The economy’s carbon intensity indicator results from the ratio between total CO 2 emissions and the Gross Domestic Product (GDP), thus making it possible to quantify the relationship between greenhouse gas emissions associated with obtaining all the goods and services produced. The indicator depends on the energy mix and energy intensity, and as such, the lower the indicator, the lower the use of fossil fuels in the energy mix. Portugal has seen a reduction over the years, driven by the reduction of coal for electricity production and the strong growth in investment in renewable energies.