Regional and urban air quality modelling under a climate change scenario

The better understanding of the interactions between climate change and air quality is an emerging priority for research and policy. Climate change will bring changes in the climate system, which will affect the concentration and dispersion of air pollutants. The main objective of the current study is to assess the impacts of climate change on air quality in 2050 over Portugal and Porto urban area. First, an evaluation and characterization of the air quality over mainland Portugal was performed for the period between 2002 and 2012. The results show that NO2, PM10 and O3 are the critical pollutants in Portugal. Also, the influence of meteorology on O3, NO2 and PM10 levels was investigate in the national main urban areas (Porto and Lisboa) and was verified that O3 has a statistically significant relationship with temperature in most of the components. The results also indicate that emission control strategies are primary regulators for NO2 and PM10 levels. After, understanding the national air quality problems and the influence that meteorology had in the historical air quality levels, the air quality modelling system WRF-CAMx was tested and the required inputs for the simulations were prepared to fulfil the main goal of this work. For the required air quality modelling inputs, an Emission Projections under RCP scenarios (EmiPro-RCP) model was developed to assist the estimation of future emission inventories for GHG and common air pollutants. Also, the current emissions were estimated for Portugal with a higher detailed disaggregation to improve the performance of the air quality simulations. The air quality modelling system WRF/CAMx was tested and evaluated over Portugal and Porto urban area and the results point out that is an adequate tool for the analysis of air quality under climate change. For this purpose, regional simulations of air quality during historical period and future (2045-2050) were conducted with CAMx version 6.0 to evaluate the impacts of simulated future climate and anthropogenic emission projections on air quality over the study area. The climate and the emission projections were produced under the RCP8.5 scenario. The results from the simulations point out, that if the anthropogenic emissions keep the same in 2050, the concentrations of NO2, PM10 and O3 will increase in Portugal. When, besides the climate change effects, is consider the projected anthropogenic emissions the annual mean concentrations of NO2 decrease significantly in Portugal and Porto urban area, and on the contrary the annual mean PM10 concentrations increases in Portugal and decrease in Porto urban area. The O3 results are mainly caused by the reduction of ozone precursors, getting the higher reductions in urban areas and increases in the surrounding areas. All the analysis performed for both simulations for Porto urban area support that, for PM10 and O3, there will be an increase in the occurrence of extreme values, surpassing the annual legislated parameters and having more daily exceedances. This study constitutes an innovative scientific tool to help in future air quality management in order to mitigate future climate change impacts on air quality.

