Major Emission Reductions Research Articles

Climate policies that achieved major emission reductions: Global evidence from two decades.

Meeting the Paris Agreement's climate targets necessitates better knowledge about which climate policies work in reducing emissions at the necessary scale. We provide a global, systematic ex post evaluation to identify policy combinations that have led to large emission reductions out of 1500 climate policies implemented between 1998 and 2022 across 41 countries from six continents. Our approach integrates a comprehensive climate policy database with a machine learning-based extension of the common difference-in-differences approach. We identified 63 successful policy interventions with total emission reductions between 0.6 billion and 1.8 billion metric tonnes CO2. Our insights on effective but rarely studied policy combinations highlight the important role of price-based instruments in well-designed policy mixes and the policy efforts necessary for closing the emissions gap.

Solar energy for societal decarbonisation: a perspective on emerging opportunities in utility-scale solar electricity and solar in the built environment

The solar resource presents almost limitless opportunities for creating clean energy – not just in the form of solar-derived electricity, but also to drive heating and cooling cycles, create solar fuels, or indeed to promote chemical and biochemical pathways for the production of food, clean water and raw materials. There is an ever-expanding plethora of applications for solar energy as a critical contributor to global decarbonization. This short Perspective is focused on two of the largest opportunities for solar energy to make major emissions reduction and deliver societal fairness and economic impacts: notably utility-scale electricity generation and the more local opportunities of the built environment. We examine the two dominant forms of solar energy – the direct generation of electrical power via the photovoltaic effect, and the indirect generation of electricity (and indeed heating and cooling energy) through solar thermal cycles. As a Perspective, it provides necessary background for the general reader, but also seeks to emphasise the specific challenges and opportunities for the interested specialist.

To what extent can clean energy development advance the carbon peaking process of China?

Many studies have demonstrated the importance of clean energy development for China to meet its carbon peaking commitments and to contribute to solving world environmental problems. However, few studies have integrated spatial correlation and carbon peaking process to fully reveal the spatial spillover effects of carbon emissions and the urgency of emission reduction. The unexpected power cuts in 2020 poses a new requirement to deeply grasp China's clean energy development and carbon peaking attainment. To this end, the spatial econometric panel model and GM (1, N) are used to explore the development of clean energy, the spatial characteristics of carbon emissions, the process of carbon peaking, and the association between them. And all these are based on the real-life dilemma of power cuts and the underlying development-emission conflict in China. The results show that: (1) clean energy development in a region will increase local carbon emissions, but will significantly suppress carbon emissions in neighboring regions; (2) there is an inverted "U" curve relationship between clean energy development and carbon emissions, and China is still in the early stage of positive correlation; (3) fossil energy saved in a region tends to flow to neighboring regions with similar scale of economic development; (4) under the current development model, only 17% of the regions with clean energy development will be able to reduce emissions and successfully reach the peak by 2030, which implies a major emissions reduction challenge for China. The situation of carbon emission reduction in China is far from optimistic. Corresponding policy recommendations are given at the end. In short, we believe that greater clean energy support, stricter emission reduction policies, more diverse emission reduction approaches, and more synergistic emission reduction models are needed simultaneously.

Enhanced sulfur in the upper troposphere and lower stratosphere in spring 2020

Abstract. Sulfur compounds in the upper troposphere and lower stratosphere (UTLS) impact the atmosphere radiation budget, either directly as particles or indirectly as precursor gas for new particle formation. In situ measurements in the UTLS are rare but are important to better understand the impact of the sulfur budget on climate. The BLUESKY mission in May and June 2020 explored an unprecedented situation. (1) The UTLS experienced extraordinary dry conditions in spring 2020 over Europe, in comparison to previous years, and (2) the first lockdown of the COVID-19 pandemic caused major emission reductions from industry, ground, and airborne transportation. With the two research aircraft HALO and Falcon, 20 flights were conducted over central Europe and the North Atlantic to investigate the atmospheric composition with respect to trace gases, aerosol, and clouds. Here, we focus on measurements of sulfur dioxide (SO2) and particulate sulfate (SO42-) in the altitude range of 8 to 14.5 km which show unexpectedly enhanced mixing ratios of SO2 in the upper troposphere and of SO42- in the lowermost stratosphere. In the UT, we find SO2 mixing ratios of (0.07±0.01) ppb, caused by the remaining air traffic, and reduced SO2 sinks due to low OH and low cloud fractions and to a minor extent by uplift from boundary layer sources. Particulate sulfate showed elevated mixing ratios of up to 0.33 ppb in the LS. We suggest that the eruption of the volcano Raikoke in June 2019, which emitted about 1 Tg SO2 into the stratosphere in northern midlatitudes, caused these enhancements, in addition to Siberian and Canadian wildfires and other minor volcanic eruptions. Our measurements can help to test models and lead to new insights in the distribution of sulfur compounds in the UTLS, their sources, and sinks. Moreover, these results can contribute to improving simulations of the radiation budget in the UTLS with respect to sulfur effects.

