Climategate (GW email leak)

[Pangloss]

It's not as catchy, but I'd prefer we call it the reality-based interpretation.

 

(Well I thought your reply was very clever!)

[iNow]

Can someone please just catch me up on what the 'decline' with tree-ring data is all about, and why the tree-ring data is no good from the 1960's? Is it to do with there not being 'long enough' time between those tree rings and now, IE: Something to do with tree-ring data only working after a certain age? Or has some other environmental effect stuffed the reliability of tree-ring growth?

 

It's called the divergence problem. In essence, the trees lose their validity as a temperature proxy when the temperature increases as quickly as it has these last several decades.

 

 

http://www.worldclimatereport.com/index.php/2008/10/23/the-divergence-problem-and-the-failure-of-tree-rings-for-reconstructing-past-climate/

Divergence results either because of some unique environmental factor in recent decades, because trees reach an asymptotic maximum growth rate at some temperature, or because higher temperatures reduce tree growth. If trees show a nonlinear growth response, the result is to potentially truncate any historical temperatures higher than those in the calibration period, as well as to reduce the mean and range of reconstructed values compared to actual. This produces the divergence effect.

 

<...>

 

The nonlinear response of trees to temperature explains the divergence problem,

[iNow]

Yep, precisely. That's pretty much all it is.

[bascule]

I think Kenneth Parcel from 30 Rock summed up the climate science deniers position pretty well:

 

"Why should we listen to what a bunch of scientists have to say?"

[JohnB]

So I take that within certain temperature ranges on the historical record trees work as a great record of temperatures, but above a certain crazy recent anthropogenic rate of increase, all sorts of things change

 

Not quite. As the article iNow linked to points out, we assume that the relationship between tree ring width and temperature is linear when it is not. The widest bands appear at the "optimal" temperature for the trees growth and as the temp gets either colder or warmer the rings will get thinnner.

 

This leads to a problem when looking at the past. If we see the rings go from thin to thick and back to thin it is interpreted as going from cool to warm and back to cool. The same tree ring pattern is also given if the temps go from cool to warm to warmer. And there is no way to tell which is correct.

 

It is one of Keith Briffas reconstructions that shows this quite clearly with the temps apparently dropping dramatically in the late 20th C. (Which they didn't do).

 

It is my view that the 20th century high point actually indicates the optimum temp for this tree series. After that, the rings are getting thinner and are interpreted as temps dropping. I believe this interpretation to be wrong and the rings are getting thinner because the temp is now above optimal temp for the trees concerned. Ergo, if the graph after the high point was reversed to show a continued climb, it would be roughly correct.

 

Tree rings going from thin to thick indicate temps are approaching optimal and those going from thick to thin show temps moving away from optimal. That is the factual interpretation. Without knowing what the actual "optimal" temp for a tree is and having some way to establish the direction of the temp away from optimal, reconstructions are often "educated guesses".

 

In essence, due to this problem, to be correct parts of some reconstructions would have to be reversed, but as I said, there is no way to tell which parts. Given this, water availability and CO2 fertilization as well as local weather patterns I think that it would be virtually impossible to show that what you have is signal rather than noise.

 

The bottom line is that tree ring proxies can be made to agree quite closely, provided you already know what the answer is. Outside that, they diverge, quite profoundly in some cases.

 

Personally I would be much happier if tree rings were given a miss all together and other proxies (like the O16/18 ratio) which are on a much firmer empirical footing were used in preference.

[Mr Skeptic]

Hm, wouldn't the solution then be to use data from multiple trees with a different optimum temperature? This would then give you the direction of the change as well.

[iNow]

Lots of techniques are available. They are used in conjunction with one another:

http://www.ncdc.noaa.gov/paleo/globalwarming/proxydata.html

[bascule]

Not quite. As the article iNow linked to points out, we assume that the relationship between tree ring width and temperature is linear when it is not.

 

Who is making that assumption? Laymen?

 

The widest bands appear at the "optimal" temperature for the trees growth and as the temp gets either colder or warmer the rings will get thinnner.

 

This leads to a problem when looking at the past. If we see the rings go from thin to thick and back to thin it is interpreted as going from cool to warm and back to cool. The same tree ring pattern is also given if the temps go from cool to warm to warmer. And there is no way to tell which is correct.

 

Nonlinearities! That makes tree rings as a proxy worthless. Let's just toss the baby out with the bathwater.

 

It is one of Keith Briffas reconstructions that shows this quite clearly with the temps apparently dropping dramatically in the late 20th C. (Which they didn't do).

