Long-term global warming not driven naturally

February 1, 2016
The Earth's thin atmosphere as viewed from space. A new study from NASA and Duke finds natural cycles alone aren't sufficient to explain warming trends observed over the last century. Credit: NASA

By examining how Earth cools itself back down after a period of natural warming, a study by scientists at Duke University and NASA's Jet Propulsion Laboratory confirms that global temperature does not rise or fall chaotically in the long run. Unless pushed by outside forces, temperature should remain stable.

The new evidence may finally help put the chill on skeptics' belief that long-term global warming occurs in an unpredictable manner, independently of external drivers such as human impacts.

"This underscores that large, sustained changes in global temperature like those observed over the last century require drivers such as increased ," said lead author Patrick Brown, a PhD student at Duke's Nicholas School of the Environment. Natural climate cycles alone are insufficient to explain such changes, he said.

Brown and his colleagues published their peer-reviewed research Feb. 1 in the Journal of Climate.

Using and NASA of Earth's energy budget from the last 15 years, the study finds that a warming Earth is able to restore its temperature equilibrium through complex and seemingly paradoxical changes in the atmosphere and the way radiative heat is transported.

Scientists have long attributed this stabilization to a phenomenon known as the Planck Response, a large increase in infrared energy that Earth emits as it warms. Acting as a safety valve of sorts, this response creates a negative radiative feedback that allows more of the accumulating heat to be released into space through the top of the atmosphere.

The new Duke-NASA research, however, shows it's not as simple as that.

"Our analysis confirmed that the Planck Response plays a dominant role in restoring global temperature stability, but to our surprise we found that it tends to be overwhelmed locally by heat-trapping positive energy feedbacks related to changes in clouds, water vapor, and snow and ice," Brown said. "This initially suggested that the climate system might be able to create large, sustained changes in temperature all by itself."

A more detailed investigation of the satellite observations and climate models helped the researchers finally reconcile what was happening globally versus locally.

"While global temperature tends to be stable due to the Planck Response, there are other important, previously less appreciated, mechanisms at work too," said Wenhong Li, assistant professor of climate at Duke. These other mechanisms include a net release of energy over regions that are cooler during a natural, unforced warming event. And there can be a transport of energy from the tropical Pacific to continental and polar regions where the Planck Response overwhelms positive, heat-trapping local effects.

"This emphasizes the importance of large-scale energy transport and atmospheric circulation changes in restoring Earth's equilibrium after a natural, unforced warming event," Li said.

Explore further: Climate models make too hot forecasts of global warming

More information: Patrick T. Brown et al. Unforced surface air temperature variability and its contrasting relationship with the anomalous TOA energy flux at local and global spatial scales, Journal of Climate (2015). DOI: 10.1175/JCLI-D-15-0384.1

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18 comments

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FritzVonDago
2 / 5 (16) Feb 01, 2016
HogWash! Another faulty warmest computer model! Follow the government grant money!
antigoracle
2.2 / 5 (13) Feb 01, 2016
Give these guys the Nobel prize. They can make a claim for LONG TERM GLOBAL climate based on just the last 15 years.
warmonger
4.6 / 5 (9) Feb 01, 2016
Yeah, because grant money is more than oil money right?
philstacy9
1.6 / 5 (7) Feb 02, 2016
mikiwud
1.4 / 5 (11) Feb 02, 2016
warmonger,
Yes it is . just check the figures. By at least ten times.
Forestgnome
1.7 / 5 (11) Feb 02, 2016
Wow. An AGW supporter fighting a battle that never started. Nobody was saying it was chaotic. It's just that the natural global temperature cycles occur in 100,000 year cycles, which can vary up to 50,000 years. So the variation extends beyond our pitifully small scale of human existence.
Steve 200mph Cruiz
4.1 / 5 (9) Feb 02, 2016
Fritz,
What about the satellites?

Antigoracle,
Why would a realization that has been around since 1880 only become true 15 years ago?
Maggnus
4.5 / 5 (8) Feb 02, 2016
warmonger,
Yes it is . just check the figures. By at least ten times.


A claim absent of fact. A lie by any other name...

Maggnus
4.6 / 5 (9) Feb 02, 2016
Wow. An AGW supporter fighting a battle that never started. Nobody was saying it was chaotic. It's just that the natural global temperature cycles occur in 100,000 year cycles, which can vary up to 50,000 years. So the variation extends beyond our pitifully small scale of human existence.


