what caused the global warming to end the last ice age... is the current world leaders stratergy to scare us?

Answer 1

The milankovitch cycle varies the insolation striking the planet's surface therefore reducing and increasing the amount of effective energy the earth's surface receives.
http://www.emporia.edu/earthsci/student/howard2/theory.htm
http://en.wikipedia.org/wiki/Holocene_Climatic_Optimum
http://links.jstor.org/sici?sici=0094-8373%28199024%2916%3A1%3C11%3AMCATEO%3E2.0.CO%3B2-H&size=LARGE&origin=JSTOR-enlargePage
http://www.ggy.bris.ac.uk/personal/AndyRidgwell/pubs/ridgwell_et_al_1999b.pdf

So no, leaders are not trying to scare us. The reality of what we are doing to our only planet is.

Regarding the answer below regarding R. Timothy Patterson and "Friends of Science" http://www.sourcewatch.org/index.php?title=Tim_Patterson

And the National Post letter to the UN? It's nothing more than a "Who's Who of the usual suspects of climate denial.

Answer 2

There are a number of cycles Earth's movement goes through, including an increase and decrease in how circular the orbit is, how tilted the axis is and where it is pointing. Variations in these cause changes in the seasons, which have a feedback effect. At the moment, the sun is furthest from the Earth around the time of the northern summer solstice, so the summers are not as warm and the winters not as cold as they would be otherwise in the North, but the reverse is true in the South. These sorts of variations lead to more or less snow, which reflects heat into space from the Sun, so the more snow there is the more there will be and vice versa. These are the sorts of factors which bring ice ages to an end and tend to set them off.

Taking the last few hundred years as an indication of what would have happened without the Industrial Revolution, there was a Little Ice Age, with more white Christmases and the possibility of frost fairs on the surface of the Thames, so it was colder. We are also due for another ice age about now anyway. Therefore, the fact that it is getting warmer is anomalous and well explained by the increase in greenhouse gases resulting from the Industrial Revolution.

Answer 3

Gwens has mentioned the key words - Milanković Cylcles and Dana and Bob have provided good answers.

Our planet goes through a series of cycles, the most obvious one is it's axial rotation - this is what gives us day and night; it's orbit around the Sun gives us the year and the seasons. But there are several other cycles as well which relate to the way our planet moves.

For example, the orbit it takes around the Sun isn't a constant one. It's an elliptical (oval shaped) orbit but it either tends to or away from circularity, meaning that it can follow an almost circular orbit or one shaped more like a cigar (not quite so extreme); this has a massive effect on our climate. In climatology and astronomy this is known as eccentricity.

The planet also tilts on it's axis, and can lean either more or less towards the Sun, this is known as axial tilt or obliquity, and again, the amount of tilting affects our climate.

Another cycle is the precessional or gyroscopic rotation about the southern pole - imagine a spinning top that's wobbling, it's the same sort of movement.

The above cycles were studied by the Serbian mathematician Milutin Milanković and are collectively known as Milanković cycles. There is another one that he didn't study and this is called orbital inclination - imagine the Earth in orbit around the Sun but bouncing up and down as it goes - this is orbital inclination.

In addition to these there are varous cycles that the Sun goes through (I won't go into details).

The interaction between these cycles leads to periods of warming or cooling and it's for this reason that the planet experiences regular ice ages. The full ice age cycle takes 125 million years but the 'mini ice age' cycle is one of 100,000 years.

When people refer to 'the last ice age' what they're talking about is the most recent glacial retreat. This process began 18,000 years ago and lasted for 7,500 years during which time the planet warmed by 7°C and the glaciers that covered much of Europe and North America retreated northwards.

Unfortunately the world leaders aren't trying to scare us. What they doing now is something they should have done decades ago.

Global warming isn't new, it was first hypothesised as far back as 1811, studied from 1824 onwards and established by the Swedish chemist Svante Arrhenius back in 1893. By the 1940's scientists were becoming increasingly concerned about our effect on the climate and spent decades imploring governments to take action. Had they heeded the warmings all those years ago then it's probable that we wouldn't be in such a mess as we are.

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EDIT: TO JIM Z

I'm referring to the climatic changes through the phanerozoic eon. This is the current geological eon that commenced 542 million years ago with the emergence of multi-cellular lifeforms on the planet. During that time there have been four periods when the planet has been glaciated (ice age) and four periods when the planet has been completely free of ice. We're currently in an ice age and have been for a little over 50 million years. The median times when the planet has been completely ice free are approx 70, 220, 370 and 500 million years ago. This Wiki page has more on the subject of paleoclimatology http://en.wikipedia.org/wiki/Paleoclimatology

Answer 4

Dana, we are in the last part of a period that has seen increased sun activity. I have never read any reputable information that says otherwise. This cycle generally lasts between 7 and 11 years.

Man made global warming is a religion.......hence Al Gore telling us we must have faith.....faith=religion

To answer your question, the sun caused the end of the last Ice age. There is one certainty in the earths temperature, it will warm, and it will cool........not a thing we can do about it.

From about 1400-1850 the world was in what scientist's call the mini ice age. The 300-400 years prior to that was the medieval warming period, and the earth was actually warmer than it is today.

The most simple of facts is that there is no "ideal global temperature". There is an ideal temperature range that benefits man, and the earth has not reached that yet.

