Energy Sector Emissions Research Articles

Klímasemleges energiatermelés – Kilátások Magyarországon 2024-ben

In order to protect our planet's climate, it is important to reduce humanity's carbon dioxide emissions significantly. The energy sector is one of the most polluting industries, but the rapid spread of renewable energy sources over the past 20 years can significantly contribute to the reduction of carbon dioxide emissions. The study examined which energy sources are used to produce electricity in Hungary, and how the proportion of renewable energy has developed in recent years compared to more polluting energy production methods. There is a strong negative exponential relationship between the share of renewable energy and the carbon dioxide emissions of the energy sector, based on which the carbon dioxide emissions of the energy sector can be significantly reduced by increasing the share of renewable energy. A forecast was made for the renewable share based on past data and the revised state of the National Energy and Climate Plan in 2023, and a linear forecast was made for the energy sector's emissions. There is a strong exponential relationship between the data series. Both models examined in the study had strong explanatory power, but neither model supports the possibility of climate-neutral energy production by 2030.

Club convergence of per capita greenhouse gas emissions in Africa: A multi-sectoral analysis of trends and drivers

This study aims to fill a significant knowledge gap by examining the dynamics of sectoral per capita greenhouse gas (GHG) emissions convergence across 54 African countries from 1980 to 2019. Using the log (t) club convergence approach, this study uncovers the presence of multiple local steady-state convergence patterns within each sector. A significant correlation emerges between the classification of countries regarding their total and energy sector emissions. In particular, less industrialized African countries with higher proportions of renewable energy consumption tend to demonstrate elevated convergence rates in both total and per capita energy emissions. Further, the analysis indicates that wealthier countries with greater trade intensity and increased industrialization are associated with a higher rate of convergence in the agriculture sector. By highlighting the heterogeneity in sectoral patterns and the evolving landscape of GHG emissions in Africa, this study provides valuable insight for the formulation of policies that concurrently address the challenges of sustainable development and climate change mitigation.

Predictive modeling of energy‐related greenhouse gas emissions in Ghana towards a net‐zero future

AbstractGhana is determined to reduce greenhouse gas (GHG) emissions by at least 15% by 2030 and attain net‐zero emissions by 2070. However, like many developing countries, Ghana must utilize its limited resources effectively to actualize its climate goals. Currently, climate policies in the country are not driven by emission data, which has important implications on effective utilization of resources and selection of efficient mitigation techniques. We analyzed energy consumption and GHG emission data between 1990 and 2016 from Ghana's energy sector which is responsible for about 36% of the country's total emissions. Predictive models were then developed using machine learning to forecast energy related emissions up to 2030. Based on the analysis and projections, attainable data‐driven recommendations were proposed to direct climate policies in the country. We found that between 1990 and 2016, petroleum fuel consumption increased by about 64.5% and the corresponding GHG emissions increased by 303%. The projections suggests that by 2030, energy sector emissions could increase by 131% compared to 2016 levels. Transport sector emission is also projected to increase by a whopping 219% and fuel consumption could hit 6742 ktoe by 2030, which is about 106% increase from the 2016 benchmark. The findings from this work will direct policy for effective mitigation of GHG emissions in the country while ensuring effective utilization of climate resources to pursue its net‐zero targets. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

The effects of environmental innovations and international technology spillovers on industrial and energy sector emissions – Evidence from small open economies.

Environmental innovations hold promise for cutting greenhouse gas (GHG) emissions, but most technology investments are made in large technologically leading countries. Thus, emission reductions in small open economies, such as the Nordic countries, depend on not only domestic technological development, but also technology spillovers from foreign countries. The present study analysed how the development of climate change technologies affected the Nordic countries' GHG emissions from the industrial and energy sectors during a particular time frame. Consequently, while controlling for economic growth and population, domestic and foreign technological development's effects on industrial and energy sector GHG emissions were examined from the 1990–2019 period. The results revealed that both domestically developed environmental technologies and technology spillovers from foreign economies mitigated GHG emissions from these nations' energy and industrial sectors, thereby providing an efficient pathway to achieving sectoral environmental sustainability. In particular, domestic environmental technologies were found to be more efficient in driving environmental sustainability in the industrial sector, whereas impacts from domestic and foreign technological development did not differ significantly in the energy sector. Furthermore, given that economic growth plays a vital role in GHG emissions, environmental Kuznets curve (EKC; inverted U-shaped and U-shaped) relationships have been observed in the energy and industrial sectors, respectively. This suggests that the examined countries' industrial sectors have more environmental quality hurdles to overcome.

