Trends in energy consumption and carbon dioxide emissions of passenger cars and buses

摘要

In this work we develop aggregate car ownership and bus fleet models in order to forecast and compare fuel consumption and CO_2 emissions from passenger cars and buses. Greece was selected as a case study, being a country fairly representative of lower-income Mediterranean and Eastern European countries and data were collected for the period 1970 to 2002. Percent adults in the population, per capita gross domestic product, inflation, unemployment, car occupancy and bus kilometers were predictors included in the car ownership and bus fleet multiple regression models. A shift in the overall trend of both models around 1995 was explained as a slope change of per capita gross domestic product, possibly reflecting the impact of a boom of the Greek Stock Market along with a retirement program for older vehicles. Predictor variables were forecast via Box-Jenkins and the models were subsequently used to develop car ownership and bus fleet forecasts to the year 2010. We predict that the contribution of cars to total CO_2 emissions will rise to an astounding 95% of total CO_2 emissions from road passenger transport (excluding taxis and mopeds), an effect expected in other Mediterranean and Eastern European countries with socioeconomic characteristics similar to Greece. Suggestions for further research include developing regional car ownership forecasts in order to compare the dynamics of different regions within a country and looking into other land transportation means (such as mopeds, taxicabs and railway).