Ziel der Arbeit ist die Gesamtbilanzierung der Treibhausgasemissionen eines Anbausystems unter Bewässerung auf einem Sandboden. Die dazu aufgestellte Treibhausgasbilanz basiert auf langjährigen Datenreihen zu Erträgen und Corg-Vorräten eines Dauerfeldversuchs sowie auf zweijährigen im Feldversuch durchgeführten N2O-Messungen. Die durchgeführten Untersuchungen zum Einfluss der Bewässerung auf die Corg-Vorräte zeigen, dass der Einsatz von mineralischem Stickstoffdünger und Bewässerung auf einem leichten Standort unter den klimatischen Bedingungen Nord-Ost-Deutschlands positive Effekte hat. Die N2O-Emissionen eines Sandbodens unter den klimatischen Bedingungen Brandenburgs sind sehr niedrig. Die Applikation von mineralischem Stickstoffdünger hat nur schwache und Bewässerung hat aufgrund der der hohen Bodendurchlüftung des Sandbodens keine Effekte auf die Höhe der N2O-Emissionen. Die direkten und indirekten Emissionen aus dem Maschinen- und Betriebsmitteleinsatz erhöhen sich bei Bewässerung und steigender Stickstoffdüngung deutlich. Bei den indirekten Treibhausgasemissionen nehmen die Emissionen der Herstellung des mineralischen Stickstoffdüngers einen bedeutenden Anteil der Gesamttreibhausgasemissionen ein. Bewässerung führt durch den erhöhten Dieselverbrauch hauptsächlich zu einer Erhöhung der direkten Emissionen. Unter Bewässerung kann jedoch ein Teil der Emissionen durch zunehmende Corg-Vorräte kompensiert werden. Somit sind in einigen Fällen die Gesamttreibhausgasemissionen pro Hektar bei Bewässerung geringer als ohne Bewässerung. Die aus Stickstoffdüngung und Bewässerung resultierenden Ertragserhöhungen führen dazu, dass die Gesamttreibhausgasemissionen bezogen auf die Ertragseinheit in den meisten bewässerten Varianten deutlich geringer sind als in den unbewässerten. Daraus lässt sich ableiten, dass Bewässerung auf einem Sandboden zu einer Verminderung der Treibhausgasemissionen beitragen kann. / The aim of this work is the estimation of the net greenhouse gas emissions by a greenhouse balance for an irrigated cropping system on a sandy soil in north-east Germany under various nitrogen fertilizer intensities. The balances are based on data of yields and SOC stocks of an irrigated long term field experiment as well as on results of N2O-measurements over two years. The results of the analysis of the long term response of irrigation and nitrogen fertilization have shown that irrigation and mineral nitrogen fertilization led to significant increases in yields and harvest residues. The increased carbon inputs from above ground harvest residues had positive effects on the SOC stocks. The results of N2O measurements indicated that N2O emissions from a sandy soil are very low. Mineral nitrogen fertilization had only marginal effects. Irrigation showed no effects on the amount of N2O emissions. On the one hand the analysis of the prepared greenhouse gas balances showed that irrigation and increased nitrogen fertilization lead to a strong increase of direct and indirect emissions from machinery and maintenance resource use. The indirect emissions of nitrogen fertilizer production took up a main part of the net greenhouse gas emissions. Irrigation mainly increased greenhouse gas emissions of fuel use and fuel production as well as the emissions of the machinery production. On the other hand the increasing SOC stocks especially in the fertilized variants under irrigation led to a compensation of a huge part of the additional emissions. Thus, in many cases the net greenhouse gas emissions per unit area was lower under irrigation. Due to the increased yields under irrigation the net greenhouse gas emissions per unit yield were lower than that under non-irrigated conditions.

