Mitigation Co-benefits Research Articles

Researching to better understand the health co-benefits of mitigation

Introduction: The Paris agreement acknowledges that climate change is a common concern of humankind, and it respect, promote and consider the right to health. It also recognizes the social, economic and environmental value of voluntary mitigation actions and their co-benefits for adaptation, health and sustainable development. The purpose of this presentation is to provide a comprehensive methodological guidance for the identification, conceptualization and quantification of health co-benefits and their inclusion in decision-support frameworks. Methods: The identification of the health co-benefits for the consideration of indirect costs and benefits of climate change mitigation was carried out. Major categories of health co-benefits of mitigation policies in different sectors were identified in the literature, with supporting evidence. Results: Quantification of health co-benefits can enable their integration into presently used decision-making frameworks, such as cost-benefit or cost-effectiveness analysis. The rapidly growing evidence that well-planned actions to reduce greenhouse gas emissions can also bring very large health gains. The most obvious gains would come through reductions in air pollution, but also in other sectors as transport, building and energy. Conclusions: Both climate-sensitive health risks, and the health benefits of cutting greenhouse gas emissions, should be central to any discussion on climate change in particular beyond Paris climate agreement.

Co-benefits of global and regional greenhouse gas mitigation on U.S. air quality in 2050.

Policies to mitigate greenhouse gas (GHG) emissions will not only slow climate change, but can also have ancillary benefits of improved air quality. Here we examine the co-benefits of both global and regional GHG mitigation on U.S. air quality in 2050 at fine resolution, using dynamical downscaling methods, building on a previous global co-benefits study (West et al., 2013). The co-benefits for U.S. air quality are quantified via two mechanisms: through reductions in co-emitted air pollutants from the same sources, and by slowing climate change and its influence on air quality, following West et al. (2013). Additionally, we separate the total co-benefits into contributions from domestic GHG mitigation versus mitigation in foreign countries. We use the WRF model to dynamically downscale future global climate to the regional scale, the SMOKE program to directly process global anthropogenic emissions into the regional domain, and we provide dynamical boundary conditions from global simulations to the regional CMAQ model. The total co-benefits of global GHG mitigation from the RCP4.5 scenario compared with its reference are estimated to be higher in the eastern U.S. (ranging from 0.6-1.0 μg m-3) than the west (0-0.4 μg m-3) for PM2.5, with an average of 0.47 μg m-3 over U.S.; for O3, the total co-benefits are more uniform at 2-5 ppb with U.S. average of 3.55 ppb. Comparing the two mechanisms of co-benefits, we find that reductions of co-emitted air pollutants have a much greater influence on both PM2.5 (96% of the total co-benefits) and O3 (89% of the total) than the second co-benefits mechanism via slowing climate change, consistent with West et al. (2013). GHG mitigation from foreign countries contributes more to the U.S. O3 reduction (76% of the total) than that from domestic GHG mitigation only (24%), highlighting the importance of global methane reductions and the intercontinental transport of air pollutants. For PM2.5, the benefits of domestic GHG control are greater (74% of total). Since foreign contributions to co-benefits can be substantial, with foreign O3 benefits much larger than those from domestic reductions, previous studies that focus on local or regional co-benefits may greatly underestimate the total co-benefits of global GHG reductions. We conclude that the U.S. can gain significantly greater domestic air quality co-benefits by engaging with other nations to control GHGs.

Reducing emissions from agriculture to meet the 2°C target.

More than 100 countries pledged to reduce agricultural greenhouse gas (GHG) emissions in the 2015 Paris Agreement of the United Nations Framework Convention on Climate Change. Yet technical information about how much mitigation is needed in the sector vs. how much is feasible remains poor. We identify a preliminary global target for reducing emissions from agriculture of ~1GtCO2 eyr-1 by 2030 to limit warming in 2100 to 2°C above pre-industrial levels. Yet plausible agricultural development pathways with mitigation cobenefits deliver only 21-40% of needed mitigation. The target indicates that more transformative technical and policy options will be needed, such as methane inhibitors and finance for new practices. A more comprehensive target for the 2°C limit should be developed to include soil carbon and agriculture-related mitigation options. Excluding agricultural emissions from mitigation targets and plans will increase the cost of mitigation in other sectors or reduce the feasibility of meeting the 2°C limit.

