New warning on Arctic ice melt
Scientists who predicted a few years ago that Arctic summers could be ice-free by 2013 now say summer ice will probably be gone within this decade.
http://www.bbc.co.uk/news/science-environment-13002706
Original ice-loss predictions were for an ice free summer some time around mid-century. I still consider that a possibility, but also possible is that the ice will detstabilise and sometime in the next 10-20 years it goes kaput. I give that latter viewpoint much more credence given that ice hasn't really had a recovery to speak of since 2007's extreme loss.
It really doesn't surprise me that they've pushed the prediction back from 2013 though.
It will depend to an extent on the definition of 'ice free'. If this means no solid ice area then that is obviously more likely than nothing above 15% coverage (the current definition for 'ice extent'). Completely free of ice seems unlikely in the near future.
As I said on my blog this morning with regards this "Reading between the lines, I think what Wieslaw Maslowski is really saying is that we shouldn't assume that it'll not be until at least 2040 before we see an ice free Arctic - it could happen sooner, perhaps as soon as 2019. Which is not the same as saying it will!"
(the media, of course will always misquote out of context and dumb down the message in order to provide a more sensational headline - though some so-called climate sceptics still naively trust every word they read, and will no doubt totally get it wrong. Again)
Edited by user 08 April 2011 10:11:06(UTC) | Reason: Not specified
All these predictions seem to think trends can only ever go one way.The natural world has a way of making them seem like idiots.The mechanisms causing ice volumes to change are not really understood as well as some like to claim.
All these predictions seem to think trends can only ever go one way.
Nope. They think if forcings are going one way then that is the way they are going.
See you in ten years...
How do you know?
Well obviously if Yellowstone erupts, all bets are off!
But at the moment there is no reason to suppose current trends will reverse any time soon.
You are absolutely right - the natural world has natural patterns and cycles. The difficulty comes when unnatural forcings are bing injected into the system.
As for ice volumes - it is extremely well understood. You have melting from below due to warmer water, melting form above due to warmer air and transport of ice out of the Arctic Basin due to the thinning and break-up of the ice. Of course the specifics are not clear but the general mechanisms quite clearly are.
What would we do without your eagle eye, SC
I have just re-read my post and I don't think I missed out anything.
You have a decision to make - are you going to declare yourself as a denialist or a sceptic? If seriously you are going to imply that there are no proven forcings at work then you are now in the denialist camp - I am assuming that it cannot be lack of understanding from some of your previous contributions.
If you think there is nothing unusual going on then please provide a sound explanation for:
Average daily ice extent:
1979-2000: 11.98 million sq km
2003-2010: 10.39
Natural, cyclical changes in ocean and atmospheric circulation?
Such as?
We've been here before. Anyone can throw such comments into the ring but they are just smoke and mirrors.
Look at the thread I started about further research into the Arctic climate in the past.
CO2 pushing towards 400 ppm. Nothing of that level in the past 800,000 years. Which natural cycle is making this happen I wonder?
I've read something on the first page on the site you've indicated on your other thread?
.Maybey it has something to do with ratings or dates?.Perhaps.
It appears, old research that turns out to be faulty can be swept under the carpet and corrected as a mere mistaken model.
Could this be another case forth comming?.
Maslowski et al.as mentioned earlier on this thread comes to mind on that point.
Are you certain about 800,000 years.The headline is 15 million.
Who is Tripati?.
Link below.BTW.Mouse over to access.
Last time carbon dioxide levels were this high: 15 million years ago, scientists report Oct 08, 2009 | not rated yet | 0
I would also be interested in any peer reviewed papers released on the subject in question by Tripati?.
A dead end if you ask me.
I am surprised at you for posting such rubbish.Gandalf.
Edited by user 08 April 2011 21:56:29(UTC) | Reason: Not specified
Been on the Guinness again AIMSIR?
I think my friend that you miss the point. It doesn't matter whether it is 800,000 years or 1 million or 10 million. The point is that we are altering the atmosphere in a significant way and there are and will be consequences.
Sometimes you can miss the wood for the trees.
Sea ice extent seems to be lingering on a crest this year.
Any ideas as to why?.Anybody.
Edited by user 09 April 2011 09:51:16(UTC) | Reason: Not specified
No it isn't - if you look at the figures you will see that we are almost 500k sq km down on ice extent compared with the peak one month ago (and over 300k in the last 7 days). The decline is proceeding apace.
And the UK has been covered in half kilometre high glaciers for 700,000 of those last 800,000 years.
Okay, just a joke, but technically one could back as much as 24 million years before CO2 was as high as today.
Here are all the CO2 estimates between 3.0 Mya and 6.0 Mya.
3.5 million years ago, the beaver pond was about 100 kms farther south, just enough to stop the ice ages from starting up as a result of the Milankovitch cycles because the summer Sun was just warm enough to melt all the snow and ice in about July even at the low point of the Milankovitch cycles. About 800,000 years later, enough continental drift had occurred so that the region became succeptible to periodic glaciations during the low point of the Milankovitch cycles.
How does CO2 explain what Bill pointed out?Could something else be involved - natural cycles perhaps
What a bizarre post Four? Bill's post demonstrates exactly my point. Where in that table do you see CO2 levels anywhere near the current level? This is most emphatically abnormal.
Weird....
Hi.
The decline since the peak is not far out of line with other years, slightly less to date but not that significant. Because the date of peak ice extent varies by about 3 weeks it is difficult to be definitive without more work but we have lost approaching 500k since the peak this year and the normal rate would be nearer 600k.
It may have something to do with the thinning ice breaking up - as ice extent is measuring areas with at least 15% coverage you can see how the extent might rise if a large piece fragmented.
I'll try to post some graphs.
I really think this year is a tad unusual as the curve seems to be flattened.
Can you not see this?.
Edited by user 10 April 2011 01:46:26(UTC) | Reason: Not specified
Mabey I was reading too much into it.
Like a dog with a bone, comes to mind.
Thanks for your explainations.I'll take them on board.
Edited by user 10 April 2011 13:28:57(UTC) | Reason: Not specified