General Climate Change Discussion.......

[jethro]

Too many argumentative pills swallowed this morning....

Folks, if you can't make your points without resorting to be rude, then perhaps you shouldn't make them eh?

Can you all please take a little more time and thought over what you're posting, say what you want to say in a polite and respectful manner.

[Solar Cycles]

Too many argumentative pills swallowed this morning....

Folks, if you can't make your points without resorting to be rude, then perhaps you shouldn't make them eh?

Can you all please take a little more time and thought over what you're posting, say what you want to say in a polite and respectful manner.

I'm sorry Jethro, but as soon as evidence is produced to counter any pro AGW argument, you get accused of talking rubbish! And this is what makes my blood boil, so you end up responding in kind. Two wrongs don't make a right though I guess!!

[Thundery wintry showers]

Jethro and Gray Wolf - really good points about our contributions and the India/China issues - it's poor that we have just shipped our pollution overseas, and things aint gonna change for the better (whatever your opinion on AGW, we all agree that reducing polluting emissions is a good thing) until we change our ways... and THAT aint gonna happen until it is economically in our interests to do so....

sss

Although it might well be true, I prefer to take a stance of not resigning ourselves to the fate that we won't reduce polluting emissions until it is economically in our interests in the short term. (I know your post never mentioned "short term" but the truth of the matter is, it could well be in our long-term economic interest to act now, but both markets and governments alike tend to think only in the short term, where it isn't).

The problem is, if we accept that a fate is inevitable, it is self-fulfilling- that fate becomes inevitable. And even if the masses within the scientific community are wrong and AGW turns out not to be a serious issue, if we don't clean up our act soon, we're going to run into a phase where we struggle to meet energy demands using fossil fuels. The result may well be a sudden sharp recession- similar to the "living on borrowed time" issue that has accentuated the recent recession. On the other hand, relatively gradual action starting now might lessen the impact and intensity of the inevitable recession.

Another problem is the desire to maintain the status quo. I do think we, at best, face an uphill struggle if we're to deviate from the "let market forces decide environmental policy" principle, but also that it's worth a try.

Re. Solar Cycles, I'm afraid the reply to my post is totally different to the replies to every other post. "Fudged data and deceitful stories"? At worst, some mistakes might have been made, but levelling accusations like those is exactly what I mean regarding total lack of respect for another point of view.

[Solar Cycles]

Although it might well be true, I prefer to take a stance of not resigning ourselves to the fate that we won't reduce polluting emissions until it is economically in our interests in the short term. (I know your post never mentioned "short term" but the truth of the matter is, it could well be in our long-term economic interest to act now, but both markets and governments alike tend to think only in the short term, where it isn't).

The problem is, if we accept that a fate is inevitable, it is self-fulfilling- that fate becomes inevitable. And even if the masses within the scientific community are wrong and AGW turns out not to be a serious issue, if we don't clean up our act soon, we're going to run into a phase where we struggle to meet energy demands using fossil fuels. The result may well be a sudden sharp recession- similar to the "living on borrowed time" issue that has accentuated the recent recession. On the other hand, relatively gradual action starting now might lessen the impact and intensity of the inevitable recession.

Another problem is the desire to maintain the status quo. I do think we, at best, face an uphill struggle if we're to deviate from the "let market forces decide environmental policy" principle, but also that it's worth a try.

Re. Solar Cycles, I'm afraid the reply to my post is totally different to the replies to every other post. "Fudged data and deceitful stories"? At worst, some mistakes might have been made, but levelling accusations like those is exactly what I mean regarding total lack of respect for another point of view.

But Manns hockey stick is just that IMO TWS, I'm not accusing forum members of such! Any way I'm taking a break from here, need some quality time away from these forums!

[jethro]

I'm sorry Jethro, but as soon as evidence is produced to counter any pro AGW argument, you get accused of talking rubbish! And this is what makes my blood boil, so you end up responding in kind. Two wrongs don't make a right though I guess!!

No problem, thanks for the apology.

