Ice age: When and How

[crzykllrghst]

When could the next ice age begin, and what would cause it. Any links and inout would be appreciated

[Primarygun]

In short, try to save energy, reduce waste of it, help rescue trees in forests so as to avoid a more serious global warming which will lead to a extinction of human beings.

 

[Edit] I forgot something. Throw away your cooling machines, air conditioners. Stopping using aerosol to style our hair.

[crzykllrghst]

In short' date=' try to save energy, reduce waste of it, help rescue trees in forests so as to avoid a more serious global warming which will lead to a extinction of human beings.

 

[Edit'] I forgot something. Throw away your cooling machines, air conditioners. Stopping using aerosol to style our hair.

You didn't answer the question. I know how we can slow global warming already

[ecoli]

Global warming can trigger an ice age... The science in the "Day after Tommorow" movie does have truth behind it.

[crzykllrghst]

Global warming can trigger an ice age... The science in the "Day after Tommorow" movie does have truth behind it.

so a balence of fresh and salt water in the oceans controls the currents

[ecoli]

The undersea currents... not the surface currents.

 

Inside the ocean there are these deep sea currents that's movement is caused by temperature density differences. These currents move independantly, and are unaffected by surface currents (the one's caused by wind)

 

These currents bring warm water up the the noth, warming up the region, and cool water to the tropical region. Extreme global warming could disprupt this deep current, by causing temp. differences to change, and the current to stop circulating.

 

This would stop the warm water being brought up to the north, creating a huge temperature drop, and possibly starting another ice age.

[crzykllrghst]

The undersea currents... not the surface currents.

 

Inside the ocean there are these deep sea currents that's movement is caused by temperature density differences. These currents move independantly' date=' and are unaffected by surface currents (the one's caused by wind)

 

These currents bring warm water up the the noth, warming up the region, and cool water to the tropical region. Extreme global warming could disprupt this deep current, by causing temp. differences to change, and the current to stop circulating.

 

This would stop the warm water being brought up to the north, creating a huge temperature drop, and possibly starting another ice age.[/quote']Wow you good at explaining this stuff thank you

[ecoli]

Thank You

 

Ps: I can't believe I forgot to put up links to back myself up! Here are some links that I just found to provide backing to this info!

http://www.alternet.org/story/17711

http://oceanworld.tamu.edu/resources/ocng_textbook/chapter13/chapter13_01.htm

http://www.eduspace.esa.int/eduspace/Background/default.asp?document=243

[crzykllrghst]

Thank You

 

Ps: I can't believe I forgot to put up links to back myself up! Here are some links that I just found to provide backing to this info!

http://www.alternet.org/story/17711

http://oceanworld.tamu.edu/resources/ocng_textbook/chapter13/chapter13_01.htm

http://www.eduspace.esa.int/eduspace/Background/default.asp?document=243

No, thank you

[Ophiolite]

When could the next ice age begin, and what would cause it. Any links and inout would be appreciated

In one sense we are still in an ice age: about 10% of the Earth’s land surface is covered by glacier ice. If all the ice in the Polar caps (mainly Antarctica) and in Greenland were to melt the world’s sea level would rise by about 300’. When the ice was at its greatest extent, covering almost 30% of the land, sea levels were 300’ lower than today. (So the total range is 600’, or almost 200m.)

We are in what at present is called an interglacial. There have been several of these since the current Ice Age began around 2.5 million years ago. The early researchers in Europe and North America thought there had been four major advances and retreats of the ice, but we now know there were many more: they have been recurring roughly every 100,000 years over the last million years, and every 40,000 years before that.

So, what causes ice ages? The cyclic advance and retreat of the ever present ice has, as noted, been a feature of the last 2 ½ million years, but it has not always been the case. During long periods of the Earth’s history the planet seems to have been ice free. This was the case, for example, during the time that the dinosaurs lived. On the other hand there has been at least one occasion when all, or almost all, the planet was covered by ice. Severe ice ages of this kind (the Snowball Earth Hypothesis) are thought to have occurred in the Pre-Cambrian. Some scientists suspect that the last of these may have generated the conditions that led to the sudden (in geological terms) appearance of many complex animal forms: an event known as the Cambrian Explosion.

So, why do sometimes glaciations occur and at other times not? Here are the major factors:

• Solar Radiation – the sun was dimmer billions of years ago. It has slowly brightened by about 30% over the last four billion years. There was therefore a greater chance of an ice age, and a major ice age at that, in the Pre-Cambrian.

• Plate Tectonics – If there is no continental mass at the poles there is nowhere for snow to build up, and sea ice is readily drifted to warmer zones by currents. (The Arctic retains so much ice because it is largely land locked.) Over time as the continents drift, one will find itself over one of the poles and the potential for an ice age is there.

• Mountain Building – associated with the plate tectonics are mountain ranges and plateaus. These not only provide high elevations on which ice may build up, but they alter the weather patterns around the globe, sometimes encouraging and other times discouraging an ice advance.

• Ocean Currents – ecoli has already made reference to these.

• Atmosphere – the concentration of greenhouse gases (e.g. methane, carbon dioxide) has varied during ice ages.

• Orbital Variations – Milankovitch refined the work of a Scottish geologist John Croll, demonstrating that variations in the orbit of the Earth, the tilt of its axis and the precession of the equinoxes would vary the amount of sunlight reaching the surface. There is a good correlation between that and the advances and retreats of the ice during the last two million years.

