Warming Arctic

[Guest Daniel]

Daniel,

Are you quoting some research here or is this just your impression?

I'd be very interested to know what the latest research on the question of whether recent years or the Medieval warm period was warmer. From what I can see there is a lot of uncertainty about this and so I doubt that it could have been as much warmer back then as you say.

I got this information from weather and climate books Such as the climate historyand the modern world plus the little ice age how climate made history and a few others. They talk about the medevial warm period summers being longer sunner and hotter that today with frost free Mays. they also talk about major wine growing over England and hills being farmed at higher levels. So the inpression I got from reading these books is that summers then were indeed a lot hotter than today. At least by 1 or 2 degrees higher on average than now which is a lot. Our most recent hot summers was 2003 and and 1976. both gave great heat and sunshine. now this would have been the average in the medevial warm period which occured just over a 1000 years agao. also the Atlantic polar side region then was also warm and it was warm enough to grow crops on parts of southern Greenland

[Methuselah]

And I don't think that you are wrong in your interpretation of the Medieval Optimum, Daniel...I just wonder how warm it would have been, had we been pumping tonnes of CO2 into the atmosphere back then, as we are now?

[reef]

Daniel,

Are you quoting some research here or is this just your impression?

I'd be very interested to know what the latest research on the question of whether recent years or the Medieval warm period was warmer. From what I can see there is a lot of uncertainty about this and so I doubt that it could have been as much warmer back then as you say.

Indeed, it wasnt warmer:

http://en.wikipedia.org/wiki/Image:2000_Ye..._Comparison.png

The 'medieval warm period' wasnt that far off our current 1960-1990 average. The chart also shows how rapidly we've warmed up since the start of the Industrial Revolution. Doesnt look like 'natural' warming to me.

[John Cox]

The clever bit is to try and find out EXACTLY what contribution 'man' has made to this warming. Then an even more difficult bit, can 'man' do anything about it, even assuming that 'he' wants to. This last statement is full of difficulty as some nations, both east and west appear unwilling to make an effort to meet with the majority of nations that feel the population of the earth should at least TRY

Ho John,

That is the 6 million dollar question.

I suspect one that we may well never know the answer to.

My "feeling" is that man's involvement is being over played by governments and the likes and that this GW period is caused by 95% natural means

[Guest Mike W]

I was just wondering how long it would take for people to give up on the idea of ever seeing a cool summer of a sever/snowy winter, because I have given up hope of that TBH. I think the BBC should do a DVD containing news archive footage of notable cool summers and severe snowy winters and other cold spells of the 20th century. I think this weather is a sad reminder that it's over for that typer of eather. This hot weather isn't going to end for a long time by the looks of it.

[su rui ke]

In answer to my own earlier question, I found this on 'realclimate.org'.

'At hemispheric or global scales, surface temperatures are believed to have followed the "Hockey Stick" pattern, characterized by a long-term cooling trend from the so-called "Medieval Warm Period" (broadly speaking, the 10th-mid 14th centuries) through the "Little Ice Age" (broadly speaking, the mid 15th-19th centuries), followed by a rapid warming during the 20th century that culminates in anomalous late 20th century warmth. The late 20th century warmth, at hemispheric or global scales, appears, from a number of recent peer-reviewed studies, to exceed the peak warmth of the "Medieval Warm Period". Claims that global average temperatures during Medieval times were warmer than present-day are based on a number of false premises that a) confuse past evidence of drought/precipitation with temperature evidence, fail to disinguish regional from global-scale temperature variations, and c) use the entire "20th century" to describe "modern" conditions , fail to differentiate between relatively cool early 20th century conditions and the anomalously warm late 20th century conditions.'

Admittedly, this is dated December 2004 and does still leave open the possibility that the UK (or at least the CET zone) was warmer in Medieval times. However, for that to be the case, it looks as if the UK would have had to be significantly warmer relative to the rest of the world than it is now.

[Dawlish]

I was just wondering how long it would take for people to give up on the idea of ever seeing a cool summer of a sever/snowy winter, because I have given up hope of that TBH. I think the BBC should do a DVD containing news archive footage of notable cool summers and severe snowy winters and other cold spells of the 20th century. I think this weather is a sad reminder that it's over for that typer of eather. This hot weather isn't going to end for a long time by the looks of it.