It is very likely that human being is contributing to the process of global warming. Industrial activities such as cement production are among the largest sources of human-induced greenhouse gas emissions. Therefore, there are ongoing efforts to reduce the CO2 emissions attributed to the cement production. In order to be able to systematically identify, classify, and evaluate the most effective, applicable, and feasible CO2 improvement measures, it is essential to have an assessment framework, which has an environmental management perspective. Such a framework should be able to cover the widest range of potential CO2 improvement measures, therefore it has to have a wide system perspective and consider all material, and energy flows within the industry as useful resources. The first part of this thesis uses the concepts of Industrial Ecology and Industrial Symbiosis as the supporting theoretical concepts for developing such assessment framework. The framework has semi-qualitative approach for assessing different measures and is developed in two parts: (1) generic and (2) site-specific assessment. The first part considers general aspects of the measures such as level of Industrial Symbiosis (i.e. complexity of business approach), the potential of each measure for reducing CO2 emissions, and their technological maturity. The second part assesses the feasibility of the measures regarding the conditions of a specific cement producing system. Aspects such as organizational applicability, technical and infrastructural applicability, and the existing level of implementation of each measure are considered. In the second part of this thesis, the developed framework is applied on a selected cement production system which is a cluster composed of three cement plants in Germany (owned by CEMEX) referred to as the Cluster West. The result of the assessment provides insights about the state-of-the-art of CO2 improvement measures in cement industry in general and also demonstrates which of these measures are most (or least) suited for development in the Cluster West. The production system of the Cluster West has effectively applied CO2 improvement measures in areas such as producing blended cement products, using alternative fuels (and renewable fuels) for clinker production. In addition, its clinker production (the Kollenbach plant that is part of the Cluster West) has relatively good energy efficiency. According to the results of the assessment, CO2 improvement measures such as co-generation (producing electricity from excess heat of the plant), using renewable fuels, using alternative materials for clinker production, and increasing the usage of alternative fuels are among the most applicable choices for further implementation. / In relation with LIU-CEMEX Indsutrial Ecology project (2011)

I Sverige pågick under 2013 efterbehandlingsåtgärder på 1789 förorenade områden. Det nationella miljömålet ”giftfri miljö” har av regeringen angetts som det styrande miljö- målet vid efterbehandling. Efterbehandlingen syftar till att minska risken för förore- ningsspridning i mark från avslutade verksamheter som industrier, vägar med mera. Schaktning av massor utförs vid efterbehandling för att avlägsna förorenade massor från platsen men innebär samtidigt utsläpp av växthusgaser. Både vid schaktning och transport av förorenade massor samt framställande och transport av fyllnadsmaterial används fordon och maskiner som genererar växthusgasutsläpp. Efterbehandlingsarbetet riskerar alltså att ge en negativ påverkan på miljömålet ”begränsad klimatpåverkan”. I denna studie söks svar på frågorna: Kan efterbehandling av förorenade områden bedri- vas med simultan hänsyn till de båda miljömålen ”giftfri miljö” och ”begränsad klimat- påverkan”? och Hur ska ett sådant arbete bedrivas? För att besvara dessa frågor använ- des det webbaserade beräkningsverktyget Carbon footprint från efterbehandling och andra markarbeten från Svenska geotekniska föreningen, SGF, samt en enkätstudie riktad till tillsynsmyndigheter. Beräkningar med verktyget visade att det som främst påverkar växthusgasutsläppen vid efterbehandling är typ av fyllnadsmassor, sammanlagd transportsträcka samt lastkapa- citet hos fordon som transporterar massor. Ingen av de tillfrågade tillsynsmyndigheterna tar hänsyn till växthusgasutsläpp vid godkännande av efterbehandlingsåtgärd. Många ställer sig dock positiva till ett verktyg som ger möjlighet att göra en avvägning mellan miljömål och tror att det skulle underlätta deras arbete. Två strategier som tar större hänsyn till växthusgasutsläpp identifierades. Strategi 1 innebär att sanering sker enligt riktvärdena för känslig eller mindre känslig mark- användning (KM/MKM) och växthusgasutsläppen minimeras genom effektiviserings- åtgärder. Som effektiviseringsåtgärd identifierades bland annat användning av lastbilar med större lastkapacitet och användning av återvunna massor som fyllnadsmaterial. Strategi 2 innebär en avvägning mellan miljömålen ”giftfri