The Naked Scientists

The Naked Scientists Forum

Author Topic: global warming can cause an ice age due to increased polar snowfall  (Read 5577 times)

Offline stevewillie

  • Sr. Member
  • ****
  • Posts: 120
    • View Profile
The usual proposed mechanism whereby global warming might trigger an ice age, or at least colder temperatures in some areas, has to do with decreased salinity of the oceans. Melting ice dilutes the seawater and thereby raises the freezing point from about -1.8 degrees C to perhaps -1.0  degrees C or more in high latitude seas. However, there is a more powerful mechanism which is rarely discussed. At present the polar regions are deserts. The deep interior of Antarctica receives almost no precipitation at all. The high Arctic receives most of its precipitation between May and September and much of that falls as rain or snow that melts. Northern Ellsmere Island receives less than 6 cm of precipitation annually.

With global warming the Arctic icepack melts. The temperatures in the Arctic rise and precipitation increases considerably. Much of it will fall as snow since winter temperatures will likely still be below freezing. Right now winter temperatures on the landmasses around the Arctic Ocean average around -30 C or lower.
If these temperatures rise to around -10 C to -5 C or so and the central Arctic Ocean is ice free (supplying more moisture), very heavy snowfalls might occur over large areas of Canada, Siberia, Greenland and the mountains of Scandinavia. Much of this snow might last through the summer. Fogs and increased cloudiness due to an ice free summer Arctic Ocean would also inhibit snow melt. All it takes a few successive years where some snow cover survives the summer to establish a basis for continental glaciation. As perennial snow cover increases, temperatures fall due to refection of solar radiation back into space (increased albedo effect).

Whether this process can produce a new glacial advance depends on the rapidity of global warming. If warming is rapid and intense, it will overcome these mechanisms and we will roast. If global warming is less intense, we may have another round of continental glaciation and we will freeze. Comments?


 

Offline graham.d

  • Neilep Level Member
  • ******
  • Posts: 2208
    • View Profile
I have found that it is unwise to speculate about the impact of global warming based on just a qualitative hypothesis. The battles about what would happen in a whole variety of complex scenarios is best left to the very complex computer models and even these are insufficient to include all the relevent variables, hence the doubts and inability to make definite predictions.

 

Offline stevewillie

  • Sr. Member
  • ****
  • Posts: 120
    • View Profile
I have found that it is unwise to speculate about the impact of global warming based on just a qualitative hypothesis. The battles about what would happen in a whole variety of complex scenarios is best left to the very complex computer models and even these are insufficient to include all the relevent variables, hence the doubts and inability to make definite predictions.



I agree. It's very complex and we don't know all the variables. However, it's fairly straightforward to expect rising (but still sub-freezing) temperatures will result in increasing snowfall in what is now a polar desert. The major lobes of the last continental glaciations in Europe were centered, not in Russia, but in Scandinavia and Great Britain where plenty of moisture was available and temperatures were not severe until the ice accumulated enough to effect temperatures. Year over year accumulations of snow pack in Scandinavia and parts of northern Canada would be a signal for a possible new glacial advance. 
 

lyner

  • Guest
You could be right but, in a system like the weather and climate, you can get chaotic behaviour. Huge swings can be caused by a factor you just didn't notice when you were making your prediction.
 

Offline stevewillie

  • Sr. Member
  • ****
  • Posts: 120
    • View Profile
You could be right but, in a system like the weather and climate, you can get chaotic behaviour. Huge swings can be caused by a factor you just didn't notice when you were making your prediction.

Of course, and this is not really a "new theory". However, this aspect of global warming is rarely discussed since it might be politically incorrect. This is not to deny global warming, but to point out a little discussed possible consequence of global warming. Monitoring expansions of perennial snowpack and glaciers is easy to do, and there is evidence that some high altitude glaciers, such as in parts of Scandinavia, have been growing year over year for the past few years.
 

lyner

  • Guest
Where would the political incorrectness come in? I could just be naive.
 

Offline stevewillie

  • Sr. Member
  • ****
  • Posts: 120
    • View Profile
Where would the political incorrectness come in? I could just be naive.

There is a political aspect to the entire global warming issue. While there is clear evidence of global warming and most climate scientists believe the human contribution to greenhouse gases is critical, some scientists challenge the latter. Such scientists are sometimes accused of being beholden to polluting industries and promoting 'junk' science.

The idea that global warming itself might lead to unexpected cooling is also controversial because it too is seen as favoring the interests of polluting industries and their polluting products. However, there is growing evidence of global "dimming" where particulate matter decreases solar energy reaching the earth's surface. This plus increased high latitude snowfall are reasonable explanations for alternative global cooling theories. In either case we are dealing with a dangerously altered ecology and polluting the atmosphere can't be defended.
« Last Edit: 16/11/2008 22:26:56 by stevewillie »
 

Offline yor_on

  • Naked Science Forum GOD!
  • *******
  • Posts: 12001
  • Thanked: 4 times
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
As far as i understand:)
Even though you are right in that there will be 'short time' strange weather where for example Scandinavia and perhaps places near the arctic will see severe rainfalls due to changed humidity, and due to streams that are changing course, that will only be short time effects.

Not the streams though:)
You have to look to the whole globe, and you need to look at it as a mostly 'isolated' system even though it communicate with spacetime.

But we will get very strange effects, on that I agree, but somewhere on our 'trip' there will be a 'change over' where the weather system(s) will find a new 'balance'.

Earth is not a static system, it's a dynamic. And dynamic systems wander between 'opposites'.
And when we've gone far enough this Earth won't be as comfortable as we want.
In fact it will be rather humanoid uncomfortable.

So yes, we will see some strange weather patterns.
But don't get your hopes up.
what we have is Greenland's inland ice moving with up to forty meters a day.
The Arctic is disappearing.
Polar bears will be extinct in about thirty years( except for the zoos:)
And 'the smart bunch' sees both that and frozen methane as a resource.
Africa is having droughts never seen before.
If you like I can give you more examples.

Not theory's, just facts, you know, like statistics.
I'm rather tired of people that think that this is some kind of a 'game'.
I have kids of my own and...

 

paul.fr

  • Guest
Even the climatologists working with the IPCC have no true idea what effect an increase in cloud cover and atmospheric water will do to a changing climate.
 

The Naked Scientists Forum


 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums
 
Login
Login with username, password and session length