In recent years, rapid economic growth and increased energy consumption has led CO2 emissions to increase in a complex phenomenon involving countries with different technology and socioeconomic structures. To better understand this phenomenon, it is important to identify the relationships between each of the different factors driving CO2 emissions and increased energy consumption. This thesis aims to disentangle the annual growth in global CO2 emissions and energy consumption into their determinants for the period between 1995 and 2009. In addition, we determine the relationships between CO2 emissions and energy consumption. We use a multi-regional input-output model and the World Input-Output Database to decompose the annual variations in global and national emissions for 41 world regions into the changes in population, final demand per capita, and the commodity structure of final demand, trade structure, and technology. Our results find that changes in CO2 emissions and energy consumption are mainly driven by the growth in final demand per capita and population. In contrast, changes in the technology and the commodity composition of final demand reduce the emissions. Moreover, the levels of energy consumption and CO2 emissions are closely linked and increase in line with each other.