The reason that leftists want us to believe that they are the source for all knowledge, is their lack of faith in a higher being. So THEY must be that higher being...........faith=religion.

If I'm going to have faith, my faith will correctly be placed in a higher being, not an arrogant buffoon like Al Gore

Edit

Bob.......if that is a reputable source..........good Lord help us..........oops I mean good Al...lol. Even N.A.S.A.'s information says different.......and this under Hansen......another buffoon. The first report you listed has been discredited by smarter people than anybody on yahoo answers. The second is a biased news report, and nothing more.
But as you have read, and replied to in my other answers, Water vapor is a far more dynamic ghg. It exists in higher quantities, and contrary to your beleif, is THE most important of the ghg's because it acts as a atmospheric coolant. If scientists can not model the most prevelant of ghg's, why should I have faith in the Man Made Global Warming religion.....oops, I mean theory.

And for those that don't know, there have been almost 500 papers written by climate researchers published by acredited scientific journals in the past 8 or so years that disagree with the whole man made part of the religion....oops theory.....so much for concensus

My belief is that there may or may not be warming(that is still up for debate). If there is, then it is part of the natural cycle.

Thankfully cooler heads prevailed this week in Bali, when the U.N. backed away from mandatory caps and fines for offenders......but those caps will be heavily lobbied for in the future and so will the fines.......and those that want the fines....proves my point.....it's all about the money honey. Global re-distribution of wealth.

Answer 5

Long term changes in the amount of solar energy which regulates the amount of sunlight earth receives as well as the strength of the sun's magnetic field are one possibility. The strength of the Suns magnetic field regulates the amount cosmic rays striking the upper atmosphere, which in turn regulates the amount of low level clouds which regulates the amount of sunlight reaching the surface.

Interglacial periods last anywhere between 10,000 - 15,000 years, the current interglacial has been occurring for about 10,500 years. Most interglacials only last 10,000 years, this is one of the problems with the Milankovitch theory, there is no periodicity with any of the orbital forcing parameters that correlates with the average 10,000 year interglacial cycles recorded so far during this ice age. The ice ages are caused by our solar systems journey throught the middle of the disk of the Milky Way galaxy, at that point cosmic rays become most intense and cloud cover generated by the increased GCR flux shields earth from much more solar radiation.

http://www.mrcpl.lib.oh.us/pdf/HenrikSvensmark-Cosmic-rays.pdf

http://arxiv.org/PS_cache/physics/pdf/0407/0407005v1.pdf

Answer 6

What casued the warming that ended the last ice age DOES NOT MATTER. Our CURRENT global warming is of an entirely different kind, and has been proven to be the result of human action. Those are scientific facts--not subject to "debate." The debate on that point is over--and has been over for years.

World leaders are not "trying to scare anyone"--the ones who are acting responsibly are trying to raise public awareness of a serious problem and develop policies for corrective action.

Answer 7

Increased solar radiation.

How do we know it's not that now? Simple, we measure the Sun. Solar radiation has actually been decreasing a bit for some time now. Proof:

"Recent oppositely directed trends in solar
climate forcings and the global mean surface
air temperature", Lockwood and Frolich (2007), Proc. R. Soc. A
doi:10.1098/rspa.2007.1880

http://www.pubs.royalsoc.ac.uk/media/proceedings_a/rspa20071880.pdf

News article at:

http://news.bbc.co.uk/1/hi/uk/6290228.stm

Global warming scientists think a lot about this stuff.

KIRK - Look just above for "reputable information that proves otherwise".

Answer 8

You will notice that the delta T is about 0.5 C. What is the percentage change in temperature?

100 * (286Kelvin-285.5K)/286 = 0.2%

In fact, this is such a small increase that drawing a correlation between it and solar output or CO2 or anything else is meaningless.
There was nothing in the pile of verbiage cited in Bob's last post that gave any rational arguement for the IPCC'c claim of a +-0.17 c error.

Answer 9

The ice age is caused by the Milankovitch cycle which is a wobble in the orbit and axis of rotation of the earth as well as continents moving toward the poles. It causes fluctuation in temperatures that have resulted in cycles of glaciation that are roughly 100,000 years apart. I have no idea what Trevor is talking about with 100,000,000 year old ice ages. That is a new one and certainly not relevant to the Cenozoic Era. He is right that we came out of the last glaciation about 10,000 years ago. Since then it warmed but the temperature has had various ups and downs related to various things from different cycles of the solar output to volcanic eruptions. His assertion that politicians aren't trying to scare us is patently absurd. Of course they are. They try to say that there is a huge problem, but don't worry we are here to help. Politicians can't help themselves. That is how they took something that should be in the realm of science and hijacked it for their political agenda. There is insufficient evidence to assume man is significantly responsible for the current warming and further that the warming has a net negative effect.

Answer 10

Increased output from the Sun caused the last ice age to end.

The Sun's output has remained unchanged on average over the past 30 years while global warming has accelerated rapidly due to increased human greenhouse gas emissions.

http://answers.yahoo.com/question/index;_ylt=Akex_vnxfhJ0mRUv3jNNOv3ty6IX;_ylv=3?qid=20071212090955AAzlZk8
http://en.wikipedia.org/wiki/Image:Climate_Change_Attribution.png

Global warming is a scientific issue, not a political one.