Hi all,
Now, i know that the earth is getting hot more and more cause of the global warming.

By logic, the global warming will cause (as we see) that the earth will get hotter and hotter.

But i recently read some articles saying that the global warming may lead the earth to an Ice Age !
I really dont know how that could happen, and i really need to know what about this theory and more information about it. And what are the possibilities for this to happen ?
How much percent this could happen ???!

Please reply

Thank you.



Hadeka.

The idea has something to do with ocean circulation, but I'm not too sure on the details either.

You can't fool me, you saw that on South Park. :)

Make lots of snow in moist, mild winters and then do not melt it all in the following colder summer, to make a really rapid onset ice age. Easily can cover DC with 100 feet of snow and not melt it all in the following colder summer - see web page under my name or my recent reply to Andre in thread “what were the errors in day after tomorrow?” of this forum.

Ice Ages: If no one has yet to reply, I will tell you that the Earth's ice ages are somewhat periodic and due to major climatic shifts that take place 10,000 years or more dependent on the changes in degree of the Earth's rotation around the Sun. The periods of change vary extensively and are not very predictable.

We are possibly entering into another ice age. The polar ice caps are "growing" not melting as some would believe. check out the site
http://www.iceagenow.com see for yourself from people who are
"experts" on this topic.
proto

This is true - in the relativiley short-to-longterm run, but we are altering the natural progression of this cycle to make it into a itsy, bitsy, short/shortterm run at our demise.

Aah, Global Earth Changes are not man made. This is a cycle. The cycle of life. This has been going on for ion's....We are just entering into another
11,500 year cycle. If you looked at the earth as a woman, i know, just for a second, a woman naturally cleanses herself (biologically) each month, well,
the earth does the same thing in a weird way. It is life and the earth is living.
So, just hang on cuz' we are in for a bumpy ride!

Yes, we already mentioned that on many other threads, but today we are seeing a dramatic change in the Earth's environment that is inconsistent with the gradual changes that have occurred during the previous cycles, and these changes today are now able to be precisely correlated scientifically with the pollution man is dumping into the Earth and up into its atmosphere.

The Earth's glacier cycles in the past varied with much longer in-between intervals and periodicities: "During the last few million years, there have been many glacial periods, occurring initially at 40,000-year frequency but more recently at 100,000-year frequencies. These are the best studied. There have been four major ice ages in the further past." source: Wikipidea.

The four in the further past were at about 1.8 mya, 290 mya, 440 mya, and 550 mya., so these were all at 1-2 million year intervals. Today we're seeing one beginning at an 11,000 year interval. This is unprecedented and has never been seen before in the history of Earth.

Hadeka, I'm no climatologist, but I think Facial's right about the ocean circulation. Warm surface currents in the tropical Atlantic are deflected northwards, making the climate of those regions on the North Atlantic coast milder than you might expect given their latitude (London is not very much further south than Moscow). As the warm surface water travels north it gives up its heat to the atmosphere and its salinity increases due to the fresh component evaporating and freezing. The water increases in density and sinks, drawing more water up from the south and perpetuating the heat conveyer.

If the northern ice caps were to rapidly melt, the sudden influx of fresh water would form a cap on the saline layer, shutting down the conveyer and depriving the North Atlantic of the Gulf Stream's warming influence.

It's surely more complicated than I have represented, but I believe that this might be the basis of the articles you read.

Hi all,
Now, i know that the earth is getting hot more and more cause of the global warming.

By logic, the global warming will cause (as we see) that the earth will get hotter and hotter.

But i recently read some articles saying that the global warming may lead the earth to an Ice Age !
I really dont know how that could happen, and i really need to know what about this theory and more information about it. And what are the possibilities for this to happen ?
How much percent this could happen ???!

Please reply

Thank you.



Hadeka.

Hadeka, the way the Earth could be tipped into an ice-age from a warming period could be a collapse of the thermohaline circulation pattern (i.e. the Gulf Stream) in the Atlantic. If that happens, the coasts of North America and Europe would be cooled down rather drastically. I suggest you read the book "The Long Summer", which has just been published. The author's surname is Fagan. Google it and you should be able to order it from Amazon, or if you're lucky you'll find it at your local bookstore.

[QUOTE=Laika]Hadeka,Warm surface currents in the tropical Atlantic are deflected northwards, making the climate of those regions on the North Atlantic coast milder than you might expect given their latitude (London is not very much further south than Moscow). As the warm surface water travels north it gives up its heat to the atmosphere and its salinity increases due to the fresh component evaporating and freezing. The water increases in density and sinks, drawing more water up from the south and perpetuating the heat conveyer.