 

Look, I don't know what your spooky FUD deleted data is all about. Some people are douchebags. Just because some people are douchebags doesn't make the science wrong. It would be helpful in responding to this stuff if you could provide a link/context for a graph like this, rather than "some random douchebag deleted his data... SEE!" (graph, not real data)

 

Just because trees responses to climate changes are nonlinear doesn't make them worthless as a proxy, as you seem to be insinuating.

 

The bottom line is that tree ring proxies can be made to agree quite closely, provided you already know what the answer is. Outside that, they diverge, quite profoundly in some cases.

 

Or provided your model output matches expected tree ring results?

[iNow]

It would be helpful in responding to this stuff if you could provide a link/context for a graph like this, rather than "some random douchebag deleted his data... SEE!" (graph, not real data)

 

He got it off of Climate Audit, a site run by Steve McIntyre.

 

http://www.sourcewatch.org/index.php?title=Stephen_McIntyre

 

 

Now... Just to be clear, it's rather obvious that we should all take Steve's word as gospel since he has worked as a director in mineral exploration for 30 years, with ties to CGX Energy, an oil and gas company, as a "strategic adviser." If we can't trust him to accurately reflect the science of global climate change, then who can we trust?

 

[/End exasperated sarcasm]

[bascule]

Now... Just to be clear, it's rather obvious that we should all take Steve's word as gospel since he has worked as a director in mineral exploration for 30 years, with ties to CGX Energy, an oil and gas company, as a "strategic adviser." If we can't trust him to accurately reflect the science of global climate change, then who can we trust?

 

Not to suggest that correlation implies causation, but I noticed Prof Fred Singer from this thread has been a consultant to companies including GE, Ford, GM, Exxon, Shell, Sun Oil, Lockheed Martin and IBM.

[iNow]

A nice article over at Scientific American:

 

http://www.scientificamerican.com/blog/post.cfm?id=climate-change-cover-up-you-better-2009-11-24

There is, in fact, a climate conspiracy. It just happens to be one launched by the fossil fuel industry to obscure the truth about climate change and delay any action. And this release of emails right before the Copenhagen conference is just another salvo—and a highly effective one—in that public relations battle, redolent with the scent of the same flaks and hacks who brought you "smoking isn't dangerous."

 

h/t swansont

[Pangloss]

Interesting article from the Beeb focuses on possible improvements to the IPCC process that could indirectly result from the affair:

 

http://news.bbc.co.uk/2/hi/science/nature/8387365.stm

 

Some interesting quotes:

 

John Houghton, chair of the science panel for the first IPCC report, says the current process could be improved, but should certainly not be scrapped in favour of something else.

 

 

"The dominant model of science is one of aggressive individual or lab-based competition to break new ground and get the most convincing arguments supported by evidence," he told me.

 

"I think that that can be an unproductive form of 'knowledge generation'. One thing for sure is that it isn't designed to produce consensus around such a complex topic as climate change.

 

"So the IPCC has serious weaknesses - but it remains the most ambitious peer review process modern science has undertaken.

 

"The problems arise at the science-policy-media interface where these headlines are translated into a shorthand that there is a 'consensus' that 'the science is finished'.

 

"We should instead be continuing to engage (the wider public) in the idea that our best current understanding justifies very pacy and bold action on the basis of intelligent risk management."

[iNow]

Enjoy.

 

 

7nnVQ2fROOg

[D H]

Here's a copy of the most relevant email:

http://www.monbiot.com/archives/2009/11/23/the-knights-carbonic/

Yes, let's just belittle the whole thing, shall we? This reaches much further than three or four people. Does the emails show a conspiracy? In the sense of that stupid parody, no. What they do show is groupthink. Some of the effects of that group think are just as pernicious as a true conspiracy. For example, the engineering of a false consensus and the manipulation of the peer review process.

 

Now... Just to be clear, it's rather obvious that we should all take Steve's word as gospel since he has worked as a director in mineral exploration for 30 years, with ties to CGX Energy, an oil and gas company, as a "strategic adviser."

Ah yes, let's just poison the well as well.

 

A nice article over at Scientific American:

 

http://www.scientificamerican.com/blog/post.cfm?id=climate-change-cover-up-you-better-2009-11-24

There is, in fact, a climate conspiracy. It just happens to be one launched by the fossil fuel industry to obscure the truth about climate change and delay any action. And this release of emails right before the Copenhagen conference is just another salvo—and a highly effective one—in that public relations battle, redolent with the scent of the same flaks and hacks who brought you "smoking isn't dangerous."

