Kasvihuonekaasupäästölaskenta kunnassa

Kiihtyvän kasvihuoneilmiön aiheuttama ilmaston lämpeneminen on modernin yhteiskunnan suurimpia haasteita. Ympäristöteknologian tavoitteena on hidastaa tämän ilmiön haitallisia vaikutuksia maailmanlaajuisesti, kansallisesti sekäkunnallisella tasolla. Tässä työssä on selvitetty, kuinka kunnallinen kasvihuonekaasupäästölaskenta toteutetaan ja voidaanko siitä saada luotettavia tuloksia. Lisäksi tulosten pohjalta on laadittu kunnallinen kasvihuonekaasupäästöjen kehitysennuste sekä toimenpide-ehdotus päästöjen leikkaamiseksi. Esimerkkikuntana on Lappeenrannan kaupunki ja päästölaskenta on kohdistettu vuoteen 2004. Lappeenrannan kaupungin alueen kasvihuonekaasupäästöt vuonna 2004 olivat 1 156 500 tonnia hiilidioksidiekvivalenttia. Alueen luonnon nieluvaikutus oli 23 500 tonnia hiilidioksidiekvivalenttia. Laskennassa käytetty aineisto, eli yritysten ja kunnallisten toimintojen päästö- ja polttoainetiedot, saatiin kirjallisuudesta, virallislähteistä sekä henkilökohtaisina tiedonantoina. Laskentaohjelmistona käytettiin Suomen Kuntaliiton kehittämää Excel-pohjaista kasvihuonekaasu-ja energiataseohjelmisto KASVENER:ia. Työssä on osoitettu, että kasvihuonekaasupäästölaskennan tarkkuus ja onnistuminen ovat riippuvaisia käytettävissä olevista resursseista, ennen kaikkea laskennan lähtötietojen laajuudesta ja tarkkuudesta. Laskentatuloksista selviää, että esimerkkikunnan kasvihuonekaasupäästöt ovat kasvaneet Suomen keskiarvoa vastaavalla tavalla. Toimenpide-ehdotuksia listatessa kävi lisäksi ilmi, että kasvihuonekaasupäästöjen leikkaaminen on melko helppoa olemassa olevalla teknologialla tiettyyn pisteeseen asti. Isompien tavoitteiden saavuttaminen edellyttää laajamittaisia investointeja ja kunnan infrastruktuurin muuttamista.

Laskentamenetelmissä tehtävien valintojen merkitys alueellisen lämmön- ja sähköntuotannon kasvihuonekaasupäästöjen kannalta

Tämän diplomityön tarkoituksena on selvittää alueellisen lämmön- ja sähköntuotannon laskentamenetelmävalintojen vaikutuksia kasvihuonekaasupäästöihin. Työn tutkimuskysymyksenä on, onko mahdollista, että laskentamenetelmän valinnalla on suurempi vaikutus alueen kasvihuonekaasupäästöihin kuin energiantuotantotekniikan valinnalla. Laskentamenetelmävalinnoista tutkitaan tarkemmin CHP-laitoksen päästöjen allokointitavan ja sähkönpäästöjen määrittämisen vaikutuksia kasvihuonekaasupäästöihin. Tutkimusmenetelminä työssä on käytetty kirjallisuuskatsausta sekä tapaustutkimusta. Kirjallisuuskatsauksen aineistona käytetään tieteellisiä artikkeleita ja tutkimusraportteja. Tapaustutkimuksessa tutkitaan yksittäistä case-kohdetta, joka on Tampereen Härmälänrannan uudisrakennusalue, ja jossa vertaillaan maalämpöpumppua ja kaukolämpöä alueen lämmitysratkaisuina. Työn tuloksena todetaan, että on olemassa sellaisia tilanteita, joissa laskentamenetelmän valinnalla on suurempi vaikutus alueen kasvihuonekaasupäästöihin kuin energiantuotantotekniikan valinnalla. Lisäksi case-tarkastelun perusteella huomataan, että laskentamenetelmävalinnoilla on sitä suurempi merkitys, mitä enemmän CHP-laitoksessa käytetään uusiutuvaa polttoainetta. Työn johtopäätöksenä voidaan todeta, että energiantuotannon kasvihuonekaasupäästölaskennassa on syytä ymmärtää ja huomioida eri laskentamenetelmävalintojen vaikutus esitettyihin tuloksiin.