miljö” och ”begränsad kli- matpåverkan”. Riktvärdena för KM och MKM kan i strategin överskridas för att mini- mera växthusgasutsläpp. Effektiviseringsåtgärderna från strategi 1 implementeras även i strategi 2. / In Sweden, 1789 contaminated sites were remediated during 2013. The government has stated the national environmental objective “A Non-Toxic Environment” as the gov- erning environmental objective in remediation. The aim of remediation is to reduce the risk of dispersion of contamination in soils from discontinued activities such as indus- tries, roads etc. Excavation of soils takes place to remove contaminated soil from the site. However, it leads to emissions of greenhouse gases. Machines that generate emis- sions of greenhouse gases are needed in excavation, transport of contaminated soils and the production and transport of filling materials. Thus, the environmental objective “Reduced Climate Impact” is likely to be adversely affected by soil remediation. This study was conducted to answer the questions: Can soil remediation be conducted with simultaneous regard to the environmental objectives “A Non-Toxic Environment” and “Reduced Climate Impact”? and How should such efforts be conducted? Two methods were used: the web based calculation tool Carbon footprint from remediation and other soil works from the Swedish Geotechnical Society, SGF, and a survey ad- dressed to regulatory authorities. Calculations with the tool showed that the main impacts on greenhouse gas emissions were choice of filling materials, total transportation distance and carrying load of the vehicles transporting soils. None of the respondent regulatory authorities take green- house gas emissions into account when approving remediation operations. However, many of them displayed positive attitude towards a tool that would make it possible to compare impacts on environmental objectives and stated that such a tool would facili- tate their work. Two strategies that give more consideration to greenhouse gas emissions were identi- fied. In strategy 1, remediation is conducted according to the guidelines of sensitive or less sensitive land use (KM/MKM). The greenhouse gas emissions are minimized through efficiency improvement measures. Use of vehicles with a greater carrying load and recovered soils as filling material are examples of identified efficiency improve- ment measures. Strategy 2 consists of achieving a balance between the environmental objectives “A Non-Toxic Environment” and “Reduced Climate Impact”. In this strat- egy, KM and MKM can be exceeded to minimize greenhouse gas emissions. The effi- ciency improvement measures from strategy 1 can be implemented in strategy 2.

Arbetet med att minska människans utsläpp av växthusgaser är en fråga som är högaktuell idag. Transportsektorn är den sektor som har näst störst klimatpåverkan inom EU-området. För att minska transportsektorns klimatpåverkan anser EU-kommissionen att en del av det gods som idag går på väg behöver flyttas till tåg eller sjö för att nå EU:s miljömål. Syftet med arbetet var att undersöka skillnaden av växthusgasutsläpp för transport av containrar beroende på transportsätt på sträckan Göteborg till Stockholm. De undersökta transportsätten var lastbil, godståg och containerfartyg. Studien använde en empirisk fallstudie där växthusgasutsläpp beräknades utifrån empiriska bränsleförbruknings data. Fallstudien kompletterades med en intervju från en person med stor erfarenhet av godstransporter på sträckan. Resultatet av undersökningen är att järnvägens miljöverkan är minst, men för tidskänsligt gods är fortfarande vägtransport det effektivaste transportslaget. För att sjöfart ska vara ett miljömässigt alternativ måste anpassningar av fartyg och/eller drift göras. / The work to reduce greenhouse emissions created by humans is a question that is highly relevant today. The transport sector is the second largest emitter of greenhouse gases in the European Union. To reduce the greenhouse emissions from the transport sector the EU commission has said that some of the freight that currently is being transported by road must move to rail or sea transport in order to reach EU environmental targets. The scope of this study is to compare the greenhouse emissions based on fuel consumption from domestic container transport between Gothenburg and Stockholm. The different modes of transports studied were trucks, freight train and container ship. The study was conducted using an empirical case study to calculate the greenhouse gas emissions using empirical fuel consumption data. The case study was supplemented by an interview with a person with great insight in the transport business. The result from the study shows that from an environmental perspective container transport by rail should be used. Transport by road is still the best means of transport for time sensitive cargo. If transport by sea is to be an environmental option, there has to be adjustments on either ships or management or both.

