An average American today (2012 data) produces 21.55 metric tons (47,510 lbs) of CO2 equivalents a year. 1 In contrast a single (average) tree can sequester 0.022 metric tons (48 lbs.) per year.2 The charcoal spheres represent the volumes of CO2 at normal temperature and atmosphere (NTP). 3
1 U.S. Greenhouse Gas Inventory Report: 1990-2014, EPA, 2016; https://www3.epa.gov/climatechange/ghgemissions/usinventoryreport.html (accessed June 1st, 2016).
NB Carbon dioxide equivalent is used to measure various types of greenhouse gases based upon their global warming potential.
2 NC State University College of Agriculture & Life Sciences, "Tree Facts," http://www.ncsu.edu/project/treesofstrength/treefact.htm (accessed June 1st, 2016). - Sarah Moos, "50,000 Trees," Scenario 04: Building the Urban Forest (2014), http://scenariojournal.com/article/50000-trees/.
3 NTP means at a temperature of 20 °C (68 °F) and an absolute pressure of 1 atm.
International Carbon Bank & Exchange, 2014; http://www.icbe.com/carbondatabase/CO2volumecalculation.asp(accessed June 1st, 2016).