General Climate Change Discussion.......

[kold weather]

Looking at the raw data what is interesting is the last 10 years have been more less steadr in terms of global temps, pretty much every month seems to have come within 0.15C of the previous month and its most impressive how consistant the global temps actually have been, despite reasonably strong La Nina and El Nino events in that timeframe. Its rather similar to the way the CET seems to be mainly always in the 10.4-10.6C range without much either side usually.

[Methuselah]

Thank you for the link, Jethro; and for the analysis, Kold. I couldn't access it, myself.

I do find all these doomsday scenarios a tad tiresome, guys. Where is the evidence for Himalayan glaciers vanishing within forty years? Global temps have stayed near-constant for 11 years now...

[jethro]

Thank you for the link, Jethro; and for the analysis, Kold. I couldn't access it, myself.

I do find all these doomsday scenarios a tad tiresome, guys. Where is the evidence for Himalayan glaciers vanishing within forty years? Global temps have stayed near-constant for 11 years now... :lol:

???? You've done it again Pete.

[Methuselah]

???? You've done it again Pete.

Done what? :lol:

[Gray-Wolf]

General Climate Change Discussion, generally what do we expect the loss of summer sea ice will have on the general running of the climate systems?

Are there any instant changes that folk can imagine taking place (apart from us changing from watching for new sea ice Min's being set to watching for the date the Arctic Basin is ice free each year...lol)

What long term changes might we expect.

Need we be concerned or is it another 'doomsday scenario' that's being overplayed?

I'm pretty entrenched in my own views/understanding of what we are to expect so I'd find it refreshing to hear others views/understandings.

[Methuselah]

General Climate Change Discussion, generally what do we expect the loss of summer sea ice will have on the general running of the climate systems?

Are there any instant changes that folk can imagine taking place (apart from us changing from watching for new sea ice Min's being set to watching for the date the Arctic Basin is ice free each year...lol)

What long term changes might we expect.

Need we be concerned or is it another 'doomsday scenario' that's being overplayed?

I'm pretty entrenched in my own views/understanding of what we are to expect so I'd find it refreshing to hear others views/understandings.

G'Day, Ian.

It is a frightening possibility, Ian; and, one that I can't see reversing itself any time soon. IMO, we can only hope that the 'presumed to be' upcoming protracted period of reduced Solar activity can reverse the recent warming?

I'm not sure that the scenario is being 'overplayed', just manipulated by politicians whose 'remedies' will only scratch the surface???

[jethro]

Done what?

Confused me and Noggin, it was her link and analysis.

[Methuselah]

Confused me and Noggin, it was her link and analysis.

Oh, yes. I keep getting you two confused. Sorry about that. I think I might be going-down with something. Please bear with me, my brain hurts?

[Solar Cycles]

Oh, yes. I keep getting you two confused. Sorry about that. I think I might be going-down with something. Please bear with me, my brain hurts?

You could do with AGW ( A Good West ) Sorry have difficulty with my Rs!!

[Gray-Wolf]

G'Day, Ian.

It is a frightening possibility, Ian; and, one that I can't see reversing itself any time soon. IMO, we can only hope that the 'presumed to be' upcoming protracted period of reduced Solar activity can reverse the recent warming?

My worry (and answer to that) is that it has taken a least 150yrs to arrive at this point. The only thing that appears (to me) to be so slow in responce are the oceans. If we are looking at minuscule alterations of all oceanic levels then it'll take a while for any changes to reverse the process.

CO2 (and other GHG's) may enable the heat to stick around longer but our storage heater is the oceans and the miners Canary (in this case) has to be the sea ice. We know that the ACC (Antarctic circumpolar Current) has most of the Antarctic in a kind of 'splendid isolation' but we can still see the impacts of warm water there (remember our seals in bathing caps and the collapse of Wilkins mid southern winter?) so the effects manifest at both ends of the globe.

Edited July 26, 2009 by Gray-Wolf

[noggin]

http://solveclimate.com/blog/20090715/james-hansen-climate-tipping-points-and-political-leadership

An article by James Hansen.

Here is a tasty morsel. I have not finished reading it yet, but after only one and a half paragraphs, I make the following observations;

1) Name-calling.....is it really necessary to refer to certain people as "fossil interests"? It is rude and rather childish.

2) Arrogance......Mr Hansen says that "knowledge and understanding of the situation is not widespread", implying that he knows better than most people. Rather closed-minded, too, IMO.

3) Dangerous (and arrogant again).....he says, re C02 levels, that "more precise knowledge is not needed immediately for the purpose of establishing present policies".There is plenty of evidence about that he may be barking up the wrong tree re AGW/GW/CC and some present policies may well do more harm than good. Somewhat closed-minded again, as well.