LCA of Primary Embodied Energy and Carbon emissions of a Commercial High Performance Building Structure and Envelope

The Building’s material embodied energy plays major role in Carbon Emissions at its production stage. Assessment of Carbon emissions at initial stages for a high performance commercial building is overlooked and the building life cycle has not found an eminent place in the country mandatory norms. An early LCA can be instrumental in taking key decisions in design and material choice to lower building Carbon emissions. This paper aims at comprehensively evaluating and analyzing a fully glazed Certified high performance Office building in Gurgaon, Haryana. Process based Life Cycle Assessment of Building Envelope and Structure for Embodied energy and Carbon emissions is done by applying recently published Indian Database. The Building is modelled using Autodesk Revit Architecture for Bill of quantities extraction. Thereafter, LCA is done in tabular format as per Global standards for two cases, Base case with conventional material and As-built case with used material. Major reductions in emissions are due to Building Envelope material and not Structure. Concrete and Steel are major contributors. Fly Ash block and Gypsum plaster play major role in carbon emission reduction whereas double glazing, Aluminum and ACP contribute towards increasing emissions. Analysis done at early stages can be beneficial in exploring more design optimized techniques that are less Carbon intensive.

Going electric: Environmental and welfare impacts of urban ground and air transport

• We study welfare and environmental effects of electric modes in cities. • Electric cars reduce CO 2 emissions despite increasing travel and congestion. • The resulting welfare losses may dominate the gains from reducing CO2. • Welfare effects of UAM depend on initial mode choice and the way of introduction. • Substituting gasoline (electric) cars, UAM decreases (increases) emissions. This research aims to assess the broader impact of electric mobility in urban settlements, paying attention to both electrified ground and air transport. Considering electric cars as well as electric passenger drones, often referred to as UAM (urban air mobility), we use an urban spatial computable general equilibrium model to assess the welfare and environmental impacts of a transition to electric mobility. A numerical simulation of the model shows that a transition from gasoline to electric cars yields major emission reductions, while leading to welfare losses due to tax-induced market distortions. Introducing UAM into a gasoline-car city leads to marginal overall welfare gains. Introducing UAM into a city with electric cars results in welfare losses. While introducing UAM as an alternative to gasoline cars decreases CO 2 emissions, the introduction of UAM as alternative to electric cars leads to increasing emissions.

Consequence of natural gas injection in blast furnace: a critical appraisal using a thermodynamic and evolutionary computation approach

ABSTRACT The data generated from a model-based simulator are used in this study for evolutionary multi-objective Optimisation, correlating input parameters like natural gas and pulverised coal injection with coke rate, carbon rate and fuel cost. Evolutionary optimisers are used to minimise coke input and total fuel cost and corresponding CO2 emissions were analysed. Co-injection of gas with coal in a blast furnace generally lowers furnace CO2 emissions by increasing hydrogen in the input fuel. This study reveals that major emission reduction possibilities at the lowest optimised coke rate and total fuel cost do not exist when coal and gas co-injection is attempted. A tri-objective Optimisation study was also conducted for simultaneous minimisation of coke rate, carbon rate and fuel cost with co-injection of gas and coal and several trends emerged. Although significant reductions of coke rate and fuel costs were predicted, no marked reduction of carbon rate, hence emissions, was foreseen.

Climate change awareness and tree planting as mitigation measure in a rural West African Community

