back to article Greenland ice SIMPLY WOULD NOT MELT in baking +8°C era 120k years ago

Scientists analysing ancient ice samples say that the Greenland ice sheet withstood temperatures much higher than today's for many thousands of years during a period of global warming more than 120,000 years ago, losing just a quarter of its mass. It had been widely suggested - by the UN Intergovernmental Panel on Climate Change …

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Black Helicopters

I don't expect this to change anything

Afterall if there is a difference between reality and the climate models it's always reality that is at fault.

MWP etc.

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Hockey stick?

I thought the point of teh hockey stick was to show that current temps are unprecedently high - but apparently 120k years ago, temp was higher than now? Continuously for a few thousand years??

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Anonymous Coward

Re: I don't expect this to change anything

It doesnt say that the Ice wont melt at all. What it actually says is summarised here: http://www.colorado.edu/news/releases/2013/01/23/deep-ice-cores-show-past-greenland-warm-period-may-be-%E2%80%98road-map%E2%80%99-continued

"Dahl-Jensen said the loss of ice mass on the Greenland ice sheet in the early part of the Eemian was likely similar to changes seen there by climate scientists in the past 10 years."

"studies have shown the temperatures above Greenland have been rising five times faster than the average global temperatures in recent years, and that Greenland has been losing more than 200 million tons of ice annually since 2003. "

...

"indicates the last interglacial period may be a good analog for where the planet is headed in terms of increasing greenhouse gases and rising temperatures."

i.e. heading for a ~8 Degrees C rise in temperature, 25 foot higher sea levels, and substantial ice melting.

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Anonymous Coward

Re: I don't expect this to change anything

There is strong evidence from the history of sea level on coasts from the Eemian that both Greenland and Antarctic ice sheets shrank notably, contributing to a globally averaged sea-level rise of very roughly 20 feet. This occurred primarily in response to a rearrangement of where sunshine reached the planet and when during the year, with more summer sunshine in the north but very little total change. And, some uncertainty has remained on the exact balance between Greenland and Antarctic contributions.

The new paper suggests that the contribution from Greenland was on the low end of the prior estimates, but has little effect on the estimated total sea-level change, which points to a larger Antarctic source than the previous best estimate.

By shifting more of the sea-level rise into the less-understood ice, and thus into the ice with greater chance of doing something rapidly, the new paper at least slightly increases the concerns for coastal planners, even if the chance of a rapid change from Antarctic ice remains small.

If anyone is thinking that this paper means we can crank up the temperature without worrying about sea level, they should seriously re-think. Overall, a great and successful scientific effort leaves us with the knowledge that warming does tend to melt ice, and that contributes to sea-level rise.

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FAIL

Re: I don't expect this to change anything

Read that again. That passage is CYA language from a scientist who doesn't want to walk the plank on his grants by fully contradicting the current faddishness. In fact, while "studies" have shown one thing, other studies have shown the precise opposite. Last fall another study of satellite data concluded that in fact, while Greenland's ice seems to have thinned around the edges, it also appeared to be gaining elevation along the crest. So in fact we know precisely what we knew before the studies were undertaken, which is precious little.

As for what the Eemian interstadial tells us, it is that no ecological catastrophe ensued from warmer temperatures. It also tells us that the present, regardless of which the thermometer is moving, not "unprecedented" in any sense. In fact, if you plot Holocene temperatures since the peak temperatures - about 8 kya - the trend is downward, which suggests that this interstadial will never see an Eemian-like climate.

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Re: I don't expect this to change anything

"Greenland has been losing more than 200 million tons of ice annually since 2003. "

Its probably lost a million times more than that since the last ice age.

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Anonymous Coward

Re: I don't expect this to change anything

But historically it lost it at a much slower rate than now. That is the concern...

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Meh

An ice cube melts in the oven

Ice cube in a glass of 30C water melts.

Why are ther no icebergs in the Med?

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Re: I don't expect this to change anything

"Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 ± 250 metres, reaching surface elevations 122,000 years ago of 130 ± 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future."

Temperature delta was a couple of degrees max over fifteen thousand years or so with about 20ft difference in sea level.

We're already on course for a temperature delta of about 0.75 of a degree *in just over sixty years."

(http://www.ncdc.noaa.gov/sotc/service/global/enso-global-temp-anom/201213.png)

So there's nothing even remotely sane or realistic comparing the current change to the usual Milankovitch heartbeat.

As for melt - a temperature delta of two degrees bv the end of the century is going to make sea level rise the least of everyone's worries.

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Re: I don't expect this to change anything

Was the issue ever ecological?

