Annual per-capita carbon dioxide (CO2) emissions. Illustration comparing four countries with the world average for actual amounts of greenhouse gases emitted per year as measured in the equivalent (e) volume of CO2 gas. Relative height labels are included, with a house and human figures providing a scale. The relative CO2-equivalent values are: USA, 18.6 metric tons; United Kingdom, 8.4 metric tons; China, 5.4 metric tons; world average, 4.8 metric tons; and India, 1.3 metric tons. Data from 2012, from CDIAC (Carbon Dioxide Information Analysis Center) and the CAIT (Climate Analysis Indicators Tool) climate data explorer.