation scenario. The mitigation costs appeared to be less then 10 $/t CO2-eq for the first mitigation scenario, and even negative for the second one. [Copyright &y& Elsevier]