Global warming

[mhaze]

Originally Posted by David Rodale
With a MWP, AGW is worthless.
​

Why?

Hansen et al 1988. The presumption that we have "unprecedented man made warming" was arrived at by looking at the standard deviation of several decades of weather. Based on that, some of the current numbers were found outside of 3 standard deviations, and Hansen concluded that it had to be man made. (I am skirting the gross errors in his logic as they are not relevant to this point.)

With a MWP, the natural variation of climate must be estimated such to include that extent of warming (and cooling for the LIA).

Current temperature numbers do not fall outside the range of natural variability. All the news reports and sensational stories about "Historically unprecented blah blah blah" are patently false.

 

[varwoche]

CO2science didn't perform the studies.

It doesn't matter. Their interpretations of studies conducted by others has already been demonstrated in this thread to consist of shameless distortions.

Links to CO2Science has no place on a skeptical forum unless the purpose is to mislead.

If you read something at CO2Science (or any other propaganda site) that you think is meritorious, you should track down a reliable source to link to instead of foisting these bozos on readers.

 

[mhaze]

Your link to "GW Evidence" in my humble opinion is nothing but shameless distortions. Their interpretations of studies conducted by others has already been demonstrated in this thread to consist of shameless distortions.

Links to http://gwstudies.blogspot.com/ - "GW Evidence" has no place on a skeptical forum unless the purpose is to mislead.

If you read something at http://gwstudies.blogspot.com/ (or any other propaganda site) that you think is meritorious, you should track down a reliable source to link to instead of foisting these bozos on readers.

 

[varwoche]

Your link to "GW Evidence" in my humble opinion is nothing but shameless distortions. Their interpretations of studies conducted by others has already been demonstrated in this thread to consist of shameless distortions.

Links to http://gwstudies.blogspot.com/ - "GW Evidence" has no place on a skeptical forum unless the purpose is to mislead.

If you read something at http://gwstudies.blogspot.com/ (or any other propaganda site) that you think is meritorious, you should track down a reliable source to link to instead of foisting these bozos on readers.

I've seen attempts at winning cheap debate points before but this takes the pathos cake and then some.

Unlike CO2Science, GWStudies does not interpret/editorialize. Not one article. Not one paragraph. Not one sentence. It's simply a list I've created emanating from these debates (with, in all cases, links to source materials, or as close to source as I can find).

True though, GWStudies only lists studies that support A/GW. If you wish to volunteer, I'll set it up so that you can post contrary studies to the site.

 

[Schneibster]

This is the Mann hockey stick (Gore thinks it is Thompson, he is just confused).

You're funny. I guess Lonnie Thompson and Ellen Mosely-Thompson are just figments of CNN's imagination. Interestingly, it appears they don't study tree rings. They study ice; specifically, glaciology and ice cores.

It's very important to you that there only be ONE hockey stick, isn't it? Unfortunately, there are two, from completely different data sources.

 

[mhaze]

You're funny. I guess Lonnie Thompson and Ellen Mosely-Thompson are just figments of CNN's imagination. Interestingly, it appears they don't study tree rings. They study ice; specifically, glaciology and ice cores.

It's very important to you that there only be ONE hockey stick, isn't it? Unfortunately, there are two, from completely different data sources.

Thanks. It really is pretty funny, isn't it?

Too bad it isn't Thompson's graph we've got here.

 

[Schneibster]

Do you not believe that there are natural climate variations? Did they suddenly stop happening after humans started industrializing?

What? This is an inauspicious beginning. Did you actually read what I said? It doesn't appear so from this.

He talks about that later, in check the section labeled (go figure) "Sulfates, Aerosols, and Dimming" You do realize that the intro was just a summary, right?

So? Because it's "just a summary" it doesn't have to be accurate?

You answered your own question, CO2 is the highest nail and the one that gets pointed at so much by the AGW side that it is the nail he focuses on.

You totally ignore the point, which is it's a strawman argument. No one but deniers claims that AGW is "all CO2."

But, regardless of that if you go through and read the whole paper

I see no reason to bother to read it all if the writer can't be bothered to be accurate at the beginning.

he talks about the different gases and isn't stuck on just CO2... it's just the one that he focuses on the most.

You can't have your cake and eat it too. Either that's what AGW is claimed to be, or it's not. The fact that it's not makes it irrelevant what arguments get presented later. If the presentation of the antithesis is incorrect, then there's no point in going on; the whole thing is a strawman argument.