So, crikey. I have read just the first little bit of his article and the following traits leap out from the page:

Rude.

Childish.

Closed-minded.

Dangerous.

Arrogant.

All-in-all, not the qualities that I expect from a scientist.

I shall now read some more of the article.

PS Here is the thing in full http://www.columbia.edu/~jeh1/mailings/2009/20090713_Strategies.pdf

Edited July 27, 2009 by noggin

[Iceberg]

I am not sure it's really name calling Noggin, it's just a collected term for the interests of the fossil fuel industry, hence fossil interests.

"Arrogance......Mr Hansen says that "knowledge and understanding of the situation is not widespread", implying that he knows better than most people. Rather closed-minded, too, IMO."

Well it's hardly arrogance he does know more than most people and understanding of climate change isn't widespread.

I agree with this comment as well "Dangerous (and arrogant again).....he says, re C02 levels, that "more precise knowledge is not needed immediately for the purpose of establishing present policies"."

Using the precautionary principle alot of climate scientists think there is enough evidence to establish policies rather than wait and see. these policies as he points our should try and reduce CO2 emissions.

I think your being rather down on him rather than looking fairly at what he's saying so far.

and before we get the (nobody is allowed to critise the GOD Hanson etc) I am not saying that in any way shape or form, but we should ensure that when we do it's valid.

I'd even say that the person being childish,closed minded and named calling is not Mr Hansen but rather somebody else.....

[Methuselah]

http://solveclimate.com/blog/20090715/james-hansen-climate-tipping-points-and-political-leadership

An article by James Hansen.

Here is a tasty morsel. I have not finished reading it yet, but after only one and a half paragraphs, I make the following observations;

1) Name-calling.....is it really necessary to refer to certain people as "fossil interests"? It is rude and rather childish.

2) Arrogance......Mr Hansen says that "knowledge and understanding of the situation is not widespread", implying that he knows better than most people. Rather closed-minded, too, IMO.

3) Dangerous (and arrogant again).....he says, re C02 levels, that "more precise knowledge is not needed immediately for the purpose of establishing present policies".There is plenty of evidence about that he may be barking up the wrong tree re AGW/GW/CC and some present policies may well do more harm than good. Somewhat closed-minded again, as well.

So, crikey. I have read just the first little bit of his article and the following traits leap out from the page:

Rude.

Childish.

Closed-minded.

Dangerous.

Arrogant.

All-in-all, not the qualities that I expect from a scientist.

I shall now read some more of the article.

PS Here is the thing in full http://www.columbia.edu/~jeh1/mailings/2009/20090713_Strategies.pdf

Thanks for the link, Noggin. But I don't quite share in your dismissal.

For example, I cannot see what's 'childish' or 'rude' about referring to large multinational conglomerates who profit by fossil-fuel extraction as 'fossil interests'? That's what they are. It's not an insult??? Surely, wind-farm owners could equally legitimately be called 'Renewable Interests.'

And, as I said in a previous reply to you (Or was it Jethro? ) that I agree with you, in that sustainability should be our ultimate goal. But, how can that goal ever be attained with without carbon-neutrality?

[Guest North Sea Snow Convection]

I've pinched this from the model thread and picked up on Snowyowl's very good observation. There is a distinct correlation between the big solar max at the end of the eighties and the +NAO dominated period that we all know has followed over the last couple of decades. It is interesting that now we see increasing (and ongoing) solar min that we have seen three summers in a row with a strongly -NAO signature generally. Yes, it is just mainly summer atm - but these things have to start somewhere.

As C23 refuses to let C24 go, like a trapped butterfly, then the trend on this graph needs watching. Not enough emphasis is attached to these cyclical phases and the result that they have on climate patterns. No coincidence that a dominant +NAO period courtesy of solar max and a +PDO phase have seen the jet stream migrated northwards over the same period and all the associated effects on arctic ice. We know the effect on UK winters too with that northerly jet stream. Also we have had a nino dominated phase of the peterbation period through these decades that has now switched to nina.

Yet AGW puts this largely at the hands of man - and over dismisses the natural cycles and the influence of the sun. Ho-hum.

Edited July 27, 2009 by North Sea Snow Convection

[chionomaniac]

Do you think NSCC, that these possible types of correlation between the jet stream positioning and solar cycles would more likely surface first in the NH summer when the stratospheric influence is reversed? Eventually through time the influence of the southerly positioned jet stream will have a greater influence over winter. I mean last winter the jet did flirt with the idea.

