What happened to the ice which covered large parts of northern latitudes a few thousand years ago?

Question

I have reason to believe it has melted, otherwise I may not be here. I didn't burn any fossil fuels at the the time, so why did it melt?

Answer 1

Skeptic Myth

Glaciers have melted before.  That is proof of nothing.  

http://gristmill.grist.org/story/2006/10...

Skeptic myth:  Greenland was once green.

http://gristmill.grist.org/story/2006/12...

"First, Greenland is part of a single region. It can not be necessarily taken to represent a global climate shift. See the post on the Medieval Warm Period for a global perspective on this time period. Briefly, the available proxy evidence indicates that global warmth during this period was not particularly pronounced, though some regions may have experienced greater warming than others."

"Second, a quick reality check shows that Greenland's ice cap is hundreds of thousands of years old and covers over 80% of the island. The vast majority of land not under the ice sheet is rock and permafrost in the far north. How different could it have been just 1,000 years ago?"

Skeptic myth:  The CO2 rise is natural.

http://gristmill.grist.org/story/2006/12...

"We emit billions of tons of CO2 into the air and, lo and behold, there is more CO2 in the air. Surely it is not so difficult to believe that the CO2 rise is our fault. But if simple common sense is not enough, there is more to the case. (It is worth noting that investigation of this issue by the climate science community is a good indication that they are not taking things for granted or making any assumptions -- not even the reasonable ones!)"

"It is true that CO2 has gone up on its own in the past, most notably during the glacial-interglacial cycles. During this time, CO2 rose and fell by over 100 ppm, ranging between around 180 to 300ppm. But these rises, though they look steep over a 400Kyr timeframe, took 5K to 20Kyrs, depending on the glacial cycle."

"By contrast, we have seen an equivalent rise of 100ppm in just 150 years! Check this plot for a dramatic juxtaposition of the slow glacial termination versus the industrial revolution."

Skeptic myth:   CO2 doesn't lead;  it lags warming.

http://gristmill.grist.org/story/2006/12...

"When viewed coarsely, historical CO2 levels and temperature show a tight correlation. However, a closer examination of the CH4, CO2, and temperature fluctuations recorded in the Antarctic ice core records reveals that, yes, temperature moved first."

"Nevertheless, it is misleading to say that temperature rose and then, hundreds of years later, CO2 rose. These warming periods lasted for 5,000 to 10,000 years (the cooling periods lasted more like 100,000 years!), so for the majority of that time (90% and more), temperature and CO2 rose together. This remarkably detailed archive of climatological evidence clearly allows for CO2 acting as a cause for rising temperatures, while also revealing it can be an effect of them."

Skeptic myth:  Volcanoes emit more CO2 than man.

http://gristmill.grist.org/story/2006/12...

"Not only is this false, it couldn't possibly be true given the CO2 record from any of the dozens of sampling stations around the globe. If it were true that individual volcanic eruptions dominated human emissions and were causing the rise in CO2 concentrations, then these CO2 records would be full of spikes -- one for each eruption. Instead, such records show a smooth and regular trend."

"The fact of the matter is, the sum total of all CO2 out-gassed by active volcanoes amounts to about 1/150th of anthropogenic emissions."

Skeptic myth:  The medieval warm period was as warm as today.

  http://gristmill.grist.org/story/2006/12...

"There is no good evidence that the MWP was a globally warm period comparable to today. Regionally, there may have been places that exhibited notable warmth -- Europe, for example -- but all global proxy reconstructions agree it is warmer now, and the temperature is rising faster now, than at any time in the last one or even two thousand years."

"Anecdotal evidence of wineries in England and Norse farmers in Greenland do not amount to a global assessment."

According to NOAA     "The idea of a global or hemispheric "Medieval Warm Period" that was warmer than today, however, has turned out to be incorrect."  NOAA is the national oceanagraphic and atmospheric administration.

Skeptic myth:  They predicted global cooling in the 70s.  

http://gristmill.grist.org/story/2006/11...

Yes about seven scientists said that and three years later, the lead scientist recanted, saying he had underestimated the amount of CO2.