Hi Mike,

I believe the world is warming - the evidence is there to see, but I don't believe we will never see another cool summer, or a cold winter, despite the world warming.

We are a tiny area of the world. That fact it is so often overlooked when talking about GW from the perspective of sitting in the UK (or lying in the sun, heh, heh). The atmosphere is a massive, chaotic system which interacts with the ocens in a far too complex way for our poor attempts at understanding in 2006. With this in mind, the chances of the UK, or any other area for that matter, behaving in a parallel way to the whole globe is close to nil.

In such a chaotic situation, over time, the UK will warm, as the Earth will warm (notwithstanding the very remote chance of a negative, such as a massive volcanic eruption, or the shutting down of the NAD), but it will not warm in a linear fashion. There will be times when the atmospheric set-up favours colder weather over our small part of the globe, whereas other areas will be being warmed even more than the global trend, to compensate and to keep the warming trend going (if, indeed, it is still going; but all the evidence points to it continuing at present).

That is why I'd much rather work in odds and percentages when talking about possible future climatic, or weather, conditions.

Instead of thinking; "the Earth is warming, therefore we won't get another cold winter", think; "the Earth is warming terefore we have a less than even chance of getting a cold winter". The difference is subtle, but it allows for chaos and a non-linear, , progression towards a warmer planet for small areas such as our own and it is much more likely to be right. If GW was linear for smaller areas, the last winter in the UK, just about average, could not have occured.

In terms of odds, I look back to the 1990s, the first full decade, in the UK, of this present warming trend. Thinking then that the climate was warming, I predicted that 7 out of the next 10 years would be warmer than average. As it turned out, there were 8. I see no change in the warming trend globally, so I don't see any reason to change the odds: 7 out of the noughties will be warmer than average, 2 will be cooler and one will be close to average (within 0.25C). This could be applied to seasons, or even months; ie this June has a 70% chance of being warmer than average, or this coming winter has a 70% chance of being warmer than average. The actual CET for June, or the actual kind of 2006-7 winter that we will get is pure guesswork, as far as my beliefs go.

In terms of daily weather; I can't see that anyone can predict over 1 week ahead with enough accuracy for them to be taken seriously and that is why the Met Office don't do it. In terms of seasons, there are some experimental predictors, like Arctic SSTs being used to provide forecasts of the NAO and by implication (though the link is far from perfect) the general winter outlook for the UK, or snow cover over Western Europe being used to predict the type of winter we may get. None of these are past the experimental stage. Pattern matching, season to season, gives you a correlation with no statistical significance.

So to answer you question, I don't think we can give up on seeing a colder winter, or a cooler summer in our lifetimes. As to seeing another winter like 1962/3, that is highly unlikely in GW UK and I would put the odds at 150/1. It is very unlikely that you, or I, will see that kind of cold again, but that was the coldest winter of the last century and 150/1 does not make it impossible, just very unlikely. The odds of seeing another summer like 2003, I'd put at 5/1 ie 2 every 10 years (at least). The odds uf the UK temperature record being broken in the next 5 years; evens. The odds of it being broken this year, 5/1. The odds of a cooler than average winter in 2006/7; 5/1 against ie - 2 chances in 10.

Food for thought? Regards, Paul

[Methuselah]

A very thought-provoking post, Paul...And one that sums-up my own thoughts exactly...

I wish I had your gift for explanation!

[Dawlish]

A very thought-provoking post, Paul...And one that sums-up my own thoughts exactly...

I wish I had your gift for explanation!

A kindness goes a long way; TY, Pete!

Regards, Paul

Edited June 4, 2006 by Dawlish

[Guest Mike W]

Sorry but I'm not as optimistic as Dawlish or anyone else, I think the days of severe, cold snowy winters and cool summers are long gone aswell as cool springs and autumns aswell as annual CET's of 8's oor 9.7's and below etc, all exterminated by GW and the clean air act [a poorly managed one].I know we didn't have them year after year but we had them quite alot of the time, and the fact we had them in the first place.

Edited June 4, 2006 by Mike W

[Methuselah]

Oh, I don't know, mate. I think that the Clean Air Acts saved quite a few lives. (Who would want a return of the London smogs of the '50s?) Okay, it's let another 'cat out of the bag' - but, hey, at least we can do something about it now that we can see it??

Edited June 4, 2006 by Superted

[West is Best]

The Attenborough programme last night was shameful piece of sensationalism but then the debate on GW left the realms of science several years ago.

