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The Orbiting Carbon Observatory 2 (OCO-2)

Saturday 18th May 2024.


The CO2 observatory in space has been in operation since 2023, because what can be measured can be reduced. Until recently, it was always claimed that CO2 could not be seen, smelled, tasted, heard or even touched. NASA’s Goddard Space Flight Centre in the USA has the largest collection of geoscientists on the planet. Their mission is to visualise CO2 and function as a key trusted source of comprehensive environmental information about both the current state and the future of the Earth. NASA scientists design, build, launch and operate missions, including satellites, to understand how our Earth works and to predict how the Earth will change in the future.

In order to explore the Earth from the unique perspective of space, the Earth Sciences department develops and operates remote sensing satellites and instruments, analysing the observation data from these spacecrafts and making it available to journalists interested in the climate crisis.

NASA’s Orbiting Carbon Observatory, 2 (OCO-2 for short) provides the most complete data set for tracking the concentration of atmospheric carbon dioxide (CO₂), the main driver of climate change. Every day, OCO-2 measures the sunlight reflected from the Earth’s surface to determine the average CO₂ mixing ratio in the dry air and provides around 100,000 cloud-free observations. Despite these advances, there are many gaps in the OCO-2 data where there is no sunlight or where clouds or aerosols are too dense to obtain CO₂ data. To close the gaps and provide a spatially complete product for scientific and application users, the OCO-2 data will be integrated into NASA’s Goddard Earth Observing System (GEOS), a complex modelling and data assimilation system used to study the Earth’s weather and climate.


GEOS also relies on satellite observations of nighttime illumination and vegetation greenness, as well as approximately one million weather observations collected every hour. These data help scientists to derive CO2 mixing ratios even in the absence of direct OCO-2 observations and provide additional information about the height of CO₂ plumes that the satellite cannot see. Together, OCO-2 and GEOS provide one of the most complete images of CO₂ in our atmosphere.

The claim that CO₂ cannot be seen or measured is now a thing of the past. Because CO₂ can be measured, not only can the CO₂ footprint of every country, every company and every citizen of the world be measured, but it can also be reduced.

Uwe Heitkamp (64)

trained TV journalist, book author and hobby botanist, father of two grown-up children, knows Portugal for 30 years, founder of ECO123. Translations: Dina Adão, John Elliot, Patrícia Lara
Photos: NASA

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