Changes In Earth's Orbit Were Key To Antarctic Warming That Ended Last Ice Age

vinces99 writes "For more than a century scientists have known that Earth's ice ages are caused by the wobbling of the planet's orbit, which changes its orientation to the sun and affects the amount of sunlight reaching higher latitudes, particularly the polar regions. The Northern Hemisphere's last ice age ended about 20,000 years ago, and most evidence has indicated that the ice age in the Southern Hemisphere ended about 2,000 years later, suggesting that the south was responding to warming in the north. But new research published online Aug. 14 in Nature (abstract) shows that Antarctic warming began at least 2,000, and perhaps 4,000, years earlier than previously thought."

Comments

Climate change is human-caused, full stop

[Anonymous Coward]

It's Cavemanthropogenic Global Warming, if you want to get technical.

Break the Ice

[Anonymous Coward]

Allow me to break the ice with the first post

Ice ages are caused by planetary wobbles

[Anonymous Coward]

But warming is caused by man.

Got it.

Re:Ice ages are caused by planetary wobbles

[SuperKendall]

Isn't it inconvenient when people who think differently than yourself speak up?

Other religious fanatics have the same reactions when their ideals are challenged.

I have found through the years, "shut up" is the sign of a weak and easily manipulated mind.

Re:Ice ages are caused by planetary wobbles

[Gavrielkay]

So, you dismiss some current science but want to make cute quips about how other current science backs you up?

If you have an actual point to make about how hundreds of climate scientists are wrong, please cite your data. Otherwise you are just insinuating that hundreds of educated people are missing something that you see... as opposed to hundreds of educated scientists knowing something about how and why these occurrences are different and can have different causes.

Re:Ice ages are caused by planetary wobbles

[blueg3]

Isn't it inconvenient when people who think differently than yourself speak up?

No, it's just inconvenient when people who don't think speak up.

Re:Ice ages are caused by planetary wobbles

[Gavrielkay]

Better my trotting out a headcount of experts than others' trotting out gut feelings. I have a degree in chemistry, I understand the scientific method. I work in programming, I understand logic. Both of those concepts help me to understand that hundreds of scientists from around the world are not making this shit up. Perhaps new data will come to light and prove some or all of the current theories wrong, but it won't come from /. posters making snide remarks.

And it won't come because some people have decided that science is great when it provides computers, internet and porn on DVD but is somehow stacked full of blithering idiots when it comes to climate change.

Re:Ice ages are caused by planetary wobbles

[khellendros1984]

If someone makes a post that seems to be making a false-equivalence between two situations, then they aren't even challenging anyone's "ideals", they're just introducing confusion for no good reason. Anthropogenic climate change and climate change through natural processes (like Earth's orbital wobble) aren't mutually exclusive, and any argument that says that they are is either disingenuous or badly confused about the claims being made. If you take the former to be true (and I do), then "shut up" is the correct response to the trolling attempt.

Re:Ice ages are caused by planetary wobbles

[Anonymous Coward]

There is little insight in a sarcastic comment expressing a common point of confusion: that climate change processes on the scale of tens to hundreds of thousands of years are going to matter to what happens in the next century or two.

I don't mind sarcasm if it's founded on an insightful understanding, but this isn't. It's just dumb. It promotes confusion, not understanding. Here, I'll rephrase it for you with an analogous situation:

"Tides are caused by the Sun and Moon"
"But waves are caused by wind"
"Got it"

What, is this supposed to be a contradiction? That the surface of the sea could be determined by *two* different processes at the same time at two different scales of observation and timescales? Gasp! Insanity! Sea level skeptics unite and resist the global sea level conspiracy!

See, I can use sarcasm and hyperbole. But it doesn't really help my argument. What matters here is the observation that the guy making his sarcastic comment about controls on climate doesn't understand that there isn't anything contradictory about climate variations due to astronomical cycles at long time scales (thousands of years) being different from human inputs at shorter timescales (centuries). It's no more contradictory than the different processes responsible for the temperature variation seen over a single day versus a season. Or does he have a problem with that as well? At least it would be consistent.