Just trying to make this place a nicer more constructive place for everyone. We're all free to disagree all we like, it's the way we do it that makes the difference to the climate area being a pleasant positive experience or somewhere to avoid like the plague.

[VillagePlank]

There is good reason to suggest that using tree proxy evidence is valid. And that reason is mathematical induction. I shall try and simplify, but, essentially, it goes like this ...

Assume a process, T(y) where T is temperature, and y is year, so that T(1) = temperature at year 1.

(i) Prove that T(1) is true.

(ii) Prove that T(1), T(2), T(3) ... T(y) is true.

(iii) Induce that T(y+1) is also true.

Let's work this through ...

Let's chop a tree down, today, and take the best estimate of global climate that we can (satellite measurement). Correlate tree rings against climate (and humidity!!) Does it correlate? If it does, (i), is true. Now, let's go one year back. We still have an accurate measure of global temps from satellites, so does the correlation hold so that we can extrapolate T(2) from T(1) based on the tree ring? If not, correlate both years (if you can - if you can't bail out it isn't going to work), otherwise move onto Y(3) and go until you run out of satellite measurements to correlate against.

If you get this far, then T(y+1) must also be true, by induction. If you can't correlate, at any stage then it can't be true.

It's a bit more involved than that, but you get the idea.

Edited October 2, 2009 by VillagePlank

[sunny starry skies]

Aye I do that, and not one of them tells us Jack squat, about past climatic conditions. The whole tree ring proxy data is flawed, from start to finish. Sunlight, water, cloud cover, and a whole host of other third parties determine tree growth!!

Lake sediments is just as flawed as tree ring proxies, and ice cores don't tell us if it was warmer in the MWP than now!! And the data from thousands of sites you mention are no indicator to the above! Fudged data, and deceitful stories, won't convince the masses!

Sounds like you have your head in the sand SC. Care to elaborate on why lake sedimentary records are 'flawed', on why tree rings tell us nothing? And I mean I want real data that shows this, not any unreviewed opinion pieces. It sounds very suspiciously like you are completely unwilling to accept that we are able to determine past climate from such records (despite the huge wealth of evidence and myriad publications to show that we can). Your desperation to suggest that every branch of palaeoclimatology is flawed sounds awfully blinkered to me. And be careful about accusations of fudged data/deception too (Friis-Christensesn and Lassen, anyone?)!

Reliance on the MWP being warmer has always amused me. Did you know that the MWP occurred earlier in Iceland, and even earlier in Greenland, than in the UK? That it was a regional warm event, much like the LIA was dominantly a regional cold event - ie most likely not global in scale or synchrony. Hence neither event is particularly pronounced when placed in a global context. Holocene records show that the Holocene Optimum was even warmer, go further back and other episodes were still warmer (eemian, Tertiary, whatever). It is interesting if temperatures have warmed beyond MPW values, but what is crucial is the global nature and the trajectory of change occurring now. Whether or not temperatures have passed MWP values does not alter the science and the basis for saying that the present change is remarkable.

sss

[sunny starry skies]

Something worth a read for those with an open mind-

http://www.realclima...-mal/#more-1184

They are quite sarcastic (though with pretty good reason given the attacks some of them have had to deal with), but the long and the short of it is a refutation of the latest attacks on dendrochronology, and a quick demonstration of how many records have the 'hockey stick' in them, not just Mann et al's, and a lovely description of how things spread through the blogosphere.

"Science is made up of people challenging assumptions and other peoples' results with the overall desire of getting closer to the 'truth'. There is nothing wrong with people putting together new chronologies of tree rings or testing the robustness of previous results to updated data or new methodologies. Or even thinking about what would happen if it was all wrong. What is objectionable is the conflation of technical criticism with unsupported, unjustified and unverified accusations of scientific misconduct. Steve McIntyre keeps insisting that he should be treated like a professional. But how professional is it to continue to slander scientists with vague insinuations and spin made-up tales of perfidy out of the whole cloth instead of submitting his work for peer-review? He continues to take absolutely no responsibility for the ridiculous fantasies and exaggerations that his supporters broadcast, apparently being happy to bask in their acclaim rather than correct any of the misrepresentations he has engendered. If he wants to make a change, he has a clear choice; to continue to play Don Quixote for the peanut gallery or to produce something constructive that is actually worthy of publication. Peer-review is nothing sinister and not part of some global conspiracy, but instead it is the process by which people are forced to match their rhetoric to their actual results. You can't generally get away with imprecise suggestions that something might matter for the bigger picture without actually showing that it does. It does matter whether something 'matters', otherwise you might as well be correcting spelling mistakes for all the impact it will have." (RealClimate group, highlight added by me)

