Cause of Earth's recent record spike in global CO2 concentration
October 18, 2017; 5:37 PM
Atmospheric carbon dioxide (CO2) increases during 2015 and 2016 were 50 percent larger than the average increases seen in recent years preceding these observations.
A new NASA study based on space-based evidence suggests that El Nino-related heat and drought occurring in tropical regions of South America, Africa and Indonesia were responsible for the record spike in global CO2, according to the NASA report.
The NOAA chart below shows the annual growth rate of CO2 from Mauna Loa Observatory in Hawaii.
As you can see, 2015 and 2016 had the highest growth rates since 1960. There was also a spike in 1998, which was a year with a strong El Nino.
These record increases occurred even though emissions from human activities in 2015 and 2016 were estimated to be roughly the same prior to the strong El Nino.
Key excerpts from the NASA report........
"Understanding how the carbon cycle in these regions responded to El Nino will enable scientists to improve carbon cycle models, which should lead to improved predictions of how our planet may respond to similar conditions in the future," said OCO-2 Deputy Project Scientist Annmarie Eldering of JPL. "The team's findings imply that if future climate brings more or longer droughts, as the last El Nino did, more carbon dioxide may remain in the atmosphere, leading to a tendency to further warm Earth."
"We knew El Ninos were one factor in these variations, but until now we didn't understand, at the scale of these regions, what the most important processes were," said Eldering. "OCO-2's geographic coverage and data density are allowing us to study each region separately."
Annually averaged atmospheric carbon dioxide concentrations have generally increased year over year since the early 1800s - the start of the widespread Industrial Revolution.
The NOAA graph below shows a plot of the total global CO2 concentration since 1960. Note the steady increase.
The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or AccuWeather.com