[Ganoderma]

I can't say that i know a whole lot about the way this thing works but i have been reading that through global warming the sea currents and air currents can change drastically. this could also lead to such disasters as ice ages. this was in teh Royal BC museum in Victoria BC canada, they had a global warming exhibit.

Can someone help explain this a little better? i understand how different water/air currents could cool the earth or warm the earth depending. but i dont see how it can cause soemthing like an ice age.

[pgrmdave]

Not having done any research, I can only repeat what I think I remember. All this information will be biased toward the East Coast of North America and Europe, as I live near the North Atlantic. Because of global warming, the glaciers are melting. Because the glaciers are melting, a lot of fresh water is being pumped into the ocean. This is disrupting the gulf stream, and has already made it noticably weaker (in the range of 80% of what it was just two or three decades ago). All the land along the North Atlantic is warmed by the gulf stream, especially Europe. Consider that Europe is far north of the USA, yet has a comparable climate, and more temperate. If the gulf stream weakened too much, Europe could cool down considerably, possibly rendering it far less habitable.

[Drip Curl Magic]

Oh, look at nature balancing itself out....

Beautiful.

[Zythryn]

Gano, it may help to consider that the ocean currents heat the North Atlantic region. The currents won't actually cool anything, they will just stop warming the area if the current breaks down.
A large enough influx of fresh water will break down the major warming current. In addition to fresh water from melting glaciers, there is also the added fresh water from rivers. As average temperatures increase more water is held in the atmosphere leading to more rain leading to more water being dumped in the oceans from NW Europe. This last bit is from memory, I apologize for not having a specific resource.

The lack of the warming current could allow glaciers to grow over the water of the far north atlantic. The question is, will it be too little to balance what we are doing, or will it over balance leading to an ice age, or somewhere in between.

[Ganoderma]

hmm i see. so its the warm water currents that are stopping the ice caps from spreading towards the equator? seems to make sense.

[Zythryn]

Originally Posted by Ganoderma

hmm i see. so its the warm water currents that are stopping the ice caps from spreading towards the equator? seems to make sense.

Well, there are not the sole reason the globe isn't covered with ice. They are a contributing factor.
Unfortunately (or perhaps fortunately) the climate is extremely complicated. There is almost nothing (actually, probably nothing) regarding the climate that is simply affected only by one other thing.
This is why I get frustrated with people saying that man's CO2 is the complete cause of global warming.
I also get frustrated at those that point at the poor mistaken people that think the above and say 'see GW can't exist because those people are wrong'.

In many parts of nature there seem to be tipping points. Ecological systems can 'bend' quite a bit. But if pushed too far they break. Similar to a tree in the wind, it will bend but if the wind becomes too great it will suddenly snap or get uprooted.

The atlantic current has already been measured at only 80% strength, so it is weakening now. We may not see any adverse effects until it gets cut off entirely, or we may see some affects at 75%. More study is needed.

[HydrogenBond]

The gulf current, among other things ,is driven by the thermal gradient between the warm gulf and cold north atlantic, with warm water flowing toward the cooler water.

Another potential is water density. Fresh water is less dense than salt water and will float on the top until it mixes in. Before we had warm-slightly less dense water from the equator flowing toward cold-denser water in the north atlantic, sort of two potentials. Now we have the same warm-less dense water from the equator flowing toward cold water that now is less dense than it used to be. The result is less potential. Once the melt down is complete and the fresh water mixes in, the stream will being to increase flow once again.

[pgrmdave]

So, how does this fit into global warming? The overall temperature of the earth will rise, causing the industrialized nations to freeze, causing CO2 emisions to plummet causing...

[Zythryn]

It is one possible result of global warming.
Over all it is always a cycle, the earth will get along just fine, and most likely will renew itself over and over again (personally I doubt that we will cause a runaway greenhouse afect such as Venus' atmosphere).
The question is do we want to deal with the suffering that goes along with it?

[zkid15]

ok one thing though...if we had another ice age wouldnt it posibly be pretty short like...100-200 years because wouldnt the glaciers freeze again setting things back to the way they were?