Re:Ice ages are caused by planetary wobbles

[cusco]

Previous "intervals of extremely rapid warming and cooling" were centuries and millenia long. We're seeing changes over the period of decades, and ice cores from Antarctica show no similar pattern for at least the last 850,000 years. If you look at the timing of the 'Little Ice Age' you may notice that it starts almost immediately after the Black Death killed off 1/3 of everyone from India to Iceland and forests re-covered eastern Europe, sequestering huge amounts of CO2. I would be surprised if your "unknown fraction" wasn't the cutting down of the forests to restore it back to farmland.

I like how the "no warming for 16 years" line has now changed to "no statistically significant warming". If I make my error bars wide enough I can also claim that there's "no statistically significant" difference between auto fatalities at 50 kph and those at 150 kph (just to make a car analogy).

Re:Ice ages are caused by planetary wobbles

[riverat1]

The purpose of peer review in general is not to determine if a paper is right or wrong but to make sure there are no obvious mistakes or elementary errors that would make it a waste of time for others in the field to read it in the first place.

And I think that climate science is not nearly as soft as you seem to think it is. Yes, it is very complex but the interactions are all physical and it's probably not necessary to know every single one. The top 10 or 20 probably cover well over 99% of the effects.

Re:Ice ages are caused by planetary wobbles

[Rockoon]

Or, you know, you might want to look in it, since if you are basing your theory on these things, then it's up to you to do the research which demonstrates how they are significant.

This statement right here is the problem with most people. They, like you, dont understand what the fuck they are talking about.

All the long-duration proxies (more than a few hundred years) do measure as an average over hundreds and even thousands of years because there is too much short term noise in the signal. Thusly statements about the rate of warming on short time scales cannot be made about periods in the past more than a few hundred years. He doesnt need to look into why this is because its proven within mathematics (more specifically, in the fields of statistics, calculus, and now information theory) rather than physics, chemistry, or "earth science."

Thousand-year running average cannot ever make meaningful statement abouts hundred year derivatives. because its impossible. You just argued that he should re-prove whats already known for an absolute undeniable fact.

Re:Ice ages are caused by planetary wobbles

[TapeCutter]

Any reputable climatologist will tell you the resolution on ancient climate reconstructions is nowhere near fine enough to pin things down to decades. The ancient climate is reconstructed by interpolating samples taken centuries apart. This article is a good example, past studies indicated the south lagged the north by 2kyr. That didn't make sense from a physical POV but that's what the sum of the evidence was telling the researchers. To say more than what the evidence is telling you is speculation, not science. This new study appears to have found evidence that there was no lag, meaning the discrepancy between theory and observation raised by the previous study is likely just a side-effect of the limited resolution of the previously available evidence..

Your claim suffers from the same limited resolution as the previous studies, neither you nor the GP can credibly claim the current change is more/less rapid than ancient changes seen in geological layers. Having said that and also acknowledging interpolation has a smoothing effect on the curve, I would be very surprised to find a 50yr spike like that of the last 50yrs in the geological record. Beside the lack of hard evidence, the basic problem I have accepting your speculation that the such spikes exist in the record is that, apart from space rock impacts, I can't think of any other natural process that would have such a rapid global effect.

Re:Ice ages are caused by planetary wobbles

[rgbatduke]

So you're saying that the Bern model for CO_2 sequestration is wrong, then? I don't think we know enough to say that it is right OR wrong yet, and won't for some time yet, but sure, it might be wrong.

However, you need to actually do the numbers before you conclude that killing off 1/3 of everybody from India to Iceland might have sequestered "huge amounts of CO_2" and you might point out some evidence that this occurred in the various CO_2 proxies before basically making something up to explain something that we currently cannot satisfactorily explain or predict even WITH the knowledge we have from proxies.

