Long-standing climate paradox resolved

May 05, 2014
The rock glacier in Great Basin National Park attests to the former Ice Age climates of the Great Basin, and is now a tiny remnant of a former valley glacier. Credit: Matthew Lachniet.

(Phys.org) —Climate scientists have long documented the strong control of Earth's orbital variations on the waxing and waning of the great ice ages, when huge "pluvial" lakes filled the valley floors of the Great Basin. For years it was thought that Great Basin climate marched to the tune of a different drummer. This paradox arose from an iconic climate record from Devils Hole, Nev., which suggested that Great Basin climate warmed out of glacial periods before warming from changes in the earth's orbit.

However, in a new study, "Orbital control of western North America atmospheric circulation and over two glacial cycles," published today in the online journal Nature Communications, scientists revealed a 175,000 year-long climate record from Great Basin that shows ice age temperature oscillations centered around changes in earth's orbit.

"Ice age temperature oscillations were the metronome and pacemaker of Great Basin climate change," said Professor Yemane Asmerom, UNM Department of Earth and Planetary Sciences, who was one of the co-authors in the study along with UNLV Geoscientist Matthew Lachniet, a former postdoctoral fellow of Asmerom's, and also former UNM student Rhawn Denniston, now a professor at Cornell College and UNM Research Scientist Victor Polyak. "The research resolves a long-standing climate paradox arising from Devils Hole, which suggested incorrectly that climate was out of step with orbital variations."

Led by Lachniet, the researchers showed that climate change in the Great Basin (and Nevada) matches the timing of orbitally-derived periods of glacial cycles, in line with the theory forwarded by Serbian scientist Milutin Milankovitch over 100 years ago.

"Our record is the first long-term and continuous record that shows unambiguously that the Great Basin climate was paced by the earth's orbit around the sun," Lachniet said. "It also includes more samples over time than any other record."

Lachniet and his team showed that the Nevada climate has followed earth's orbital variations like clockwork over the past 175,000 years, getting warmer and colder between conditions like today and the ice ages. The intensity of summertime solar radiation controlled temperature variations. These data help resolve the long-standing paradox from Devils Hole.

The researchers' data covers some of the same time intervals as Devils Hole, but show that climate was actually in sync with Milankovitch forcing. The data match the phasing and amplitudes of summer insolation (650N), including the classic saw-tooth pattern of global ice volume and on-time terminations. Together with the observation of cold conditions during the marine isotope sub-stage glacial inception (5d), the data documents a strong precessional-scale Milankovitch forcing of southwestern paleoclimate.

"This stalagmite-based record has precise absolute chronology, unlike the ice-core record that has to rely on compaction model derived relative ages," said Asmerom. "As a result, we established the timing of these clime transitions with unprecedented certainty. Our clean lab room here at the University of New Mexico enables us to do this kind of work. We are one of the few places in the nation positioned to do this type of work."

The climate history was constructed from cave deposits that were collected between 2011-13 in Nevada – areas included Pinnacle Cave on Mt. Potosi in Clark County; Leviathan Cave, north of Pahranagat Wildlife Refuge; and Lehman Caves in Great Basin National Park. It is the first long, continuous speleothem-based iconic climate record coming straight from the source to Devil's Hole.

The stalagmites were age-dated precisely using uranium series isotopes at UNM, while the was put together using oxygen isotope analysis at UNLV's Las Vegas Isotope Science Laboratory.

"This work is part of a larger global effort at generate high-resolution records of climate change at various time scales," Polyak said.

In addition, researchers showed that the growth of the iconic pluvial lakes in the Great Basin were controlled by this metronomic pulsing of climate changes linked to Earth's orbit. The pluvial lakes were huge lakes that covered a large portion of northern Nevada during the last ice age when climate was much wetter than it is today. The Great Salt Lake in Utah is a tiny remnant of the past lakes in this area.

Based on this relationship of the variations in the earth's orbit and Nevada's climate, Lachniet and his team suggest that the region won't see the re-appearance of these pluvial lakes for at least another 55,000 years. They also see evidence that the Great Basin climate has been warming for the past 1,600 years, which may indicate a human-control of because it departs from the orbital climate control, which should continue to cool for another 1,000 years.