I thought it was about whether the US cornfields would be superceded by Sibera and wealthy property owners in London, NY and SanFran would have to buy new somewhere else.

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Anonymous Coward

Re: I don't expect this to change anything

"no ecological catastrophe ensued from warmer temperatures" - well that largely depended if you happened to be a species now living on land now 25 foot below sea level or not...

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Anonymous Coward

Re: I don't expect this to change anything

Unless you live in Norwich, Florida, Bangladesh or numerous other islands / coastal regions of course....

All those webbed fingers in Norwich might finally be a Darwinian advantage!

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Anonymous Coward

Re: I don't expect this to change anything

Wealthy property owners in London will be on the edge of a new coastline with a mediterranean climate - I'm sure that won't be too bad for them....

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Happy

Re: I don't expect this to change anything

Perhaps the webbed fingers actually evolved last time this all happened.

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Re: I don't expect this to change anything

Yet in 1420 the chinese fleet produced map of the greenland coastland, and 30+ vessels made their way from north america back to china over the north-west passage and the north-east passage - without issue.

So in 1420 you could see the greenland coastline, not the 3 miles of ice that now covers it.... interesting for a 10 year period MASSIVE ice shrinkage - guess that was the SUN hiccup.

And in 625AD krackatoa errupted, and for next 10 years no tree on earth shows any significant growth - the dark ages - 10 years no sign of sun due to dust....

if these two events can alter climate THAT much, man has no effect whatsoever.

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Re: I don't expect this to change anything

"Yet in 1420 the chinese fleet produced map of the greenland coastland"

No the whole 1420 China thing is a myth.

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Re: Hockey stick?

You don't understand the hockey stick graph then. That graph is to show how the rate of temperature change increased vastly at the time of the industrial revolution. It has nothing to do with temperatures 100k years ago.

What this study says is that the localised warmer temperatures around Greenland led to significant melting, that contributed around 2m to sea level rise.

In the Eemian sea levels were 6m higher than they are today. The warming was closer to the poles - the tropics were cooler than today.

So, hotter temperatures lead to significantly increased melting which leads to higher sea levels. In addition if interglacials can get so much warmer, then we can expect the same from the current interglacial, except faster because of the human contribution to climate change. But still over periods of hundreds of years.

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Re: I don't expect this to change anything

"As for what the Eemian interstadial tells us, it is that no ecological catastrophe ensued from warmer temperatures. "

I'm sure that it was all dandy for animals back then. I bet nothing went extinct as a result, nor did entire species have to relocate to deal with the effects of the warmer temperatures (i.e., their foodstuffs growing further north).

Who knows how many humans and other human species died during that time? Clearly it wasn't conducive conditions to getting beyond the stone age however.

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Anonymous Coward

Re: I don't expect this to change anything

"Overall, a great and successful scientific effort leaves us with the knowledge that warming does tend to melt ice, and that contributes to sea-level rise".

The most important word in that sentence is "tend". Certainly, warming does *tend* to melt ice; the question is, how much ice can a certain amount of warming melt? Science is about accurately quantifying tendencies.

"In physical science the first essential step in the direction of learning any subject is to find principles of numerical reckoning and practicable methods for measuring some quality connected with it. I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of Science, whatever the matter may be".

- Lord Kelvin [PLA, vol. 1, "Electrical Units of Measurement", 1883-05-03]

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Anonymous Coward

Temp is just one variable. The make up of the air was probably different and weather patterns different too.

Things are melting now, so there is a problem.

It's not just temps and ice, you have to wonder where all the fuel, water and food will come from if we carry on the way we are.

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Mushroom

things have melted before

and there is NO problem.

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Actually, that's a good point; during the last warming period, it was possible to grow wheat and other crops in places it would never survive today. Plants love heat; rising temperatures would mean a huge surge in available cropland. Managed correctly, that would mean an accompanying surge in grains and other produce.

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It was certainly hot in America last year so by your reasoning they should have had a bumper harvest. Let's see how that worked out:

http://www.guardian.co.uk/business/economics-blog/2012/aug/13/america-corn-harvest-hit-world-poor

We may gain some crop growing areas, but you forget about all the growing areas that will be lost from seawater flooding, droughts and temperatures too high for current crops in those areas to cope with.

http://sks.to/species

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Anonymous Coward

"Actually, that's a good point; during the last warming period, it was possible to grow wheat and other crops in places it would never survive today. Plants love heat; rising temperatures would mean a huge surge in available cropland. Managed correctly, that would mean an accompanying surge in grains and other produce."

You would have thought, eh? But maybe not., depending on where you live.

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Facepalm

Did you miss the bit where the ice is actually growing then?

