Summary for Policymakers IPCC Fourth Assessment Report, Working Group III

A. Introduction 1. The Working Group III contribution to theIPCC Fourth Assessment Report (AR4) focuses on new literature on thescientific, technological, environmental, economic and social aspects ofmitigation of climate change, published since the IPCC Third AssessmentReport (TAR) and the Special Reports on COB2B Capture and Storage (SRCCS)and on Safeguarding the Ozone Layer and the Global Climate System (SROC).The following summary is organised into six sections after thisintroduction: - Greenhouse gas (GHG) emission trends, - Mitigation in theshort and medium term, across different economic sectors (until 2030), -Mitigation in the long-term (beyond 2030), - Policies, measures andinstruments to mitigate climate change, - Sustainable development andclimate change mitigation, - Gaps in knowledge. References to thecorresponding chapter sections are indicated at each paragraph in squarebrackets. An explanation of terms, acronyms and chemical symbols used inthis SPM can be found in the glossary to the main report

CO2 emissions from passenger transport in Rio de Janeiro

Transport externalities have generally been discussed at the local level perspective. Aspects related to local atmospheric and noise pollution from vehicles, for instance, have been analysed in great depth and their impact in urban centres has been studied and discussed. On the other hand, some aspects related to the wider contribution of transport to environmental impacts have been neglected or considered of less importance. The main objective of this paper is to evaluate how urban passenger transport contributes to CO2 (carbon dioxide) emissions and to the greenhouse effect. The study takes into account road transport emissions in the Metropolitan Region of the Brazilian city of Rio de Janeiro, focusing on the comparison between urban bus emissions and private car emissions. The conclusions reached highlight some viable transport policies to be adopted in the city and the importance of increasing public transport use if CO2 emissions from traffic are to be reduced.

Assessing total and renewable energy in Brazilian automotive fuels. A life cycle inventory (LCI) approach

This article uses a first approach LCI procedure to evaluate total and renewable energy and CO2 emissions in Brazilian automotive fuels life cycle (LC). The LC model is structured and modular, capable of being successively refined if necessary. The procedure is applied to passenger car use in urban traffic, comparing three fuels used in Brazil (gasoline with 25% ethanol, pure ethanol and compressed natural gas), considering their use in urban traffic in the city of Rio de Janeiro. An in deep research was made to collect representative and unpublished data of Brazilian automotive fuels LC reality, what is considered a main contribution. The results show where specific advantages occur, particularly in the use of renewable fuels made from biomass, an option already practiced and appropriate for Brazilian reality. The use of gasoline with 25% ethanol shows the lowest total energy consumption for the LC, with similar performance to that of compressed natural gas and 36% better than ethanol from sugarcane. However, the last alternative has the advantage of depending almost exclusively on renewable energy (93%) and producing less net CO2 emissions.Renewable energy Total energy Transportation Life cycle Biofuels