Climate change awareness and tree planting as mitigation measure in a rural West African Community Background: Africa is under significant threat from climate change. In accordance with the Paris Agreement, after 2020, the global community has agreed to major emission reduction programs. Reforestation can complement these emission reduction strategies. Due to carbon sequestration of forests, reforestation has remained a climate mitigation tool. However, at individual and community level, such mitigative response are possible when individuals understand climate change and its impacts. Education is thus an essential element of the global response to climate change. This study was therefore conducted to assess Climate change awareness and tree planting amongst members of a rural West African Community. Methods: A cross-sectional, community based descriptive study conducted among household heads in Nasarawan Buhari, a rural agrarian community in Nigeria. An interviewer-administered questionnaire was used to collect data from 104 household heads, selected using systematic random sampling technique. Data was analyzed using IBM SPSS (version 20).Results:A majority of the respondents were males (79.8%) and their mean age was 40.6 ± 12.6 years. Half (50%) were aware of climate change and their main source of information was radio (63.5%). Most (98.1%) use fire wood for cooking in their households. Only a minority (27.9% ) planted a tree in the past 1 year preceding the study. Climate change awareness was not a determinant of tree planting (P=0.827)Conclusion:Half of respondents were aware of climate change but most use firewood for household cooking. Tree planting is practiced by few. There is need for a climate change education campaign that will elaborate the relationship between deforestation/reforestation and climate change and encourage use of clean cooking methods and tree planting. Key words: Climate awareness, tree planting, rural West African Community

Drivers of provincial SO2 emissions in China – Based on multi-regional input-output analysis

Studying the driving factors of pollutant emissions is of great significance for China in the formulation of pollution control strategies. Existing studies mainly focus on the causes of national aggregate emission changes. However, considering the large differences among provinces in China and their close economic linkages, it is necessary to develop a provincial-level analysis to shape provincial policies for emission reduction. Using the multi-regional input-output (MRIO) tables of 30 provinces in China and adopting structural decomposition analysis, we analyze how changes in the end-of-pipe treatment, cleaner production, economic production structure, domestic final use, domestic exports and international exports drive national and provincial SO2 emissions. Decomposition results show that during 2002–2010 the absolute value of each effect based on the MRIO model is higher than that based on the national aggregate input-output model, which indicates that the existing studies adopting the national average data conceal the variation in the driving factors and underestimate their contributions to SO2 emission changes. The decomposition results based on MRIO model further show that the end-of-pipe treatment and cleaner production are the major emission reduction factors for all provinces, and the effect of the former has noticeably increased during 2007–2010. For the eastern provinces, interestingly, the economic production structure becomes a major emission reduction factor during the period of 2007–2010. Changes in domestic final demand, domestic exports and international exports exhibit significantly different contributions among provinces. The increased final demand in eastern provinces largely drive SO2 emissions for all provinces. Based on the above findings, policy implications that address the SO2 emission reduction issues are proposed.

The global carbon nation: Status of CO2 capture, storage and utilization

As the world transitions toward cleaner and more sustainable energy generation, Carbon Capture and Sequestration/Storage (CCS) plays an essential role in the portfolio of technologies to help reduce global greenhouse gas (GHG) emissions. The projected increase in population size and its resulting increase in global energy consumption, for both transportation and the electricity grid —the largest emitters of greenhouse gases, will continue to add to current CO2 emissions levels during this transition. Since eighty percent of today’s global energy continues to be generated by fossil fuels, a shift to low-carbon energy sources will take many decades. In recent years, shifting to renewables and increasing energy efficiencies have taken more importance than deploying CCS. Together, this triad —renewables, energy efficiency, and CCS— represent a strong paradigm for achieving a carbon-free world. Additionally, the need to accelerate CCS in developing economies like China and India are of increasing concern since migration to renewables is unlikely to occur quickly in those countries. CCS of stationary sources, accounting for only 20% reduction in emissions, as well as increasing efficiency in current systems are needed for major reductions in emissions. A rising urgency for fifty to eighty percent reduction of CO2 emissions by 2050 and one hundred percent reduction by 2100 makes CCS all that more critical in the transition to a cleaner-energy future globally.

Trends and variability in surface ozone over the United States

AbstractWe investigate the observed trends and interannual variability in surface ozone over the United States using the Global Modeling Initiative chemical transport model. We discuss the roles of meteorology, emissions, and transport from the stratosphere in driving the interannual variability in different regions and seasons. We demonstrate that a hindcast simulation for 1991–2010 can reproduce much of the observed variability and the trends in summertime ozone, with correlation coefficients for seasonally and regionally averaged median ozone ranging from 0.46 to 0.89. Reproducing the interannual variability in winter and spring in the western United States may require higher‐resolution models to adequately represent stratosphere‐troposphere exchange. Hindcast simulations with fixed versus variable emissions show that changes in anthropogenic emissions drive the observed negative trends in monthly median ozone concentrations in the eastern United States during summer, as well as the observed reduction in the amplitude of the seasonal cycle. The simulation underestimates positive trends in the western United States during spring, but excluding the first 4 years of data removes many of the statistically significant trends in this region. The reduction in the slope of the ozone versus temperature relationship before and after major emission reductions is also well represented by the model. Our results indicate that a global model can reproduce many of the important features of the meteorologically induced ozone variability as well as the emission‐driven trends, lending confidence to model projections of future changes in regional surface ozone.