Inledning- Det har satts upp mål på både global och nationell nivå för att bekämpa klimatförändringarna som sker på vår planet. Mat och måltider berörs direkt och indirekt av flera av dessa mål. På avdelningen Måltidsservice i Härryda kommun har arbete med att miljöutveckla skolmaten skett i mer än ett decennium, något som de ansvariga önskade en uppföljning på.  Syfte- Att undersöka om och i så fall hur klimatavtrycket från skolmaten i Härryda kommuns gymnasieskola har förändrats från år 1993 till 2020. Ett andra syfte är att undersöka eventuella förändringar i skollunchernas innehåll med avseende på livsmedel under samma tidsperiod. Material och metod- För att undersöka eventuella förändringar i klimatavtryck över tid har skolluncher från stickprov i tidsperioden 1993-2020 klimatberäknats. För att se eventuella förändringar i skollunchernas innehåll har frekvenser på fem utvalda livsmedel studerats.  Resultat- Det finns ingen signifikant skillnad i CO₂emellan period 1 (1993+1998+2003) och period 2 (2013+2018+2020). Där finns svaga tendenser som tyder på minskning i skolmatens klimatavtryck under det senaste decenniet. Förekomsten av rent nötkött, produkter av gris och ris har minskat i skolluncherna medan vegetabiliskt protein och kött från fågel har ökat.  Slutsats-Någon signifikant skillnad i klimatavtryck mellan 1993 och 2020 kunde inte fastställas. Det fanns tydliga förändringar i skollunchernas innehåll med avseende på livsmedel under samma tidsperiod. / Introduction-Targets have been set at both global and national levels to fight the climate changes that are happening on our planet. Food and meals directly and indirectly affect several of these goals. For more than a decade the Meal service-department in Härryda kommun have been working on making their school meals more sustainable and now they want a follow-up on that.  Aims- To investigate if and in that case how the carbon footprint from the high school of Härryda kommun’s school meals has changed from 1993 to 2020. A second purpose is to investigate any changes in the content of the school lunches referred to foods. Materials and methods-In order to investigate possible changes in carbon footprints over time, samples of school lunches in the time period 1993-2020 have been calculated. In order to see any changes in the content of the school lunches, frequencies of five selected foods have been studied. Results-There is no significant difference in CO₂e between period 1 (1993 + 1998 + 2003) and period 2 (2013 + 2018 + 2020). There are small tendencies that indicate a decrease in carbon footprint from the school meals in the last decade. The presence of pure beef, products of pig and rice have decreased in the school meals, while plant-based protein and meat from birds have increased. Conclusion-No significant difference in climate imprint between 1993 and 2020 could be determined. There were obvious changes in the content of the school lunches with regard to food during the same time period.

The construction sector accounts for about one fifth of Sweden's greenhouse gas emissions. It is also the sector that produces the second most waste in Sweden. Today there is an increased need for housing in Sweden, at the same time as the construction sector must reduce its greenhouse gas emissions. Usually when renovating a building, construction products are disposed despite having a remaining service of life. The purpose of this study is to investigate how the reuse of construction products can be increased in the construction sector. And to find out how companies in Växjö work with reusing construction products. The work was based on the project Kv. Stommen, the project was about a new preschool in Vikaholm, Växjö. In the project the buyer had requested that some construction products should be reused. The purpose of the study was addressed by using interview methodology and partaking in focus group discussion with Godahåll during their meeting. According to the results there are seven challenges that must be overcome before the reuse of construction products in the construction sector can increase. The representatives from the companies in Växjö, who were interviewed had a positive attitude towards reuse of construction products. One conclusion is that there is an interest in the construction sector to use reused construction products and that it will increase in the future. Another conclusion is that by using reused construction products, the construction sector´s waste volumes can be reduced and contribute to a circular construction.