SEWGS integration in a direct reduction steelmaking process for CO2 mitigation

The iron and steel industry represents one of the most carbon intensive sectors accounting for roughly 25% of CO2 emissions generated by the industrial sectors and for 7% of total energy sector emissions. The aim of this work is to assess the techno-economic analysis of the integration of the SEWGS technology in the DRI-EAF process to reduce the carbon footprint of this steelmaking route. The study has been carried out using plant data taken from literature and investigating possibilities of GHG mitigation by introducing carbon-capture technologies such as MEA and MDEA scrubbing or the SEWGS technology. The latter solution shows environmental and economic advantages compared to the cases based on amine scrubbing. A reduction of CO2 emissions close to 90%, with respect to the BF-BOF route, can be achieved with the implementation of the SEWGS when a renewable electricity scenario is considered. Economic KPIs such as the Levelised Cost of Hot Rolled Coil and the Cost of CO2 avoided have been computed for all the plants. In addition, a sensitivity analysis on natural gas and electricity prices has been carried out. The integration of the SEWGS technology represents a promising solution for the reduction of the carbon footprint of the DRI-EAF process and, potentially, it could be commercially viable in the near future considering that the DRI and EAF processes are already globally commercialised.

Long-term spatial and temporal evaluation of the PM2.5 and PM10 mass concentrations in Lithuania

Evaluating the spatio-temporal trends of particulate mass concentration is beneficial for appraising the risk to human health and environmental quality. In this study, the long-term observational data of particulate matter mass concentration (PM2.5, PM10), and PM2.5/PM10 ratios' variability of sixteen EPA air pollution monitoring stations in Lithuania over 17 years (2006–2022), were analyzed. A seasonal-trend decomposition procedure using Loess and Mann-Kendall regression with Sen's slope was used to qualify long-term trends and seasonality. The Theil-Sen analysis estimated significant reductions of −2.66, −4.42, and −1.89% per year for PM10, PM2.5, and PM2.5/PM10 ratios after 2013. The possible reasons for these changes are the reduction in liquid fuel consumption, the mitigation of energy sector emissions, as well as Lithuania's positive gross domestic product (GDP) in recent years. The results also revealed a significant increasing trend (+4.48%/year) for PM10 in rural areas, due to increased agricultural emissions. Trend analysis was also applied to different quartiles. The upper and middle values of PM2.5 and the upper values of PM10, responsible for high PM mass concentration, underwent a significant decrease.

Impact of carbon price on Indonesia’s power sector up to 2050

This study uses TIMES model to assess Indonesia’s power sector’s carbon price impact from 2020 to 2050 and the price needed by 2030 to meet the Paris Agreement NDC target. Four scenarios are used to model the impact of carbon price up to 2050: no carbon price, Indonesia’s current price of USD 2.02/tCO2e, ICPF middle- and high-income countries, USD 50/tCO2e and USD 75/tCO2e. Four price scenarios—10, 25, 35, and 150 USD/tCO2e —are added to better understand the carbon price’s effects. As carbon prices rise, installed capacity and power generation will shift to lower-carbon technology. Ultracritical coal, gas-fired, solar, geothermal, and hydropower plants will replace subcritical coal. Investment, fixed, and variable costs would exceed BaU with a higher carbon price. 2.02 to 25 USD/tCO2e can start the coal-to-gas switch but not significantly change the generation profile. The generation will change significantly above 35 USD/tCO2e. Carbon emissions peak lower with rising carbon prices. USD 25 carbon price reduces emissions significantly; a carbon price below that is costly and ineffective. Indonesian Law No. 16 of 2016 ratified the Paris Agreement NDC, committing Indonesia to reduce greenhouse gas emissions by 29% by 2030 or 41% with international assistance. Energy sector emissions need to decrease by 11% for a 29 percent reduction and 14% for a 41 percent reduction. A 29% reduction requires USD 39.65/tCO2e carbon price, while a 41% reduction requires USD 43.78/tCO2e. These prices are still within the reasonable ICPF price limit for Indonesia to approach the middle-income country price floor.