"This is an opener of what we to be a more extensive effort centered in the climate of the Western United States, including the Southwest. The National Science Foundation just awarded us a three year grant to continue the work," Asmerom said.

Explore further: New high-resolution record of middle to late Miocene climate evolution

More information: "Orbital control of western North America atmospheric circulation and climate over two glacial cycles." Matthew S. Lachniet,et al. Nature Communications 5, Article number: 3805 DOI: 10.1038/ncomms4805. Received 09 December 2013 Accepted 04 April 2014 Published 02 May 2014

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Benni
2.1 / 5 (30) May 05, 2014
Climate change brought about by orbital variations is not what the "political class" wants to hear. They want last weeks tornadoes in the southern US states to be blamed on smokestack emissions from the Boeing plant in S Carolina because isn't unionized, all the while ignore the huge forest fires presently raging in Siberia paling into insignificance the totality of smoke-stack emissions worldwide. This is what you get when the drivers of the climate change debate can't function in an intelligible manner beyond grade school math.
ThomasQuinn
4.2 / 5 (27) May 05, 2014
Climate change brought about by orbital variations is not what the "political class" wants to hear. They want last weeks tornadoes in the southern US states to be blamed on smokestack emissions from the Boeing plant in S Carolina because isn't unionized, all the while ignore the huge forest fires presently raging in Siberia paling into insignificance the totality of smoke-stack emissions worldwide. This is what you get when the drivers of the climate change debate can't function in an intelligible manner beyond grade school math.


Ironic that there are hardly any serious scientists who side with you on climate change, then. I suppose all scientists "can't function in an intelligible manner beyond grade school math"? Or maybe you're simply engaging in a little mindless propaganda that twists the truth beyond all recognition?
freeiam
1.5 / 5 (23) May 05, 2014
Seems like exellent research.
This means that it is official, CO2 is out of the climate forcing picture.
supamark23
4.5 / 5 (22) May 05, 2014
lol apparently some people didn't actually read the article to the end...

"They also see evidence that the Great Basin climate has been warming for the past 1,600 years, which may indicate a human-control of regional climate because it departs from the orbital climate control, which should continue to cool for another 1,000 years."

In other words, warming cannot be due to orbital variation since we're in the wrong part of the cycle for that.
Pejico
May 05, 2014
This comment has been removed by a moderator.
supamark23
4.6 / 5 (20) May 05, 2014
There are many types of orbital variations, one of which is where the motion of other planets gets involved


You know that we're continually being affected by the gravity of the other planets, right? Both the article and myself are referring to Milankovitch cycle.
Pejico
May 05, 2014
This comment has been removed by a moderator.
Maggnus
4.6 / 5 (19) May 05, 2014
Benni, you are just spouting political ideology. Climate change brought about by orbital changes is well known and well understood.

Of course, politically driven scientifically illiterate rants are what you get deniers.
Maggnus
4.6 / 5 (21) May 05, 2014
Seems like exellent research.
This means that it is official, CO2 is out of the climate forcing picture.
It IS excellent research. That you don't understand what is being said in the article is not a surprise either.
Dug
1.3 / 5 (12) May 05, 2014
If you look at human population curves for past 1600 years, human related CO2 and other anthropogenic impacts don't seem significant until post industrial revolution when population went nearly straight up. (http://en.wikiped...e_world)

I would agree this work is likely more accurate and definitive than questionable ice core records - which according to many climate alarmist were essentially fool proof. It's good that we have more accurate climate measurements, but we should learn some humility from what this means about the lesser accuracy from other recent climate analysis techniques - and the logically less accurate models built upon their assumptions. Climatology is a young science and we have a lot learn - if egos and greed can get out of the way fast enough.
Shabs42
5 / 5 (10) May 06, 2014
Seems like exellent research.
This means that it is official, CO2 is out of the climate forcing picture.


