How did the Earth "thaw out" after the ice age?

Question

The Earth did warm up right?
So was it some sort of ancient civilization that burned fossil fuels and left the bathroom light on all night?
Or, do you think maybe, just maybe there is some sort of natural warming phenonmea that "thawed out" the earth?

Answer 1

Well of course it was a natural cycle! I take it you are a skeptic of the theory of manmade global warming, right? So you'd agree with me that, if the earth could warm up without mankind before, it can obviously do it now? It bugs me SO much that people don't see that.

Answer 2

Ice ages are driven by changes in the Earth's orbit and tilt: the Milankovich cycles, which control the amount of sunlight reaching the Earth. The Malankovich cycle causes a reduction in sunlight, bringing on the Ice Age, and then it causes an increase in sunlight, ending it.

As the Ice Age ends, there is positive feedback of greenhouse gasses: as the extra sunlight warms the Earth, carbon dioxide and methane are released from the oceans and soil. These help increase the speed of the warming. The sea level rises by 300 meters in 15,000 years.

This release of carbon dioxide by warming has been used as a skeptical argument, saying that warming causes carbon dioxide and not the other way around. This is, of course, illogical---just because warming generates carbon dioxide, this does not mean that carbon dioxide cannot generate warming. Warming caused by carbon dioxide is a process which is an easily-verifed physical fact.

The really critical question is: why does this warming, with positive feedback, come to an end, resulting in a stabilization of temperature after the Ice Age? Temperatures after Ice Ages do not get too high, so why should we think the current global warming might get bad? One reason is that the Milankovich cycle can reduce the amount of sunlight, reducing the warming. Another is that there are various negative feedback processes, which remove greenhouse gasses as the climate warms. One such process is the building of coral reefs, which remove carbon dioxide from the air and turn it into rock. But these processes have natural timescales---for example, if it warmed too fast, the coral reefs might drown instead of keeping up with the rising sea level. So coral reefs might provide a large negative feedback to a slow rise in temperature, but a smaller negative feedback to a fast rise in temperature.

These feedback processes are not well understood, but they will determine our future. The current rise in temperature is about 0.02 C per year---this is *much* faster than the typical temperature rise following an Ice age, about 0.001 C per year. So it is possible that the negative feedbacks take thousands of years to operate, while the positive feedbacks occur very quickly. There is evidence that this may have happened in the great Permian extinction, where an enormous volcanic eruption caused a rapid rise in temperature followed by rapid postive feedback of greenhouse gasses. The global average temperature rose by 30 C, resulting in the extinction of most species.

Answer 3

The Earth thawed out when the people of Atlantis were burning fossil fuels in their giant Atlantean SUV's. But then the global warming that ended the most recent Ice Age flooded the Continent of Atlantis.

Really!
/Sarc

Answer 4

Human Made Global Warming is a vague lie that is spearheaded by rich liberals, Polatitians that have no " Real " agenda to run for office and sell out professors that care nothing more than making/stealing Glacial amounts of money from a never ending pool of unknowing victims that set up a perfect " Ponzi " Scheme. The easiest way to convince a person that believes this Hollywood garbage is " Follow the Money "! Albert Gore and his wife Tipper ( I created The PMRC which also makies millions ) Gore have made millions for themselves and have earned billions for thier greedy investors. Follow the money.

Answer 5

Previous ice ages are believed to have been caused by variations in Earth's orbit around the sun, called Milankovitch cycles. These slight changes in Earth's eccentricity, axial tilt, and precession alter the seasonality of radiation that reaches Earth's surface. That is, Milankovitch cycles affect the contrasts between the seasons.

The amount of snow that falls and melts each years has a great deal of influence on the climate. If, for example, more snow falls during the Winter than is normally melted in Summer for a few years, the albedo, of reflectivity, of the planet's surface will be raised, cooling the atmosphere and setting conditions right for the advance of glaciers. In contrast, if more snow melts during the Summer than falls during the Winter, the planet will undergo warming, and the glaciers will tend to retreat.

Given scientist's high level of understanding of these cycles, and the feedback mechanisms that result from them, it seems very unlikely that the current warming is being affected by them. In fact, calculations show that, were it not for human influence on the climate, the planet would actually be undergoing a cooling trend.

Answer 6

The scientific reason recent ice ages came to an end is because of changes in the relative positions of the Earth and Sun known as "Milhankovic cycles".

How do we know the present warming isn't that?

It's really simple. The effects of the cycles aren't mysterious. They cause easily measurable changes in solar radiation. We're not seeing those.

Additionally it's the wrong time (by many thousands of years) for a Milhankovic cycle to be heading up fast, but the real point is the paragraph above.

Answer 7

There are numerous competing theories why the glaciers retreated and no credible ones involve CO2, natural or man made. The only theory that works, however is decreased cloud cover caused by a decrease in intergalactic cosmic ray penetrations into the earths atmosphere.

http://biocab.org/Cosmic_Rays_Graph.html

This theory also works on short term climate variability as well. A doubling of CO2 in the atmosphere would be more than canceled by a mere 1% increase of cloud cover. The CO2 based AGW theory is a dark time for climate science. There will be a number of people made fools in just a few years, we are still in an iceage, just an interglacial interlude.

http://www.21stcenturysciencetech.com/Articles%202004/Winter2003-4/global_warming.pdf

Answer 8

orbital cycles are mostly to blame for "thawing out" and ice ages. However, this warming is a slow process that takes thousands of years to complete and does not explain the rapid increase in temperatures we have seen in the last 50-100 years.

It is important to understand that the greenhouse effect is not debatable. It is scientific fact- and it is scientific fact that, despite what any right wing propaganda site says, human activity is increasing greenhouse gas concetration in the atmosphere.

http://www.epa.gov/climatechange/science/stateofknowledge.html

Rapid increase of greenhouse gases appears to have happened millions of years ago. This increase would have lead to rapid climate change which initiated extinction events. One example:

http://en.wikipedia.org/wiki/Clathrate_gun_hypothesis


Then there was a natural source for the increase (extreme volcanic activity, methane clathrate decomposition, co2 vents, ect) Now the increased concentration appears to be completely related to human activity.

Answer 9

It is indeed a natural phenomena. It happens about every 100,000 years... Like joecool said, there wasn't only one ice age... It's the way for the earth to clean itself if I can put it that way.
It sure isn't man-made, pollution in the other hand is man-made, but it doesn't cause global warming

Answer 10

you're confused.

we just had an ice age.

in the late 60's and thru the 70's the "experts" said another ice age was immanent by the year 2000, due to man's use of fossil fuels.

famines, death and areas of the earth became uninhabitable.

during the 90's these same "experts" warned that if man didn't stop using fossil fuels global warming would occur.

famines, death and areas of the earth will become uninhabitable. again.

prior ice ages, before mans callous disregard for the earth was so common,
ice ages were thawed by large herds of Norwegian moose belching their way to warmth.