1. Yes, that is just a nit-pick... "Climatic" can also refer to a tipping point or peak, so he's probably just being clever and witty with a nice double-entendre.

Ummm, he used "climactic" not "climatic," which was my point in the first place- and "climatic" doesn't refer to tipping points or peaks, it refers to climate, period. "Climactic" refers to a climax, AKA tipping point or peak; and it does NOT refer to climate.

2. I'm glad you picked up on the feedbacks thing. That's kind of one of the major points in his article (and I don't see where you get him limiting it to just a single specific feedback).

Ummm, because that's what he said?

We have a very poor understanding of feedbacks right now,

I disagree. We design and build systems with both positive and negative feedback in them to encourage desirable characteristics and discourage undesirable ones all the time. Feedback is an extremely well-understood phenomenon.

If you mean, we have a very poor understanding of what feedbacks operate in the climate system, I'd both have to disagree with that statement, since I can name five just off the top of my head, to wit:
tropospheric water vapor and temperature
continental position and ice ages
ice and albedo
GWG concentrations and temperature
ocean temperature and CO2 absorption capacity
and point out that we seem to have a good enough understanding to make a climate model in the 1980s that appears to have correctly predicted what's happening now, twenty years later, in terms of temperature.

yet the AGW side wants to say that there are far more positive feedbacks when it comes to CO2 then negative feedbacks which would make for a fundamentally unstable system.

Name a negative CO2 feedback. Now name a chlorofluorocarbon negative feedback. Now name a negative methane feedback.

As far as whether climate is a fundamentally unstable system, it would appear so. Have you noticed we're in an ice age, and the climate has been fluctuating back and forth between glaciations and interglacials for the last several million years? Looks pretty unstable to me.

Yes, we don't know feedbacks very well, so why does the AGW side rely on them so much?

Ummm, because that's how the atmosphere works?

You have a bizarre idea of propaganda.

I know it when I smell it. Strawman arguments are usually a good starting indication.

Yes, the areas where it would be best for people to farm might change with the climate change *gasp*

Have you looked at the geology of the areas it's likely to change to? Could be a bit of a problem if the good growing place with regard to climate turns out not to have enough dirt, don't you think? It's a little hard to farm without dirt, in case you hadn't noticed.

But assuming that things will always stay the same if we aren't pumping CO2 and other chemicals into the air is naive.

Strawman: no one claims they will.

Fish populations change, animal populations change, the world's climate will change, but it doesn't always have to be our fault.

Strawman: no one claims it always is.

It seems like the AGW and environmentalists in general feel that way though.

It seems like you like strawman arguments, and like you don't know much about geology or farming, not to mention climate. It doesn't seem like you've asked many questions about what environmentalists think; you've assigned them a position. And that is a strawman argument. You might want to ask some questions instead of assuming you know the answers.

Overall, it's apparent you don't have a clear understanding of what's involved in the conversation, and you don't seem to really care whether a source you cite is accurate or not. It doesn't seem to be particularly important to you precisely what a position you oppose consists of; you don't really appear (and neither does the author of the paper you cite) to have a clear idea of what AGW means. It's therefore difficult for me to understand what you think you're opposed to, since you don't seem to understand it well yourself. I suggest both you and the individual who wrote the article you cited have a great deal more study to do before you start saying AGW is wrong, to wit, you need a much better understanding of what it actually consists of, rather than a mythology you've made up and assigned to it.

 

[CapelDodger]

No CD, it is your side obsessed with climate models. You just proved it with resurrecting Hansen once again. GCM's are the Holy Writ of AGW.

Let's revisit what I was responding to from you :

What crystal ball are you using? More climate model soothsayer prophecies that need constant "updates" and "new and improved" predictions that can't be validated?

It was you who brought up models (unsurprisingly given your fixation on them).

The Hansen et al 1988 model predictions have not been updated, they remain what they were in 1988. They can be validated against the real world outcome.

Once again, ending in 2006 with the correct zero starting point:
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But as your side always say, 10 years isn't long enough right? Unless of course it's Hansen's unimpressive carnival guess.

Not a carnival guess, and pretty impressive. See http://www.realclimate.org/index.php/archives/2007/05/hansens-1988-projections/ for details, including

"From 1984 to 2006, the trends in the two observational datasets are 0.24+/- 0.07 and 0.21 +/- 0.06 deg C/decade, where the error bars (2) are the derived from the linear fit. The 'true' error bars should be slightly larger given the uncertainty in the annual estimates themselves. For the model simulations, the trends are for Scenario A: 0.39+/-0.05 deg C/decade, Scenario B: 0.24+/- 0.06 deg C/decade and Scenario C: 0.24 +/- 0.05 deg C/decade."