And in case anyone thinks they are actually afraid the palaeoclimate science is wrong...

http://www.realclima...ick-were-wrong/

"The main reason for concern about anthropogenic climate change is not that we can already see it (although we can). The main reason is twofold.

(1) Carbon dioxide and other greenhouse gases are increasing rapidly in the atmosphere due to human activity. This is a measured fact not even disputed by staunch "climate skeptics".

(2) Any increase in carbon dioxide and other greenhouse gases will change the radiation balance of the Earth and increase surface temperatures. This is basic and undisputed physics that has been known for over a hundred years.

But how strong is this warming effect? That is the only fundamental doubt about anthropogenic climate change that can still be legitimately debated. We climatologists describe this in terms of the climate sensitivity, the warming that results in equilibrium from a doubling of CO2. The IPCC gives the uncertainty range as 1.5-4.5 ºC. Only if this is wrong, and the true value is lower, can we escape the fact that unabated emissions of greenhouse gases will lead to the warming projected by the IPCC.

Chances for that are not good. A new large uncertainty analysis that appeared this week in Nature shows that it is very difficult to get a climate sensitivity below 2 ºC in a climate model, no matter how one changes the parameters. And climate history, with its Ice Ages and other large changes, also speaks strongly against low climate sensitivity." (RealClimate, Stefan Rahmstorf)

The Nature article is here: http://climatepredic...rst_results.pdf

Right, I've said enough for now! sss

[Methuselah]

Guys,

There are many available proxies for global climate: of which, pollen records, tree rings, ice cores, glacial deposits and varves are just five...How (without a TARDIS) do we 'know' how warm the Mediaeval Warm Period was? How cold the Younger Dryas was? The Cretaceous? The Carboniferous? Surely, either we trust that the Scientific Method will continue to bear fruit or, we dismiss it entirely?

That said, does anyone with a modicum of statistical/scientific knowledge really take the (sample size of 12) hockey-stick graph as the be-all-and-and-all of Climate Change?? IMO, it's a Straw Man, courtesy of the AGW Lobby itself...

[Thundery wintry showers]

<snip>

But how strong is this warming effect? That is the only fundamental doubt about anthropogenic climate change that can still be legitimately debated. We climatologists describe this in terms of the climate sensitivity, the warming that results in equilibrium from a doubling of CO2. The IPCC gives the uncertainty range as 1.5-4.5 ºC. Only if this is wrong, and the true value is lower, can we escape the fact that unabated emissions of greenhouse gases will lead to the warming projected by the IPCC.

Chances for that are not good. A new large uncertainty analysis that appeared this week in Nature shows that it is very difficult to get a climate sensitivity below 2 ºC in a climate model, no matter how one changes the parameters. And climate history, with its Ice Ages and other large changes, also speaks strongly against low climate sensitivity." (RealClimate, Stefan Rahmstorf)

The Nature article is here: http://climatepredic...rst_results.pdf

Right, I've said enough for now! sss

Another pretty good post, and I am very much in agreement that it's not the existence of AGW that is open to debate, but rather the extent. The 1.5 to 4.5C of warming is from an earlier IPCC report though (2001 I think), the latest word is a larger range from 1.1 to 6.4C though some of this is dependent on "emissions scenarios" as well as climate model biases.

