| Author |
Message
|
| CShark |
 Posted: Mon May 19, 2008 1:14 pm Post subject: The next ice age is not that far away! |
 |
|
Forum Sophomore
Joined: 08 May 2008
Posts: 169
Location: East Coast of Canada
|
| According to at least one report (I can dig up the ref is required), the earth is at the tail end on an inter-glacial period. We are 'due' for another ice age in the next one-thousand years, a blink of an eye in cosmic terms. Of course, we have no idea how the current global warming trend will affect this... what do you think ? |
|
| Back to top |
|
 |
| Lawrence |
| Posted: Mon May 19, 2008 2:04 pm Post subject: |
|
|
Forum Freshman
Joined: 19 May 2008
Posts: 28
Location: United Kingdom
|
That is a widely accepted theory, and does encompass global warming. That's why those who research GW and eco-sciences deeply aren't so concerned about GW in the first place. Global Warming can be considered as a side effect to the ice-age. I can't quite remember the source, or the reason, so until I find it:
http://www.google.com/search?client=safari&rls=en&q=global%20warming%20ice%20age&ie=UTF-8&oe=UTF-8
That should provide better answers than me. Remember not to be influenced by inaccurate hobbyists or manipulating news articles, some of which are designed to trigger panic etc. Although you probably already knew that, making this whole paragraph a pointless addition to what will soon be an RSI.
_________________
Just to be clear - I'm a student in IT. I am not a scientist, or trained philosopher, I'm just trying to portray my ideas. |
|
| Back to top |
|
|
| Bunbury |
| Posted: Mon May 19, 2008 4:54 pm Post subject: |
|
|
Forum Ph.D.
Joined: 26 Sep 2007
Posts: 919
|
I hadn't heard that theory, unless you're referring to the idea that the thermohaline circulation might shut down, causing cooling in the North Atlantic region. The THC shutdown was proposed as a possible result of global warming, but I think the theory has few supporters today.
Other than that, it's my understanding that a near-term ice age is nothing more than speculation, the contributing factors being complex and mostly pointing in the other direction, so I'd be interested in reading your reference. |
|
| Back to top |
|
|
| Lynx_Fox |
| Posted: Mon May 19, 2008 7:11 pm Post subject: Re: The next ice age is not that far away! |
|
|
Forum Sophomore
Joined: 16 Apr 2007
Posts: 127
|
| CShark wrote: |
| According to at least one report (I can dig up the ref is required), the earth is at the tail end on an inter-glacial period. We are 'due' for another ice age in the next one-thousand years, a blink of an eye in cosmic terms. Of course, we have no idea how the current global warming trend will affect this... what do you think ? |
Excluding our effects on the planet, crude estimates of future climate depend on solar variations due to astronomical changes referred to as Milankovitch Theory.
Sometime the earth's orbit in eliptical other times nearly circular, this is called eccentricity and has a period of about 100,000 years.
The last of course it the direction of that tilt spins much like a top in a 20,000 year period. This is called precession.
We are currently closest to the sun during the Northern hemispheric winter and this makes them a bit milder than average. But eccentricity is dropping, in other world our orbit is becoming circular which will reduce the seasonal effect of precession.
The tilt of the earth changes as well ranging between 22.1 and 24.5 degrees from perpendicular to the sun, this is called Axial obliquity and has a period of about 40,000 years. When the angle is high the seasons are exaggerated summers being very warm and winters very cold. We're now about 23.4 and decreasing so we're heading for milder seasons.
Ice age and solar radiation based on Milankovitch Theory at about 65 degree North is reasonable prediction of ice ages for the past couple hundred thousand years. If you use Milankovitch theory into the future you find a very slight cooling that doesn't approach ice age conditions for tens of thousands of years.