Skeptic myth:  There is no consensus.

http://gristmill.grist.org/story/2006/11...

"No one in the climate science community is debating whether or not changes in atmospheric CO2 concentrations alter the greenhouse effect, or if the current warming trend is outside of the range of natural variability, or if sea levels have risen over the last century"

Specifically, the "consensus" about anthropogenic climate change entails the following:

"The climate is undergoing a pronounced warming trend beyond the range of natural variability;

the major cause of most of the observed warming is rising levels of the greenhouse gas CO2;

the rise in CO2 is the result of burning fossil fuels;

if CO2 continues to rise over the next century, the warming will continue; and

a climate change of the projected magnitude over this time frame represents potential danger to human welfare and the environment.

While theories and viewpoints in conflict with the above do exist, their proponents constitute a very small minority. If we require unanimity before being confident, well, we can't be sure the earth isn't hollow either."

"This consensus is represented in the IPCC Third Assessment Report, Working Group 1 (TAR WG1), the most comprehensive compilation and summary of current climate research ever attempted, and arguably the most thoroughly peer reviewed scientific document in history. While this review was sponsored by the UN, the research it compiled and reviewed was not, and the scientists involved were independent and came from all over the world."

Skeptic myth:  Consensus is collusion.

http://gristmill.grist.org/story/2006/11...

"The growing confluence of model results and the increasingly similar physical representations of the climate system from model to model may well look like sharing code or tweaking 'til things look alike. But it is also perfectly consistent with better and better understanding of the underlying problem, an understanding that is shared via scientific journals and research. This understanding is coming fast as we gather more and more historical and current data, all of which provides more testing material for model refinement."

"Viewing the increasing agreement among climate models and climate scientists as collusion instead of consensus is a rather conspiratorial take on the normal course of scientific investigation. I suppose that fewer and fewer scientists disagreeing with the status quo is indeed consistent with some kind of widespread and insidious suppression of ideas, but you know, it is also consistent with having the right answer."

Skeptic myth:  Antarctic sea ice is increasing.

http://gristmill.grist.org/story/2006/11...

  "Sure, sea ice is shrinking in the Arctic, but it is growing in the Antarctic. Sounds like natural fluctuations that balance out in the end.

Answer: Overall, it is true that sea ice in the Antarctic is increasing.

"Around the peninsula, where there is a lot of warming [PDF], the ice is retreating. This is the area of the recent and dramatic Larsen B and Ross ice shelf breakups."

But the rest of the continent has not shown any clear warming or cooling and sea ice has increased over the last decade or so.

This is not actually a big surprise."

"In fact, it is completely in line with model expectations that CO2-dominated forcing will have a disproportionately large effect in the north. The reasons lie in the much larger amount of land in the northern hemisphere and the fact that the ocean's thermal inertia and ability to mix delay any temperature signal from the ongoing absorption of heat. The local geography also plays a dominating role. The circumpolar current acts as a buffer preventing warm water from the tropics from transporting heat to the South Pole, a buffer that does not exist in the north."

You see, what is happening is not in conflict with what IPCC scientists said. this is another of those imagined issues the skeptics like to repeat over and over again.

Skeptic argument: The climate is always changing.

http://gristmill.grist.org/story/2006/12...

"Yes, climate has varied in the past, for many different reasons, some better understood than others. Present-day climate change is well understood, and different. Noting that something happened before without humans does not demonstrate that humans are not causing it today."

"For example, we see in ice core records from Antarctica and Greenland that the world cycled in and out of glacial periods over 120Kyr cycles. That climate cycle's timing is fairly well understood to be caused by changes in the orbit of the earth, though the mechanism behind the response has not been conclusively established. These orbital cycles are regular and predictable and the

Answer 2

Dino farts, cavemen driving large SUVs, smelting metal and bronze released tons of CO2 and Pre-Al Gore was not there to sell carbon credits so it is Al Gore's fault or rather his family ancient ancestors fault. BLAME AL GORE FOR NOT SELLING CARBON CREDITS QUICK ENOUGH WE ARE DOOMED DOOMED I AM TELLING YOU.

