El Nino-fueled CO2 spike tied to plant harm, fires
WASHINGTON >> A new NASA satellite has found another thing to blame on El Nino: A recent record high increase of carbon dioxide in the air.
The super-sized El Nino a couple of years ago led to an increase of 3 billion tons of carbon in the air, most from tropical land areas. The El Nino made it more difficult for plants to suck up man-made carbon emissions and sparked fires that released more carbon into the atmosphere.
The effect was so large that it was the main factor in the biggest one-year jump in heat-trapping gas levels on record, NASA scientists said.
Scientists have long known that carbon dioxide levels spike during an El Nino, the natural occasional warming of parts of the central Pacific that causes droughts in some places, floods in others and generally adds to warmer temperatures worldwide. Data from NASA’s Orbiting Carbon Observatory-2, which was launched in 2014, provides more specifics on how that happens, by continent. Researchers found that in drought-stricken parts of South America plants grew less, there were more fires in Asia, and there was an increased rate of leaf decay in Africa. The findings were published Thursday in the journal Science.
That 3 billion tons of carbon, while significant, is still dwarfed by the 10 billion tons a year that comes from the burning of coal, oil and gas, said Scott Denning, a Colorado State University atmospheric scientist. Study co-author Annmarie Eldering, NASA’s deputy project scientist for the satellite, said the new results show how El Nino can counteract efforts to reduce carbon emissions.
Human-caused carbon dioxide emissions were roughly flat in 2014, 2015 and 2016, but National Oceanic and Atmospheric Administration figures show that 2015 saw a rise in carbon in the air of 3.03 parts per million, the largest since scientists started tracking emissions in Hawaii in 1959.
Normally about 25 percent of the human-caused carbon emissions are sucked up by plants on land, but during this powerful El Nino that was only 5 percent, said Junjie Liu, a NASA scientist and study lead author.