Here's a pretty good paper that describes Milankovitch theory and that it predicts up to 50,000 years before we see a deep ice age.
http://amper.ped.muni.cz/gw/articles/html.format/orb_forc.html |
|
| Back to top |
|
|
| marnixR |
| Posted: Mon May 19, 2008 11:39 pm Post subject: |
|
|
Forum Isotope
Joined: 10 Apr 2007
Posts: 2783
Location: Cardiff, Wales
|
the problem with a geological "soon" is that it's very hard to determine whether it means 10 years or 1000 years from now
historically, interglacials have lasted for an average of about 10,000 years, but there's plenty of variation in the actual figures
_________________
if you find this place too crowded or too confrontational, how about trying Philosophorum,
the amicable forum where small is beautiful and even the trolls are intelligent
biology without evolution is but stamp collecting |
|
| Back to top |
|
|
| sunshinewarrior |
| Posted: Tue May 20, 2008 4:40 am Post subject: |
|
|
Forum Ph.D.
Joined: 26 Sep 2007
Posts: 1049
Location: London
|
| marnixR wrote: |
the problem with a geological "soon" is that it's very hard to determine whether it means 10 years or 1000 years from now
historically, interglacials have lasted for an average of about 10,000 years, but there's plenty of variation in the actual figures |
Yup. Much like the inversions in the earth's magnetic fields: it may be soon, but probably not in our lifetimes, and maybe not in the lifetime of anybody this century. So how soon is soon? |
|
| Back to top |
|
|
| 425 Chaotic Requisition |
| Posted: Tue May 20, 2008 4:49 am Post subject: |
|
|
The Doctor
Joined: 18 Jun 2007
Posts: 3443
Location: England, UK.
|
Even if it does happen in 1000 years, lucky you atheists don't have to worry about reincarnation. 
_________________
"Victory is in trying. Defeat is in not". - SVRDW. |
|
| Back to top |
|
|
| marnixR |
| Posted: Tue May 20, 2008 6:17 am Post subject: |
|
|
Forum Isotope
Joined: 10 Apr 2007
Posts: 2783
Location: Cardiff, Wales
|
didn't know reincarnation was part of christian dogma
_________________
if you find this place too crowded or too confrontational, how about trying Philosophorum,
the amicable forum where small is beautiful and even the trolls are intelligent
biology without evolution is but stamp collecting |
|
| Back to top |
|
|
| sunshinewarrior |
| Posted: Tue May 20, 2008 7:17 am Post subject: |
|
|
Forum Ph.D.
Joined: 26 Sep 2007
Posts: 1049
Location: London
|
| marnixR wrote: |
| didn't know reincarnation was part of christian dogma |
And some Buddhists can be considered atheists - they do not consider the existence of a deity to be an issue - yet they may consider metempsychosis important...  |
|
| Back to top |
|
|
| CShark |
| Posted: Tue May 20, 2008 2:01 pm Post subject: |
|
|
Forum Sophomore
Joined: 08 May 2008
Posts: 169
Location: East Coast of Canada
|
| Bunbury wrote: |
I hadn't heard that theory, unless you're referring to the idea that the thermohaline circulation might shut down, causing cooling in the North Atlantic region. The THC shutdown was proposed as a possible result of global warming, but I think the theory has few supporters today.
Other than that, it's my understanding that a near-term ice age is nothing more than speculation, the contributing factors being complex and mostly pointing in the other direction, so I'd be interested in reading your reference. |
Thanks for the response. I was reading a paper at work, which I copied, but did not keep the reference  The title is "The Climate Shapes Man's Destiny". Let me quote a bit:
"At the moment the Earth is passing through an interglacial which has lasted for around 10,000 years following the last Ice Age, which in turn went on for some 100,000 years...Perhaps ominously for man, the pattern suggest that ice ages last around 100,000 years on average and the shorter, warmer interglacials around 10,000 years - so we are nearing the end of our current warmer period. However, there is no need for any alarm at this thought. The next ice age could be up to 1000 years away."
Also, I found this http://books.google.com/books?vid=ISBN0826400647&id=BXkWAAAAMAAJ&q=%22Ice,+the+Ultimate+Human+Catastrophe+%22&dq=%22Ice,+the+Ultimate+Human+Catastrophe+%22&pgis=1[url][/url] which tells of a much sooner possible cooling down.