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Anonymous Coward

"Temp is just one variable. The make up of the air was probably different and weather patterns different too.

Things are melting now, so there is a problem."

Are you so driven by (C)AGW that you refute scientific data with a simple shrug of the shoulders and a fatuous comment rooted in "probably"?

Are you so dismissive of (C)AGW data?

Just intrigued, that's all.

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Anonymous Coward

> It was certainly hot in America last year so by your reasoning they should have had a bumper harvest. Let's see how that worked out:

The problem is that the poor corn harvest was caused by drought, not temperature.

You might like to argue that droughts in the US will become more frequent but then the data contradicts you. From Andreadis and Lettenmaier (2006) Trends in 20th century drought over the continental United States:

Droughts have, for the most part, become shorter, less frequent, less severe, and cover a smaller portion of the country over the last century.

The guardian article talks about increasing food prices but makes no mention of one of the main causes, biofuels. Since the use of biofuel became compulsory food is now being diverted for use as fuel with a resultant increase in prices.

Finally, there has been a six fold increase in corn yields since 1940.

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Unhappy

"Actually, that's a good point; during the last warming period, it was possible to grow wheat and other crops in places it would never survive today. Plants love heat; rising temperatures would mean a huge surge in available cropland."

A good theory.

Now how much current farmland is less than 25 feet above sea level?

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How much?

Very little considered globally. Quite a lot from some local points of view - e.g. Central California, the Netherlands.

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Anonymous Coward

> 25 feet above sea level

According to NOAA the Envisat satellite shows a sea level rise of two or three inches per century which means the farmland under 25 feet above sea level might be in danger some time over the next 10,000 to 15,000 years.

In order for sea levels to rise by 25 feet over the next century there needs to be an acceleration of the current rate and there is no empirical evidence for this.

Sea levels have been rising continuously since the last ice age.

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Anonymous Coward

Core samples, tide gauge readings, and, most recently, satellite measurements tell us that over the past century, the Global Mean Sea Level (GMSL) has risen by 4 to 8 inches (10 to 20 centimeters).

However, the annual rate of rise over the past 20 years has been 0.13 inches (3.2 millimeters) a year, roughly twice the average speed of the preceding 80 years, and this is accelerating.

A recent study says we can expect the oceans to rise between 2.5 and 6.5 feet (0.8 and 2 meters) by 2100, enough to swamp many of the cities along the U.S. East Coast. More dire estimates, including a complete meltdown of the Greenland ice sheet, push sea level rise to 23 feet (7 meters), enough to submerge London and Los Angeles.

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Bronze badge

So we have just 9 decades to improve our flood defences?

I kid, I kid. My serious point is that these DOOMDEATH predictions treat humans as passive recipients of Gaia's wrath, when they were quite happy to invoke humans as active causers of AGW. Why would we cause the problem and then just sit there, slack jawed and watching Big Brother MCMXXXIV, while the waters lapped around the 40th floor of the Shard?

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Facepalm

Facts, the climate-monger way

"push sea level rise to 23 feet (7 meters) enou to submerge London and Los Angeles"

This is the kind of drivelling nonsense that I refer to in other Posts.

According to City of Los Angeles, it's average elevation is 70 meters (it's a big place), even at the Coast, tidal levels can differ by as much as 9meters right now - meanwhile, London averages a 24 meter elevation.

Sober dialogue it ain't - emotive "see, do something or your selling out the human race" commentary just gets my 'oh bugger off' gene running in overdrive.

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Anonymous Coward

> However, the annual rate of rise over the past 20 years has been 0.13 inches (3.2 millimeters) a year, roughly twice the average speed of the preceding 80 years, and this is accelerating

You are of course referring to Sallenger 2012 which isn't about global sea levels but the sea level off the East coast of the USA. The paper shows a trend from 1935 to 2008 of 3cm/decade with a trend from 1990 to 2008 of 3.6cm/decade (a 20% increase, not a doubling). However, the choice of 1990 for comparison is a little fortuitous. If you use 1985 to 2008 you get about the same rate (3cm/decade) or if you use 1996 to 2008 you get considerable less (0.241cm/decade). Overall, the empirical data presented in the paper does not show any evidence of acceleration. The acceleration only appears in the output from the models they use to "project" future rises.

In fact, the only acceleration in the data is a negative one (slowing down of sea level rises) but it would incredibly stupid to extrapolate what is just natural variation into a long term trend.

> A recent study says we can expect the oceans to rise between 2.5 and 6.5 feet ....