What concerns me is that, while some recent papers have highlighted areas of considerable uncertainty regarding the carbon cycle, modes of atmospheric circulation and solar activity, the climate models are by and large showing more sensitivity to AGW as time goes on, rather than less, and the "best guess" continues to rise. I hope they are wrong, but they are the best we have at the moment and it doesn't look good.

[VillagePlank]

btw, whoever, and I can't be bothered to look back and check, who wrote the "recent 'my god we are warming' post" is in error.

I would suggest if you want to construct an argument on that basis then you need to do it on the basis of the rate of change. ie calculus. If you don't, well, then you are open to all sorts of inquiry of why you don't want to. Calculus is the ***VERY START*** of analysis and linear trend graphs are not.

I can post the graphs, here, if you like, but I think it's better if you are not lazy and investigate it yourself. After all, you wouldn't want to seem to be an idiot, stupid, or utter ignoramus.

Would you? Or do you want to be that way?

Edited October 2, 2009 by VillagePlank

[MR EXTREMES]

Sounds like you have your head in the sand SC. Care to elaborate on why lake sedimentary records are 'flawed', on why tree rings tell us nothing? And I mean I want real data that shows this, not any unreviewed opinion pieces. It sounds very suspiciously like you are completely unwilling to accept that we are able to determine past climate from such records (despite the huge wealth of evidence and myriad publications to show that we can). Your desperation to suggest that every branch of palaeoclimatology is flawed sounds awfully blinkered to me. And be careful about accusations of fudged data/deception too (Friis-Christensesn and Lassen, anyone?)!

Reliance on the MWP being warmer has always amused me. Did you know that the MWP occurred earlier in Iceland, and even earlier in Greenland, than in the UK? That it was a regional warm event, much like the LIA was dominantly a regional cold event - ie most likely not global in scale or synchrony. Hence neither event is particularly pronounced when placed in a global context. Holocene records show that the Holocene Optimum was even warmer, go further back and other episodes were still warmer (eemian, Tertiary, whatever). It is interesting if temperatures have warmed beyond MPW values, but what is crucial is the global nature and the trajectory of change occurring now. Whether or not temperatures have passed MWP values does not alter the science and the basis for saying that the present change is remarkable.

sss

well lets forget the mwp and consider this most of the globe was covered in ice why?

and why did it melt away without the aid of man?

[VillagePlank]

well lets forget the mwp and consider this most of the globe was covered in ice why?

and why did it melt away without the aid of man?

Good questions. And very difficult, regardless of what everyone else will tell you, questions to answer. And that means either way. Whether you are 'into' warming or you are not, the sheer quantity of papers that suggest it both ways are staggering.

BTW - just because its difficult, it doesn't make it right to make a call on 'cooling' or "warming" or the endless other tripe I see "sceptics", or "pro-AGWs" utter.

Edited October 2, 2009 by VillagePlank

[MR EXTREMES]

can low solar activity volcanic activity have an effect on our climate of coarse it can.

has there been warming caused by man maybe a little.

will we cool off ofcorse we will.

thing is never under estimate power of nature and the power of climate,

i think to be honest the warmest period of the recent couple of decades is slowing and likely to reverse in the next 5 years or so.

and i do think this trend will continue for many years.

but i also agree that warming will be back id be foolish to think that when the cooling is over warming wont happpen again and next time i feel it will be around the predicted amounts being said.

Good questions. And very difficult, regardless of what everyone else will tell you, questions to answer. And that means either way. Whether you are 'into' warming or you are not, the sheer quantity of papers that suggest it both ways are staggering.

BTW - just because its difficult, it doesn't make it right to make a call on 'cooling' or "warming" or the endless other tripe I see "sceptics", or "pro-AGWs" utter.

im with you on that one.

Edited October 2, 2009 by badboy657

[pottyprof]

Something worth a read for those with an open mind-

http://www.realclima...-mal/#more-1184

They are quite sarcastic (though with pretty good reason given the attacks some of them have had to deal with), but the long and the short of it is a refutation of the latest attacks on dendrochronology, and a quick demonstration of how many records have the 'hockey stick' in them, not just Mann et al's, and a lovely description of how things spread through the blogosphere.

