could another ice age happen?

with all the talk about the earth geting hot could we have a new ice age happen? i just saw the history ch. show how the earth was made tonight and did a story about the least ice age! love dr

 

Theory is that if enough ice melts and dumps enough freshwater in the Atlantic it will shut down the Gulf Stream stopping warm water and air from circulating northwards thus plunging most of the northern hemisphere into an ice age.

 

I saw that movie. Didn't turn out too well for Canada.

 

The first scientificly correct thing you've ever said.

"Could another ice age happen?"

Yes.

There've been five of them in Earth's some 5-billion year history. So it seems likely we'll get another one sometime in the next billion years or so.

 

can, and will, happen. Short of us getting to the point where we can control things ourselves, bound to happen. natural cycles for the planet, slight orbital patterns, etc. Part of how the earth renews itself on occasion, as well.

 

A slightly off-topic, but related matter:

I don't recall there ever being an ice age in the southern hemisphere. Anybody know if there has been and if not, why not?

 

Hate to break it to y'all but we are still in an ice age.

From Wiki

Thus global warming is natural.

 

Yeah, one of the "anti-global warming" things I hear is that it's the Earth still trying to come out of the latest Ice Age. Which I believe could very likely be. (Because, yes, we're still in an Ice Age.)

 

Aside from today (Antarctica is completely ice-covered), both the Ordovician glaciation and the late Paleozoic ice age were centered in the southern hemisphere. In the late Paleozoic ice age, glaciation was widespread over South America, India, southern Africa, Australia, and Antarctica. In addition, two of the three late Precambrian "Snowball Earth" glaciations included ice in the southern hemisphere, but ice was basically global then anyway.

 

Beaten to it, but we are still in an ice age.

 

So some ice ages are primarily in the south and other primarily in the north? And some in both hemispheres?

 

Yes, it depends on where the continents were located. In the Paleozoic, the supercontinent of Gondwana was located near the south pole and there were no continents at high northern latitudes. There would have been sea ice but the sedimentary evidence for glaciation is based on terrestrial and shallow marine continental margin sediments. There may have been a small ice sheet at high northern latitudes in the middle Permian in what is now northeast Siberia.

 

Not for many tens of thousands of years if Milankovitch Theory is correct -- even if anthropogenic global warming is not taken into account.

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

ETA: There is an alternative hypothesis based on the inclination of the Earth's orbit with respect to the ecliptic.

http://muller.lbl.gov/papers/sciencespectra.htm

http://muller.lbl.gov/papers/nature.html

This is apparently a better fit for the periodicity of ice ages over the past million years. It makes a similar prediction to MT for the likely onset of the next ice age.

 

Everything cycles.

It's not a matter of IF but of WHEN.

 

Thanks! It just always seemed that whenever I watch a documentary about an ice age, it's always about the one in North America (Europe and Asia neven even get a mention ).

 

That's because our ice ages are way better than the other ice ages.

 

Guess we can thank ILM for that.