This video has been produced in partnership with EUMETSAT.

When studying carbon dioxide (CO₂) in the atmosphere, it is important to know where it is now, but it is also vital to know where it came from and where it has been in order to understand processes that control the amount of the greenhouse gas in the atmosphere.

NASA’s Orbiting Carbon Observatory-2 (OCO-2) satellite performs 14 orbits per day with 72,000 high-quality CO₂ observations per each orbit. Chemical transport models (CTM) can be used to travel back the air masses in order to see where the CO₂ most likely originated from. These models combine information from general circulation models or from meteorological analyses with additional information on atmospheric chemical compounds, including their reactions, their sources on Earth’s surface and the processes that remove them from the atmosphere, known as sinks.

The abundance of CO₂ in the atmosphere rises and falls each year as plants, through photosynthesis and respiration, take up the CO₂ in spring and summer, and release it in autumn and winter. However, the total amount of CO₂ in the atmosphere has been increasing steadily as human activity has been adding about 40 billion tonnes of CO₂ into the atmosphere each year, only half of which is aborbed by carbon sinks.

Featured Educator

• Dr David Crisp, Atmospheric Physicist, NASA-JPL

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In partnership with EUMETSAT