Balanç de carbó atmosfèric: raó entre les emissions de metà de les vaques i el segrest forestal de CO2

Treball de recerca realitzat per un alumne d'ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l'any 2009. L’objectiu d’aquest treball és determinar la capacitat de segrest de CO2 d’un bosc dels Pirineus, per tal de reduir el seu efecte hivernacle, en relació a l’impacte climàtic que tindrien les emissions de metà de les vaques. La metodologia s’ha basat en estimar la producció de fusta a partir d’inventaris forestals d’un bosc del Pallars Sobirà, i calcular-ne el segrest de CO2. Per altra banda, s’ha estimat bibliogràficament les emissions de metà d’una vaca. A partir de factors de conversió s’ha estimat la superfície de bosc que compensaria l’efecte hivernacle de les emissions de metà d’una vaca durant un any. El valor obtingut és de 0,727 hectàrees de bosc per vaca i any. Amb aquest valor s’ha estimat la superfície de bosc necessària per compensar les emissions de metà de la població de vaques de Catalunya. Aquests resultats són aproximats, donades les diferències en el creixement dels boscos de Catalunya. Aquest estudi dóna una dada comprensible que posa de manifest el concepte de balanç de carboni i els diferents elements que el formen.

Calculation of the carbon footprint of Finnish barley products - methodology and possible applications

The purpose of this thesis was to define how product carbon footprint analysis and its results can be used in company's internal development as well as in customer and interest group guidance, and how these factors are related to corporate social responsibility. From-cradle-to-gate carbon footprint was calculated for three products; Torino Whole grain barley, Torino Pearl barley, and Elovena Barley grit & oat bran, all of them made of Finnish barley. The carbon footprint of the Elovena product was used to determine carbon footprints for industrial kitchen cooked porridge portions. The basic calculation data was collected from several sources. Most of the data originated from Raisio Group's contractual farmers and Raisio Group's cultivation, processing and packaging specialists. Data from national and European literature and database sources was also used. The electricity consumption for porridge portions' carbon footprint calculations was determined with practical measurements. The carbon footprint calculations were conducted according to the ISO 14044 standard, and the PAS 2050 guide was also applied. A consequential functional unit was applied in porridge portions' carbon footprint calculations. Most of the emissions from barley products' life cycle originate from primary production. The nitrous oxide emissions from cultivated soil and the use and production of nitrogenous fertilisers contribute over 50% of products' carbon footprint. Torino Pearl barley has the highest carbon footprint due to the lowest processing output. The reductions in products' carbon footprint can be achieved with developments in cultivation and grain processing. The carbon footprint of porridge portion can be reduced by using domestically produced plant-based ingredients and by making the best possible use of the kettle. Carbon footprint calculation can be used to determine possible improvement points related to corporate environmental responsibility. Several improvement actions are related to economical and social responsibility through better raw material utilization and expense reductions.

Biogenic nitric oxide emissions from soils: impact on NOx and ozone over West Africa during AMMA (African Monsoon Multidisciplinary Analysis) - Modelling study

Nitrogen oxide biogenic emissions from soils are driven by soil and environmental parameters. The relationship between these parameters and NO fluxes is highly non linear. A new algorithm, based on a neural network calculation, is used to reproduce the NO biogenic emissions linked to precipitations in the Sahel on the 6 August 2006 during the AMMA campaign. This algorithm has been coupled in the surface scheme of a coupled chemistry dynamics model (MesoNH Chemistry) to estimate the impact of the NO emissions on NOx and O3 formation in the lower troposphere for this particular episode. Four different simulations on the same domain and at the same period are compared: one with anthropogenic emissions only, one with soil NO emissions from a static inventory, at low time and space resolution, one with NO emissions from neural network, and one with NO from neural network plus lightning NOx. The influence of NOx from lightning is limited to the upper troposphere. The NO emission from soils calculated with neural network responds to changes in soil moisture giving enhanced emissions over the wetted soil, as observed by aircraft measurements after the passing of a convective system. The subsequent enhancement of NOx and ozone is limited to the lowest layers of the atmosphere in modelling, whereas measurements show higher concentrations above 1000 m. The neural network algorithm, applied in the Sahel region for one particular day of the wet season, allows an immediate response of fluxes to environmental parameters, unlike static emission inventories. Stewart et al (2008) is a companion paper to this one which looks at NOx and ozone concentrations in the boundary layer as measured on a research aircraft, examines how they vary with respect to the soil moisture, as indicated by surface temperature anomalies, and deduces NOx fluxes. In this current paper the model-derived results are compared to the observations and calculated fluxes presented by Stewart et al (2008).

