Why would global warming trigger an ice age?

Question

I dont get it. I assume it would have something to do with ocean currents but I think that the net effect would be to get warm not cold.

Answer 1

Dude.....things are MELTING!! GETTING HOTTER!!! Once you raise the temperature, it still goes up. We're like frogs in a pan. The frog will die before realizing the increase of temperature.

Answer 2

The thermohaline current and the effects global warming could have on that current are the reason.

Europe and much of the northern parts of both Eurasia and North America are warm and habitable because of warm currents that bring heat from the equatorial regions. England for instance is at approximately the same latitude as the Hudson Bay in Canada but is far warmer because of these currents.

The currents flow primarily because as water nears the poles it starts to cool and also has been evaporating the whole trip and there for is also saltier. These two things make it heavy and therefore it sinks. That sinking basically drags the current up towards the poles.

Global warming could cause a huge amount of fresh water to enter the Northern Atlantic if it causes much of the Greenland Ice cap to melt. If that where to happen rapidly it could make the waters of the North Atlantic much less salty and therefore could stop it from sinking. If that were to happen the warm currents could slow down or in the extreme case stop entirely.

With little to no warm water flowing into the North Atlantic it would become much colder and would cause Europe to cool off considerably and therefore trigger a local ice age. At the same time that Europe would get colder, the heat that used to be carried north by the current would now stay in the tropics so the tropics would actually heat up. So this would not be a world wide ice age but rather a localized ice age and in fact the average temperature of the Earth would likely continue to rise. Global warming would not stop but climates would be radically changed throughout the world.

Eventually this current would begin to flow again and the climate would be restored but it would likely take hundreds to thousands of years for the current balance to be regained.

Answer 3

My theory - pretty long one - i hope you won't get too bored:

global warming happens because of carbon dioxide in the air right? (for the most part, don't worry about methane and other gases yet). more global warming will release more and more carbon dioxide (oceans have tons of carbon dioxide, and warm water will contain less carbon dioxide and there is a lso a buffering mechanism, the hotter it gets, the buffers gets messed up a bit, releasing more CO2). and so will the moisure content

Now, at some point, there will be a lot of carbon dioxide and water vapor in the air, trapping a lot of heat (once again, I have to explain a lot I guess, if we need to go into details - carbon dioxide usually absorbs longer infrared, water vapor can absorb a wider spectrum) even before it reaches the surface of the planet. Remember, hot stuff likes to stay higher and thermal conduction isn't that good for the heat to come down. So, theoretically at some point, you can have pretty hot air much higher and the earth surface is getting cooler and cooler).

And this is the time to discuss few physicall phenominons, some things in nature work like push pull and some just want to stabilize somewhere (el nino is push pull, going back and forth, oceans temperatures are usually stabilized). So, assume this is push pull, earth surface is getting a lot cooler, let's say becomes colder than 0 degress celcius, in a few days/weeks/years or whatever, but quicker, it will start sucking moisture from air and convert it to ice (again, here there are lot of complications, but let's stick to the basics), and ice and snow is a good reflector of light (snow is all white, right?) and doesn't absorb heat very well like vegetation, hills etc.

so, there you go, you got tons of snow that refuses to take in heat, slowly atmosphere is losing water vapor and co2 but at some point, the air is clear again but suns heat is just getting reflected, instead of being absorbed and radiated (radiated heat is in far infrared radiation, which is what is trapped by the atmosphere to make our planet warm enough to live).

and i could keep going on with my bla bla and bla - but i guess you get how the cycle works.

Answer 4

I am comfused on the same thing.  They call it Global warming but yet it's not getting any warmer.  When I think of Ice ages, I think of prehistoric animals like Dinosaurs.  When I think of Global warming I think of the greenhouse effect and the warming trend how winters are getting milder.