Interesting read.

The only problem I have with real climate is the fact that any request for data on some older research is met with an avoidance and they constantly refer people to recent research data. It makes you wonder if they are hiding something. I only say this as I noticed a few comments were still having this sort of response in the blog you linked to.

Surely, if there was nothing to hide, then why all this fuss? Surely to eliminate doubt from anyone's mind then all data should be placed either in the public domain or at the least in the hands of interested parties.

[masheeuk]

There are signs of a change coming from China though, they're forging ahead in green technology. I don't for one minute think it's because they're suddenly concerned about the environment or want to comply with Kyoto or son of Kyoto; there's money to be made and they want a slice of the pie.

Snip

. Solar panels and the like a prohibitively costly at the moment, give China a few years and we'll all be fitting them.

http://www.grist.org/article/2009-09-17-chinas-rear-view-mirror/

http://www.nytimes.com/2009/09/27/opinion/27friedman.html?_r=1&em

http://www.time.com/time/world/article/0,8599,1925804,00.html

I was having a drink last night and listening to the loudmouth, every pub has one along with the man who makes a pint last three hours and will tell you the last 30 years history of the pub.

The loudmouth was saying that global warming has been dreamt up by the US to limit power for China/India so they can slow down the financial/economic growth of these countries which will make the US a has been country. Hows that for a conspiracy theory.

[pottyprof]

Hows that for a conspiracy theory.

Well.. It fits better than any of PP's theories.

[Methuselah]

Well.. It fits better than any of PP's theories.

Area 51? Then again - maybe not...

[masheeuk]

Area 51? Then again - maybe not... :ph34r:

buy some people a couple of drinks and its amazing what they will come up with.

[Paul]

Thought now would be a timely time to remind everyone of the code of conduct for this part of the forum, as we have just had to stop someone from posting in here for a month for continually going against the guidelines.

http://www.netweather.tv/forum/index.php?app=forums&module=forums&section=rules&f=8

[Gray-Wolf]

Any suggestions why the (current) worst polluter in the first world also holds the title of the "developed worlds most climate illiterate"? .....and do we think that being Republican should automatically make you twice as likely to be climate illiterate as a Democrat??

[PersianPaladin]

Minqi Li: Despite the rhetoric the US and China are not doing much about carbon emissions

[Gray-Wolf]

Minqi Li: Despite the rhetoric the US and China are not doing much about carbon emissions

All well and good insofar as current emissions are concerned but if we look to our historical debt the UK (per capita head) are responsible for the greatest CO2 emissions in the atmosphere today. Kinda like pointing the finger at Brazil for tree felling when we know we deforested our own country.......

We have to take responsibility for what we have done (being the lead nation in the industrial revolution and the coal that fuelled it) if we are to expect to be taken seriously by the nations who are now leading CO2 output.

There is no 'get out of jail free ' card in climate change, we started the issue, we should atone.

[sunny starry skies]

well lets forget the mwp and consider this most of the globe was covered in ice why?

and why did it melt away without the aid of man?

Pretty basic climatology badboy. Only it wasn't 'most of the globe' (minor point). You can do some reading about our best ideas about why ice ages occurred in the last 2 million years or so (geologic, orbital forcing etc). It seems clear from ocean and ice core records that the Milankovitch orbital cycles are the key driver of ice ages. As far as the melting of the last one - use the same overall driver, and follow it up with a series of positive feedbacks to remove the ice relatively quickly. These include lowering albedo, lowering elevation of the ice sheets as they melt, among other things. Increased CO2 also happens and would enhance the change, but it followed the change and didn't start it. I know you were on the wind-up, but there are more processes than Man to cause large-scale climate change!

We know that large CO2 increases follow large-scale deglaciations, and we know that physics tells us CO2 traps heat in the Earth's atmosphere... but we also know that we have come up with a novel way or releasing CO2 into the atmosphere, quite unrelated to past large-scale glaciations. And of course unrelated to the MWP too!