That's like reading an article about cancer rates over time and then saying, "it's official, murder is out of the cause of death picture."
Rustybolts
3.6 / 5 (7) May 06, 2014
Another step closer to understanding our Universe. I don't understand why this would need further research. Why map all the climate before man stepped into the picture. You could never use this data to say this is going to happen next. We are destroying this planet like never seen before in time. It is nice to see you prove Milankovitch cycles but that's were it stops.
Anonym
1 / 5 (14) May 06, 2014
The statement that "warming for the past 1,600 years ...may indicate a human-control of regional climate" is absurd. Was he misquoted? Humans have never "controlled" the climate. And few would claim humans have had any significant effect on the climate whatsoever until modern times. Furthermore, there were only a few, pre-industrial humans in that region during the period --- CO2 emissions came from scattered camp fires and there was no urban heat island.

Why would he make such a silly statement?

Ah, the tip-off is in the last graf: his grant has been renewed. Lysenkoism has come to climate science.
EnricM
5 / 5 (10) May 06, 2014
Climate change brought about by orbital variations is not what the "political class" wants to hear.


That's what has been said though.
And it has nothing to do with anti-AGW, read again.
Or am I experiencing a case of cherry picking? ;)

Just to ease your mind: Climate Change has nothing to do with gun control. You will be allowed to keep all your guns no matter what the IPCC says.
Chilling now? Nice ;)
Eddy Courant
1.9 / 5 (9) May 06, 2014
"The Polar Bears will be fine." ~ Milutin Milankovitch
Shootist
May 06, 2014
This comment has been removed by a moderator.
runrig
5 / 5 (12) May 06, 2014

I'll take all your Boffins and raise you one Freeman Dyson

As a general rule if Freeman Dyson doesn't understand something, you don't,


Mr Shootist that statement is laughable...

Brethren we are gathered here in the face of our lord Dyson.

Let us bow down to the great God of climate science
And verily we shall take of his word
And dismiss all that be discovered not in thy name
Thy word shall be the science, the power and the climate
For ever and ever.
Amen
PinkElephant
5 / 5 (12) May 06, 2014
@Anonym,
Humans have never "controlled" the climate.
Note: regional climate is not the same thing as global climate.
Furthermore, there were only a few, pre-industrial humans in that region during the period --- CO2 emissions came from scattered camp fires and there was no urban heat island.
One doesn't need CO2 emissions to affect local climate. For instance, it doesn't take very many humans to quickly (on a scale of mere centuries) change the landscape by deliberately setting fires to forests and prairies... I'm not saying this is actually the case in that particular instance (or that the observed change is in fact due to humans), but it's not out of the realm of possibility.
Why would he make such a silly statement?

Ah, the tip-off is in the last graf: his grant has been renewed. Lysenkoism has come to climate science.
Yes of course, the most ridiculous explanation must be the correct one because your politics says so...
Maggnus
4.3 / 5 (12) May 07, 2014
I'll take all your Boffins and raise you one Freeman Dyson

As a general rule if Freeman Dyson doesn't understand something, you don't, either.


And as a general rule, a person who can do nothing except parrot the ideas of another is considered a jester and a fool. You ever consider thinking for yourself?

Last time I checked there is only one person who was claimed to be perfect, and he was hung on a cross about 2000 years ago.

Why don't you grow a set and make your own arguments?
supamark23
4.3 / 5 (12) May 07, 2014


I'll take all your Boffins and raise you one Freeman Dyson

As a general rule if Freeman Dyson doesn't understand something, you don't, either


Well, considering Freeman Dyson believes that AGW is a real thing, and that CO2 is a big driver of the rise in avg. global temperature... can we assume you've come to your senses and now agree with pretty much every actual scientist that's looked at this?
ryggesogn2
1 / 5 (12) May 07, 2014
And as a general rule, a person who can do nothing except parrot the ideas of another is considered a jester and a fool.


That's what all the AGWites do here, parrot the ides of AlGore the Magnificent.

change the landscape by deliberately setting fires to forests and prairies.

Humans have been doing this for thousands of years.

Other animals, like beaver change the landscape and local climate, among many others.
runrig
4.7 / 5 (12) May 07, 2014
And as a general rule, a person who can do nothing except parrot the ideas of another is considered a jester and a fool.


That's what all the AGWites do here, parrot the ides of AlGore the Magnificent.

change the landscape by deliberately setting fires to forests and prairies.

Humans have been doing this for thousands of years.