Slower ozone production in Houston, Texas following emission reductions: evidence from Texas Air Quality Studies in 2000 and 2006

Abstract. Airborne measurements from two Texas Air Quality Study (TexAQS) field campaigns have been used to investigate changes of ozone production in Houston, Texas, from 2000 to 2006, a period of major emission reduction measures for petrochemical and other sources. Simultaneous declines in nitrogen oxides (NOx = NO + NO2) and highly reactive volatile organic compounds (HRVOCs) were observed between the two periods. We simulate HOx (OH and HO2) and organic radicals with a box model, the Dynamically Simple Model of Atmospheric Chemical Complexity, constrained by available airborne observations. Parameters such as total radical production, total OH reactivity of VOCs and ozone production rate (OPR) are computed to characterize the change of ozone production between 2000 and 2006 in the Houston area. The reduction in HRVOCs led to a decline in total radical production by 20–50%. Ozone production rates in the Houston area declined by 40–50% from 2000 to 2006, to which the reduction in NOx and HRVOCs made large contributions. Despite the significant decline in OPR, ozone production efficiency held steady, and VOC-sensitive conditions dominated during times of most rapid ozone formation, while the slow ozone formation continued to be NOx-limited. Our results highlight the importance of a balanced approach of ongoing HRVOC controls with NOx controls to further reduce O3 levels in the Houston area.

Political barriers of implementing carbon markets in Japan: A Public Choice analysis and the empirical evidence before and after the Fukushima nuclear disaster

The Great Tōhoku-Earthquake and the following nuclear meltdown in Fukushima called the world’s attention to Japans’ energy and climate policy. Japan is one of the biggest emitters of greenhouses gases in the world and is still facing problems of reaching its Kyoto target by domestic reductions. Emissions trading has been used in Japanese climate policy since 2005. However, major emission reductions have not been achieved and a functioning market does not exist. Hence, using an advanced Public Choice approach, we ask for the political reasons for the failure of ambitious carbon markets in Japan and how the earthquake has influenced the political chances of emissions trading. Also, we evaluate Public Choice’s arguments and environmental policy making. We show that in Japan, even after some positive promising developments, chances for an ambitious carbon market are still very low. We also show that a Public Choice that takes exogenous conditions into account delivers important insights into climate policy decision making.

The Future of Fracking: New Rules Target Air Emissions for Cleaner Natural Gas Production

Natural gas is lauded as a cleaner-burning fuel than either coal or oil, but getting the fuel out of the ground can be a dirty process, especially given the widespread adoption of the technology known as hydraulic fracturing (“fracking”). Concerns about toxic air emissions from previously unregulated fracking sites led to the U.S. Environmental Protection Agency (EPA) announcement on 18 April 2012 of new and updated air pollution regulations for these facilities and certain other elements of oil and natural gas production and transmission.1 Compliance with the new regulations is expected to result in major reductions in emissions of methane and volatile organic compounds (VOCs), particularly from new fracked natural gas wells. The rules were a hot topic nationally, drawing more than 156,000 comments after the proposed version was released in mid-2011. Under the final rules, companies have until January 2015 to fully phase in the control measures needed; by comparison, the initial proposal called for a 60-day phase-in for many major requirements. The EPA says about half of all new wells already use the equipment needed to capture the targeted emissions.2 A hydraulic fracturing natural gas drilling rig on the eastern Colorado plains. In 2009 there were more than 38,000 natural gas wells in the state. Many environmental groups consider the new regulations an improvement over the existing situation, but they tend to be disappointed much more wasn’t done. “This is quite a milestone,” says Jeremy Nichols, Climate and Energy Program director for the advocacy group WildEarth Guardians, one of two groups that filed suit against the EPA in 2009 to force action on the issue. “But is the work done? No, of course not. It’s a floor to build on, providing a minimal level of protection.” The oil and natural gas industry has its own concerns about the new rules but has indicated it can work with them. In a press release issued the day the rules were announced, Howard Feldman, director of regulatory and scientific affairs for the American Petroleum Institute, said, “EPA has made some improvements in the rules that allow our companies to continue reducing emissions while producing the oil and natural gas our country needs.”3

Ozone Air Pollution: How Low Can You Go?

Ozone Air Pollution: How Low Can You Go?