Poland’s energy transformation in the context of the challenges of the European green deal

One of the most important socio-economic challenges is the skilful transformation of the economy towards low and zero-emission energy sources. This transformation is ongoing, and Poland, due to its high dependence on coal and high emissions has a challenging task to perform. Hence, the article aims to indicate the activities undertaken by Poland as part of the energy transformation related to the European Green Deal and the impact of energy transformation on the Polish economy. Therefore, the issues discussed include: explaining the principles characterizing the European Green Deal programme, describing the current state of the Polish energy sector, indicating activities that will make Poland a zero-emissions nation, and highlighting the economic implications of this energy transformation at the national level. The analysis shows that the transformation of the domestic energy sector is a long-term, ongoing process. The share of green energy in the national mix is systematically, albeit slowly, growing, and energy sector emissions show a downward trend, although in the current difficult energy situation in Europe, this trend may slow down. Moreover, for systemic and financial reasons it is not possible to quickly replace energy production from coal with other low or zero-emission energy carriers. The study used a critical analysis of the literature and strategic documents on the energy sector, the institutional and legal method, the prognostic method, and inductive inference.

A Critical, Temporal Analysis of Saudi Arabia’s Initiatives for Greenhouse Gas Emissions Reduction in the Energy Sector

The per capita greenhouse gas (GHG) emissions of Saudi Arabia were more than three times the global average emissions in 2019. The energy sector is the most dominant GHG-emitting sector in the country; its energy consumption has increased over five times in the last four decades, from over 2000 quadrillion joules in 1981 to around 11,000 quadrillion joules in 2019, while the share of renewable energy in 2019 was only 0.1%. To reduce GHG emissions, the Saudi Arabian government has undertaken initiatives for improving energy efficiency and increasing the production of renewable energies in the country. However, there are few investigative studies into the effectiveness of these initiatives in improving energy efficiency and reducing greenhouse gas emissions. This study provides an overview of the various energy efficiency and renewable energy initiatives undertaken in Saudi Arabia. Then, it evaluates the effectiveness of energy-related policies and initiatives using an indicator-based approach. In addition, this study performs temporal and econometrics analyses to understand the trends and the causal relationships among various drivers of energy sector emissions. Energy intensity and efficiency have improved moderately in recent years. This study will support policymakers in identifying significant policy gaps in reducing the emissions from the energy sector; furthermore, this study will provide a reference for tracking the progress of their policy initiatives. In addition, the methodology used in this study could be applied in other studies to evaluate various climate change policies and their progress.

Modeling temporal variability in the surface expression above a methane leak: The ESCAPE model

Leaks in natural gas distribution networks are often initially detected by odor and then localized during operators' walking surveys. The size of the enhancement detected and the leak's proximity to infrastructure are used to determine leak severity of the leak and how quickly it is repaired. Methane (CH4) enhancements on the surface above the leak change with atmospheric conditions, but currently the leak severity assessment is made without considering the environmental conditions and could result in misdiagnosis of the leak. This study has developed the “ESCAPE” model, a tool that can be used to estimate CH4 enhancements on the surface above a leak using meteorological and leak data as input. Surface CH4 concentrations calculated using the ESCAPE model agrees well with measurements made during controlled experiments (m = 0.95 and R2 = 0.95). This study highlights the effect of micrometeorology on gas transport from the surface to the atmosphere, where the surface and the atmospheric conditions have the largest effect on the flux. Here, recommendations are made to improve industry best practices, including recording the meteorological conditions at the time of the leak detection, avoiding walking surveys on days where there are strong winds or strong solar irradiance and that known leak locations should be revisited and measured in different conditions. Mitigating CH4 emissions from the gas distribution network is a cost-effective and economically realistic target. Distribution operators can be directed by the output of ESCAPE model to correctly identify and repair the largest distribution leaks and could reduce annual CH4 emissions by 0.69 Tg, this may go some way to reducing energy sector emissions in accordance with the Paris Agreement.