The thesis deals with the negotiations on the EU framework for climate and energy in the period from 2020 to 2030 which were held in the Council of the EU and the European Council from January to October 2014. The text focuses on coordination of common negotiating position and common requirements of the Visegrad countries, Bulgaria and Romania which played an important role as an advocacy coalition during the negotiations on climate and energy package. They aimed to push through solutions of the issue of unequal costs placed on individual EU member states, with heavier burden put on the low-income countries. The thesis looks into the V4+2 group particular claims and evaluates how successful the coalition was in its efforts to set their ideas into the final formulation of the EU climate and energy policy for the period after 2020. The thesis is based on theoretical concepts of agenda-setting and advocacy coalition and uses also knowledge from theoretical research on the EU decision process.

Several categories of emissions are presented in Ericsson ́s sustainability report, among them emissions from product transportation is the largest one within Ericsson ́s own business. However, it is only a part of the transportation flow that is included in the report. The sustainability report covers transportations from distribution centers to customer sites, but now Ericsson will expand the range to cover a larger part of the supply chain, from first tier suppliers, through production, to customer sites. The change would provide Ericsson with better visibility and control over the supply chain and therefore enable the possibility to find new solutions the reduce greenhouse gas emissions. One strategy to reduce product transportation greenhouse gas emissions is regionalization, which Ericsson is already implementing for the production sites. Moving forward they also want to evaluate the possibility to regionalize the external suppliers. Therefore, the aim of the study is to evaluate the effects of a regionalized supply on product transportation from first tier supplier to customer sites, with focus on greenhouse gas emissions. Transportation data including weight, distance and transport mode was collected. Calculations was then done on an aggregated level and did not get into details regarding vehicle utilization or fuel usage. Data collected was inadequate in some part of the supply chain and the gaps were filled with assumptions based on initial interviews. The current emissions for the part of the supply chain that goes from suppliers to distribution hubs was calculated to 30 000 ton CO2e, but with regard to sensibility analysis the true value of emissions is higher. Further, the total current emissions were calculated by adding the new calculatedpart with Ericsson’s reported numbers, which gave the total emissions in the flow to be 169 000 ton CO2e. After the benchmark was established the effect of a regionalized supply was examined. Ericsson has divided the world into three supply regions, the America region, the Europe, Middle east and Africa region and Asia and Pacific Ocean region. The same regions were used to regionalize the suppliers. The suppliers that were located in a different region than the receiving plant were moved to a location that were deemed appropriate by interviews. In the America region the suppliers were placed in Mexico, in the Europe region the suppliers were placed in Romania and in the Asia region the suppliers were placed in China. With the regionalization of the suppliers the total emissions were reduced by 4 % regarding the baseline. Another conclusion from the regionalization was that the supply chain became less emission efficient because the transportation work by truck increased and decreased for boat. The results contain many uncertainties mostly because the regionalization is happening in the part of the supply chain that is mainly based on assumptions to begin with. Based on interviews regionalized suppliers would entail increased costs and loads of initial work, but shorter lead times. The interviewees also said that it is the mechanical components that is appropriate to regionalize since they are heavy, cheap and easy to produce compared to the electronical components. The electronical components were not deemed possible to regionalize. In summery Ericsson can expect reduced greenhouse gas emissions if they regionalize their 1st suppliers, but the size of the reduction needs further examination. Especially better data is needed to establish the benchmark, something that Ericsson will continue working on. / Följande arbete berör Ericssons växthusgasutsläpp från produkttransporter. I Ericssons hållbarhetsredovisning presenteras i dagsläget olika kategorier av utsläpp. Av de utsläppen som sker inom Ericssons verksamhet är produkttransporterna den största kategorin, trots att endast en del av flödet ingår i de presenterade siffrorna. Ericsson redovisar utsläppen för transporter från en distributionshub ut till kundsite, men vill nu utöka omfånget till att gå från förstaledsleverantörer, via produktion, ut till kundsite. Förändringen ämnar ge Ericsson bättre visibilitet och kontroll över