Response of Surface Water Acidification in Upper Yangtze River to SO2 Emissions Abatement in China

Surface waters in Europe and North America are slowly recovering from acidification following major reductions in emissions of sulfur dioxide (SO(2)) since the 1980s. In contrast, regions affected by acid rain have been reported to be growing in China. Here we show that the rapid change in surface water chemistry in the 1990s in large areas in Southwestern China, specifically the tributary rivers of the Upper Yangtze River, caused by increasing SO(2) emissions, has leveled off. During the 1990s the sulfate (SO(4)(2-)) concentrations in river water increased rapidly and, on average, doubled in only eight years. Simultaneously, calcium (Ca(2+)) concentrations increased, while pH values decreased. In the following decade (2000s), SO(2) emissions stabilized, causing a subsequent stop to the increasing SO(4)(2-) concentrations and pH decline in river water. Although a rapid response to future reduction in SO(2) emissions can be expected, a rapid increase of nitrogen (N) emissions could lead to increases in N leaching and delay recovery.

Did the Japanese Patient Follow the Doctor's Orders? Mostly No! A Public Choice Analysis of Greenhouse Gas Emissions Trading Schemes in Japan Before and after the Earthquake

The Great Tohoku-Earthquake and the following nuclear meltdown in Fukushima called the world’s attention to Japans’ energy and climate policy. Japan is one of the biggest emitters of greenhouses gases in the world and still far away from reaching its Kyoto target. Emissions trading systems have been used in Japanese climate policy since 2005. However, experiences have been disillusioning: Major emission reductions have not been achieved, and a function-ing market does not exist. Hence, we ask what the political reasons for the failure of carbon markets in Japan are and how they can be overcome. We use Public Choice arguments, but also analyze actual climate policy making in Japan on a case study basis. Thus, on the one hand, we identify the political obstacles of implementing ambitious greenhouse gas emissions trading systems in Japan, and, on the other hand, we evaluate Public Choice’s arguments and environmental policy making.

A system dynamics model of CO 2 mitigation in China’s inter-city passenger transport

Mitigation of greenhouse gas emissions from transportation has become increasingly important and challenging especially for developing countries. This paper takes the inter-city passenger transport in China as a case, and develops a system dynamics model for policy assessment and CO 2 mitigation potential analysis. It is found that the future demand for China’s inter-city passenger transport is expected to be large, with the turnover volume growing at a rate of 9% per annum and amounting to 6600 billion p-km in 2020. Major emissions reduction potential exists in inter-city passenger transport. In 2020, comparing to the case without any specific policies stressing mitigation, the reduction of CO 2 emissions ranges from 26% to 32% under those scenarios with policy controls. Sensitivity analysis reveals that the CO 2 mitigation will be best achieved by accelerating the development of railway network, together with slowing down the extension of highway network and imposing fuel taxes.

Detection of Automotive Catalysts Failure by Use of On-Board Diagnostics

Although major emission reductions from gasoline vehicles have been achieved with the help of catalytic exhaust gas after-treatment, durability of the systems involved is still difficult to guarantee with high confidence levels. On-board diagnosis (OBD) of the main emission control systems is expected to play a central role in any modern emission reduction policy. An overview of theoretical principles regarding catalytic converter operation characteristics, catalyst activity deterioration and OBD system requirements is initially presented. The most important existing approaches to catalytic converter on-board diagnosis are examined by means of presenting principles of operation, assessment methodologies and practical problems associated with each of them. The techniques examined cover dual lambda sensor, hydrocarbon and temperature measurement methods, some of which have already been applied to conform to transitional OBD regulations. It appears, however, that significant work remains to be carried out in order to develop reliable and cost-effective catalytic converter OBD technology to cover legislation requirements, especially for modern low-emitting vehicles.

Control techniques and strategies for regional air pollution control from energy and industrial sectors

The technological options currently available to reduce SO2 and NOx emissions including abatement technologies and high efficient energy conversion technologies are reviewed. The energy emission model EFOMENV (Energy Flow Optimization Model-Environment) which takes into account all relevant emission reduction measures is used to determine the cost optimized energy pathway, the ranking of reduction measures and the corresponding costs as a function of given reduction levels of SO2 and/or NOx emissions for different scenarios in selected Central and Eastern European countries. It is shown that restructuring of the energy system is a major emission reduction option in all countries but with a potential varying greatly from country to country depending mainly on the existing structure and the age of the plants and on the development of the energy demand. The emission reduction costs for SO2 in Central and Eastern European countries are 50% to 70% lower than in Western countries due to high potential of fuel/technology switching and energy saving measures. Cost efficient measures to reduce CO2 emissions also lead to a significant decrease of SO2 and NOx emissions.