Ecocentric

Studies of the Past Show an Ice-Free Arctic Could Be in Our Future [UPDATE]

Human civilization didn't exist the last time that carbon levels in the atmosphere were as high as they are now. As a new study shows, temperatures were much higher—and the Arctic was largely ice free.

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Image courtesy of Jens Karls

An aerial view of the ice core drilling platform at Lake El'gygytgyn in Russia

UPDATE 5/10/13 10:30 AM: And so the threshold has been passed—at least according to the National Oceanic and Atmospheric Administration. The agency reported that the daily average of carbon concentration levels at the Mauna Loa observatory on May 9 was 400.3 ppm—as far as I know, the first time carbon has passed the 400 ppm mark since well before modern humans were making a mark on the planet. It’s all new from here on in.

As I wrote last week, the carbon concentration in the Earth’s atmosphere is nearing 400 parts per million (ppm). (399.71 ppm right now, according to the Scripps readings Mauna Loa.) The last time carbon levels in the atmosphere were that high was at least 800,000 years ago, and quite possibly much, much longer. What we do know is that the climate was much warmer—up to 11 F warmer on average—and very, very different than the one we’ve lived in rather successfully for thousands of years.

Just how different the climate was is underscored by a new study published in the May 9 Science. Researchers at American, Russian and German universities traveled in the winter of 2009 to the ice-covered Lake El’gygytgyn in far northeastern Russia, more than 50 miles north of the Arctic Circle. The lake was formed some 3.6 million years ago when a massive meteorite struck the Earth’s surface, gauging out a deep crater. Sediment collected in the crater over time, which has made the lake a gold mine for geoscientists, who are able to analyze the past climate of the surrounding area through the rock record.

(MORE: Exclusive: Timelapse Satellite Videos Show Decades of Drastic Changes on Earth)

The scientists took core samples of the sediment—records in rock of the past that go back millions of years ago. And their findings suggest that the Arctic was very warm between 3.6 and 2.2 million years ago, during the middle Pliocene and Early Pleistocene epochs. So warm in fact—with balmy summer temperatures in the between 59 and 61 F, more than 14 F warmer than they are today—that the Arctic was largely without sea ice, and was thickly forested, more like southern Canada than the forbidding region we know today. And this came during a time period when atmospheric carbon levels were not much higher than they are today.

Lead author Julie Brigham-Grette of the University of Massachusetts-Amherst said in a statement:

While existing geologic records from the Arctic contain important hints about this time period, what we are presenting is the most continuous archive of information about past climate change from the entire Arctic borderlands. As if reading a detective novel, we can go back in time and reconstruct how the Arctic evolved with only a few pages missing here and there.

And that detective novel may not have a happy ending—at least for human civilization as we know it. As the authors write in the Science paper: “this could tell us where we are going in the near future. In other words, the Earth system response to small changes in carbon dioxide is bigger than suggested by earlier climate models.”

(MORE: Climate Change: Polar Ice Sheets Melting Faster, Raising Sea Levels)

There are still pieces to the climate puzzle that need to be filled in. The study shows that unusually warm temperatures in the Arctic seemed to persist even as glaciers we’re begin to expand in the Northern Hemisphere. But studies like this one help us understand just how changeable our climate—so secure during the history of human civilization—has been in the past, and underscores just how momentous our impact on the planet through the burning of fossil fuels is likely to be. We are well into uncharted territory.

But there’s something about the sheer scale of what’s happening that makes it hard for us to really comprehend. The same day the Science paper came out, a new Yale University poll came out showing that the percentage of Americans who believed global warming had dropped to 63% from 70% in the fall—a change that pollsters blamed on the unusually cold winter and spring that hit parts of the country. That’s not surprising—belief in climate change has usually been broad but deep, easily affected in either direction by passing weather events. But as the deep past show us, the climate works on time scales far bigger than a single season. It’s something we may have to experience before we can ever understand it.

MORE: Why Seeing Is Believing—Usually—When It Comes to Climate Change

15 comments
glubber
glubber like.author.displayName 1 Like

Bryan ... there is no facts references in your articles! For us to believe it must be able to control the presentet content truth. Isce melting in the artic is not raisung the water level, rather the oppposite, this is fysical facts about water and ice volumes. Water expands in volume when frozen..

Andrew.G.O.M
Andrew.G.O.M

@glubberIt is true that water expands when going from the liquid phase to the solid phase.  At low temperatures (about 3 degrees C and below), the water molecules begin to space out as they assemble into the lattice structure characteristic of ice.  This phenomenon can be seen in the decrease in density that water undergoes from about 3 degrees C to the freezing point and then the big density drop at the transition from the liquid phase (water) to solid phase (ice).  By definition, density is mass per volume.If we assume that the mass remains constant, then the only way for the density to decrease as the temperature decreases is for the volume to increase.  We can experience this phenomenon if we stick a full water bottle in the freezer.  Come back after the water has frozen and the water bottle will be bulging!

However, above this about 3 degree C threshold, water behaves in response to temperature as any other fluid would-- it expands with heating (decreased density) and contracts with cooling (increased density).  Essentially, hotter water has more energy and the water molecules are zooming around in the fluid faster than they would be at a cooler temperature.  The macro-state of these faster moving molecules is for them to be more spaced out, which we quantify as water with a lesser density (i.e. greater volume).  You can experience this phenomenon when heating water in a pot on your stove!