A fact rolled into a misunderstanding, compounded by ignorance.

There IS a roughly 100,000 year cycle - and a 26,000 year cycle - and a 21,000 year cycle - and a 41,000 year cycle - and a roughly 413,000 year cycle. Each of these has error bars, and the different periodicities are the result of the Earth's orbit and tilt, including precession, inclination, obliquity, and eccentricity. None of these supports a 50,000 year cycle.

It is the chaotic nature of the earth's orbit and spin that leads to these different cycles.

The explanation extends well beyond your pitifully small scale understanding of climate cycles - or climate in general.
Solon
1.6 / 5 (7) Feb 02, 2016
Obama's Paris Global Warming Treaty Will Cost At Least $12.1 Trillion
http://dailycalle...rillion/

Most of the worlds countries are already broke, so we need to go to the rich private investors and go even further into debt to them to deal with a problem that can not be proven to be caused by humans in the first place?
Steve 200mph Cruiz
4.6 / 5 (9) Feb 02, 2016
Solon,
How could every government on earth agree to commit 14 trillion dollars to something they had doubts about.

Countries don't commit billions of dollars when there is no payoff. These guys have ivy league educations, they understand basic finance and risk
Maggnus
5 / 5 (8) Feb 02, 2016
Solon,
How could every government on earth agree to commit 14 trillion dollars to something they had doubts about.

Countries don't commit billions of dollars when there is no payoff. These guys have ivy league educations, they understand basic finance and risk


BECAUSE THE LIZARD PEOPLE FROM BETA-REGULLUS ARE REPLACING OUR LEADERS AND STEALING OUR MINDS SO THAT THEY CAN ENSLAVE US UNDER A SOCIALIST ONE WORLD GOVERNMENT THAT WILL STEAL OUR FREEDOMS AND OUR WATER AND STUFF!!

Gawd, anyone with a half a brain knows that!
antigoracle
1 / 5 (3) Feb 02, 2016
Countries don't commit billions of dollars when there is no payoff.

How many TRILLIONS of dollars was committed to the wars in the Middle East and what was the payoff?
TehDog
5 / 5 (8) Feb 02, 2016
"How many TRILLIONS of dollars was committed to the wars in the Middle East and what was the payoff?"
Dunno, why don't you tell us?
Seriously, find that info and tell us (Don't worry about non-US expenditure, that's gonna be hard to quantify).
We like data, not caps.
Mike_Massen
3.1 / 5 (7) Feb 03, 2016
Solon claims
.. can not be proven to be caused by humans...
Utterly Wrong

IS proven but, NEEDs education in heat & sad that even some older engineers, who did get grounding in essentials of heat, just__cannot__connect__dots with gases irrefutable vibrational properties, graphically shown here
http://cbc.arizon.../sim/gh/

Key Physics & Math
https://en.wikipe...transfer
Directly leads to
https://en.wikipe..._forcing

Never refuted & known for >100yrs so learn physics please Solon ?

Can *any* denier anywhere in *any* way at all offer *any* refutation instead of barking dumb political Crap, isn't that smarter ?

Essential for education
https://en.wikipe...capacity
To understand why we're very lucky re ocean thermal mass !

World burns overall, petrol ~230,000L/sec ea & Every second !
http://woodfortre...esrl-co2

Over to you Solon - Physics & Math, *any* refutation with key dialectic ?
Steve 200mph Cruiz
5 / 5 (3) Feb 03, 2016
Goracle,
I pluralization of "country" was the key word.
The political insanties of governance are hardly a fair measure to hold any country.
America is still an awesome country that serves as an over all force for global good even if we do stupid things.

I think we can both agree that western society and ideals have helped more people out of poverty and has/is creating a better future for humanity if you view it through an inclusive context. There are real reasons love America
SLOOHCox
1.8 / 5 (5) Feb 06, 2016
Give these guys the Nobel prize. They can make a claim for LONG TERM GLOBAL climate based on just the last 15 years.


anti, I would like to hang you by the balls and see you publicly flogged.
bluehigh
1 / 5 (1) Feb 06, 2016
Mike,

I've edited your comment. Once again to remove your dummy spit.

--------

--------

Much better.

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