försörjningskedjan för att därigenom kunna hitta lösningar för att minska växthusgasutsläppen. En strategi för att minska växthusgasutsläpp från produkttransporterna som Ericsson undersöker är regionalisering, något som redan genomförts för produktionen. Framöver vill Ericsson även utvärdera möjligheten av att regionalisera leverantörerna. Därför är syftet med studien att utvärdera effekterna av regionaliserad försörjning i Ericssons produkttransportflöde från förstaledsleverantörer till kundsiter, med fokus på växthusgasutsläpp. För att genomföra studien samlades transportdata med information kring vikt, sträcka och transportmedel in. Beräkningarna genomfördes på en aggregerad nivå och gick inte in på en djupare nivå såsom fyllnadsgrader eller bränsle som använts. Data var bristfällig på en del ställen i flödet och där fylldes luckorna på med antaganden baserade på intervjuer. Nuvarande utsläpp från flödet som går mellan leverantörer och distributionshubbar beräknas 2019 vara 30000 ton CO2e, men med hänsyn till känslighetsanalyser uppskattas det verkliga utsläppet vara högre. Det framtagna utsläppet slogs samman med de utsläppen Ericsson redan redovisar och de totala utsläppen för flödet blev därför 169 000 ton CO2e. Efter att ett utgångsläge fastställts undersöktes påverkan av en regionalisering av de externa förstaledsleverantörerna. Ericsson har delat in världen i tre regioner, dessa är Amerikaregionen, regionen för Europa, Mellanöstern och Afrika samt regionen för Asien och Stillahavet. Samma regioner används för regionaliseringen av leverantörer. De leverantörer som låg i en annan region än deras mottagare förflyttades till ett land som utifrån intervjuer ansågs lämpligt. För Amerikaregionen placerades leverantörerna i Mexiko, för Europaregionen placerades de i Rumänien och Asienregionen i Kina. Resultatet av regionaliseringen blev att utsläppen minskade med 4 % sett till det totala utgångsläget. Det visade sig även att utsläppseffektiviteten blev lägre eftersom mängden transportarbete för vägtransporter ökade och sjötransporterna minskade. Resultaten från scenariot med regionaliserade leverantörer har dock mycket osäkerhet i sig vilket främst grundar sig i att förändringarna sker i den delen av flödet där minst tillgång till data fanns att tillgå. Utifrån intervjuer framkom det även att regionalisera leverantörerna förmodligen skulle medföra ökade kostnader och initialt arbete, men kortare ledtider. Det framkom även att det främst var för mekanikkomponenter som regionalisering är ett alternativ då de är relativt tunga, billiga och enkla att tillverka i jämförelse med elektronikkomponenter. Elektronikkomponenterna ansågs inte vara lämpliga att regionalisera. Sammanfattningsvis kan Ericsson förvänta sig en minskning av växthusgasutsläpp vid en regionalisering av leverantörer, men storleken på minskningen behöver undersökas vidare. Framförallt behövs bättre data kring nuläget i början av flödet, vilket är något som Ericsson kommer att jobba vidare med.

Ethiopia is one of the sub-Saharan Africa countries whose energy depends on traditional use of biomass such as wood, charcoal, agricultural residues and animal dung. The traditional use of biomass mainly wood and charcoal leads the country to massive deforestation and forest degradation. Negative environmental impacts from poorly managed municipal solid waste are also serious problems in the country. Moreover, there is a wide range of fossil fuels demand in the country fully covered by importing which results to a significant expenditure from the country’s budget. This study investigates the long-term shifts in bioenergy use of the country and evaluates the expected social, environmental and economical implications. For this purpose, three scenarios are formulated within a timeframe that goes from 2013 to 2030. The baseline scenario assumes the existing energy practices of the country would undergo no significant change in the future while the moderate shift and high shift scenarios consider the long-term shifts in bioenergy use with and without considering constraints respectively. In this context, long-term shifts means: transition from traditional use of biomass to efficient and modern in the household sector, biofuels deployment in the transport sector, introduction of agricultural residues as a fuel for cement production, and electricity generation from bagasse and municipal solid waste. To model and analyze the scenarios, the long-range energy alternatives planning system (LEAP) software tool is used. Taking the results of high shift scenario by 2030, the use of improved wood stoves and fuel switch stoves could save 65 million tons of wood. The foreign currency saving from using biofuels and agricultural residues as fossil fuels substitute would reach to 674 million USD. The greenhouse gas emissions reduction is equivalent to 46 million tons of CO2e which is about 18.4% of the CO2e abatement target of the country for 2030. The corresponding revenue from carbon trading schemes would reach to 231 million USD. Electricity generation from bagasse and municipal solid waste would be 3,672 GWh that is around 3.7% of the total electricity generation target for 2030.