As for no warming vs no statistically significant warming, they are precisely the same thing, are they not? Or do you claim perfect knowledge WITHOUT error bars. For part of that interval there is equally statistically insignificant cooling. The point is that the GCMs have almost without exception predicted significant warming across that same interval. Indeed, if one uses actual statistical analysis and hypothesis testing the way it is axiomatically supported, to test the GCMs instead of to take untested GCMs en masse and use them to make literally indefensible statements about the probability of future warming scenarios, one would reject nearly all of the GCMs one at a time, easily at the 5% confidence level and many of them at the 3% or even less confidence level. They are all significantly too warm.

Finally, you might consider what the error bars on our probable knowledge of things like global temperature really are, instead of introducing a false analogy. For example, how many significant digits do you think you might get measuring the average air temperature in your own back yard? How many thermometers might it take, and where might you locate them? How well would they agree with thermometers located across the street, or two blocks over? How would you measure this average? How well would this average extrapolate and infill to predict the average temperature of your city, your county, your state, the United States (if you American)?

Curiously, James Hansen has spoken on this in a Q/A and the answers might surprise you.

In the meantime, the way temperature is reported is as an "anomaly", in part because the various models used to extrapolate, infill, and otherwise massage the actual raw data produce global averages that differ by over a degree F. Since there aren't that many of them, this is a reasonable lower bound estimate for sigma. Of course, the models themselves all extrapolate and infill and use data that is itself corrupted and imperfect in various ways, so that the models have a model error that is almost certainly at least as large, and because they are using overlapping data one cannot conclude that the spread in model means represents this internal purely statistical and experimental error. I would be rather surprised if we know global average temperature to within 1 C.

Now let's put your analogy into true perspective. The actual absolute temperature involved is pretty close to 300 C, so let us go with that and equate it to 30 mph. Our probable error in this number is around 1 C, or 0.1 mph. The entire post LIA warming is around 1 C -- barely resolvable. The entire warming from the beginning of the instrumental era to the middle of that era is around 0.4 C, with almost all of that increase occurring from 1910 to 1940 and not, according to climate scientists, attributable to increased CO_2 (as this was largely pre-industrial as far as the world is concerned and CO_2 hadn't started to bump yet. So we have 0.4 over 30 years, mind you, little or no CO_2 involved, all instrumental records and hence at least moderately reliable although -- note well, we're really talking about variation that is on the order of the error bar on absolute temperature (where we could then get into a HUGE discussion of whether one can cheat statistics and claim a smaller one on the ANOMALY, arguing effectively that we somehow know the second moment of a distribution mo

Re:Ice ages are caused by planetary wobbles

[infinitelink]

It is full of blithering idiots when it comes to climate change: blithering idjuts who were wise enough to make a stink about the initial publications of warming offworld corresponding with that on earth...because it could threaten grants (one on my campus who happened to be world famous started receiving death threats when he took a hard look at it, and changed his mind to deem human activity real, but insignificant); blithering idiots who hide and manipulate data and just make it up (they've got deadlines and entire careers that can go out the window: the university is about the furthest place from where people will care for you as there is); blithering idiots who know damn well (I've talked to a few at some prestigious research institutions with labs that are influential in this crap--it's good to have friends) that the models are bullshit, because even with all the apparently complexity and supercomputers running them, relative to actual conditions they're simplistic guesswork: Freeman flippin' Dyson brought this up and despite being a physicist had climate scientists screaming that he was unqualified because "you're not a climate scientists!!!!" The last one I spoke with said that since there is little to no actual data or modelling on the effects of biota on all this (which are terribly important and well-known to be), that existing studies correlate a little between them and changes but can't scale or adjust as biology would, and don't take particulates into account (exceedingly important, diverse, and...really hard to include) at all, he doesn't understand why they even get any funding: except the politics and that they engage in FUDing everyone.