Sorry if you disagree.I have been a fence sitter for some time but I have come down firmly on the sceptic side after a trawl through the evidence.

I bet you haven't gone through the evidence. Programme 1 was superbly presented, with a range of scientists, including counter-arguments but which wound up with a conclusion that GW is happening from human influence. The Hadley human impact chart was impressive, if alarming, as were the range of scientists who have changed in the last 5 years.

GW is happening. Its effects are starting to be dramatic, and alarming. Those who disagree are rapidly being left in the loony fringe and fortunately no-one is paying them attention. It's too serious now to mess around with.

We don't know what temperatures might have been in Svalbard 200, 2,000 or 10,000 years ago.

Actually, glaciers reveal a huge amount about climate going back a long, long, way.

[Gray-Wolf]

So far as 'cold winters' go I do not think that Global warming means the end (immediately) of cold winters. For warm air to move North (or south in the southern Hemisphere) an equal amount of cold has to head for the equator. If you're sat in the way of 4 or 5 of these 'cold plunges' over 1 winter then you get the kind of conditions seen in parts of Eastern Europe/Japan/Indian sub-continent over the past winter.

Over winter, due to the lack of solar heating, the pole gets very cold and this cold will travel (nature abhors imbalence). Global warming will just drive a more dynamic version of the weather that we are used to having (higher energy environment due to the 'extra' heat) and obviously lead to the summer ablation of most all of our snow/ice (which, once things have settled, will just be the previous years build up of snow /ice).

[Thundery wintry showers]

What global warming means is that as cold air sources get less cold, more potent cold blasts are required in order to bring the snow. Thus, you might get moderate-intensity blasts that bring sleet, which would have brought snow had temperatures in the Arctic or Russia been close to the long-term average, but if you get a high-intensity blast, or a blast from a source that isn't anomalously warm at a given time, it will still snow.

Meteorological examples show that snow is not a thing of the past for Britain. March/April 2006 was a good example, with both north and east winds bringing some significant snow events (including snow in places which rarely see much in even the coldest winters), and quite late on in the season. The main thing that helped in March was the fact that the cold air sources were near-average for the time of year when we got the cold blasts. In April temperatures in the Arctic were above average, yet northerly winds still brought widespread snow showers with a big fall in parts of the South East on the 9th.

Of course it does depend to some extent on how anomalously warm the Arctic is; in early April 2006 the anomalies were positive by up to 5C, while around 13 February 2005 the Arctic was some 15-20C warmer than average, resulting in our northerly straight from the pole that day bringing near-average temperatures and a wintry mix.

The main problem for cold snowy winters remains the changes in synoptics caused by a warmer globe and particularly warm SSTs, generating a northward shift of the PFJ and keeping both north and east winds at bay. It is probably no accident that the warm anomalies around Iceland had largely gone by the beginning of March 2006, which in turn was cold and snowy. Warm SSTs around Iceland don't prevent north and east winds, but they make them harder to achieve.

[BrickFielder]

There are a number of problems with looking at the temperature records for svalbard this year and concluding that global warming has taken place. Lets look a little closer at the claims firstly :

April measurements for artic svalbard produced record temperatures of 7.5C which is the highest temperature measured on Svalbard since measurements began in 1912.

This is actually measurements from two different stations , Isfjord Radio and svalbard airport. The accuracy of records of both have come into question in a number of years. If we take into account the nearest readings of Tromso and Jan Meyen then we see some anomalies which again call into question the validity of the temperature records from Svalbard. For the moment lets assume that the temperature records are a reasonable reflection of the conditions there. Investigations by by Hanssen-Bauer and Forland of the Norwegian Met. Service (DNMI) came to the conclusion that generally the records where reasonable and temperatures tended to reflect the circulation changes and sea ice changes. Their conclusion was that small changes in circulation patterns have a large effect on ice extents and temperatures. With a major stratospheric warming and the NAO (North Atlantic Oscillation) turning largely negative over the period in question leaving high pressure over scandinavia we should not be surprised by the high temperatures in Svalbard or by correspondingly low temperatures in continental Europe. Whether the stratospheric warming was due to ozone depletion or to particularly aggresive MJO (Maden Julian Oscillation) event out in the Pacific due to warming there is open to debate. In any case it is a lot more complex than a simple link between global warming and temperature increases.

