In this policy note we propose a new country-based sustainability index comprised of three main drivers: climate change, energy use, and resource depletion. We argue that increases in clean energy intensity (clean energy per dollar of GDP), decreases in carbon intensity (carbon emission per dollar of GDP), and water intensity (water used per dollar of GDP) significantly affect sustainability. Supplementary, we compare our proposed index with macroeconomic indicators like GDP, Income per capita and other development indices such as the Human Development Index and the GINI, showing marked differences, which we interpret as unexplored areas for sustainable gains.