Spanish versions of these resources are also available for download (en Español).
Current consumption of fossil fuel releases more than 25 billion tons of CO2 into the atmosphere every year. If current trends continue, there will be a tripling of atmospheric CO2 by the end of the century—levels not seen for more than 40 million years. By measuring our carbon footprint, we can learn how we are contributing to this rise in atmospheric CO2 and how we might use energy more efficiently.