Eco-benefits assessment on urban industrial symbiosis based on material flows analysis and emergy evaluation approach: A case of Liuzhou city, China

Chinese government promotes ecological civilization in the “13th five year planning” (2016–2020) period. As a result, ecological impacts become highlight in the national circular economy practices. To apply the eco-industrial development strategy to address the intertwined industrial and regional economic development, as well as related environmental and ecological challenges is key point. Urban industrial symbiosis provides a novel approach to realize the above expectation. Traditional evaluation on circular economy provided critical environmental insights, while to date, ecological evaluation has been rather few for urban industrial symbiosis promotion. With this circumstance, this paper developed an integrated material flows analysis (MFA) and emergy evaluation model to investigate the environmental and ecological benefits of urban industrial symbiosis implementation in one typical industrial city in China. Local oriented urban industrial symbiosis network was analyzed. Inter flows and related environmental benefits of symbiotic network were quantified with MFA, and further ecological impacts were evaluated with emergy approach and the designed emergy index. From the environmental perspective, results highlighted, in general, urban industrial symbiosis generated significant life cycle environmental benefits, especially the reduction of upstream resource mining and downstream waste disposal within the regional metabolism. In total, around 204.7 million tons ore mining, 6.9 million ton solid waste and 2.3 million tons CO2 emissions were reduced per year. From the ecological perspective, total emergy input was reduced by 1.3×1022 sej, which reflected the reduction of ecological burden. Particularly, as a key indicator for ecological lost caused by pollution, dilution emergy was decreased by 2.5×1016 sej, resulting from carbon mitigation co-benefit of urban industrial symbiosis. This paper provided modeling approach to understand the ecological benefits and trade-offs of circular economy practices, and critical insights on regional eco-industrial development. It will shed a light on ecological civilization construction in China in the new national planning period.

How climate compatible are livelihood adaptation strategies and development programs in rural Indonesia?

Achieving climate compatible development (CCD) is a necessity in developing countries, but there are few examples of requisite planning processes, or manifestations of CCD. This paper presents a multi-stakeholder, participatory planning process designed to screen and prioritise rural livelihood adaptation strategies against nine CCD criteria. The process also integrated three principles of adaptation pathways: interventions should be (1) ‘no regrets’ and maintain reversibility to avoid mal-adaptation; (2) address both proximate and underlying systemic drivers of community vulnerability; and (3) linked across spatial scales and jurisdictional levels to promote coordination. Using examples of two rural sub-districts in Indonesia, we demonstrate the process and resulting CCD strategies. Priority strategies varied between the sub-districts but all reflected standard development interventions: water management, intensification or diversification of agriculture and aquaculture, education, health, food security and skills-building for communities. Strategies delivered co-benefits for human development and ecosystem services and hence adaptive capacity, but greenhouse mitigation co-benefits were less significant. Actions to deliver the strategies’ objectives were screened for reversibility, and a minority were potentially mal-adaptive (i.e. path dependent, disproportionately burdening the most vulnerable, reducing incentives to adapt, or increasing greenhouse gas emissions) yet highly feasible. These related to infrastructure, which paradoxically is necessary to deliver ‘soft’ adaptation benefits (i.e. road access to health services). Only a small minority of transformative strategies addressed the systemic (i.e. institutional and political) drivers of vulnerability. Strategies were well-matched by development programs, suggesting that current interventions mirror CCD. However, development programs tackled fewer systemic drivers, were poorly coordinated and had a higher risk of mal-adaptation. We conclude that the approach is effective for screening and prioritising no regrets CCD, but more extensive learning processes are necessary to build decision-makers’ capacity to tackle systemic drivers, and to scrutinise potentially mal-adaptive infrastructural investments.