Because of the complexities of the above, especially the variations in greenhouse gas caused by human activity, and uncertainties in the details of some of the mechanisms at work it is really impossible to say when the next ice age proper may arrive. Perhaps we have forestalled it by our flagrant use of fossil fuels. Perhaps not.

I imagine that is the longest way of saying ‘I don’t know’ you have seen. Hope it was helpful.

[Aardvark]

Global warming can trigger an ice age... The science in the "Day after Tommorow" movie does have truth behind it.

 

That wouldn't be an ice age even if it did happen. It would simply be some regional cooling. An ice age would be a global decrease in temperature.

 

And the science behind that silly film seems overly speculative at best.

[Ophiolite]

Some links:

 

University of Berkley site on the Pleistocene. Brief, focusing on animals, but has some interesting links:

http://www.ucmp.berkeley.edu/quaternary/ple.html

 

This site focuses on the current Ice Age:

http://museum.state.il.us/exhibits/ice_ages/

 

This is a nice summary of the Quaternary period:

http://qra.org.uk/what.html

 

A nice summary of some of the theories on causes:

http://www.sentex.net/~tcc/iceage.html

 

A word of warning. I just quickly googled these. They are reliable, but there are a lot of links that are nonsense. Watch out for them.

 

 

And Aardvark, yes the film was silly, but it could initiate an ice age thus:

• Temperature rises
  
• Oceanic evaporation increases
  
• Precipitation increases
  
• In high latitudes and at high altitudes this falls as snow.
  
• Ice thickness increases
  
• Glaciers and ice caps advance
  
• Albedo increases
  
• Global temperature drops
  

Edit: By the way CrazyKillerGhost you will have a ringside seat in Chicago if the glaciers head south in your lifetime.

[ecoli]

That wouldn't be an ice age even if it did happen. It would simply be some regional cooling. An ice age would be a global decrease in temperature.

 

And the science behind that silly film seems overly speculative at best.

 

Oh yes...the science was quite ridiculus, but there was a grain of truth behind it.

 

Couldn't the regional cooling trigger furthur global cooling.

[Aardvark]

Oh yes...the science was quite ridiculus' date=' but there was a grain of truth behind it.

 

Couldn't the regional cooling trigger furthur global cooling.[/quote']

 

Like Ophiolite mentions, more snow in Europe and parts of North America would result in more solar radiation being reflected. But on a global scale that really seems pretty minor, not enough to actually set up enough positive feed back to get a net cooling effect. I don't have any exact figures, but just from looking at a global it doesn't appear that big an area effected to have serious global climatological impact.

 

The diversion of the North Atlantic Drift would cause a regional cooling, but i highly doubt it would result in any net global cooling. Especialy considering the apparent momentum toward global warming already in the system.

[crzykllrghst]

Thank you everyone for the input, althought i had to read it 4 times before it all settled in properly. One more question, the interglacial time we are in, is cooling towards and ice age of is it going the other way. Oh and Ophiolite I'll be sure to get you some good pictures. lol

[crzykllrghst]

Some links:

 

University of Berkley site on the Pleistocene. Brief' date=' focusing on animals, but has some interesting links:

http://www.ucmp.berkeley.edu/quaternary/ple.html

 

This site focuses on the current Ice Age:

http://museum.state.il.us/exhibits/ice_ages/

 

This is a nice summary of the Quaternary period:

http://qra.org.uk/what.html

 

A nice summary of some of the theories on causes:

http://www.sentex.net/~tcc/iceage.html

 

A word of warning. I just quickly googled these. They are reliable, but there are a lot of links that are nonsense. Watch out for them.

 

 

And Aardvark, yes the film was silly, but it could initiate an ice age thus:

• Temperature rises
  
• Oceanic evaporation increases
  
• Precipitation increases
  
• In high latitudes and at high altitudes this falls as snow.
  
• Ice thickness increases
  
• Glaciers and ice caps advance
  
• Albedo increases
  
• Global temperature drops
  

Edit: By the way CrazyKillerGhost you will have a ringside seat in Chicago if the glaciers head south in your lifetime.

What is Albedo?

[Dave]

I believe it measures the amount of solar radiation that is reflected away from the planet.

[crzykllrghst]

I believe it measures the amount of solar radiation that is reflected away from the planet.

Not to be rude but how sure are you?

[ecoli]

he might not be sure... but I am. Albedo is indeed the amount of sunlight reflected...by snow, clouds. Whatever.

[Primarygun]

When I was young, I was keen to save energy, save water.

Now, my brain is full of the warning stuff concerning on the earth, I do not persist my action. LOL

[coquina]

Please remember, there is a difference in "Global Warming" and "Anthropocentric Climate Forcing". The first refers to what happens naturally, for the reasons Ophie mentoned. The second is the result of human influence.

 

Here is a link to the USGS Library associated with the Global Change Research Program.

http://www.usgcrp.gov/usgcrp/Library/

In addition to the main documents, you can click on the left hand side to read background documents.

[ecoli]

Good point coquina...often confused terms are also "Global Warming" - the process by which the earth heats up.

 

and "th Greenhouse Effect" - Certain gases that keep infrared energy, reradiated from the earth (original source is the sun) close to the earth's surface.

[crzykllrghst]

he might not be sure... but I am. Albedo is indeed the amount of sunlight reflected...by snow, clouds. Whatever.

cool thanks