VP - presumably you were having a go at me for my graphs? of course calculus is important, but I think you'll find the first step is a linear analysis (where dy/dx = constant). It's a little foolish to suggest that linear regression is not a valid scientific technique! I understand a point that says that the rate of change may be declining, based on the last few years, but the data since the mid-1960s shows a very respectably linear trend. I would not be inclined to put a curve through it. And my point was to show that the recent trend is still upwards, despoite a few recent cooler years. The only way you see a declining rate of change is if you consider the last 3 years, which on the fuller dataset is well within the bounds of stochastic noise. However.... if 2010 and 2011 show distinct downward trending then maybe the near-linear trend will break, but even then you can look back at periods with sharp temperature drops (post-Pinatubo 1992-93 for instance), and where a maximum was not re-exceeded for many years (1981-1987, 1990-1997) which still lie within the steady upward trend.

sss

[VillagePlank]

VP - presumably you were having a go at me for my graphs? of course calculus is important, but I think you'll find the first step is a linear analysis (where dy/dx = constant). It's a little foolish to suggest that linear regression is not a valid scientific technique! I understand a point that says that the rate of change may be declining, based on the last few years, but the data since the mid-1960s shows a very respectably linear trend. I would not be inclined to put a curve through it. And my point was to show that the recent trend is still upwards, despoite a few recent cooler years. The only way you see a declining rate of change is if you consider the last 3 years, which on the fuller dataset is well within the bounds of stochastic noise. However.... if 2010 and 2011 show distinct downward trending then maybe the near-linear trend will break, but even then you can look back at periods with sharp temperature drops (post-Pinatubo 1992-93 for instance), and where a maximum was not re-exceeded for many years (1981-1987, 1990-1997) which still lie within the steady upward trend.

Hi SSS, sorry if it came across as 'having a go' I think you will have to to take my word for it - it wasn't intended.

Linear regression is, as you say an important tool; but it is often misused, and certainly misappplied, countless times by both sides of the 'divide' and by both professional and amateur alike. Indeed, there is a strong argument to be had that just because it's easy to do (in Excel) that that is no reason for actually doing it (if you get Excel to display the r² value along with the trend, then you can see how far off a good representation it really is - for instance, the CO2/temp correlation from the Vostok ice core records, from the original paper, has an r² 'score' of 0.72, which is compelling, a linear trend with even a moderately good sample will score very badly)

However, that is not my principle objection. My principle objection for avoiding such 'trend' lines are because that author can arbitrarily choose the independent value (the x-axis) This means, of course, and well demonstrated here, is how far back do we have to go before it becomes representative? Of course, whilst a linear trend helps the eye out, a bit, statistically, you can go back as far as you want and the r² value will almost always show that it is entirely unrepresentative.

That said, of course, using high-order polynomials is absolutely essential (a high order polynomial uses the same techniques as a straight line, except you extend the coefficient vector, and terms matrix to include the relevant degree. A straight line is of degree 2) if you want to model relationships and you need to approximate the function, y=f(x), say. An essential tool. I've never seen it used that way, here. Indeed it is often used for 'seeing through noise' (which is why the r² is so important, because it tells you how much has been filtered - sort of), but, here, we are interested in seeing the ups and downs, and, for a start, any series that doesn't factor out teh ENSO 'noise' of the late 20th century, is sure to get a skew, unless a very very large sample with a small(ish) variance is used. But that's all for another day, and another discussion, I think. You could, I guess, take a sample big enough to produce a near normal distribution .....

Now, non-linear regression? That's another baby ...

EDIT: If you want me to post up the PDF of how you do it (I think I've already posted something before, somewhere, but I can't find it) let me know, and I'll post up the technique, and, possibly, the source code.

EDIT: Part 2.

The reason why I think that the dT/dt is a better way of displaying what's going on is that the results actually don't change when the independent value, or length of time, is chosen - ie for each period, the chart looks the same. I guess I should stop being lazy, and actually do it. I will post something when I get to work tomorrow - where I have the data in the nice relational tuple ...

Edited October 6, 2009 by VillagePlank