Since the last two years, a NASA satellite has been watching the earth breathe from space, measuring human emissions of carbon dioxide. Called the Orbiting Carbon Observatory, OCO-2, it is NASA’s first dedicated remote sensing satellite studying atmospheric carbon dioxide from Space. Launched in July 2014, OCO-2 collects space-based global measurements of atmospheric CO2 with the precision, resolution, and coverage needed to characterize sources and sinks on regional scales.
Based on the data collected by OCO-2, the Finnish Meteorological Institute (FMI) has created the first global maps of CO2 produced by humans. This feat is unique because these are the first-ever maps that have been created solely from satellite observations of the greenhouse gas. Earlier, scientists had to incorporate estimates from economic data and modeling results also.
FMI has produced three maps centered on the planet’s highest carbon dioxide emitting regions: the eastern United States, central Europe and East Asia. Research scientist Janne Hakkarainen, who led this study, calls OCO-2 a very powerful tool which has given researchers new insight. “It can even detect smaller, isolated emitting areas like individual cities,” he said.
The research methodology employed by FMI makes use of a new data-processing technique to isolate recent emissions from the background level of carbon dioxide. This method takes several factors into account, including seasonal changes in carbon dioxide, the result of plant growth and dormancy, as well as the background carbon dioxide level. Currently, the background level of carbon dioxide in the atmosphere is about 400 parts per million. Hakkarainen believes that human emissions within the past year may add only something like three parts per million to that total.
FMI validated its study by correlating the results with measurements of nitrogen dioxide taken from a Dutch-Finnish instrument called the Ozone Monitoring Instrument deployed on NASA’s Aura satellite.
The results of the study have been published in the journal Geophysical Research Letters.