Management of plantation forests for bioenergy generation, timber production, carbon emission reductions, and removals

Abstract Management of plantation forests for multiple purposes is critically important in the fight against climate change and loss of natural forests. This study aims to assess bioenergy generation, timber production, carbon emission reductions, carbon removals, and related carbon revenues through the management of plantation forests in Myanmar. We used the latest data from the forest resource assessment to develop the forest land use and growing stocks models for fast-growing and slow-growing plantation forests between 2000 and 2040. We found that natural forests lost 2.6% annually but only 0.02% was converted to plantation forests. Total growing stocks for both forest types increased from just 8.9 million m3 in 2000 to 39.8 million m3 in 2040. Total carbon removals were 1.2 Tg CO2 yr−1 between 2000 and 2040 and 1.3 Tg CO2 yr−1 during the Paris Agreement timeframe. The use of thinned wood and wood biomasses to substitute the fossil combustion could reduce 12.7 Tg CO2 yr−1 of carbon emissions. If combined, total emission reductions from bioenergy generation and carbon removals accounts for 82% of Myanmar's total emissions in energy sector. This study concludes that management of plantation forest could contribute to climate change mitigation while reducing timber demand from natural forests.

Late-spring and summertime tropospheric ozone and NO<sub>2</sub> in western Siberia and the Russian Arctic: regional model evaluation and sensitivities

Abstract. We use a regional chemistry transport model (Weather Research and Forecasting model coupled with chemistry, WRF-Chem) in conjunction with surface observations of tropospheric ozone and Ozone Monitoring Instrument (OMI) satellite retrievals of tropospheric column NO2 to evaluate processes controlling the regional distribution of tropospheric ozone over western Siberia for late spring and summer in 2011. This region hosts a range of anthropogenic and natural ozone precursor sources, and it serves as a gateway for near-surface transport of Eurasian pollution to the Arctic. However, there is a severe lack of in situ observations to constrain tropospheric ozone sources and sinks in the region. We show widespread negative bias in WRF-Chem tropospheric column NO2 when compared to OMI satellite observations from May–August, which is reduced when using ECLIPSE (Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants) v5a emissions (fractional mean bias (FMB) = −0.82 to −0.73) compared with the EDGAR (Emissions Database for Global Atmospheric Research)-HTAP (Hemispheric Transport of Air Pollution) v2.2 emissions data (FMB = −0.80 to −0.70). Despite the large negative bias, the spatial correlations between model and observed NO2 columns suggest that the spatial pattern of NOx sources in the region is well represented. Scaling transport and energy emissions in the ECLIPSE v5a inventory by a factor of 2 reduces column NO2 bias (FMB = −0.66 to −0.35), but with overestimates in some urban regions and little change to a persistent underestimate in background regions. Based on the scaled ECLIPSE v5a emissions, we assess the influence of the two dominant anthropogenic emission sectors (transport and energy) and vegetation fires on surface NOx and ozone over Siberia and the Russian Arctic. Our results suggest regional ozone is more sensitive to anthropogenic emissions, particularly from the transport sector, and the contribution from fire emissions maximises in June and is largely confined to latitudes south of 60∘ N. Ozone dry deposition fluxes from the model simulations show that the dominant ozone dry deposition sink in the region is to forest vegetation, averaging 8.0 Tg of ozone per month, peaking at 10.3 Tg of ozone deposition during June. The impact of fires on ozone dry deposition within the domain is small compared to anthropogenic emissions and is negligible north of 60∘ N. Overall, our results suggest that surface ozone in the region is controlled by an interplay between seasonality in atmospheric transport patterns, vegetation dry deposition, and a dominance of transport and energy sector emissions.