Either way, things CAN'T change (regards human activity) even if we are affecting things in terrible ways, fast enough to undo any of it: billions of people are struggling to survive/eat still, s owe might as well just try to fix things, build dikes, walls, and ways for swimming things to get-through to somewhat-preserve ecosystems, and try to get along with an earth that actually really genuinely is-acknowledge-as-truly-started start to warm before any of the industrial revolutions began. It's not anti-science but realism. The Indonesians, Thai, Vietnamese, Chinese, "Indians" (in quotes because that place is far from a nation-state), etc. all need to keep developing, so the do-gooders here either get over it (and stop hindering development and direct funds instead into fundamental research as well as practical developments to mitigate harms as much as possible) or get left behind.

Don't let ice build up!

[NotQuiteReal]

All that ice on the poles made the Earth all wobbley, which led to Bad Things. We should de-ice the planet, as a precaution so it doesn't happen again!

I mean, you don't let ice build up on your roof, in your freezer, or on airplanes... ice is always bad unless it is in my drink!

Re:Don't let ice build up!

[Darinbob]

More margaritas for everyone, to save the planet!

Before anyone drags climate change into it..

[sl4shd0rk]

FTFA: "Changes in Earth's orbit today are not an important factor in the rapid warming that has been observed recently...Earth's orbit changes on the scale of thousands of years, but carbon dioxide today is changing on the scale of decades so climate change is happening much faster today."

Re:Before anyone drags climate change into it..

[Gavrielkay]

Or, it was a (partially) successful attempt to deflect the rash of comments about how their research on the previous ice age must invalidate lots of other research on current climate change.

Re:Before anyone drags climate change into it..

[Arker]

Ah yes, the requisite recitation of faith.

And the rest of this is horribly confused. They talk about 'orbit' when they mean 'rotation' (as in around the poles, not around the sun) and they keep talking about an ice age when they are referring to an individual glaciation.

Re:Before anyone drags climate change into it..

[Anonymous Coward]

Please, before you post anything on this topic, go to this site and check if it hasn't been debunked. By endlessly repeating long-discredited views, you're only adding noise to the discussion.

Re:Before anyone drags climate change into it..

[riverat1]

What's really funny is all the people who say we're in a cooling trend lately when the warmest year on record was 2010. All I can say is enjoy it while it lasts, I doubt you'll still be able to say that in 2020. The greenhouse effect is still in effect.

Re:Before anyone drags climate change into it..

[bluefoxlucid]

There was a Russian scientist who took that bet in 2000 and won. Are we there again? Can I bet you $1000 and win?

The charts are showing me a 0.8C movement since 1900, which doesn't seem to be correlated to anything interesting. CO2 levels are strange--I'd like to see a chart of industrial CO2 output and the INTEGRAL of CO2 output (i.e. total CO2 output since baseline), because warming would tend to make CO2 less soluble and thus CO2 would emit from the oceans (or dissolve less). That means that CO2 output might not have an impact immediately because it gets dissolved; then it suddenly comes back into the atmosphere as it warms, creating an anomaly that doesn't line up. Or it could mean that sunspots cause the earth to warm, driving more CO2 into the earth, creating a pretty graph that correlates CO2 ppm to temperature.

All kinds of funny shit. Given the rate at which we burn fuel, and the massive fluctuations (including trends that are solidly and disturbingly down), a graph of industrial output would be interesting. Since we can't scrub CO2 out of the air except by ocean absorption, how in the hell do we actually go down in global temperature so solidly as around 1900-1910, 1940-1950, 1960-1968, etc? How did the Great Depression signal a massive increase in global temperature, when the economic climate would indicate a slowing of industry and reduction of output (CO2, thermal energy, etc.)?

Actual human *activity* is actually of interest to me. All I hear is a calling out of CO2 numbers and "Man it was hot this year". The funny thing is the fluctuation is so small that nobody should be able to notice it--the limit of human hearing is 1dB but you can subconsciously respond to differences in volume of as low as 0.2dB (louder sounds better); while 1 degree C is 1/100 of the temperature difference in the liquid phase of water, and Farenheit is just arbitrary shite, it stands to reason that a fluctuation of 0.2 degrees shouldn't be causing "Man it's hot this year, last year wasn't so damn bad!"