Answer 3

Yes it did melt and the water went to raise sea levels, and also created and filled the Great Lakes in America and other huge lakes in Russia....not sure why it melted, but I think it was that the tilt of the year altered, which it does every few thousand years and thus more sunlight fell on the earth in the Northern Hemisphere causing the ice to eventually melt.

Answer 4

There's many factors which influence global warming and cooling. Greenhouse gases is one of them.

Basically when warming or cooling starts, the factors stack up to accelerate it even further.

Climate is far more complex than lay internet-opinionists make it out to be. You can't simply dismiss human influence just because of previous ice age and interglacial periods.

Answer 5

Natural Climate Change, especially at the end of the last Ice Age some 10,500 years ago and most of the next 7,500 years were warmer than now. See - www.Marshall.org - for a good article.

Answer 6

And how old are you.

Answer 7

The earths revolutions change over time.Imagine a spinning top,as it slows down it makes an exagerated loop at the top,when the earth makes that loop as it spins we get hot conditions as the loops mean we are nearer to the sun.In an ice age the earth spins faster and the loop decreases, so further away from sun.The ice recedes and increases every 10,000 to 50,000 years.The river thames marks the line of how far down the last ice age reached.The ice was 500metres deep in places and you could walk to mainland europe as the north sea froze.The ice age impact was still felt in the 1600s as winters were very cold and thing froze that never do now,ie the thames.

Answer 8

it melted because the earth changes

every few thousand years the earth goes through this little thing called a climate change [ice age/earth heat]

that was during a earth heat time

right now we're supposed to be in a ice age time

but we're not because of the fossil fuels

but i have to agree

how old are you?

you learn this kinda stuff in 7th grade! its called EVOLUTION!

Answer 9

It all melted in ten years, right?

Answer 10

Sometimes the best arguments come from the alarmists.  There views are so often fraught with misperceptions.  You would think they would know the science better since they claim it is on their side.  Nickel says that CO2 levels should be lower.  That is rediculous.  The CO2 concentrations do not drive temperature.  In fact there is an 800 year lag time indicating that temperature drives CO2 concentrations.  Therefore if it warms, as the alarmist argue, then CO2 levels should be expected to naturally increase.  CO2 levels have increased dramatically since 10,000 years ago.

Answer 11

It meleted becasue of the planet's natural cycle same thing that is happening now.

Answer 12

OMG you mean we have had documented and numerous cases of Global Warming that weren't caused by mankind more specifically us evil uncaring Americans???  How is this possible???

Answer 13

LOL, see how they attack you when you throw simple questions at them that they CAN'T answer???

Go and look at my answers where I point out that CO2 cools every single night after the sun goes down...  It is really rather laughable...

Their Global Warming theory can't even muster a single Day, yet they are adamant that CO2 holds temp for 10, 20, 30 and more years???  REALLY FUNNY AIN'T IT?

They forgot how Greenland originally got its name but Gore touted Greenland throughout his movie, which makes me laugh even harder....

Answer 14

I burned 'em.  You've found me out!

Larry, wrong as always.  The Vikings landed in Iceland first.  It was temperate and suitable for farming.  They tried to encourage colonists to go there but found that many were detered by the name they had given it.  So when they found Greenland they gave it a more inviting name, even though it was entirely covered by the Ice Cap.

Answer 15

Wow!  Nobody has thought of that before!  Great question!  Write to somebody quick because you've found the smoking gun!  Clearly there is no cause for concern.  

Get a tuxedo with tails because you can't meet the King of Sweden in jeans and a t-shirt.

Answer 16

Man's at fault....igloos.  We over-used this natural resource in the production of disposible housing.  We're so wasteful...

Answer 17

Because of the cyclical Earth tilting...

Right now, we should (in +/-500 years) head toward a cooling phase and CO2 levels should then naturally decrease.... guess what??? it´s absolutely not the case !!!

We were already at close to maximum temperatures for the interglacial period and temperatures are increasing even more...

Do you know how we know about such previous ice ages atmospheres? through the "bubbles" of air emprisoned in ice cores dating back to hundreds of thousands of years ago...    now there is the risk that for the first time in such a long period Greenland has its glaciers entirely melting.