A continued role of short-lived climate forcers under the Shared Socioeconomic Pathways

Abstract. Mitigation of non-CO2 emissions plays a key role in meeting the Paris Agreement ambitions and sustainable development goals. Implementation of respective policies addressing these targets mainly occur at sectoral and regional levels, and designing efficient mitigation strategies therefore relies on detailed knowledge about the mix of emissions from individual sources and their subsequent climate impact. Here we present a comprehensive dataset of near- and long-term global temperature responses to emissions of CO2 and individual short-lived climate forcers (SLCFs) from 7 sectors and 13 regions – for both present-day emissions and their continued evolution as projected under the Shared Socioeconomic Pathways (SSPs). We demonstrate the key role of CO2 in driving both near- and long-term warming and highlight the importance of mitigating methane emissions from agriculture, waste management, and energy production as the primary strategy to further limit near-term warming. Due to high current emissions of cooling SLCFs, policies targeting end-of-pipe energy sector emissions may result in net added warming unless accompanied by simultaneous methane and/or CO2 reductions. We find that SLCFs are projected to play a continued role in many regions, particularly those including low- to medium-income countries, under most of the SSPs considered here. East Asia, North America, and Europe will remain the largest contributors to total net warming until 2100, regardless of scenario, while South Asia and Africa south of the Sahara overtake Europe by the end of the century in SSP3-7.0 and SSP5-8.5. Our dataset is made available in an accessible format, aimed also at decision makers, to support further assessment of the implications of policy implementation at the sectoral and regional scales.

Comparing health benefit calculations for alternative energy futures

Emissions from energy production, conversion, and use are associated with adverse effects on human health and climate. We use the Community Multiscale Air Quality (CMAQ) model and the Benefits Mapping and Analysis Program (BenMAP) to quantify effects of three potential emission abatement policies in the USA. The policies impose emission fees designed to internalize externalities associated with ozone and particulate matter (PM) pollution and greenhouse gas emissions. A business as usual case is compared to policies in which fees are applied to energy sector emissions of health impacting pollutants: NOx, SO2, PM10, PM2.5, and volatile organic compounds (VOCs), and/or greenhouse gases: CO2 and CH4. Net policy benefits are calculated by summing the health and climate benefits and subtracting the increased energy system cost. For comparison with the detailed model results, benefits are also estimated by the simplified approach of multiplying emission changes by fixed estimates of health damages per ton of emissions. Annual net benefits in 2045 are $173 billion with health-related fees and $116 billion with climate-based fees. A combined policy, with fees on emissions of both greenhouse gases (GHG) and health impacting pollutants, has annual net benefits of $189 billion in 2045. Co-benefits are unevenly distributed. Health benefits of GHG fees are only 40% as large as health benefits from air quality fees. Climate benefits of health fees are 87% as large as those from climate-based fees. Thus, each policy has comparable climate benefits, but air quality and corresponding health improvements are smaller when not specifically targeted.

Increasing the integration of solar photovoltaics in energy mix on the road to low emissions energy system – Economic and environmental implications

The EU policy aims towards low carbon economy by establishing a goal of reduction of 93–99% in greenhouse gas emissions in energy sector by 2050. This means a complete energy transition from the fossil fuel based systems to mostly renewable and low-carbon based energy systems. In order to integrate variable renewable energy sources, day-ahead and intraday electricity markets influence, demand – response technologies implementation and fossil fuel powered thermal power plants’ flexibility considerations need to be analysed. Along with the integration of solar photovoltaics, demand – response technologies (power-to-heat and vehicle-to-grid concepts) needed to balance the system, were deployed. In calculations performed on the case study of Croatia in years 2014 and 2030, a moderate introduction of heat storages in Croatian combined heat and power plants, introduction of electric vehicles and flexible operation of power plants enabled the integration of up to 2000 MW installed capacities of solar photovoltaic plants. The main integration criteria, a cumulative critical excess electricity production from solar and wind power, was kept under 5%. Results of this approach are the reduction in full load hours of economically feasible operation for Croatian power plants up to 2000 and combined heat and power plants to up to 3000.