Well actually no. When you are cutting and pasting verbatim from a site like National Geographic you should at least verify what they are talking about. The study they are referring to was 5 years ago. It wasn't a study on how temperature will change but a study on how ice will flow. It assumed that temperatures would rise significantly and from that estimated how the ice would flow from the Greenland ice sheets and from that what the possible impact would be. Since 2008 most estimates of climate sensitivity have decreased which means their temperature assumptions are incorrect. They also assumed a lack of stability in the ice sheet with increasing temperatures but that has been undermined in a study this month (not 5 years ago) by the University of Copenhagen which showed that the Greenland ice sheet is not as sensitive to temperature increases as was previously thought.

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Fuel is licked

At least the fuel thing is licked. Fracking in the U.S. has found enough energy reserves to last a very long time, and new nuclear designs can take over from there.

As for water: Desalination would work for people living near the coast (thanks to abundant energy supplies), but ultimately you're right. The people living inland will eventually need to start trucking in their water or find another solution, if one even exists. One solution is to use economics to balance water usage. Right now in the U.S., water is being sold at insanely cheap rates in locations that have dwindling water supplies. This leads to high consumption and no immediate incentive to conserve. You can use this to restrict consumption down to a level more closely approaching the replenishment rate of the aquifers.

As for food, scientists and researchers are working on it. They already know how to raise lots more food using much smaller plots of land than what is currently used. I don't know why they don't do it yet, but I'm sure there's a reason (expense, scalability, etc.).

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Mushroom

@Flatpackhamster I agree, but what if *now* is the time to act? The problem* was built over the course of a couple of centuries, what if it takes at least that long to reverse?

It's right that there is research done in to both sides of the argument, the problem is how emotive it all gets. People like Lewis writing articles that effectively boil down to "ner ner de ner ner, someone with a PhD has disagreed with someone else with a PhD, so my point is proved" is just idiotic. Unfortunately, too many people have an economic position with proving things one way or the other.

The simplest argument is: If it doesn't happen, we've lost very little by trying to prevent it; if it does, we're potentially screwed (although we probably will adapt). However, the first part is only true if there is a global agreement to act, which I would put serious money on won't happen.

Ah, well; there goes my hope that the El Reg commentards were going to solve the whole thing.

* If there is one

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Alert

lost very little ?

> The simplest argument is: If it doesn't happen, we've lost very little by trying to prevent it; if it does, we're potentially screwed (although we probably will adapt) <

If the global warming solutions being offered were palatable enough then I'm sure most people would agree with that argument. The problem is that the response so far seems to be riding rough-shod over people's rights (see Agenda 21) and possibly even forced reduction of population (eugenics) in order to reduce levels of consumption. It is those which a great many people find unpalatable.

Given the debatable level of proof supporting AGW and the obvious scaremongering involved, the restrictions on rights and the loss of democratic checks and balances in forcing the response measures through is not seen to be in proportion, or indeed "very little", by many people.

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Stop

Yes, yes, yes. Extrapolations can lead us to fascinating conclusions.

The Mississippi River is convoluted with twists, turns, and backtracks. Erosion, earthquakes, and other natural events tend to straighten out the river over time. Mark Twain engaged in a little 'scientific' interpolation of these events (note, he refers to the city of Cairo that's in Missouri, not Egypt). In his words, " In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. This is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oolitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upward of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-rod. And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three-quarters long, and Cairo and New Orleans will have joined their streets together, and be plodding comfortably along under a single mayor and a mutual board of aldermen. There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact."

Anyone who foolishly takes a brief period of natural history and extrapolates the future (or the past) and believes they have reached a realistic conclusion, is simply divorced from reality.

Man does not need fear a warmer climate, but the likelihood of a future ice age should give him pause for concern.

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Devil

@AC changing weather patterns

The change in climate results in a change in weather patterns. Weather patterns change, you don't get a consistent rainfall or snow to replace the water in the region.

Traditional crop lands dry up, resulting in lower food production.

Now what has a greater effect on weather patterns?

A) a shift in the earth's gravitational poles?

B) increased solar activity? Aka Sun spots?

C) natural volcanic events?

D) cooling of the earths molten core?

E) man made pollution?

If you've said E) you just might have a future in climatology and slinging BS

Note: I am all for cleaner air, but using junk science? Really?

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suntan lotion

"Plants love heat"... True. And many of the new plants that will crowd in, will compete with whatever plant we were hoping would grow better. This is why biologists talk in terms of ecological niches - like an area of mountain, low enough to support, for instance, Engelmann Spruce, but high enough to eliminate competing trees, which grow one km downhill. You increase the average temperature, and maybe they both start growing higher on the mountain. Or maybe the mountain ends if it's not high enough, and the Englemann Spruce gets squeezed out. Or maybe some of the trees can't stand the thinner air, or the thinner soil, or maybe the wasps that pollenate them can't fly that high. So some plants will thrive, some will fade, and some will go extinct.