 

h/t swansont

And re-poison the well.

 

Some people are indeed acting like the tobacco industry -- the ones who engineered this false consensus. They are also acting a lot like another person caught by the release of damaging material. His response was "I am not a crook." That of course did not work.

[iNow]

Would I be correct to assume from your post, DH, that you reject that anthropogenic contributions of CO2 to the atmosphere are the primary radiative forcing agent which has led to the recent increasing trend in the global average annual temperatures? If so, then perhaps you can offer which mechanism is leading to this upward trend we've been measuring? If not, then I apologize for misinterpreting your response, and am glad to find common ground with you there.

 

I accept that there are more specific arguments which can be made against deniers, and most of them have been made. However, at some point when logic falls on deaf ears there really is not much left to do but laugh at them and dismiss them summarily. This is the same thing we do when people still try to argue that smoking cigarettes does not lead to a greater cancer risk or when people argue that the earth is only 6000 years old and evolution is a big lie or that relativity is bollocks.

Edited December 5, 2009 by iNow

[Cap'n Refsmmat]

It's possible for anthropogenic climate change to be real but climate scientists to still be engaging in groupthink and bad practices.

[D H]

Would I be correct to assume from your post, DH, that you reject that anthropogenic contributions of CO2 to the atmosphere are the primary radiative forcing agent which has led to the recent increasing trend in the global average annual temperatures?

To deny that the climate is warmer now than it was 300-400 years ago is ludicrous. Of course things have warmed up since then. However, most of that warming occurred in the first half of the 20th century -- before we started dumping CO₂ into the atmosphere at a ferocious rate.

 

To deny Beer's law is also ludicrous. Of course increasing CO₂ will cause some amount of warming. The question is, how much? To get to the numbers engineered by those who figure so prominently in those emails, they had to create positive feedbacks. It is those positive feedbacks that I have my doubts with.

 

One way to look at the climate over the last billion years is that it has fluctuated wildly. Another way to look at it is that climate has been remarkably robust in spite of significant changes in the Sun's luminosity, the shape of the continents, the orientation of the Earth, and the shape of the Earth's orbit. Such robustness suggests to me that the dominant characteristic is one of negative feedbacks rather than positive feedbacks.

 

If the dominant feedbacks are negative rather than positive, those numbers in the IPCC are sheer alarmism meant to effect a political outcome. The same goes for making the Medieval Warm Period and the Holocene Optimum disappear. These scientists have switched from being scientists to being politicians. Lousy politicians, I might add. Any politician worth his or her salt knows that one should never commit to written words various machinations needed to achieve an end, or what one really thinks about an opponent.

[iNow]

I appreciate the clarity with which you've articulated your doubts above. I can very easily align with your words and concerns. However, you did not address my central question.

 

If the current trend is not caused by human additions of CO2 to the atmosphere, then what mechanism do you propose is resulting in the change? You concede that CO2 will lead to some degree of warming as per Beer's Law, but you do not seem to think CO2 can account for the amount of warming we're experiencing. So then... What does?

[D H]

What caused the ice ages? We've got an inkling, but we don't really know. What caused the Medieval Warm Period and the Holocene Optimum? What caused the Little Ice Age?

 

There is nothing wrong with "we don't know (yet)". There are lots of things in science where the truthful answer is "we don't know (yet)". That (yet) of course means that this is an interesting scientific problem to be solved.

 

Claiming to know the answers to unanswered questions is the realm of politicians and religious proselytes.

[iNow]

Okay, well here's the deal. CO2 seems to fit well with observations. Your personal interpretation is that CO2 can't account for the intensity of change. When asked for a mechanism which can account for the intensity of the change, you could provide none.

 

With that said, CO2 is the current best explanation. While I will remain open to other possibilities, I will accept as valid the suggestion that CO2 is the current primary driver in the warming trend, and will continue to do so until you (or others) present a valid alternative explanation or plausible warming mechanism.

 

Fair?

[D H]

More (but not much more, I'm going out soon):

 

Is this truly our most pressing problem? Will the proposed changes "fix" it? Will there be adverse side-effects?

 

The only thing that could justify the horrendously costly remedies proposed to fix AGW is that AGW is the most pressing problem faced by humanity. I do not think this is anywhere close to truth. I do not think that AGW is the most pressing environmental problem facing humanity. We have changed the face of the planet, often times for the worse. Some of that change is unavoidable sans killing off 90% of humanity. Some of the damage can be remediated. Remediating the damage our sheer numbers and our mismanagement of the environment will require money, and lots of it.