Contribution of biomass combustion to air pollutant emissions

In Portugal, it was estimated that around 1.95 Mton/year of wood is used in residential wood burning for heating and cooking. Additionally, in the last decades, burnt forest area has also been increasing. These combustions result in high levels of toxic air pollutants and a large perturbation of atmospheric chemistry, interfere with climate and have adverse effects on health. Accurate quantification of the amounts of trace gases and particulate matter emitted from residential wood burning, agriculture and garden waste burning and forest fires on a regional and global basis is essential for various purposes, including: the investigation of several atmospheric processes, the reporting of greenhouse gas emissions, and quantification of the air pollution sources that affect human health at regional scales. In Southern Europe, data on detailed emission factors from biomass burning are rather inexistent. Emission inventories and source apportionment, photochemical and climate change models use default values obtained for US and Northern Europe biofuels. Thus, it is desirable to use more specific locally available data. The objective of this study is to characterise and quantify the contribution of biomass combustion sources to atmospheric trace gases and aerosol concentrations more representative of the national reality. Laboratory (residential wood combustion) and field (agriculture/garden waste burning and experimental wildland fires) sampling experiments were carried out. In the laboratory, after the selection of the most representative wood species and combustion equipment in Portugal, a sampling program to determine gaseous and particulate matter emission rates was set up, including organic and inorganic aerosol composition. In the field, the smoke plumes from agriculture/garden waste and experimental wildland fires were sampled. The results of this study show that the combustion equipment and biofuel type used have an important role in the emission levels and composition. Significant differences between the use of traditional combustion equipment versus modern equipments were also observed. These differences are due to higher combustion efficiency of modern equipment, reflecting the smallest amount of particulate matter, organic carbon and carbon monoxide released. With regard to experimental wildland fires in shrub dominated areas, it was observed that the largest organic fraction in the samples studied was mainly composed by vegetation pyrolysis products. The major organic components in the smoke samples were pyrolysates of vegetation cuticles, mainly comprising steradienes and sterol derivatives, carbohydrates from the breakdown of cellulose, aliphatic lipids from vegetation waxes and methoxyphenols from the lignin thermal degradation. Despite being a banned practice in our country, agriculture/garden waste burning is actually quite common. To assess the particulate matter composition, the smoke from three different agriculture/garden residues have been sampled into 3 different size fractions (PM2.5, PM2.5-10 and PM>10). Despite distribution patterns of organic compounds in particulate matter varied among residues, the amounts of phenolics (polyphenol and guaiacyl derivatives) and organic acids were always predominant over other organic compounds in the organosoluble fraction of smoke. Among biomarkers, levoglucosan, β-sitosterol and phytol were detected in appreciable amounts in the smoke of all agriculture/garden residues. In addition, inositol may be considered as an eventual tracer for the smoke from potato haulm burning. It was shown that the prevailing ambient conditions (such as high humidity in the atmosphere) likely contributed to atmospheric processes (e.g. coagulation and hygroscopic growth), which influenced the particle size characteristics of the smoke tracers, shifting their distribution to larger diameters. An assessment of household biomass consumption was also made through a national scale survey. The information obtained with the survey combined with the databases on emission factors from the laboratory and field tests allowed us to estimate the pollutant amounts emitted in each Portuguese district. In addition to a likely contribution to the improvement of emission inventories, emission factors obtained for tracer compounds in this study can be applied in receptor models to assess the contribution of biomass burning to the levels of atmospheric aerosols and their constituents obtained in monitoring campaigns in Mediterranean Europe.

The impact of biofuels for road traffic on air quality : a modelling approach

The selection of the energy source to power the transport sector is one of the main current concerns, not only relative with the energy paradigm but also due to the strong influence of road traffic in urban areas, which highly affects human exposure to air pollutants and human health and quality of life. Due to current important technical limitations of advanced energy sources for transportation purposes, biofuels are seen as an alternative way to power the world’s motor vehicles in a near-future, helping to reduce GHG emissions while at the same time stimulating rural development. Motivated by European strategies, Portugal, has been betting on biofuels to meet the Directive 2009/28/CE goals for road transports using biofuels, especially biodiesel, even though, there is unawareness regarding its impacts on air quality. In this sense, this work intends to clarify this issue by trying to answer the following question: can biodiesel use contribute to a better air quality over Portugal, particularly over urban areas? The first step of this work consisted on the characterization of the national biodiesel supply chain, which allows verifying that the biodiesel chain has problems of sustainability as it depends on raw materials importation, therefore not contributing to reduce the external energy dependence. Next, atmospheric pollutant emissions and air quality impacts associated to the biodiesel use on road transports were assessed, over Portugal and in particular over the Porto urban area, making use of the WRF-EURAD mesoscale numerical modelling system. For that, two emission scenarios were defined: a reference situation without biodiesel use and a scenario reflecting the use of a B20 fuel. Through the comparison of both scenarios, it was verified that the use of B20 fuels helps in controlling air pollution, promoting reductions on PM10, PM2.5, CO and total NMVOC concentrations. It was also verified that NO2 concentrations decrease over the mainland Portugal, but increase in the Porto urban area, as well as formaldehyde, acetaldehyde and acrolein emissions in the both case studies. However, the use of pure diesel is more injurious for human health due to its dominant VOC which have higher chronic hazard quotients and hazard indices when compared to B20.