Note that real world temperatures, as observed, have been increasing at about 0.2C per decade.

Where are the cloud feedbacks? Precipitation calculations? Solar? It was nothing but a best guess based on an already established decadal temperature trend, but you treat his scenarios like error bars, which of course he doesn't include. There's nothing impressive about it.

Models are based on the physical principles involved as we understand them, and they're pretty well-understood. From RealClimate :

"These experiments were started from a control run with 1959 conditions and used observed greenhouse gas forcings up until 1984, and projections subsequently (NB. Scenario A had a slightly larger 'observed' forcing change to account for a small uncertainty in the minor CFCs)."

How this equates to "an already established decadal warming trend" escapes me, since the world didn't warm up much (if at all) between 1959 1975.

Cloud feedbacks are included, in that the model predicts the pole-ward movement of rain bands. Precipitation calculations are not within the remit of the model, that's essentially about temperatures. Meteorologists can make such calculations given any projected climate.

What cloud feedbacks do you think haven't been included, and what are the observed cloud feedbacks in the meantime?

By the end of next year it will have been 20 years and your unwaivering loyalty to Hansen will look even more silly.

The model's hardly going to go wildly wrong over the next few months, given that it deals in annual averages and 2007 is within the trend. Twenty years of success and some people are still going on about its inherent inaccuracies.

I realize you don't want to see them, but they won't go away if you close your eyes.

What you think you realise is your own strange business. I loked at some last night and I'm not impressed. Lots of editorial, and not good editorial either.

Climate models, any model for that matter, must include all relevant factors for them to be considered skillful. Hindcasting is not "validation"; the models are parameterized, or tuned, to get the results they want. Here again, on clouds, just one missing from climate models:
http://irina.eas.gatech.edu/EAS_spring2006/Stephens2005.pdf

If you want to believe in 5-8 years temperatures will rise excessively, fine. However, there is nothing truthful in that statement; it hasn't happened yet and your saying that has no basis in science. Climate models are not evidence.

Three to eight years. That dates back to mhaze quoting a magazine article in support of his cherished 60-80 year cycle. In it the chap with the cycle said "the next five to ten years will tell if the ice is coming back", or words to that effect. Since the article was dated 2005 and we had record Arctic sea-ice retreat this summer, there's just three to eight years left for mhaze's cycle.

I haven't predicted excessive warming, just continued warming. There'll be impressive warming come the next long El Nino, but that could be anytime.

Three to eight years will also see off the "cooling since 1998" claim, and the general "no current warming" claims.

Let's recap Met O's predictions:
2003- "new" climate model more accurate; temperatures to continue to rise:
Didn't happen.

2005 was warmer than 2003, so they did continue to rise. And they will continue to rise, mark my words. The science behind that prediction is very sound.

January 2007- 2007 will be warmest year on record, eclipsing 1998.
Didn't happen.

That was based on El Nino conditions early in the year, but that El Nino turned out to be exceptionally short-lived. Not exactly a damning indictment of the Met Office.

August 2007- "new and improved" climate model; global warming will return with a vengeance by ~2012, starting in 2009.
That's what you're hanging your hat on, and Met O is counting on SC24. Good luck, because that's all you've got left. It must mean global warming has stopped. How can that be?

You're hanging your hat on SC24. What crystal ball are you depending on?

The Met Office is hanging its hat on a climate model, with predictions extending well beyond 2012. After which SC24, according to Solar Cyclists, will be cooling things down. The next eight years should test that idea to destruction.


Do Solar Cyclists have models to predict the next ten years, given various sunspot scenarios? With modern computers they could run many more than three scenarios, after all. Do they have any figures? Heaven forfend they're waiting on events and will retroactively claim all the warming as down to SC24. That's what I expect from you over the next five years, but I'd be interested in any actual predictions you're hanging your hat on.

If Hansen's model was right, why all the fuss constantly improving on current models? It would have saved a lot of money and Met O could have saved themselves the embarrassment. What did Hansen's model predict for 2007?

Because the Hansen et al model can be improved upon. Sopwith Camels did the job in their day, but later on we built Spitfires. Computers have moved on quite considerably since 1988. I don't have a graph to present, but trust me on that. I was there back in 1988, after all, working in the IT field.