This would tend to point to a reduction in sea ice around Svalbard as the main culprit for the high temperatures. If we look at the record of the two glaciers Midre LovenBreen and Austre Broggerbreen on SvalBard since the late 1960s we have slightly shrinking glaciers. In contrast we see the largest icecap in Svalbard (Austfonna) having an upper accumulation area showing a remarkable thickening, which, when converted to an ice equivalent value, represents a 36% increase in accumulation rate. Taking into account how small the LovenBreen and Broggerbreen are surge glaciers which experience rapid advances lasting 5 to 7 years, then slow retreats for the next 80 to 100 years we can not conclude much. My personal feeling is that with the smaller glaciers being on the warm atlantic side of the archipelago that conditions reflect a warming of the seas around Svalbard. This to me reflects the Atlantic Sea Surface Temperature patterns and has been shown to be clearly linked to the Atlantic Multidecal Pattern changes. Having read Carinthians regular sea ice reports and taking into account his views from the people who actually measure sea ice and from fishermen who use the waters then sea ice and temperatures tend to increase in one area and decrease in others.

In conclusion I would say that the abnormal temperatures are largely due to a number of coincidental but normal factors with global warming being a secondary factor.

[johnholmes]

thanks for putting a sensible perspective on this thread Brick.

[Gray-Wolf]

I don't know whether pedantry needs accolades really, I have trouble gauging exactly what kind of evidence our resident septics would need for them to concede that something other than 'natures cycles' is happening all around them and if they could find no relevant cycle they would say this is the first of a new natural cycle. I find it sad that meteorologists cannot be trusted to set up weather stations in an area that doesn't leave themselves open for dispute further down the line.

I don't get out much and rely heavily on others for my information and to find that all I can read is wrong because this little bit doesn't add up or that little bit doesn't add up leaves me exasperated when the larger picture is undeniable (in fact at least).

[Methuselah]

I think that you misunderstand John's response, G-W: Brickfielder's post is very well put and very well argued, and is certainly not written in such a way as to stifle further debate...

I am also a skeptic, mate. ( I'm sure your septics typo wasn't meant to sound anti-American? :lol: ) It's just that, for the life of me, I cannot see how our emissions can be neutral, whilst their 'natural' counterparts are not??

I may be wrong, you may be wrong, BFTP may be wrong, we ALL may be wrong? We cannot all be right...But, at the end of the day, I'll wager that we are all both right and wrong; and that the world will not fall nicely into our either-or classifications of it??? :unsure:

I have a headache! :lol:

[Thundery wintry showers]

I think what BrickFielder says is probably correct- it's not dissimilar to the conclusion that I arrived at, about SSTs and ice loss being the main factors.

What I would question is whether the recent changes in atmsopheric circulation have been entirely "natural". There is certainly nothing remarkable about having a Scandinavian High, but there seems to have been a discernible northward shift in the storm track over the Atlantic in recent years. My suspicion has long been that some of this might be being exaggerated by the warming, in particular the locally high SSTs that seem to form around Iceland almost every winter. The northward storm track then pumps warm air into the Arctic.

As with most areas of GW debate, the above suspicion cannot be proved or disproved beyond all reasonable doubt, at least not unless our understanding improves significantly. However, correlations can certainly be used to reach a conclusion that these kind of relationships are possible or even probable, while not certain.

[PersianPaladin]

I don't know whether pedantry needs accolades really, I have trouble gauging exactly what kind of evidence our resident septics would need for them to concede that something other than 'natures cycles' is happening all around them and if they could find no relevant cycle they would say this is the first of a new natural cycle. I find it sad that meteorologists cannot be trusted to set up weather stations in an area that doesn't leave themselves open for dispute further down the line.

I don't get out much and rely heavily on others for my information and to find that all I can read is wrong because this little bit doesn't add up or that little bit doesn't add up leaves me exasperated when the larger picture is undeniable (in fact at least).

I agree that global warming is real and happening and is accelerating considerably. However, i believe that the media AND politicans on both sides of the debate are exaggerating or spinning things for their own corporate or geopolitical ends. Milkankovitch or obliquety cycles aside; mankind IS exarcebating the natural warming of this planet and there is a real risk of a tipping point. The globe may recover, but it may be too late for US by the time it does.