Integrating Global Climate Change Mitigation Goals with Other Sustainability Objectives: A Synthesis

Achieving a truly sustainable energy transition requires progress across multiple dimensions beyond climate change mitigation goals. This article reviews and synthesizes results from disparate strands of literature on the coeffects of mitigation to inform climate policy choices at different governance levels. The literature documents many potential cobenefits of mitigation for nonclimate objectives, such as human health and energy security, but little is known about their overall welfare implications. Integrated model studies highlight that climate policies as part of well-designed policy packages reduce the overall cost of achieving multiple sustainability objectives. The incommensurability and uncertainties around the quantification of coeffects become, however, increasingly pervasive the more the perspective shifts from sectoral and local to economy wide and global, the more objectives are analyzed, and the more the results are expressed in economic rather than nonmonetary terms. Different strings of evidence highlight the role and importance of energy demand reductions for realizing synergies across multiple sustainability objectives.

Quantifying the co-benefits of decarbonisation in China’s steel sector: An integrated assessment approach

The rapid growth of energy consumption in China has led to increased emissions of CO2. As a response, the Chinese government has proposed a series of carbon mitigation strategies, such as switching the production structure and implementing energy-saving and emission–reduction technologies in energy-intensive sectors. In this paper, an integrated assessment approach was developed by combining the Stock-based model, the China-TIMES model and the co-benefits analysis model. The approach was applied to China’s steel sector to simulate the trends of energy consumption and air emissions (CO2, SO2, NOx, and PM10) during 2010–2050, under a reference scenario and three alternative carbon mitigation scenarios. The model quantified the air emission reductions, water conservation, and associated co-benefits during the study period. The modeling results show that by switching the production structure and implementing energy-saving and emission–reduction technologies, China’s steel sector can achieve significant co-benefits of carbon mitigation, water conservation, averted mortality and averted morbidity. Despite certain limitations and uncertainties associated with the elements of the integrated assessment approach, the results demonstrate that substantial social benefits and health effects could be realized through carbon mitigation strategies in China’s steel sector.

Assessment of crop yield losses in Punjab and Haryana using 2 years of continuous in situ ozone measurements

Abstract. In this study we use a high-quality data set of in situ ozone measurements at a suburban site called Mohali in the state of Punjab to estimate ozone-related crop yield losses for wheat, rice, cotton and maize for Punjab and the neighbouring state Haryana for the years 2011–2013. We intercompare crop yield loss estimates according to different exposure metrics, such as AOT40 (accumulated ozone exposure over a threshold of 40) and M7 (mean 7-hour ozone mixing ratio from 09:00 to 15:59), for the two major crop growing seasons of kharif (June–October) and rabi (November–April) and establish a new crop-yield–exposure relationship for southern Asian wheat, maize and rice cultivars. These are a factor of 2 more sensitive to ozone-induced crop yield losses compared to their European and American counterparts. Relative yield losses based on the AOT40 metrics ranged from 27 to 41 % for wheat, 21 to 26 % for rice, 3 to 5 % for maize and 47 to 58 % for cotton. Crop production losses for wheat amounted to 20.8 ± 10.4 million t in the fiscal year of 2012–2013 and 10.3 ± 4.7 million t in the fiscal year of 2013–2014 for Punjab and Haryana taken together. Crop production losses for rice totalled 5.4 ± 1.2 million t in the fiscal year of 2012–2013 and 3.2 ± 0.8 million t in the year 2013–2014 for Punjab and Haryana taken together. The Indian National Food Security Ordinance entitles ~ 820 million of India's poor to purchase about 60 kg of rice or wheat per person annually at subsidized rates. The scheme requires 27.6 Mt of wheat and 33.6 Mt of rice per year. The mitigation of ozone-related crop production losses in Punjab and Haryana alone could provide > 50 % of the wheat and ~ 10 % of the rice required for the scheme. The total economic cost losses in Punjab and Haryana amounted to USD 6.5 ± 2.2 billion in the fiscal year of 2012–2013 and USD 3.7 ± 1.2 billion in the fiscal year of 2013–2014. This economic loss estimate represents a very conservative lower limit based on the minimum support price of the crop, which is lower than the actual production costs. The upper limit for ozone-related crop yield losses in all of India currently amounts to 3.5–20 % of India's GDP. The mitigation of high surface ozone would require relatively little investment in comparison to the economic losses incurred presently. Therefore, ozone mitigation can yield massive benefits in terms of ensuring food security and boosting the economy. The co-benefits of ozone mitigation also include a decrease in the ozone-related mortality and morbidity and a reduction of the ozone-induced warming in the lower troposphere.