If the northern ice caps were to rapidly melt, the sudden influx of fresh water would form a cap on the saline layer, shutting down the conveyer and depriving the North Atlantic of the Gulf Stream's warming influence.QUOTE]
Laika is correct, but the upper atmospheric Northerthly circulation occurs world-wide above the in the upper hemisphere: not just in the Atlantic.

"Polar cell is a simple system. Though cool and dry relative to equatorial air, air masses at the 60th parallel are still sufficiently warm and moist to undergo convection and drive a thermal loop. Air masses circulate meridionally within the troposphere, limited vertically by the tropopause at about 8 km, with (on average) polewards motion aloft and equatorial motion closer to the surface. When the air reaches the polar areas, it has cooled considerably, and descends as a cold, dry high pressure area." Wikipedia

If you warm the atmosphere in the "tropical Atlantic deflected northwards," then this will warm the upper Polar Cell circulation: "northern ice caps would rapidly melt."

I don’t think anyone is sure about the cause of ice ages. The most popular theories seem to relate to known small changes in the Earth’s orbit and axis orientation wrt the plain of the ecliptic.

There seems to be two serious problems with this idea:

(1) They reappear at irregular intervals and last for very different periods.
(2) Once fully developed, the solar reflectivity off the snow and ice (the albedo) is very significantly greater. I.e. How can any ice age end?

These problems go away, if the orbit of the Earth is occasionally modified by a relatively massive object from space passing by (or thru ) the solar system. The Earth's 1AU distance from the sun makes all three phases of H2O possible, even in Earth’s nearly circular orbit, but it does not take much eccentricity to give real problems for life on Earth.

For example (Taken from book Dark Visitor) a 2.2 solar mass “dark visitor” passing 12 AU from Earth nearly perpendicular to the ecliptic, with essentially all of its gravitational impulse over in a few months, can change the current eccentricity from 0.017 to 0.0836, which is still less than Mar’s eccentricity. If it should happen that the new apogee (about 11% farther from the sun and 20% less solar heating) is during the Northern Hemisphere’s summer, then an ice age would rapidly return, beginning in the North but progressing rapidly South as the albedo increases.

This is because the Northern winters (at perigee) are wet and milder. Heavy “spring snows” would fall every day. Washington DC would get about 100 feet of snow the first new-orbit winter and it would not all melt in the colder summer that follows. At perigee, closer to the sun, the Southern Hemisphere would be in summer, but only slightly warmer as that hemisphere is mainly oceans, which would be evaporating to cover the Earth (except for artic region) with clouds, from which the North’s heavy snow falls come. Most prior ice ages have not had such bad luck and some ice accumulated in both hemispheres, but I live in Brazil so the dark visitor ice age only wipes out life in the Northern Hemisphere. :) See web site under my name for more details, the physics hidden in book, and why I wrote the book

I think that these climate changes are the major cause of ice ages. In the case of the late Permian 275 mya, Pangea formed causing massive volcanoes to erupt that covered the atmosphere reducing the sunligt - sea levels and ocean temperatures then dropped that led to the massive glaciation during this time period.

Similarly the massive glaciation at the end of the Ordovician 443mya occurred as a result of Godwana moving over the South Pole that caused sea levels to drop - glaciers formed.

"Modern theories tend to revolve around periodic oscillations in the Earth's orbit, hypothesized periodic changes in solar output, and/or the effects of continental masses drifting into polar regions where Antarctica currently resides." Wikipedia

I think that these climate changes are the major cause of ice ages. In the case of the late Permian 275 mya, Pangea formed causing massive volcanoes to erupt that covered the atmosphere reducing the sunligt - sea levels and ocean temperatures then dropped that led to the massive glaciation during this time period.

Similarly the massive glaciation at the end of the Ordovician 443mya occurred as a result of Godwana moving over the South Pole that caused sea levels to drop - glaciers formed.

"Modern theories tend to revolve around periodic oscillations in the Earth's orbit, hypothesized periodic changes in solar output, and/or the effects of continental masses drifting into polar regions where Antarctica currently resides." WikipediaThe problem with "volcanoes" etc as cause is the duration of ice age. And the question as to why the ice-covered, high-albedo, Earth every comes out of one as more solar heat is relfected back to space than pre-ice age is not answered.

>> global warming may lead the earth to an Ice Age ! >>

indeed, it requires heat to create an ice age.

I do not think it has started yet, we are still in melt down, IMO.