Attribution of recent increases in atmospheric methane through 3-D inverse modelling

Abstract. The atmospheric methane (CH4) growth rate has varied considerably in recent decades. Unexplained renewed growth after 2006 followed 7 years of stagnation and coincided with an isotopic trend toward CH4 more depleted in 13C, suggesting changes in sources and/or sinks. Using surface observations of both CH4 and the relative change of isotopologue ratio (δ13CH4) to constrain a global 3-D chemical transport model (CTM), we have performed a synthesis inversion for source and sink attribution. Our method extends on previous studies by providing monthly and regional attribution of emissions from six different sectors and changes in atmospheric sinks for the extended 2003–2015 period. Regional evaluation of the model CH4 tracer with independent column observations from the Greenhouse Gases Observing Satellite (GOSAT) shows improved performance when using posterior fluxes (R=0.94–0.96, RMSE =8.3–16.5 ppb), relative to prior fluxes (R=0.60–0.92, RMSE =48.6–64.6 ppb). Further independent validation with data from the Total Carbon Column Observing Network (TCCON) shows a similar improvement in the posterior fluxes (R=0.87, RMSE =18.8 ppb) compared to the prior fluxes (R=0.69, RMSE =55.9 ppb). Based on these improved posterior fluxes, the inversion results suggest the most likely cause of the renewed methane growth is a post-2007 1.8±0.4 % decrease in mean OH, a 12.9±2.7 % increase in energy sector emissions, mainly from Africa–Middle East and southern Asia–Oceania, and a 2.6±1.8 % increase in wetland emissions, mainly from northern Eurasia. The posterior wetland flux increases are in general agreement with bottom-up estimates, but the energy sector growth is greater than estimated by bottom-up methods. The model results are consistent across a range of sensitivity analyses. When forced to assume a constant (annually repeating) OH distribution, the inversion requires a greater increase in energy sector (13.6±2.7 %) and wetland (3.6±1.8 %) emissions and an 11.5±3.8 % decrease in biomass burning emissions. Assuming no prior trend in sources and sinks slightly reduces the posterior growth rate in energy sector and wetland emissions and further increases the magnitude of the negative OH trend. We find that possible tropospheric Cl variations do not influence δ13CH4 and CH4 trends, although we suggest further work on Cl variability is required to fully diagnose this contribution. While the study provides quantitative insight into possible emissions variations which may explain the observed trends, uncertainty in prior source and sink estimates and a paucity of δ13CH4 observations limit the robustness of the posterior estimates.

Meeting conditional targets in nationally determined contributions of developing countries: Renewable energy targets and required investment of GGGI member and partner countries

Under the Paris Agreement, countries submitted nationally determined contributions (NDCs) including their GHG emission reduction targets and mitigation measures. Around 175 Parties have mentioned in their NDCs to reduce energy sector emissions by increasing the share of renewable energy in the energy mix. Dissemination of renewable energy requires substantial investment and low and middle-income developing countries tend to present conditional targets assuming external support, therefore essential to estimate how much funding developing countries require and explore how they attract international investment to meet their renewable energy targets. This study examines contributions to carbon mitigation and necessary investment for expansion of renewable energy in Global Green Growth Institute (GGGI) member countries by analyzing their NDCs and national energy plans. It is estimated that the 27 GGGI member and partner countries analyzed in this study would conditionally reduce at least 5058 MtCO2eq of GHG by 2030 and increase the cumulative renewable energy generation capacity up to around 356,184 MW by 2030. To accomplish these pledges, an investment of at least US$258 billion will be required by 2030: US$98–260 billion for solar photovoltaics (PV); US$76–139 billion for wind energy; US$57–330 billion for hydropower; US$10–23 billion for bioenergy; and US$16–45 billion for geothermal.