Overall to me I've seen normal temperature--when I was sent home in second grade due to an in-classroom temperature of 102F and an outside temperature of like 105F, it was uh... 1990. In 2011 when the temperature hit 106F people were like... damn, that was a hot day. It seems to me that there were more sustained hot days in the summer when I was a kid, but I probably more just remember hot summers because they were hot; more likely it went up and down and I didn't leave my house enough to care. These days I wonder why my summer's so cold because it hasn't been consistently above 98F all the fucking time.

So yeah. The science, the numbers, they're telling me 0.8C degrees in 100 years should be panicking me, and folks are telling me wait another decade and see how I like the heat. The real-life environment, it's like, I don't notice anything really spectacular, and I wonder why it doesn't snow (we had a blizzard 3 feet of snow in 1995 and 1998, and also in 2011 ... other than that, once in a while we get a few inches of snow; most winters are unspectacular) and why it's not extremely hot (it's been extremely hot a few times, I expect extremely hot in the summer). And then people waive the "cause" of this only-noticeable-on-paper non-issue in my face, and I'm like, "... so there's correlations both ways, an increase in temperature will cause this and you're telling me this will cause an increase in temperature... it doesn't seem to line up with human activity, but you're telling me this is human-caused. Are you sure?" and people point and laugh and go "U SO DUM!" like they heard it on TV and it must be true.

You're all nuts.

Earth's balance off because of too many people?

[VinylRecords]

Maybe the earth's orbit changes right now are because there are too many people living in one area and they are weighing down the earth like a seesaw? Like if too man people live on one side of an island the island tips over?

http://www.youtube.com/watch?v=cesSRfXqS1Q

Re:So basically...

[i kan reed]

No, it's pretty much just "no". The phrase "global warming" conventionally describes the unprecedentedly rapid rise in temperatures since the industrial revolution. That is entirely "our fault" because of aforementioned unprecedented rate, and that data is quite incontestable without dramatic misrepresentation of what is being compared.

I tell you Krypton is merely shifting its orbit

[sandbagger]

Relax, Jor-El.

Author is so full of it his eyes are brown...

[dtjohnson]

"For more than a century scientists have known that Earth’s ice ages are caused by the wobbling of the planet’s orbit.

There are so many blatant errors in just this one sentence that it's publication is astounding. First, the Earth is currently in the middle of its 5th "ice age," the "Pliocene-Quaternary glaciation," (which began 2.5 million years ago) and what the article calls 'ice ages' are termed by real scientists to be "glacial periods" within the current ice age. The Earth is presently in what is called an "interglacial period" and the next "glacial period" is likely to begin within the next 1,000 to 2,000 years. Next, there is certainly no consensus that either the Earth's "Ice Ages" or "Glacial Periods" are caused by wobbling of the planet's orbit. General consensus by scientists is that both ice ages and glacial periods within those are caused by a variety of factors including atmospheric changes, solar changes, changes in the position of tectonic plates which affect ocean circulation, variations in the Earth's orbit (which are currently considered more likely to affect glacial and interglacial cycles rather than to initiate or end ice ages), and volcanism. In short, TFA is utter bullshit.

Re:Are they confused?

[riverat1]

Both the revolution of the Earth and its orbit around the Sun change over time. The changes in the orbit are driven by interactions with the gravitational fields of other objects in the solar system, primarily Jupiter and Saturn.

Re:Are they confused?

[riverat1]

Don't forget that as the orbit gets more eccentric it shortens the time spent near perihelion and lengthens the time near aphelion. Also the relationship between insolation and distance from the Sun isn't 1 to 1. To quote the eccentricity section of the Milankovitch Cycles article on Wikipedia:

For the current orbital eccentricity this amounts to a variation in incoming solar radiation of about 6.8%, while the current difference between perihelion and aphelion is only 3.4% (5.1 million km).

The cycle of glaciations for the past million years appears to follow the 100,000 year beat cycle of eccentricity most closely.

Re:So basically...

[dave420]

He probably blames them on the left.