It is also true that melting of arctic sea ice will not increase sea levels.  Sea ice melting is analogous to ice cubes melting in a cup of water--after the ice has melted, the water level in the cup will be the same as it was before the cubes melted.  This is because in order for the ice to float in the water, it must displace an equivalent mass in water as its own mass (i.e. Archimedes Principle).  However, if you drop an ice cube into a glass of water or pour more water into that glass, then the water level will rise.  Sea levels will rise if ice sheets or glaciers melt (this is like adding more water into the water glass) or calve (this is like dropping an ice cube into a water glass).

You statement: 'Isce melting in the artic is not raisung the water level' would be correct if you had restricted it to only sea ice (i.e. floating ice).  However, warming arctic temperatures are not only accelerating the melting of floating arctic sea ice but also non-floating ice, such as the Greenland Ice Sheet and glaciers/ice sheets in Alaska, northern Canada, and northern Eurasia.  This melting of non-floating ice is adding an additional mass source into the ocean, which will result in raising sea levels.


Your statement: '… rather the oppposite, this is fysical facts about water and ice volumes. Water expands in volume when frozen.' is true; however, it only would be relevant to the question of sea levels if we were envisioning the oceans transitioning from a liquid to solid state, which would be like taking a cup of water and putting it in the freezer--once it froze, you would expect the level of the ice surface to be higher than what the level of the water surface had been.  However, as pointed out above, except for a very small window around the freezing point, water generally decreases in density with increased temperatures.  Accordingly, a 1 degree C warming of the oceans would results in a decrease in the density.   Assuming a constant mass, the only way to decrease the density of the water would be to increase the volume, which would result in an increase in the sea level.

In summary, the effects of warmer temperatures on sea level are two-fold:

1. Warmer temperatures tend to accelerate the melting (and other forms of mass loss) of ice sheets and glaciers (i.e. non-floating ice), which increases the mass flux into the oceans.  This increase of mass flux into the oceans will result in a greater total amount of water in the oceans, which will result in higher sea levels.

2. Warmer temperatures will result in a decrease in the density of ocean water.  A less dense ocean would occupy a greater volume, which would increase the sea level.

gopvictory
gopvictory

The ozone hole disappeared 2 years ago over the Antarctic , not reported.  Why?

woodchuck
woodchuck like.author.displayName 1 Like

dear mister senior editor..."with balmy summer temperatures in the between 59 and 61"  How about in between 59 and 61?


And "even as the glaciers we're begin to expand"  How about even as the glaciers were beginning to expand?


Come On.

harte.ryan
harte.ryan

"It's not the end of the world ... but you can see it from here."

RudyHaugeneder
RudyHaugeneder like.author.displayName 1 Like

Serious, serious problem this carbon-dioxide stuff -- for future generations, that is, probably even my own children and/or grandchildren by the time they reach my age which is not that far from 70.
However, nature is slowly brewing a solution: several lethal pandemics simultaneously inventing themselves at the same time old killer diseases are also fast genetically mutating to feed off rather than be destroyed by our miracle antibiotics. Seven-plus billion of us may be reduced to Columbus-like 1942 population of around a half billion folks, or less, organized into nations and tribes -- an organizational structure that won't exist after Nature rearranges our numbers.
Either way, via Climate Change or unsustainable population growth, we have nobody to blame but ourselves for the bad times the future holds.

notLostInSpace
notLostInSpace

@RudyHaugeneder  Good post Rudy.  Hard to figure out what should scare us the most (as you mention unsustainable population, the underlying problems being massive starvation and massive water shortages).  I would add that climate change will be a direct factor in the massive starvation and massive water shortages.  The western part of the US is just beginning to fully understand that water is not something to be taken for granted.   Sadly, it may be that one would rather die from a flu epidemic like in 1918 instead of starvation. 

BorisIII
BorisIII

I'm sure when developed countries start to flood govs. well get together and stop the increase in global warming.  The hardest part will be countries that are becoming developed to have them fork over all the money it will take to stop using cheap CO2 pollution.  So I wouldn't hold your breath.  At least in my life time.

notLostInSpace
notLostInSpace like.author.displayName 1 Like

@BorisIII  it will be too late; wars will be fought over resources, great death toll; desperate foes will use nasty wmd......will countries get together?  Like our own Congress can't agree on whether it is Friday? 

vsskeptica
vsskeptica

I get an entirely different interpretation from this investigation than the scientist does who posted the report: CO2 level has little to do with temperatures. The report says it was 14 degrees warmer with just slightly more CO2 than today.

If one looks at the paleoclimatic record for millions of years there are graphs that indicate the temperature doesn't always link up with CO2 levels. There are huge divergences. There is just so much global warming hysteria. People need to take a very long look at global temperatures and realize that climate change is a natural occurance that has been going on since the birth of our planet. And sometimes global temperature change is very abrupt and it has nothing to do with human burning of fossil fuels. But this is not an excuses to be wastefully buring the stuff either.

mtngoatjoe
mtngoatjoe like.author.displayName 1 Like

@vsskepticaEverybody know that climate change is a natural phenomenon. What the experts are worried about is that we are causing a rapid, unnatural warming. (And by rapid, we talking a century or so, maybe less). Another fear is that the warming is accelerating and that there is likely nothing that can be done to stop it. Even cutting emissions 100% won't make much difference in the next 100 years (though it might help the outlook past that).

Everybody knows the climate models are not 100% accurate. But the scary thing is that they seem to have predicted less change than we are already seeing. Maybe things won't turn out as bad as the doomsdays say it will. But maybe things will be worse than the skeptics believe. So, I ask you, what level of worse are you prepared to bet our children’s future on? The worst case scenario for sea level rise is like 30 feet. But is 3 feet ok? There are many places in the world where 3 feet would be disastrous, even some places in the U.S.

Are you really saying we should do nothing and hope that things are ok? Does anyone really think that is a responsible plan?