Modeling of policies for reduction of GHG emissions in energy sector using ANN: case study—Croatia (EU)

This study describes the development of tool for testing different policies for reduction of greenhouse gas (GHG) emissions in energy sector using artificial neural networks (ANNs). The case study of Croatia was elaborated. Two different energy consumption scenarios were used as a base for calculations and predictions of GHG emissions: the business as usual (BAU) scenario and sustainable scenario. Both of them are based on predicted energy consumption using different growth rates; the growth rates within the second scenario resulted from the implementation of corresponding energy efficiency measures in final energy consumption and increasing share of renewable energy sources. Both ANN architecture and training methodology were optimized to produce network that was able to successfully describe the existing data and to achieve reliable prediction of emissions in a forward time sense. The BAU scenario was found to produce continuously increasing emissions of all GHGs. The sustainable scenario was found to decrease the GHG emission levels of all gases with respect to BAU. The observed decrease was attributed to the group of measures termed the reduction of final energy consumption through energy efficiency measures.

Potential impact of a US climate policy and air quality regulations on future air quality and climate change

Abstract. We have investigated how future air quality and climate change are influenced by the US air quality regulations that existed or were proposed in 2013 and a hypothetical climate mitigation policy that aims to reduce 2050 CO2 emissions to be 50 % below 2005 emissions. Using the NASA GISS ModelE2 general circulation model, we look at the impacts for year 2030 and 2055. The US energy-sector emissions are from the GLIMPSE project (GEOS-Chem LIDORT Integrated with MARKAL (MARKet ALlocation) for the Purpose of Scenario Exploration), and other US emissions data sets and the rest of the world emissions data sets are based on the RCP4.5 scenario. The US air quality regulations are projected to have a strong beneficial impact on US air quality and public health in year 2030 and 2055 but result in positive radiative forcing. Under this scenario, no more emission constraints are added after 2020, and the impacts on air quality and climate change are similar between year 2030 and 2055. Surface particulate matter with a diameter smaller than 2.5 µm (PM2.5) is reduced by ∼ 2 µg m−3 on average over the USA, and surface ozone by ∼ 8 ppbv. The improved air quality prevents about 91 400 premature deaths in the USA, mainly due to the PM2.5 reduction (∼ 74 200 lives saved). The air quality regulations reduce the light-reflecting aerosols (i.e., sulfate and organic matter) more than the light-absorbing species (i.e., black carbon and ozone), leading to a strong positive radiative forcing (RF) over the USA by both aerosols' direct and indirect forcing: the total RF is ∼ 0.04 W m−2 over the globe, and ∼ 0.8 W m−2 over the USA. Under the hypothetical climate policy, a future CO2 emissions cut is achieved in part by relying less on coal, and thus SO2 emissions are noticeably reduced. This provides air quality co-benefits, but it could lead to potential climate disbenefits over the USA. In 2055, the US mean total RF is +0.22 W m−2 due to positive aerosol direct and indirect forcing, while the global mean total RF is −0.06 W m−2 due to the dominant negative CO2 RF (instantaneous RF). To achieve a regional-scale climate benefit via a climate policy, it is critical (1) to have multinational efforts to reduce greenhouse gas (GHG) emissions and (2) to simultaneously target emission reduction of light-absorbing species (e.g., BC and O3) on top of long-lived species. The latter is very desirable as the resulting climate benefit occurs faster and provides co-benefits to air quality and public health.

Going to the Source: Using an Upstream Point of Regulation for Energy in a National Chinese Emissions Trading System

There are many choices within the design of an emissions trading system. In this paper we focus on one specific aspect – the point of regulation for the energy sector. This choice affects transaction costs; comprehensiveness, and hence the amount of emissions covered and the extent to which the potential cost-effectiveness gains are realised; and credibility of the system. We discuss how an “upstream” energy sector emissions trading system works and present arguments for going upstream (in particular, simplicity of administration) while also discussing arguments for other points of regulation in light of the Chinese circumstances. We present experiences with the New Zealand system, the only system that is entirely upstream for energy, showing ways to address issues that may arise with an upstream system. Ultimately the success of emissions trading depends on markets that operate in a relatively free and competitive way. Simply copying others’ systems to the context of a largely controlled economy such as the Chinese one is likely to be ineffective; each system must be uniquely tailored to local circumstances, possibly in China more than ever before.