Edited July 27, 2009 by chionomaniac

[Thundery wintry showers]

Some of the Northern Hemisphere warming could well be related to the NAO (I recall a paper from Brian Hoskins around 2002 which mentioned this). For example in the "Global and Regional Climate in X" articles in Weather, it was noted that 1995 was a warm year partly because of a dominance of warm anomalies over land masses and cool anomalies over the oceans, and this pattern was then reversed in 1996- and land masses get greater anomalies than the ocean areas, which are moderated by the SSTs. A positive NAO helps to bring about that pattern of cool oceans and warm land masses.

The NAO issue is one of two main factors which leads me to believe that the Northern Hemisphere warming between 1980 and 2000 probably wasn't close to being entirely anthropogenic in origin, the ENSO state being the other.

However the NAO cannot explain any of the Southern Hemisphere warming. It is interesting, though, that most of the Northern Hemisphere warming occurred after 1990, with a tailing off in recent years, while the Southern Hemisphere warming started in the late 1970s/1980s and tailed off towards the late 1990s. ENSO may well be largely responsible for those Southern Hemisphere fluctuations on top of a slowly rising average.

[Guest North Sea Snow Convection]

Do you think NSCC, that these possible types of correlation between the jet stream positioning and solar cycles would more likely surface first in the NH summer when the stratospheric influence is reversed? Eventually through time the influence of the southerly positioned jet stream will have a greater influence over winter. I mean last winter the jet did flirt with the idea.

Hi - nice to see you post on here, glad you have posted on this

Very interesting point you make - I think what you say is entirely feasible. Put it this way it will be a good test of how much of any climate direction has any AGW component in it if a tipping point was to be revealed in terms of the jet plugging away still to the north, depite the emergence of these negative feedbacks - and speaking here mainly wrt to winter. But personally, yes, I think that there could well be a transitional period over a few years (maybe more likely a decade or so) where we see a gradual but steady reversion of the last two decadal trends.

The winter is hard to evaluate atm - a displaced jet such as we saw last winter did indeed show the possibilities emerge. We believe, don't we, that with an easterly QBO last winter in tandem with the MMW and the way that the jet aligned itself NW-SE would have had all the hallmarks of a much missed deep cold spell?. A reduced seasonal summertime jet stream on a southerly track has also shown exactly the sort of massive northern blocks that are possible in the recent summers as well as the present one.

Time will tell with this one - a case of watching the solar min, the PDO, incidencies of nina vs nino, the jet and probably a few more stratosphere watch winter studies But an interesting debate.

[Thundery wintry showers]

My opinion is that last winter suggested that cold snowy winters, while less likely than in the past, are by no means a thing of the past yet in the UK. We got no deep cold air, except briefly from that easterly on the 2nd February, yet over the country as a whole it was the snowiest winter since 1995/96, and probably slightly above the 20th century average.

I think we are already seeing a reversal of the trends in the 1980s and 1990s. Although the winters have still been slightly more "westerly" than usual since 2000, they have been markedly less so than in the 1990s. Until around 2006 the winter jet trended further and further north, but in 2007/08 it returned to 1990s levels, and in 2008/09 it shifted another notch southwards. Meanwhile, summers, after a succession of warm dry sunny ones in the 1990s, have returned to being more akin to those of the 1970s and 1980s rainfall sunshine and synoptics wise. Whether this reversal is just a blip, or a longer term thing, remains to be seen.

[Iceberg]

My opinion is that last winter suggested that cold snowy winters, while less likely than in the past, are by no means a thing of the past yet in the UK. We got no deep cold air, except briefly from that easterly on the 2nd February, yet over the country as a whole it was the snowiest winter since 1995/96, and probably slightly above the 20th century average.

I think we are already seeing a reversal of the trends in the 1980s and 1990s. Although the winters have still been slightly more "westerly" than usual since 2000, they have been markedly less so than in the 1990s. Until around 2006 the winter jet trended further and further north, but in 2007/08 it returned to 1990s levels, and in 2008/09 it shifted another notch southwards. Meanwhile, summers, after a succession of warm dry sunny ones in the 1990s, have returned to being more akin to those of the 1970s and 1980s rainfall sunshine and synoptics wise. Whether this reversal is just a blip, or a longer term thing, remains to be seen.

For me this switch since 2007 of Jet placement bares too much coincidence with the then La Nina forming as I mentioned in the model thread, with a possible Autumn/Winter El Nino on the cards it will be interest to watch to see if a return to a northerly Jet is seen.

WRT this summer, The Jet has only really been southerly for the last 3 weeks, so it's too early yet to say that this is a pattern for summer 2009 as a whole.

[Guest North Sea Snow Convection]

The lack of deep cold air penetrating last winter to our mid latitudes (apart from the start of Feb very briefly) can be seen by the fact that the AO stubbornly refused to hold negative. Westerly QBO one main factor in this - despite the MMW. However even in the absence of this, we still achieved a reasonably colder winter overall and seeing much lower heights over europe was one of the biggest changing factors away from the zonal GIN set up.

