One metric ton of carbon dioxide (CO2) gas. Illustration of a sphere of CO2 gas that is 10 metres in diameter (535 cubic metres), as used in a set of visualisations showing the amount of greenhouse gases as measured in the equivalent (e) volume of CO2 gas. This volume represents a metric ton (tonne), or 1000 kilograms. In 2012, over 39 billion metric tons of carbon dioxide was added to the atmosphere worldwide, 1237 metric tons a second, 1237 of these spheres being produced every second. One day of emissions would produce a pile of these spheres 3.7 kilometres high and 7.4 kilometres across. These figures are from 2012.