New York City Panel on Climate Change 2015 Report. Conclusions and recommendations.

New York City Panel on Climate Change 2015 Report. Conclusions and recommendations.

Agriculture Under UNFCCC and Its Policy Implications

Agriculture is a vulnerable sector to climate change because it is a primary industry directly exposed to climate. At the same time, it is a sector emitting greenhouse gases during agricultural activities, thereby affecting climate change. However, agriculture is a nascent subject under the UNFCCC. The agriculture sector needs both adaptation and mitigation. Currently, co-benefit of adaptation and mitigation is emphasized during climate change negotiation. Developing country parties are in a position to focus on adaptation rather than mitigation. As a result, mitigation is not being addressed enough during climate negotiation. Agriculture has been addressed through Nairobi Work Programme and NAPA. Since current efforts for greenhouse gas reduction are not sufficient for stabilizing the atmospheric system of the Earth to prevent climate change, the agriculture sector should also be considered for greenhouse gas reduction. For this, MRV for small farmers in developing countries and incentives for their mitigation efforts should be developed in agriculture sector. In addition, it is necessary to strengthen international cooperation for developing capacities for vulnerable countries and people to climate change.

Environmental education and the health professions: framing climate change as a health issue

The likelihood of adverse health impacts from climate change is high. Actions to reduce emissions, however, not only mitigate climate change but often have more immediate health co-benefits. One substantial co-benefit is gained through reductions of the high health costs of pollution from fossil fuel power stations, particularly coal. Evidence indicates that the combustion of coal for electricity is responsible for over 200,000 deaths globally per year. Reducing such deaths is a health co-benefit of greenhouse mitigation actions that promote renewable energy or energy efficiency. Together, health co-benefits of mitigation and the health risks of climate change strengthen the calls from climate action networks for cleaner energy production and for other initiatives to reduce greenhouse emissions. The purpose of this scholarly review is to highlight the value of reframing climate change as a health issue to environmental movements and to environmental education and environmental education research. The purpose is also to highlight the potential for further collaboration between formal and informal environmental educators/researchers and the health professions. Health professionals and health educators would bring new voices for climate action to public and policy discourse as well as facilitate mitigation in their organisations and communities.

Estimating the health effects of greenhouse gas mitigation strategies: addressing parametric, model, and valuation challenges.

Background: Policy decisions regarding climate change mitigation are increasingly incorporating the beneficial and adverse health impacts of greenhouse gas emission reduction strategies. Studies of such co-benefits and co-harms involve modeling approaches requiring a range of analytic decisions that affect the model output.Objective: Our objective was to assess analytic decisions regarding model framework, structure, choice of parameters, and handling of uncertainty when modeling health co-benefits, and to make recommendations for improvements that could increase policy uptake.Methods: We describe the assumptions and analytic decisions underlying models of mitigation co-benefits, examining their effects on modeling outputs, and consider tools for quantifying uncertainty.Discussion: There is considerable variation in approaches to valuation metrics, discounting methods, uncertainty characterization and propagation, and assessment of low-probability/high-impact events. There is also variable inclusion of adverse impacts of mitigation policies, and limited extension of modeling domains to include implementation considerations. Going forward, co-benefits modeling efforts should be carried out in collaboration with policy makers; these efforts should include the full range of positive and negative impacts and critical uncertainties, as well as a range of discount rates, and should explicitly characterize uncertainty. We make recommendations to improve the rigor and consistency of modeling of health co-benefits.Conclusion: Modeling health co-benefits requires systematic consideration of the suitability of model assumptions, of what should be included and excluded from the model framework, and how uncertainty should be treated. Increased attention to these and other analytic decisions has the potential to increase the policy relevance and application of co-benefits modeling studies, potentially helping policy makers to maximize mitigation potential while simultaneously improving health.Citation: Remais JV, Hess JJ, Ebi KL, Markandya A, Balbus JM, Wilkinson P, Haines A, Chalabi Z. 2014. Estimating the health effects of greenhouse gas mitigation strategies: addressing parametric, model, and valuation challenges. Environ Health Perspect 122:447–455; http://dx.doi.org/10.1289/ehp.1306744