Climate models can't be expected to predict the temperature of any particular year. The Hansen et al 1988 model has it about right, though. I realise this is a lucky guess in your opinion, but it's a guess that's stayed lucky.

 

[CapelDodger]

Your link to "GW Evidence" in my humble opinion is nothing but shameless distortions. Their interpretations of studies conducted by others has already been demonstrated in this thread to consist of shameless distortions.

You have no shame, do you?

 

[mhaze]

Three to eight years. That dates back to mhaze quoting a magazine article in support of his cherished 60-80 year cycle. In it the chap with the cycle said "the next five to ten years will tell if the ice is coming back", or words to that effect. Since the article was dated 2005 and we had record Arctic sea-ice retreat this summer, there's just three to eight years left for mhaze's cycle.

A sidetrack, but Dr. Chad Dick had an article published which we missed at the time of that discussion. Quite interesting stuff, going through the old mariner logs to figure this type of thing out.

I'll get the full article shortly.

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, C01001, doi:10.1029/2004JC002851, 2006

Historical variability of sea ice edge position in the Nordic Seas
Dmitry V. Divine and Dr. Chad Dick

Abstract Historical ice observations in the Nordic Seas from April through August are used to construct time series of ice edge position anomalies spanning the period 1750–2002. While analysis showed that interannual variability remained almost constant throughout this period, evidence was found of oscillations in ice cover with periods of about 60 to 80 years and 20 to 30 years, superimposed on a continuous negative trend. The lower frequency oscillations are more prominent in the Greenland Sea, while higher frequency oscillations are dominant in the Barents. The analysis suggests that the recent well-documented retreat of ice cover can partly be attributed to a manifestation of the positive phase of the 60–80 year variability, associated with the warming of the subpolar North Atlantic and the Arctic. The continuous retreat of ice edge position observed since the second half of the 19th century may be a recovery after significant cooling in the study area that occurred as early as the second half of the 18th century.

 

[CapelDodger]

It's very important to you that there only be ONE hockey stick, isn't it? Unfortunately, there are two, from completely different data sources.

Haven't you heard? All datasets have to be cleared by Mann, and the scientists involved know what will happen to them if they don't present the right goods, capisce? Mann's deputising for Hansen, who's still busy blow-torching pack-ice in the Arctic. Meanwhile Al Gore, the eminence grise, surfs the champagne-circuit. Not much chance of losing a toe or finger there

The same can't be said for the guys turning in unwelcome data. It's no coincidence that ice-scientists have fewer digits than the average trend-line suggests. But it seems they've learned the lesson.

There's a climate of fear in the climate field, and guess what? It works.

 

[CapelDodger]

A sidetrack, but Dr. Chad Dick had an article published which we missed at the time of that discussion. Quite interesting stuff, going through the old mariner logs to figure this type of thing out.

I'll get the full article shortly.

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, C01001, doi:10.1029/2004JC002851, 2006

Historical variability of sea ice edge position in the Nordic Seas
Dmitry V. Divine and Dr. Chad Dick

Abstract Historical ice observations in the Nordic Seas from April through August are used to construct time series of ice edge position anomalies spanning the period 1750–2002. While analysis showed that interannual variability remained almost constant throughout this period, evidence was found of oscillations in ice cover with periods of about 60 to 80 years and 20 to 30 years, superimposed on a continuous negative trend. The lower frequency oscillations are more prominent in the Greenland Sea, while higher frequency oscillations are dominant in the Barents. The analysis suggests that the recent well-documented retreat of ice cover can partly be attributed to a manifestation of the positive phase of the 60–80 year variability, associated with the warming of the subpolar North Atlantic and the Arctic. The continuous retreat of ice edge position observed since the second half of the 19th century may be a recovery after significant cooling in the study area that occurred as early as the second half of the 18th century.

Not much to hang your hat on, is it?

"Can partly be attributed", "may be a recovery", and only for the Nordic Seas. So we could be looking at a North Atlantic cycle, not an Arctic one. Regional cycles can involve redistributions of energy, whereas global cycles must involve variation in total energy.

I don't doubt that the paper's good. Error bars and caveats galore, as is only proper when you're extrapolating a lot of your data from whaler's logs. Dr Dick has been quoted as saying (in essence) that if the ice-retreat doesn't turn around in the next three to eight years something new is going on. The obvious candidate being AGW, don't you think? After all, what else is there?

 

[Schneibster]

Thanks. It really is pretty funny, isn't it?