So do bugs love heat. Many of the new bugs that show up, will eat the plants or trees, where they didn't before. I remember reading about one kind of beetle; if there's a frost below -2C, the larvae, who have dug into tree bark, die that year, just like how the citrus fruit harvest gets wiped out upon a frost. Temperatures rise, and the beetle can munch trees a few degrees further north.

Our flora and fauna will tend to move away from the equators, and further up the mountainsides. The ones that can't adapt to their new neighbors, and the new soil, and the new humidity, will fade away. The ones that survive will tend to be the more flexible ones, the ones that are harder to kill - weeds, wasps, termites, ants, rats, and pigeons.

So be sure to smear on some bug repellant along with your suntan lotion.

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just sit there, slack jawed

"Why would we cause the problem and then just sit there, slack jawed"

Because we don't have control over it.

Yes, humans created all the excess CO2, but not intentionally, in order to alter the climate. And in fact we can't stop burning it on a dime and reverse it - we're too hooked on the fossil energy that's causing the problems. And all the solutions we're trying just seem to not work well.

- Hybrid cars give off a little bit less CO2, not half as much.

- Electric cars still get most of their energy from burning carbon.

- Canadian tar sands take so much energy to produce, they generate about the same as coal.

- Carbon sequestration is smoke-and-mirrors; it would take almost as much energy as the CO2 it's storing.

- So many of the solutions tend to need fossil fuels somewhere along the way, or at least their own energy as overhead.

If we stopped carbon burning tomorrow, the temperature would still continue to rise - it's just that the rate of rising would level off.

The hottest year on record (at the time) was 1998. It broke the record of the previous hottest year, 1997. Which broke the previous record from 1995. Lately, it's cooled off so we've only had three years above 1998. But every year since 2001 has been hotter than the 1997 record - every single year. This ain't no interglacial warming; it's happening a lot faster, and it's starting at a warmer time, that's already interglacial.

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Re: Fuel is licked

"Fracking in the U.S. has found enough energy reserves to last a very long time"

Remember that natural gas still gives off CO2 - just half as much as coal. And it takes 40 years for our energy consumption to double. The reason we're going with gas and hydrogen is because it's hard to get away from energy sources from burning. Natural gas is a stopgap, not a solution.

We will look back upon these times fondly, as the good old days, back when hurricanes didn't do much damage.

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Boffin

"so the models are evidently wrong"

As all models are since it would take a model the size & complexity of the thing being modeled to be an exact representation. The best we can do is add information and adjust the models as best we can and see how well they fit when presented historical data and asked to predict current conditions. My understanding is that we aren't particularly good at this with climate modeling yet, so we, as all serious scientists must, need to take the results of the models in that context and treat them as such.

Unless of course you were to build the ultimate computer to determine the ultimate question to Life, the Universe and Everything... I'll have to put my heads togetehr and see if maybe, just maybe...

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Coat

Re: "so the models are evidently wrong"

Well of course there models were wrong, the dolphins are still here...!

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jai
Silver badge

Re: "so the models are evidently wrong"

it's 42

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Thumb Up

Re: it's 42

Right, that's the *answer*, now we just need the *question*, because once you know what the question actually is, you'll know what the answer means.

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g e
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Holmes

Re: "so the models are evidently wrong"

Which would be fine if the anti-common-sense Inquisition didn't spout these models as gospel and denounce all else as heresy.

But they do. Which is not science, it's politics.

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Happy

Re: it's 42

There is a theory that It is actually impossible for both the ultimate question and the ulitmate answer to be known at the same time, if it ever happens the universe will instantly disappear and be replaced by something even more bizarre abd inexplicable.

There is another theory that this has in fact already happened.

From the HHGttG, Douglas Adams

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Silver badge

Re: "so the models are evidently wrong"

>But they do. Which is not science, it's politics.

Look at a graph of our population over time... it can either continue but this would require the population of new worlds and habitats- or it could plateau (but by what mechanism?) or it could crash, as the is pattern of organisms that outgrow their habitat. Or indeed, the majority of agricultural civilisations in the past.

What, exactly, makes this difficult to understand? I don't really give a shit if we starve because because crops yields suffer from climate change (by whatever mechanism), or if we starve because there are just too many of us.

Its notable that longest lasting civilisations have not based themselves on continued economic growth- China, for example, has for millennia has placed lower status on traders than it has farmers.

The lessons aren't just in the climate models, but are found in history and biology as well.

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