Methodology To model the energy and greenhouse gas emissions of electronic software distributions

A new electronic software distribution (ESD) life cycle analysis (LCA)methodology and model structure were constructed to calculate energy consumption and greenhouse gas (GHG) emissions. In order to counteract the use of high level, top-down modeling efforts, and to increase result accuracy, a focus upon device details and data routes was taken. In order to compare ESD to a relevant physical distribution alternative,physical model boundaries and variables were described. The methodology was compiled from the analysis and operational data of a major online store which provides ESD and physical distribution options. The ESD method included the calculation of power consumption of data center server and networking devices. An in-depth method to calculate server efficiency and utilization was also included to account for virtualization and server efficiency features. Internet transfer power consumption was analyzed taking into account the number of data hops and networking devices used. The power consumed by online browsing and downloading was also factored into the model. The embedded CO2e of server and networking devices was proportioned to each ESD process. Three U.K.-based ESD scenarios were analyzed using the model which revealed potential CO2e savings of 83% when ESD was used over physical distribution. Results also highlighted the importance of server efficiency and utilization methods.

Radiative forcing due to aviation water vapour emissions

Three emissions inventories have been used with a fully Lagrangian trajectory model to calculate the stratospheric accumulation of water vapour emissions from aircraft, and the resulting radiative forcing. The annual and global mean radiative forcing due to present-day aviation water vapour emissions has been found to be 0.9 [0.3 to 1.4] mW m^2. This is around a factor of three smaller than the value given in recent assessments, and the upper bound is much lower than a recently suggested 20 mW m^2 upper bound. This forcing is sensitive to the vertical distribution of emissions, and, to a lesser extent, interannual variability in meteorology. Large differences in the vertical distribution of emissions within the inventories have been identified, which result in the choice of inventory being the largest source of differences in the calculation of the radiative forcing due to the emissions. Analysis of Northern Hemisphere trajectories demonstrates that the assumption of an e-folding time is not always appropriate for stratospheric emissions. A linear model is more representative for emissions that enter the stratosphere far above the tropopause.

Photon-induced multiple particle emissions of Zr90 and natZr from 10 to 140 MeV

A comprehensive analysis of electrodisintegration yields of protons on Zr90 is proposed taking into account the giant dipole resonance, isovector giant quadrupole resonance (IVGQR), and quasideuteron contributions to the total photoabsorption cross section from 10 to 140 MeV. The calculation applies the MCMC intranuclear cascade to address the direct and pre-equilibrium emissions and another Monte Carlo-based algorithm to describe the evaporation step. The final results of the total photoabsorption cross section for Zr90 and relevant decay channels are obtained by fitting the (e,p) measurements from the National Bureau of Standards and show that multiple proton emissions dominate the photonuclear reactions at higher energies. These results provide a consistent explanation for the exotic and steady increase of the (e,p) yield and also a strong evidence of a IVGQR with a strength parameter compatible with the E2 energy-weighted sum rule. The inclusive photoneutron cross sections for Zr90 and natZr, derived from these results and normalized with the (e,p) data, are in agreement within 10% with both Livermore and Saclay data up to 140 MeV. © 2007 The American Physical Society.

Multiple particle and cluster emissions from Zr following intermediate energies photo absorption

A new approach based on a N-a cluster photoabsorption model is proposed for the understanding of the puzzling steady increase behavior of the 90Zr (e, α) yield measured at the National Bureau of Standards (NBS) within the Giant Dipole Resonance and quasideuteron energy range. The calculation takes into account the pre-equilibrium emissions of protons, neutrons and alpha particles in the framework of an extended version of the multicollisional intranuclear cascade model (MCMC). Another Monte Carlo based algorithm describes the statistical decay of the compound nucleus in terms of the competition between particle evaporation (p, n, d, α, 3He and t) and nuclear fission. The results reproduce quite successfully the 90Zr (e,α) yield, suggesting that emissions of a particles are essential for the interpretation of the exotic increase of the cross sections.