Edited June 5, 2006 by PersianPaladin

[Snowly does it]

I agree that global warming is real and happening and is accelerating considerably. However, i believe that the media AND politicans on both sides of the debate are exaggerating or spinning things for their own corporate or geopolitical ends. Milkankovitch or obliquety cycles aside; mankind IS exarcebating the natural warming of this planet and there is a real risk of a tipping point. The globe may recover, but it may be too late for US by the time it does.

Good point well made. There is clearly cause for concern, but how much concern, and how soon? The answer depends entirely on who is giving it, from what camp, and to what end. Were it the case that we were at tipping point to any percentage approaching 'yipe!' level, then there would be more noise and less fluff. My personal belief is that mankind is exacerbating a natural cycle and pushing it somewhat beyond its 'natural' limits, but whether this leads to an inexorable decline or sparks off something dramatic and rather earlier than intended by way of natural reverse technique remains to be seen. If its the former then the future of the world lies squarely in the hands of the voting public in democratic countries, if the evidence were so overwhelming and so incontrevertible then why are those in positions of authority in the scientific and academic worlds not mortgaging their souls to fund the Green Parties of the planet? Then again, if we have nothing to worry about, why all the coverage? Somehwere in the middle there is sensible ground and a reasoned way out and it requires something a little more palatable than 'switch off the kettle or fry by 2050' to set it in motion.

[Dawlish]

Having read Carinthians regular sea ice reports and taking into account his views from the people who actually measure sea ice and from fishermen who use the waters then sea ice and temperatures tend to increase in one area and decrease in others.

In conclusion I would say that the abnormal temperatures are largely due to a number of coincidental but normal factors with global warming being a secondary factor.

Just a small quote, from a very well argued post (really, thanks Brickfielder, the debate needs posts of this quality, it certainly shows a degree of research and/or knowledge about Svarlbad's geography, that I certainly don't have). I take what you say about anomalies in the temp measurements, though I'd love to read the research that has highlighted these anomalies. Do you have a link please?

However, I'm really not convinced about the bit about; "sea ice and temperatures tend to increase in one area and decrease in others". from fishermen's memories, or from people who measure sea ice in the area. It may have done 25 years ago, but where exactly is the sea ice increasing to compensate for this decrease around Svarlbad today? Sea ice in the Greenland Sea is well below the long term average this year:

http://arctic.atmos.uiuc.edu/cryosphere/IM...m.region.5.html

In addition, sea ice in the Arctic basin was at a record measured low last year and all the indications are that this record low will be beaten this summer, as nearly every peripheral Arctic area is melting faster than it was last May (updates on the cryosphere site always lag a little behind the date).

If you can convince me in which areas sea ice is increasing, to compensate for the losses here, I'd believe you about GW being a secondary factor in the demise of Svarlbad's, or the Arctic's, sea ice. In my opinion, the ice is melting due to a combination of increasing air and sea temperatures and that is down to Global Warming as the prime cause, not a secondary one.

Regards, Paul

Edited June 5, 2006 by Dawlish

[Mr Sleet]

Daniel,

Are you quoting some research here or is this just your impression?

I'd be very interested to know what the latest research on the question of whether recent years or the Medieval warm period was warmer. From what I can see there is a lot of uncertainty about this and so I doubt that it could have been as much warmer back then as you say.

I'd say that if you could grow food on Greenland it's a pretty safe bet that it was warmer then than it is now. In fact ever wondered why it's called GREENland ? It's because there was no ice on it.

[Methuselah]

I'd say that if you could grow food on Greenland it's a pretty safe bet that it was warmer then than it is now. In fact ever wondered why it's called GREENland ? It's because there was no ice on it.

Well Mr Sleet. I will certainly agree with you, that Greenland had less ice then than it has now; especially at the southeastern (?) extremity settled by the Scandinavians...But 'no ice on it'? Are you quite sure you are not exaggerating a tad??

Edited June 6, 2006 by Superted

[Mr Sleet]

Well Mr Sleet. I will certainly agree with you, that Greenland had less ice then than it has now; especially at the southeastern (?) extremity settled by the Scandinavians...But 'no ice on it'? Are you quite sure you are not exaggerating a tad??

Mostly icefree during the MWP.If I can find the info on the internet, anyone can.

I bet if I told you that hurricane frequency had decreased in the last 100 years and continues on a downward trend you wouldn't believe that either