 

The natural resources that we use are not infinite. Neither are capital resources. Spending monies on solving minor problem when there are much more immediate and much more severe problems is, to be blunt, stupid.

 

It does help achieve a political agenda, however.

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Okay, well here's the deal. CO2 seems to fit well with observations.

How is that? Yes, it has warmed since the mid 1800s. Most of that warming occurred well before we pumped immense amounts of CO₂ into the atmosphere.

 

Don't confuse correlation with causation.

[bascule]

The only thing that could justify the horrendously costly remedies proposed to fix AGW

 

Or instead of trying to fix it, we can mitigate it, by limiting carbon emissions.

[Mr Skeptic]

While I am not completely convinced that we need to cut CO2 for the sake of the planet, what is undoubtedly true is that eventually we will have to stop using fossil fuels (because they will eventually run out). As for oil specifically, too much blood has been spilt for it and too much of our money is going to people who don't like us. As for coal, there are lots of mining deaths and also coal has very nasty stuff in it, even if they do filter most of it. So most of what they are proposing is stuff we will need to do eventually. Carbon capture technology though just seems stupid.

[iNow]

horrendously costly

<...>

will require money, and lots of it.

 

The natural resources that we use are not infinite. Neither are capital resources. Spending monies...

 

Actually, more important than the concept of "cost" in and of itself is the need to properly represent "cost." Most people (and seemingly you, as well) care only about short-term immediate monetary costs, and lose total sight of long-term health, security, and opportunity costs... or the cost of failing to take action now. Those are the true costs to consider IMHO.

 

Supporting these points, a recent study found that the annual health costs as a result of our burning fossil fuels are about $120 billion. The majority of these costs are related to premature deaths as a result of pollution as well as preventable diseases like asthma. None of these costs can be found in the price we pay for a gallon of gas or a kilowatt-hour of electricity.

 

http://www.nap.edu/catalog.php?record_id=12794

 

 

Another study found that global production of the six largest crops suffered significant losses due to global warming between 1981 and 2002. The study also found that global wheat growers lost $2.6 billion in 2002. Again, none of these costs end up on our monthly utility bill.

 

http://www.iop.org/EJ/article/1748-9326/2/1/014002/erl7_1_014002.html

 

 

Then there are the national security costs. A RAND Corporation study released earlier this year looked at the cost to the U.S. taxpayer of protecting the supply and transit of oil from the Persian Gulf. The study found that the annual cost to U.S. taxpayers is more than $90 billion — about 12% to 15% of the current U.S. defense budget. Once again, these costs are not included in the price we pay for gas or electricity.

 

http://www.rand.org/nsrd/

 

 

And, there are countless other "costs" which require inclusion in these discussions. If you're going to raise the specter of "cost," then you need to at least represent the issue authentically and honestly, and include in your calculations the cost if we do nothing and later discover that the projections about CO2 are fully accurate.

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Yes, it has warmed since the mid 1800s. Most of that warming occurred well before we pumped immense amounts of CO₂ into the atmosphere.

I'm sorry, DH, but that is simply untrue. A simple review of the below chart shows clearly that "most" of the warming has occurred well after the aforementioned pumping of large amounts of CO2 into the atmosphere...with roughly 60-80% of the warming which has occurred since the mid-1800s taking place between 1940 and the present... and projections show this will only continue to climb in a non-linear fashion.

 

Edited December 6, 2009 by iNow
Consecutive posts merged.

[D H]

Another graph:

 

 

Those two graphs are qualitatively similar: Both show a decline up to around 1910, significant warming the next thirty years, a decline in the 1940s, more or less flat from about 1945 to 1975, and a marked warming from 1975 to 2005.

 

However, the HADCRUT graph makes it look like the majority of the warming has occurred since 1980 (0.167 °C/decade since 1980). The Japan Meteorological Agency shows a slightly different story: The majority of the warming occurred before 1980.

 

The warming since 1980 is key. We have had satellites observing the globe since then. What does the satellite record say?

 

 

0.127 °C/decade, considerably less than that reported by HADCRUT (and GISS). The greatest warming in the land-based datasets occur in the Antarctic, the Arctic, and Africa -- precisely the places where the differences between the satellite and land-based datasets are the greatest, and precisely the places where the land-based data has the least coverage.