Nursing and climate change: An emerging connection

Awareness of the importance of climate change to public health has been growing. Calls for health professionals, including nurses, to take action to prepare for, and mitigate, climate change have been coming from a number of credible sources. This paper will assist nurses to recognise the health consequences of climate change, to generate and disseminate knowledge about these health consequences, to be active in mitigating emissions locally and within their organisations and to advocate and have input into policy processes. It is valuable for nurses to understand the health co-benefits of emission mitigation and the current health costs of fossil fuels. As advocates for evidence-based public health initiatives, nurses have a role to play in communicating to the public and to policy makers accurate information, including about the health costs of fossil fuel policies and the affordability of renewable energy technologies.

A 100-year conservation experiment: Impacts on forest carbon stocks and fluxes

Forest conservation is an important climate change mitigation strategy. National parks in Canada’s Rocky and Purcell Mountains offer a rare opportunity to evaluate the impacts of a century of conservation on forest carbon (C) stocks and fluxes. We studied forest ecosystem C dynamics of three national parks in the Rocky and Purcell Mountains of British Columbia – Yoho, Kootenay, and Glacier National Parks – over the period 1970–2008 using the CBM-CFS3 inventory-based forest C budget model. We hypothesized that parks and protected areas would contain higher forest C density and have lower CO2 uptake rates compared to their surrounding reference areas because of the exclusion of timber harvesting and resulting predominance of older, slower growing forest stands. Results for Glacier National Park relative to its reference area were consistent with our hypothesis. Forests in Kootenay National Park were substantially younger than those in its reference area despite the exclusion of harvesting because natural disturbances affected large areas within the park over the past century. Site productivity in Kootenay National Park was also generally higher in the park than in its reference area. Consequently, Kootenay National Park had both higher C density and higher CO2 uptake than its reference area. Yoho National Park forests were similar in age to reference area forests and more productive, and therefore had both higher C stocks and greater CO2 uptake. C density was higher in all 3 parks compared to their surrounding areas, and parks with younger forests than reference areas had higher CO2 uptake. The results of this study indicate that forest conservation in protected areas such as national parks can preserve existing C stocks where natural disturbances are rare. Where natural disturbances are an important part of the forest ecology, conservation may or may not contribute to climate change mitigation because of the risk of C loss in the event of wildfire or insect-caused tree mortality. Anticipated increases in natural disturbance resulting from global warming may further reduce the climate change mitigation potential of forest conservation in disturbance-prone ecosystems. We show that managing for the ecological integrity of landscapes can also have carbon mitigation co-benefits.

Thailand's Low-Carbon Scenario 2050: The AIM/CGE analyses of CO2 mitigation measures

Climate change and CO2 mitigation have become increasingly important environmental issues. Recently Thailand has proposed policies on GHG mitigation such as Thailand’s Nationally Appropriate Mitigation Action (NAMA), which aims at GHG mitigation in the energy sector. This study used the computable general equilibrium (CGE) model, called “AIM/CGE” model, to analyse GHG mitigation measures under emission trading and carbon capture and storage (CCS) technology in Thailand. Results show that the international free emission trading policy can drive more GHG reduction by decreasing energy supply and demand, and increasing prices of emissions. The CCS technologies would balance emission reduction but they would reduce energy efficiency improvement and renewable energy utilization. In the energy security aspect, the policy options in this study would improve energy security, energy import dependency, and co-benefits of GHG mitigation in forms of improving local air quality. Results are also helpful to GHG mitigation policy in developing countries.