Too bad it isn't Thompson's graph we've got here.

Too bad you're wrong. Look at the hockey sticks! My goodness, they're everywhere!

You really ought to bother to do some research before you say something stupid like this.

 

[a_unique_person]

The map links world wide to peer reviewed studies which show the MWP, thus contradicting the claim of Mann that the MWP was only European in nature.

That means we don't have an "unusual and historically unprecedented warming". And that means AGW went byby...

Next.

Given their looseness with other studies they have provided as evidence before, I would find it very hard to trust their presention of evidence. For a start, they divide up the sites by their own criteria as supporting directly or indirectly their interpretation the studies. That is, the indirect data is just what they think it says.

AGW, as directly measured and observed, stands entirely on it's own, completely independently of proxy data from the past.

 

[CapelDodger]

If you mean, we have a very poor understanding of what feedbacks operate in the climate system, I'd both have to disagree with that statement, since I can name five just off the top of my head, to wit:
tropospheric water vapor and temperature
continental position and ice ages
ice and albedo
GWG concentrations and temperature
ocean temperature and CO2 absorption capacity
and point out that we seem to have a good enough understanding to make a climate model in the 1980s that appears to have correctly predicted what's happening now, twenty years later, in terms of temperature.

Further to that, the negative feedbacks predicted twenty years ago have failed to materialise. Changes in cloud-cover and Lindzen's Iris being examples.

Have you looked at the geology of the areas it's likely to change to? Could be a bit of a problem if the good growing place with regard to climate turns out not to have enough dirt, don't you think? It's a little hard to farm without dirt, in case you hadn't noticed.

Further to that , if the grain-belt moves polewards it becomes smaller. That's in the nature of living on a sphere.

When it comes to agriculture, Siberia's cheap but a fixer-upper. Which is not to say the Chinese won't do that - they have plenty of loess top-soil to take with them, after all.

 

[Pipirr]

Hansen et al 1988. The presumption that we have "unprecedented man made warming" was arrived at by looking at the standard deviation of several decades of weather. Based on that, some of the current numbers were found outside of 3 standard deviations, and Hansen concluded that it had to be man made. (I am skirting the gross errors in his logic as they are not relevant to this point.)

With a MWP, the natural variation of climate must be estimated such to include that extent of warming (and cooling for the LIA).

Current temperature numbers do not fall outside the range of natural variability. All the news reports and sensational stories about "Historically unprecented blah blah blah" are patently false.

So... the MWP proves Hansen wrong, and therefore "AGW is worthless"?

There is rather more to the hypothesis than just Hansen 1988.

 

[CapelDodger]

AGW, as directly measured and observed, stands entirely on it's own, completely independently of proxy data from the past.

Absolutely, and thus the very evident refuge-in-the-past sought by contrarians. "Give me a proxy or give me death" being the watchword. They even prefer sunspot numbers to direct observations of solar output. Reality has not been kind to the denialist cause over the last few decades.

Nor has it been kind to Australians, but I've already said my piece on that. It's up to you whether you heed it or not .

 

[mhaze]

With a MWP, the natural variation of climate must be estimated such to include that extent of warming (and cooling for the LIA).

Current temperature numbers do not fall outside the range of natural variability. All the news reports and sensational stories about "Historically unprecented blah blah blah" are patently false.
​

So... the MWP proves Hansen wrong, and therefore "AGW is worthless"?

There is rather more to the hypothesis than just Hansen 1988.

The last two comments I made don't refer strictly to Hansen 1988. They address a fundamental question that we seek a high quality, evidence based furthering of --

What is natural variability in climate?
​

 

[mhaze]

Given their looseness with other studies they have provided as evidence before, I would find it very hard to trust their presention of evidence. For a start, they divide up the sites by their own criteria as supporting directly or indirectly their interpretation the studies. That is, the indirect data is just what they think it says.

You are welcome to spot check a few of the peer reviewed citations and see if there are problems. I have an almost identical concern with surRealClimate and always do this there. So we're good on that.

AGW, as directly measured and observed, stands entirely on it's own, completely independently of proxy data from the past.

AGW can be supported or completely refuted by the past.

Obviously.

 

[a_unique_person]

The last two comments I made don't refer strictly to Hansen 1988. They address a fundamental question that we seek a high quality, evidence based furthering of --

What is natural variability in climate?
​

You say it like it's an act of god that we can't understand. We have science, and we can measure and understand. Natural is well researched.