Volatile organic compounds at the air-sea interface : gas exchange rates, oceanic emissions and the effect of ocean acidification

Oceans are key sources and sinks in the global budgets of significant atmospheric trace gases, termed Volatile Organic Compounds (VOCs). Despite their low concentrations, these species have an important role in the atmosphere, influencing ozone photochemistry and aerosol physics. Surprisingly, little work has been done on assessing their emissions or transport mechanisms and rates between ocean and atmosphere, all of which are important when modelling the atmosphere accurately.rnA new Needle Trap Device (NTD) - GC-MS method was developed for the effective sampling and analysis of VOCs in seawater. Good repeatability (RSDs <16 %), linearity (R2 = 0.96 - 0.99) and limits of detection in the range of pM were obtained for DMS, isoprene, benzene, toluene, p-xylene, (+)-α-pinene and (-)-α-pinene. Laboratory evaluation and subsequent field application indicated that the proposed method can be used successfully in place of the more usually applied extraction techniques (P&T, SPME) to extend the suite of species typically measured in the ocean and improve detection limits. rnDuring a mesocosm CO2 enrichment study, DMS, isoprene and α-pinene were identified and quantified in seawater samples, using the above mentioned method. Based on correlations with available biological datasets, the effects of ocean acidification as well as possible ocean biological sources were investigated for all examined compounds. Future ocean's acidity was shown to decrease oceanic DMS production, possibly impact isoprene emissions but not affect the production of α-pinene. rnIn a separate activity, ocean - atmosphere interactions were simulated in a large scale wind-wave canal facility, in order to investigate the gas exchange process and its controlling mechanisms. Air-water exchange rates of 14 chemical species (of which 11 VOCs) spanning a wide range of solubility (dimensionless solubility, α = 0:4 to 5470) and diffusivity (Schmidt number in water, Scw = 594 to 1194) were obtained under various turbulent (wind speed at ten meters height, u10 = 0:8 to 15ms-1) and surfactant modulated (two different sized Triton X-100 layers) surface conditions. Reliable and reproducible total gas transfer velocities were obtained and the derived values and trends were comparable to previous investigations. Through this study, a much better and more comprehensive understanding of the gas exchange process was accomplished. The role of friction velocity, uw* and mean square slope, σs2 in defining phenomena such as waves and wave breaking, near surface turbulence, bubbles and surface films was recognized as very significant. uw* was determined as the ideal turbulent parameter while σs2 described best the related surface conditions. A combination of both uw* and σs2 variables, was found to reproduce faithfully the air-water gas exchange process. rnA Total Transfer Velocity (TTV) model provided by a compilation of 14 tracers and a combination of both uw* and σs2 parameters, is proposed for the first time. Through the proposed TTV parameterization, a new physical perspective is presented which provides an accurate TTV for any tracer within the examined solubility range. rnThe development of such a comprehensive air-sea gas exchange parameterization represents a highly useful tool for regional and global models, providing accurate total transfer velocity estimations for any tracer and any sea-surface status, simplifying the calculation process and eliminating inevitable calculation uncertainty connected with the selection or combination of different parameterizations.rnrn

Photophysical properties and quantum chemical studies of poly(2,7-9,9'-dihexylfluorene-dyil)

This work reports the photophysical properties (excitation and fluorescence spectra, fluorescence quantum yield, fluorescence lifetimes) of the poly(2,7-9,9'-dihexylfluorene-dyil) in dilute solutions of four solvents (toluene, tetrahydrofuran, chloroform and ethyl acetate) as well as the properties in solid state. Photoluminescence showed spectra characteristic of disordered α-backbone chain conformation. Simulation of the electronic absorption spectra of oligomers containing 1 to 11 mers showed that the critical conjugation length is between 6 and 7 mers. We also estimated the theoretical dipole moments which indicated that a coil conformation is formed with 8 repeating units per turn. We also showed that some energy transfer process appears in solid state which decreases the emission lifetime. Furthermore, based on luminescent response of the systems herein studied and electroluminescent behavior reported on literature, both photo and electroluminescence emissions arise from the same emissive units.