I put this out for discussion, not as my personal opinion. I'd like to hear more about your thoughts on this. |
|
| Back to top |
|
|
| marnixR |
| Posted: Tue May 20, 2008 3:01 pm Post subject: |
|
|
Forum Isotope
Joined: 10 Apr 2007
Posts: 2783
Location: Cardiff, Wales
|
on the other hand, the usual pattern seems to be that of an ice age gradually establishing itself, in a series of ups and downs but with an overall downward trend - definitely not as fast as the warming at the end of the most recent glacial period !
[if i remember correctly the warming climax was reached about 5000 years ago, and since then a cooling has set in, but as i said with many ups (e.g. the medieval optimum, the most recent warming period) and downs (e.g. the little ice age)]
_________________
if you find this place too crowded or too confrontational, how about trying Philosophorum,
the amicable forum where small is beautiful and even the trolls are intelligent
biology without evolution is but stamp collecting |
|
| Back to top |
|
|
| Lynx_Fox |
| Posted: Tue May 20, 2008 5:15 pm Post subject: |
|
|
Forum Sophomore
Joined: 16 Apr 2007
Posts: 127
|
Posting just the eccentricity. Note we're going into a period where the orbit is nearly circular--this will minimize the effects of procession--it won't matter which hemisphere faces the sun during the winter or summer because they'll be roughly the same. This is why the models suggest a very prolonged warm period with no deep ice age coming for 50,000 years.
Click on the image to view it at its original size |
|
| Back to top |
|
|
| theQuestIsNotOver |
| Posted: Tue May 20, 2008 9:38 pm Post subject: Re: The next ice age is not that far away! |
|
|
Forum Senior
Joined: 25 Aug 2007
Posts: 362
Location: grail search
|
| CShark wrote: |
| According to at least one report (I can dig up the ref is required), the earth is at the tail end on an inter-glacial period. We are 'due' for another ice age in the next one-thousand years, a blink of an eye in cosmic terms. Of course, we have no idea how the current global warming trend will affect this... what do you think ? |
If what you say is true, as a ferret or jourbel I would be worried (not known for migration).
But, you know, as we age, things get drier: cracks appear..........our spirit and hydration disappears.
_________________
It is impossible to get a correct answer when being tested on something you don't care about.
(god is here for good, he ain't leave'n)
If Jesus does not call for a scientist to save society, if we are lead to believe science will save us, then we must all depend on faith. |
|
| Back to top |
|
|
| CShark |
| Posted: Thu May 22, 2008 8:12 am Post subject: Re: The next ice age is not that far away! |
|
|
Forum Sophomore
Joined: 08 May 2008
Posts: 169
Location: East Coast of Canada
|
| theQuestIsNotOver wrote: |
| CShark wrote: |
| According to at least one report (I can dig up the ref is required), the earth is at the tail end on an inter-glacial period. We are 'due' for another ice age in the next one-thousand years, a blink of an eye in cosmic terms. Of course, we have no idea how the current global warming trend will affect this... what do you think ? |
If what you say is true, as a ferret or jourbel I would be worried (not known for migration).
But, you know, as we age, things get drier: cracks appear..........our spirit and hydration disappears. |
Jourbel !!@??? Do I look like a gerbil  |
|
| Back to top |
|
|
| CShark |
| Posted: Thu May 22, 2008 8:15 am Post subject: |
|
|
Forum Sophomore
Joined: 08 May 2008
Posts: 169
Location: East Coast of Canada
|
| Lynx_Fox wrote: |
Posting just the eccentricity. Note we're going into a period where the orbit is nearly circular--this will minimize the effects of procession--it won't matter which hemisphere faces the sun during the winter or summer because they'll be roughly the same. This is why the models suggest a very prolonged warm period with no deep ice age coming for 50,000 years.
Click on the image to view it at its original size |
Interesting argument. I have to agree with you Lynn, from the little I understand about how the orbit of earth effects our long-term weather, it looks like you are correct.
Nicely posted. |
|
| Back to top |
|
|
|
|