Proposta de uma matriz de indicadores de sustentabilidade para Estarreja

Esta dissertação centra-se na elaboração de uma proposta de matriz de indicadores de sustentabilidade a aplicar ao município de Estarreja. Apesar dos mais recentes desafios e requisitos em matéria de monitorização de planos, projectos e actividades com implicações sobre o ambiente e a sustentabilidade, o acompanhamento da evolução económica, social e ambiental, de uma forma integrada, pelo município tem sido escasso. A literatura da especialidade bem como diversas experiencias municipais nacionais e internacionais têm revelado que a adopção de sistemas de indicadores de sustentabilidade tem um grande potencial não apenas para avaliar o progresso dos municípios em direcção à sustentabilidade ambiental, mas também para induzir melhores formas de governação local. O principal objectivo desta dissertação é a construção de uma matriz de indicadores que avalie a sustentabilidade do município de Estarreja ao nível ambiental. A metodologia adoptada neste trabalho consiste em cinco fases, sendo a primeira fase, a revisão da literatura, através da análise de artigos científicos da especialidade. Na segunda fase é feito o enquadramento legislativo das responsabilidades de monitorização ambiental que cabem aos municípios portugueses. Numa terceira fase, desenvolve-se o levantamento e análise de indicadores sectoriais existentes, já recolhidos e tratados por instituições do Concelho de Estarreja. Na quarta fase procede-se à construção da matriz de indicadores de sustentabilidade, agregando os indicadores já recolhidos pelas iniciativas municipais a um novo conjunto de indicadores de sustentabilidade capazes de analisar a evolução do município no que respeita às pressões sobre o ambiente e sobre os níveis de qualidade ambiental. Na quinta fase são apresentadas as principais conclusões do trabalho e feitas recomendações para tornar exequível e eficiente a monitorização da matriz. O trabalho está organizado em cinco capítulos sendo estes coincidentes com as cinco fases da metodologia. A região de Estarreja tem implantado no seu concelho um dos maiores complexos industriais do país e, em consequência disso, tem vindo a sofrer ao longo dos anos o impacto das actividades industrial e urbana. O procedimento para a construção do sistema de indicadores, bem como a identificação dos eixos temáticos necessários para descrever o contexto que influencia a sustentabilidade do desenvolvimento local, teve por base outros sistemas de indicadores de sustentabilidade local e fornece uma ampla avaliação das características ambientais do município. As dimensões ambientais incluem água, gestão de resíduos, solos, ruído, protecção da natureza, biodiversidade, qualidade do ar, energia e espaços verdes e estão distribuídas por 60 indicadores. Entre estes, 32 já estão a ser monitorizados e 28 foram acrescentados no âmbito deste trabalho. A monitorização dos indicadores propostos não exige grande investimento em capital humano e financeiro, no entanto, constitui um desafio, uma vez que pressupõe a interacção, partilha de informação e transparência por parte das diferentes entidades e empresas municipais.

Energy efficiency and climate policy in the management of public spaces: public lighting

Public Lightning is an important part of municipality’s nighttime landscape. Lighting can be used to enhance public safety and security while improving the aesthetic appeal of the surrounding properties but with the current global financial crisis, such lighting systems must also be sustainable. Most climate policy efforts focus on the state and international level, however national governments won’t be able to meet their international commitments without local action. In Portugal, the Public Lighting is responsible for 3% of energy consumption. The problem is that the trend is to increase (about 4-5% per year) which represents very high costs for the municipal authorities. In terms of numbers are analyzed in this thesis 45 of 278 existent in Continental Portugal what represents only 16,2 % of the counties. This where the local authorities in Portugal that had a Sustainable Energy Action Plan (SEAP) that had been accepted and made available in the Covenant of Mayors website until the end of year 2013. It is important that the Covenant of Mayors will increase the local authorities awareness for energy efficiency and especially to public lighting because there is still a long way to go in terms of energy consumption reduction. In future works it would be interesting to see the payback of the EolGreen post in a real scenario due to lack of energy consumption from the grid it would allow to have a pretty high initial investment even with the maintenance that those technologies need.