Influence of memory in deterministic walks in random media: Analytical calculation within a mean-field approximation

Consider a random medium consisting of N points randomly distributed so that there is no correlation among the distances separating them. This is the random link model, which is the high dimensionality limit (mean-field approximation) for the Euclidean random point structure. In the random link model, at discrete time steps, a walker moves to the nearest point, which has not been visited in the last mu steps (memory), producing a deterministic partially self-avoiding walk (the tourist walk). We have analytically obtained the distribution of the number n of points explored by the walker with memory mu=2, as well as the transient and period joint distribution. This result enables us to explain the abrupt change in the exploratory behavior between the cases mu=1 (memoryless walker, driven by extreme value statistics) and mu=2 (walker with memory, driven by combinatorial statistics). In the mu=1 case, the mean newly visited points in the thermodynamic limit (N >> 1) is just < n >=e=2.72... while in the mu=2 case, the mean number < n > of visited points grows proportionally to N(1/2). Also, this result allows us to establish an equivalence between the random link model with mu=2 and random map (uncorrelated back and forth distances) with mu=0 and the abrupt change between the probabilities for null transient time and subsequent ones.

Hyperpolarizabilities of the methanol molecule: A CCSD calculation including vibrational corrections

In this work we present the results for hyperpolarizabilities of the methanol molecule including vibrational corrections and electron correlation effects at the CCSD level. Comparisons to random phase approximation results previously reported show that the electron correlation is in general important for both electronic contribution and vibrational corrections. The role played by the anharmonicities on the calculations of the vibrational corrections has also been analyzed and the obtained results indicate that the anharmonic terms are important for the dc-Pockels and dc-Kerr effects. For the other nonlinear optical properties studied the double-harmonic approximation is found to be suitable. Comparison to available experimental result in gas phase for the dc-second harmonic generation second hyperpolarizability shows a very good agreement with the electronic contribution calculated here while our total value is 14% larger than the experimental value.

Approximation to density functional theory for the calculation of band gaps of semiconductors

The local-density approximation (LDA) together with the half occupation (transitionstate) is notoriously successful in the calculation of atomic ionization potentials. When it comes to extended systems, such as a semiconductor infinite system, it has been very difficult to find a way to half ionize because the hole tends to be infinitely extended (a Bloch wave). The answer to this problem lies in the LDA formalism itself. One proves that the half occupation is equivalent to introducing the hole self-energy (electrostatic and exchange correlation) into the Schrodinger equation. The argument then becomes simple: The eigenvalue minus the self-energy has to be minimized because the atom has a minimal energy. Then one simply proves that the hole is localized, not infinitely extended, because it must have maximal self-energy. Then one also arrives at an equation similar to the self- interaction correction equation, but corrected for the removal of just 1/2 electron. Applied to the calculation of band gaps and effective masses, we use the self- energy calculated in atoms and attain a precision similar to that of GW, but with the great advantage that it requires no more computational effort than standard LDA.

Historical carbon emissions and uptake from the agricultural frontier of the Brazilian Amazon

Tropical ecosystems play a large and complex role in the global carbon cycle. Clearing of natural ecosystems for agriculture leads to large pulses of CO(2) to the atmosphere from terrestrial biomass. Concurrently, the remaining intact ecosystems, especially tropical forests, may be sequestering a large amount of carbon from the atmosphere in response to global environmental changes including climate changes and an increase in atmospheric CO(2). Here we use an approach that integrates census-based historical land use reconstructions, remote-sensing-based contemporary land use change analyses, and simulation modeling of terrestrial biogeochemistry to estimate the net carbon balance over the period 1901-2006 for the state of Mato Grosso, Brazil, which is one of the most rapidly changing agricultural frontiers in the world. By the end of this period, we estimate that of the state`s 925 225 km(2), 221 092 km(2) have been converted to pastures and 89 533 km(2) have been converted to croplands, with forest-to-pasture conversions being the dominant land use trajectory but with recent transitions to croplands increasing rapidly in the last decade. These conversions have led to a cumulative release of 4.8 Pg C to the atmosphere, with similar to 80% from forest clearing and 20% from the clearing of cerrado. Over the same period, we estimate that the residual undisturbed ecosystems accumulated 0.3 Pg C in response to CO2 fertilization. Therefore, the net emissions of carbon from Mato Grosso over this period were 4.5 Pg C. Net carbon emissions from Mato Grosso since 2000 averaged 146 Tg C/yr, on the order of Brazil`s fossil fuel emissions during this period. These emissions were associated with the expansion of croplands to grow soybeans. While alternative management regimes in croplands, including tillage, fertilization, and cropping patterns promote carbon storage in ecosystems, they remain a small portion of the net carbon balance for the region. This detailed accounting of a region`s carbon balance is the type of foundation analysis needed by the new United Nations Collaborative Programmme for Reducing Emissions from Deforestation and Forest Degradation (REDD).