L'Union Européenne a un programme ambitieux pour faire face aux effets du changement climatique, les institutions européennes devant désormais prendre en compte l'environnement dans le cadre de ses politiques. L'objectif de ma thèse consiste à évaluer les impacts des politiques publiques européennes sur l'agriculture et l’environnement, de mesurer leurs effets croisés et d'évaluer l'intérêt d'une meilleure coordination de ces politiques. La thèse vise à enrichir l'analyse économique sur des problématiques importantes recentrées sur la réduction des émissions de gaz à effet de serre (GES) agricoles dans l'UE et le niveau de la production agricole, sous un angle quantitatif. La méthodologie repose sur un modèle de programmation mathématique qui simule l’offre agricole européenne (AROPAj), utilisant les données du Réseau d'Information Comptable Agricole. L'analyse est réalisée à plusieurs niveaux, européen, national, régional et infra-régional, tenant compte de la variabilité du contexte économique qui caractérise l'agriculture européenne sur les six années 2007-2012. Nous évaluons tout d'abord comment l'agriculture peut contribuer à l'atténuation des émissions de GES dans l'UE et nous offrons une analyse détaillée des courbes de coûts marginaux d'abattement. Les résultats indiquent qu’en moyenne, sur la période 2007-2012, l’agriculture européenne peut réduire ses émissions d’environ 10%, 20% et 30% respectivement, pour les prix des émissions de 38, 112.5 et 205 Euros/tCO2eq. Nous montrons que l’agriculture peut offrir une atténuation substantielle et que le potentiel et les coûts d’atténuation varient substantiellement dans le temps et dans l’espace. La deuxième problématique étudiée porte sur la compatibilité entre l’augmentation de la production agricole et la diminution de l’impact de l’agriculture sur l’environnement. En introduisant une approche primale (via un prix du carbone) et une approche duale (via un objectif calorique), nous montrons qu’on peut réduire les émissions de GES et modifier l’offre agricole tout en augmentant la quantité en calories alimentaires. On étend la problématique des émissions de GES, en dissociant les prix des deux gaz (CH4 et N2O). Un système de prix différenciés permet de mieux adapter la politique de régulation climatique en fonction de l'horizon de temps sur lequel on se projette, offrant une flexibilité dans la réduction des coûts d’abattement des émissions. / The European Union has an ambitious agenda to deal with the effects of climate change, the European institutions must now take environment into account within the framework of its policies. The objective of my thesis is to evaluate the impacts of European public policies on agriculture and environment, to measure their crossed effects and to assess the potential for a better coordination of these policies. The thesis aims to enrich the economic analysis on important issues refocused on the reduction of agricultural greenhouse gas emissions in the EU and the level of agricultural production, from a quantitative perspective. The methodology is based on a mathematical programming model that simulates the European agricultural supply (AROPAj), using data from the Farm Accountancy Data Network. The analysis is carried out at several levels, European, national, regional and sub-regional, taking into account the variability of the economic context that characterizes the European agriculture over the six years 2007-2012. We first assess how agriculture may contribute to the mitigation of EU GHG emissions and provide a detailed analysis of marginal abatement cost curves. The results show that, on average, over the period 2007-2012, EU agriculture may reduce its emissions by around 10%, 20% and 30%, respectively for emission prices of 38, 112.5 and 205 EUR/tCO2eq. We show that agriculture may offer substantial mitigation and that mitigation costs and potential vary in time and in space. The second issue studied concerns the compatibility between the increase in agricultural production and the reduction of the impact of agriculture on the environment. By introducing a primal approach (via a carbon price) and a dual approach (via a calorie target), we show that we can reduce GHG emissions and change agricultural supply while increasing the quantity of food calories. We extend the issue of GHG emissions by separating the prices of the two gases (CH4 et N2O). A differentiated price system allows to better adapt the climate regulation policy according to the time horizon on which we are projected, offering flexibility in reducing the emission abatement costs.