New analysis of NOAA’s long-term air samples by NOAA and CIRES scientists finds that the North American terrestrial biosphere takes up unexpectedly large amounts of carbon in response to elevated carbon dioxide levels during El Niño years.
Scientists have long known that the rate of carbon dioxide, or CO2, entering the atmosphere tends to increase during El Niños, the cyclical warming of the equatorial Pacific that influences weather worldwide. This increase was thought to be primarily influenced by a rise in CO2 emitted by tropical ecosystems. The response from regions outside the tropics was thought to be small.
Instead, analysis of 20 years of NOAA atmospheric sampling over North America showed that the biosphere soaks up the equivalent of 2.24 billion tons more carbon dioxide per year during El Niño periods than La Niña periods, or approximately one-third of the total annual CO2 emissions for the continent. The finding was published in the journal Science Advances.
Lead authors Lei Hu, a CIRES scientist working at NOAA, and Arlyn Andrews, chief of NOAA’s Carbon Cycle and Greenhouse Gases group at NOAA’s Global Monitoring Division, said the amount of variability was very surprising - and important for understanding climate change.
Continue reading at NOAA.
Image via NOAA.