Distributional impacts of climate change mitigation in Indian electricity: The influence of governance

Abstract Studies that examine the distributional impacts of climate change mitigation policies often neglect the influence of institutions that implement these policies. This study examines the short-term consumption-side distributional impacts of expanding low-carbon electric supply in the state of Maharashtra, India with a focus on the influence of regulatory discretion in pricing. Households' welfare impacts from economy-wide electricity price shocks are simulated against a baseline that is calibrated to actual household economic and electricity service conditions, including actual electricity budgets, block tier prices and supply rationing. Industrial price impacts are propagated to households using a Leontief input–output analysis. Regulatory pricing decisions are evaluated based on social welfare metrics for economic efficiency and income inequality. The analysis reveals new linkages between climate change mitigation, electricity policy and income distribution. Low-income households can be shielded from mitigation impacts without losses in aggregate welfare to the extent that regulators can recover mitigation costs through industrial price increases. Regulators' flexibility to distribute costs across households is constrained by industrial customers' migration off the grid. Reduced supply interruptions to the rural poor from the resulting demand contraction are a potential co-benefit of mitigation. Distributional impacts, therefore, depend on other electricity policies that are driven by the political economy of the sector.

Climate adaptation as mitigation: the case of agricultural investments

Successful adaptation of agriculture to ongoing climate changes would help to maintain productivity growth and thereby reduce pressure to bring new lands into agriculture. In this paper we investigate the potential co-benefits of adaptation in terms of the avoided emissions from land use change. A model of global agricultural trade and land use, called SIMPLE, is utilized to link adaptation investments, yield growth rates, land conversion rates, and land use emissions. A scenario of global adaptation to offset negative yield impacts of temperature and precipitation changes to 2050, which requires a cumulative 225 billion USD of additional investment, results in 61 Mha less conversion of cropland and 15 Gt carbon dioxide equivalent (CO2e) fewer emissions by 2050. Thus our estimates imply an annual mitigation co-benefit of 0.35 GtCO2e yr−1 while spending $15 per tonne CO2e of avoided emissions. Uncertainty analysis is used to estimate a 5–95% confidence interval around these numbers of 0.25–0.43 Gt and $11–$22 per tonne CO2e. A scenario of adaptation focused only on Sub-Saharan Africa and Latin America, while less costly in aggregate, results in much smaller mitigation potentials and higher per tonne costs. These results indicate that although investing in the least developed areas may be most desirable for the main objectives of adaptation, it has little net effect on mitigation because production gains are offset by greater rates of land clearing in the benefited regions, which are relatively low yielding and land abundant. Adaptation investments in high yielding, land scarce regions such as Asia and North America are more effective for mitigation. To identify data needs, we conduct a sensitivity analysis using the Morris method (Morris 1991 Technometrics 33 161–74). The three most critical parameters for improving estimates of mitigation potential are (in descending order) the emissions factors for converting land to agriculture, the price elasticity of land supply with respect to land rents, and the elasticity of substitution between land and non-land inputs. For assessing the mitigation costs, the elasticity of productivity with respect to investments in research and development is also very important. Overall, this study finds that broad-based efforts to adapt agriculture to climate change have mitigation co-benefits that, even when forced to shoulder the entire expense of adaptation, are inexpensive relative to many activities whose main purpose is mitigation. These results therefore challenge the current approach of most climate financing portfolios, which support adaptation from funds completely separate from—and often much smaller than—mitigation ones.