Other animals, like beaver change the landscape and local climate, among many others.


What???
The ideas are not Gore's you idiot.
They are those of science - he is only the messenger ... and you do know about the idiocy of shooting the messenger?
Obviously not.
FFS.

Correct - humans have been doing stuff for thousands of years - but only since the industrial revolution and the need to sustain billions of people has the pollution of the planet been shown up to be suicidal by diligent scientists using modern technology.
Yet we still have idiots who deny this.
And why?
Because it's "my tax dollars"
Ah diddums
FFS squared.
witt
5 / 5 (10) May 07, 2014
Seems like exellent research.
This means that it is official, CO2 is out of the climate forcing picture.

Not at all. Nobody ever claimed that CO2 was the only factor. There is nothing at all about this bit of research into a different factor that proves that it is the exclusive controlling variable either. The world science explores, unlike some political positions, is quite complex.
witt
5 / 5 (9) May 07, 2014
The statement that "warming for the past 1,600 years ...may indicate a human-control of regional climate" is absurd.

Human beings have long taken actions which altered the landscape, and thus the microclimate. Setting fires to force game to run into traps or clear the land for crops results in a major change in local climate. Hunting species to extinction, or severely diminishing their numbers, and thus altering the ecology through their removal, can result in major changes in vegetation and thus in local climate. A number of game animals went extinct following the arrival of human beings in the Americas. The ecology changed; and the climate with it.
FastEddy
1 / 5 (7) May 12, 2014
Benni, you are just spouting political ideology. Climate change brought about by orbital changes is well known and well understood. Of course, politically driven scientifically illiterate rants are what you get deniers.


Right! ... but for the wrong reasons. We are shocked, shocked! to discover there is politics in science.
FastEddy
1 / 5 (7) May 12, 2014
Another step closer to understanding our Universe. I don't understand why this would need further research. Why map all the climate before man stepped into the picture. You could never use this data to say this is going to happen next. We are destroying this planet like never seen before in time. It is nice to see you prove Milankovitch cycles but that's were it stops.


Well, there was weather before man got here. There was also science before man got here, it just wasn't recorded, yet.

Least we not forget: Increasing taxes has never in man's history changed the weather.
FastEddy
1 / 5 (7) May 12, 2014
...What???
The ideas are not Gore's you idiot.
They are those of science - he is only the messenger ... and you do know about the idiocy of shooting the messenger?
Obviously not.
FFS.

... only since the industrial revolution ... shown up to be suicidal by diligent scientists using modern technology.
Yet we still have idiots who deny this.
And why?
Because it's "my tax dollars"
Ah diddums
FFS squared.


In this case, the messenger should be shot: Al Gore's Fear of Global Warming Church IS advancing the concept that increasing taxes will somehow offset the changing climate. Blaming the US populace seems to be runrig's cause de celebra' ... Is it possibly that increasing the revenues to the vast military/industrial complex might just make matters much worse?

Please bear in mind that government's past history of taxing and manipulating has not worked, scientifically or otherwise. Got EPS's MTBE? Got Sadamn's "oil weapon"? And how will arming FEMA somehow "fix" climate change?
Shootist
1 / 5 (5) May 12, 2014
I'll take all your Boffins and raise you one Freeman Dyson.

"Generally speaking, I'm much more of a conformist, but it happens I have strong views about climate because I think the majority is badly wrong, and you have to make sure if the majority is saying something that they're not talking nonsense." - Freeman Dyson

"What I'm convinced of is that we don't understand climate." - Freeman Dyson

As a general rule if Freeman Dyson doesn't understand something, you don't, either. And yeah, Madame Editor, I'm talking to you.
rockwolf1000
4 / 5 (4) May 12, 2014
I'll take all your Boffins and raise you one Freeman Dyson.

"Generally speaking, I'm much more of a conformist, but it happens I have strong views about climate because I think the majority is badly wrong, and you have to make sure if the majority is saying something that they're not talking nonsense." - Freeman Dyson

"What I'm convinced of is that we don't understand climate." - Freeman Dyson

As a general rule if Freeman Dyson doesn't understand something, you don't, either. And yeah, Madame Editor, I'm talking to you.


Still sucking Dyson's schlong I see.