A trend southwards does seem to have started - as ever time will tell where we go from here. But I think the original point of this is that we must watch these cyclical factors very closely and not to be too quick to evaluate AGW contributions too prematurely.

For me this switch since 2007 of Jet placement bares too much coincidence with the then La Nina forming as I mentioned in the model thread, with a possible Autumn/Winter El Nino on the cards it will be interest to watch to see if a return to a northerly Jet is seen.

WRT this summer, The Jet has only really been southerly for the last 3 weeks, so it's too early yet to say that this is a pattern for summer 2009 as a whole.

How do you explain the strongly +NAO conditions which occured at the same time of the big nina event of 1999/2000 then?

Edited July 27, 2009 by North Sea Snow Convection

[Iceberg]

I fully admit I can't Tamara.

Various factors might have come into play, I don't think there is a hard and fast rule for Jet placement, if there where it would make forecasting our seasons much too easy.!

IF the ENSO state of the last couple of years was the main driver for the southerly Jet through this Autumn/Winter will help to prove or disprove it.

I agree that there is still uncertainty in the relationshup though.

http://www.emc.ncep.noaa.gov/seminars/old/presentations/2004/Wu_COLA2004.ppt

Show a NOAA presentation where they conclude.

"The observational evidence showed that NAO interannual variability is well correlated to ENSO variability in the tropical pacific."

Also.

http://www.agu.org/pubs/crossref/2006/2005GL024557.shtml

"Based on the nonlinear techniques for estimation of coupling between oscillatory systems, we investigate the dynamics of climatic modes characterizing global and the Northern Hemisphere (NH) processes. In particular, indices of the North Atlantic Oscillation (NAO) and El Niño–Southern Oscillation (ENSO) for 1950–2004 are analyzed. The methods based on phase dynamics modeling and nonlinear “Granger causality” are used. We infer that ENSO affects NAO during the last half a century with confidence probability higher than 0.95. The influence is characterized with time delay in the range from a couple of months up to three years and increases during the last decade."

[Guest North Sea Snow Convection]

I fully admit I can't Tamara.

Various factors might have come into play, I don't think there is a hard and fast rule for Jet placement, if there where it would make forecasting our seasons much too easy.!

IF the ENSO state of the last couple of years was the main driver for the southerly Jet through this Autumn/Winter will help to prove or disprove it.

I agree that there is still uncertainty in the relationshup though.

http://www.emc.ncep....Wu_COLA2004.ppt

Show a NOAA presentation where they conclude.

"The observational evidence showed that NAO interannual variability is well correlated to ENSO variability in the tropical pacific."

Also.

http://www.agu.org/p...5GL024557.shtml

"Based on the nonlinear techniques for estimation of coupling between oscillatory systems, we investigate the dynamics of climatic modes characterizing global and the Northern Hemisphere (NH) processes. In particular, indices of the North Atlantic Oscillation (NAO) and El Niño–Southern Oscillation (ENSO) for 1950–2004 are analyzed. The methods based on phase dynamics modeling and nonlinear "Granger causality" are used. We infer that ENSO affects NAO during the last half a century with confidence probability higher than 0.95. The influence is characterized with time delay in the range from a couple of months up to three years and increases during the last decade."

Both strong nino and nina events appear to support a strong pacific to atlantic jet stream. That is a factor I think is reasonably conclusive - but of course the uncertainty you mention means there is more to it than that with other factors obviously involved.

So imo if we take solar and PDO phases in conjunction with a predisposition one or the other wrt to ENSO then this starts to provide some clues that do appear to tie up in cycle periods over twenty/thirty years. AGW, at least imo, gets tied up and confused/over stated with these.

[Thundery wintry showers]

Aye, this is also my understanding- weak La Nina/El Nino can be associated with cold winters and strong La Nina/El Nino with positive NAO, westerlies and predominantly mild weather.

1998/99 was also a La Nina winter with mostly westerly winds, though not as strongly so as 1999/2000.

[Iceberg]

A very quickly put together graph showing ENSO (pink) against NAO average for each winter since 93/94.

There is some kind of pattern in there, but buggered if I can find it. Inconclusive is the best that can be said.

We could say that every major positive peak has occured with a ENSO of +1 or above or -1 or below.

The low NAO winters have generally had a ENSO of around -0.7 or so. So weak La Nina.

So an ENSO of +1 or above is not welcome this coming winter, if it does then past form tells us that the NAO will be positive as it has been for every ENSO +1 or greater during winter since 93.

[Thundery wintry showers]

Your graph also suggests that the decline in the NAO might not have been as large as I originally suspected, with the 2000s still having an overall bias towards positive values.