Mitigation Co-Benefits of Adaptation Actions in Agriculture: An Opportunity for Promoting Climate Smart Agriculture in Indonesia

The government of Indonesia has been promoting the system of rice intensification with emphasis on resource use efficiency and climate change adaptation benefits. One question remained to be seen is how the system of rice intensification compares with other technologies such as zero tillage, composting, and leaf color charts which have also been advocated for resource conservation, climate change adaptation and mitigation benefits. In this paper, we made an attempt to quantify the mitigation co-benefits of various agriculture technologies and compared them with the system of rice intensification through marginal abatement costs and cost benefit analysis. The analysis has indicated higher mitigation potential for the system of rice intensification compared to other technologies in question. However, zero tillage provides least marginal abatement cost and higher returns per dollar invested and hence could be a better choice. When assessed for the nationwide mitigation potential, system of rice intensification provides greater mitigation potential compared to other technologies.

Analysis of motorcycle fleet in Hanoi for estimation of air pollution emission and climate mitigation co-benefit of technology implementation

A fleet of over two million motorcycles (MC) in Hanoi is believed to contribute a substantial emission of air pollutants and climate forcers but has not been thoroughly characterized. This study conducted a survey of the MC technologies and activities in Hanoi using questionnaires, GPS monitoring, and video camera in 2008. The data were collected for three typical road types (highways, arterials, residential streets) in 3 zones of the city. Majority of MC in Hanoi were relatively new (3.6 years), had 4-stroke engine, but only 6% was equipped with catalyst exhaust control devices. About 35% of the fleet did not comply with any EURO standards. The MC daily driving was 20 km, mostly done on arterial streets. The main driving features in Hanoi arterials and residential streets were of low speeds with frequent starts/stops and idling. International Vehicle Emissions (IVE) model produced adjusted emission factors (EFs) that were compared with the limited available measurement data. The fleet emission was estimated for 2008 as a base case and for two “what-if” faster technology implementation scenarios: scenario 1 assumed that the entire fleet in 2008 conformed at least EURO2 and scenario 2 assumed 100% MC met the EURO3 standard. Total emissions from the fleet in 2008 of CO, VOC, NOx, SO2, PM10, and CH4 were 158, 51.5, 9.5, 0.17, 2.4 and 9.5 kt, respectively. Emissions of 1,3-butadiene, acetaldehydes, formaldehydes and benzene were 0.26, 1.2, 4.9 and 2.1 kt, respectively. Faster EURO3 technology intrusion in scenario 2 would significantly reduce the emission of pollutants (by 53–94%) and climate forcers in CO2-equivalent (53% for 20-year and 38% for 100-year horizon), which tripled the reductions obtained under scenario 1. Substantial co-benefits for air quality and climate forcer mitigation could be achieved by the faster technology implementation.

Assessing the co-benefits of CO2 mitigation on air pollutants emissions from road vehicles

This paper quantitatively assesses the co-benefits of atmospheric CO2 stabilization at 400ppmv by 2100 on air pollutants emissions from road vehicles using a global energy system model treating the road transport sector in detail. It is estimated that the reduction rate of global cumulative emissions of SO2, NOx, and PM from road vehicles during the period 2020–2100 in the 400ppmv CO2 stabilization scenario compared to the no CO2 constraint scenario is 22.1%, 10.8%, and 14.4%, respectively. Such co-benefits are the largest for SO2 because biomass-derived Fischer–Tropsch products are chosen as a major alternative fuel for road transport in the former scenario and because their SO2 emission factor is zero, whereas their NOx and PM emission factors are lower than those for petroleum products only by 27% and 21%, respectively. This implies that introducing liquid biofuels would not lead to a noticeable reduction in NOx and PM emissions. Such co-benefits are the smallest for NOx. The first reason is that, except for 2100 in the no CO2 constraint scenario, heavy-duty trucks account for the largest share of global road vehicles’ NOx emissions in the two scenarios throughout the time horizon. The second reason is that in each time period, heavy-duty trucks emit almost the same amount of SO2, NOx, and PM between the scenarios because of almost the same technology and fuel choices in this sector. This implies the necessity of promoting R&D for developing cost-effective low-carbon alternatives to diesel heavy-duty trucks to achieve a further reduction in global air pollutants emissions from road vehicles.