Environment

NASA satellite spots cause of unprecedented spike in atmospheric CO2

NASA satellite spots cause of ...
Atmospheric data gathered by the NASA satellite OCO-2 has revealed that certain tropical regions are responsible for an unprecedented spike in CO2 levels in 2015 and 2016
Atmospheric data gathered by the NASA satellite OCO-2 has revealed that certain tropical regions are responsible for an unprecedented spike in CO2 levels in 2015 and 2016
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Atmospheric data gathered by the NASA satellite OCO-2 has revealed that certain tropical regions are responsible for an unprecedented spike in CO2 levels in 2015 and 2016
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Atmospheric data gathered by the NASA satellite OCO-2 has revealed that certain tropical regions are responsible for an unprecedented spike in CO2 levels in 2015 and 2016
The effects of the 2015 El Nino event in different tropical regions, which in turn caused a large spike in atmospheric CO2 emissions
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The effects of the 2015 El Nino event in different tropical regions, which in turn caused a large spike in atmospheric CO2 emissions

Since the Industrial Revolution in the early 1800s, atmospheric carbon dioxide (CO2) concentrations have been steadily increasing, but 2015 and 2016 saw an unprecedented spike. A NASA study has now analyzed data gathered by the atmosphere-monitoring satellite, the Orbiting Carbon Observatory-2 (OCO-2), over more than two years and pinpointed the cause: the El Nino weather effect caused certain tropical regions to release far more CO2 than they normally would.

Although there's been some huge efforts to reduce the amount of CO2 produced through human activity, the amount of the gas pumped into the atmosphere has still increased by an average of 2 parts per million (about 4 gigatons of carbon) annually, in recent years. But 2015 and 2016 broke the trend with the largest spikes on record: up to 3 parts per million, amounting to 6.3 gigatons of carbon. Emissions from human activity stayed roughly the same in those years, so where was it all coming from?

The climate cycle El Nino was a prime suspect, but it wasn't clear exactly how. This phenomenon occurs over the Pacific Ocean every few years, when warmer water from near the Phillipines and Indonesia drifts east towards South America, and the effects can be strong enough to alter weather across the entire planet. Warmer waters at the surface of the ocean drag the rains with it, lowering precipitation and causing droughts in areas like Australia, India, Southeast Asia, Indonesia, northeastern South America, while increasing rainfall in places like Peru, Chile and Ecuador.

The El Nino event in 2015 was one of the strongest since the 1950s, so it's no coincidence that 2016 was the hottest year ever recorded. To study what effects the event may have had on atmospheric CO2 concentrations, NASA researchers analyzed 28 months of data gathered by the OCO-2 satellite, which can take thousands of readings of carbon dioxide levels per day in a given area, as well as measure how well vegetation is processing the gas via photosynthesis.

The team compared that data to 2011 as a reference year, when weather and carbon cycle processes were normal. Their conclusion? The increase was due to warmer-than-average temperatures and drought in tropical parts of South America, Africa and Indonesia, which in turn were caused by El Nino.

The effects of the 2015 El Nino event in different tropical regions, which in turn caused a large spike in atmospheric CO2 emissions
The effects of the 2015 El Nino event in different tropical regions, which in turn caused a large spike in atmospheric CO2 emissions

"These three tropical regions released 2.5 gigatons more carbon into the atmosphere than they did in 2011," says Junjie Liu, lead author of the study. "Our analysis shows this extra carbon dioxide explains the difference in atmospheric carbon dioxide growth rates between 2011 and the peak years of 2015-16. OCO-2 data allowed us to quantify how the net exchange of carbon between land and atmosphere in individual regions is affected during El Nino years."

The researchers combined the OCO-2 data with that gathered by other satellites, to figure out the specific processes in each of those regions that were contributing to the extreme increase in CO2. Drought ravaged eastern and southeastern tropical areas of South America, bringing about the driest year in the last three decades. Coupled with higher than average temperatures, vegetation in these regions were stressed and as such, photosynthesis slowed, meaning the plants plucked less carbon from the atmosphere.

Meanwhile, tropical Asia suffered through its second-driest year in 30 years, which increased the severity of forest fires that in turn pumped more carbon into the air. During the same time, tropical Africa endured hotter temperatures but no drought, which sped up the rate of decomposition of dead trees and plants, resulting in more CO2 emissions.

"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," says Annemarie Eldering, Deputy Project Scientist on the OCO-2 mission. "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. 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."

These naturally-occurring processes may be seen by some as evidence against human-induced climate change, but they're snowballing symptoms of bigger anthropogenic causes. After all, increased carbon levels are believed to contribute to more frequent and severe El Nino events, which in turn can speed up these "natural" processes and exponentially alter the Earth's climate.

The research was published in the journal Science.

Source: NASA

15 comments
flyerfly
This is very interesting. But what is more interesting to me is why people spend billions of dollars on something that they can't really fix. Nature and this world are much to large for humans to be able to manage. We can't fix global warming/cooling. The world will do what it will...and we are along for the ride, we need to stop being chicken little and enjoy life. If the sky is falling get an umbrella or a jacket and just deal with it. Cheers.
Pierre Collet
@firefly: this is fine if you have the dough to buy an umbrella or a jacket. For people who cannot afford to move / buy themselves the means of surviving these climate changes, they will have to deal with it the hard way. The question is not whether we can fix Nature or not, but whether we can help with it on a global scale. Even if a raise in CO2 is being caused by El Niño or whatever that may or may not be anthropogenic, if on our side, we can slightly reduce our production of CO2 by reducing our consumption of fossil fuel, well, we will make the world a better place for all. But clearly, those who can afford making an effort towards improving conditions for all are not the poor, who struggle to survive due to droughts and ensuing famine and paltry but the rich... who, it is interesting to note, are not exempt from ill effects from global warming: go and tell californians to buy an umbrella and a jacket to just deal with the drought related fires that are burning their houses and lives... "Thanks to" globalization (this is ironic) the world has become a small place where everyone is holding each other by the short hairs...
MartinVoelker
This study contained a key reminder about Global Warming: heat stressed plants have a lower photosynthesis "metabolism" and bind less carbon. Sounds like another dreaded feedback mechanism. And for those who think higher temps are not so bad consider that food crop production can't just move north as higher latitude soils are notoriously poor.
watersworm
So ? Hot water release CO2 in the atmosphere !!! What a surprise ! Will the IPCC incorporate this fantastic news in its next report ? Do you if know if Al Gore do agree ?? Satellites makers thank the "Global Community" $$$$
Bill13
The alternative identified here isn't that a new source of carbon has been found but that a new reason that carbon is not converted back to oxygen has been found. This tells me carbon emissions need to be reduced.
Bob
Global warming is the least of my worries. Global politics, war, disease, and famine will quickly thin out the human race long before rising sea levels.
watersworm
0 bill : "Carbon converted back to oxygen ???? Show me this trick !
Robert in Vancouver
Honest studies show that human activity has very little impact on climate change. If our leaders were honest about this issue we would be spending our time and money on preparing for climate change instead of using it as a reason to raise taxes and control people.
JimFox
Flyerfly-- proving inadvertently that what he says can't be done HAS been done. AGW is a fact despite all the deniers. That we have pumped billions/trillions of tons of [let's say] POLLUTION into the atmosphere over 200 years of industrial revolution is not in dispute... nor is the fact that it MUST have an effect above & beyond any natural one. Can it be curbed? That's another story...
Douglas Bennett Rogers
What stands out in the picture is the light color of the deserts. This may swamp out the other variables.