Tuesday, August 25, 2009

A bizarre rewriting of history

I've got a lengthier post in the works, but since Roger Pielke Sr is demanding a response to this I will simply observe that for his new definition of "The Issue That James Annan and Gavin Schmidt Should Focus On With Respect To The Klotzbach Et Al 2009 Paper" he is quoting a paper on...impacts of land use cover change on climate! (the hint is in the title, folks)

However, Klotzbach et al repeatedly and emphatically talked about differences due to CO2 and other atmospheric factors:

The rate of heat loss to space is dependent on several factors, including cloudiness and the local atmospheric concentrations of carbon dioxide and of water vapor (e.g., Pielke, 2002). Under cloudy conditions, cooling is much less. An atmosphere with higher concentrations of the greenhouse gases, CO2 and H2O, also reduces the cooling at night.

Consequently if, for instance, there is a long-term positive trend in greenhouse gas concentrations or cloudiness over the observing site, it may introduce an upward bias in the observational record of minimum temperatures that necessarily will result in an upward bias in the long-term surface temperature record.

Because of changes to the atmosphere over the past century, there are several reasons why we should expect the nighttime cooling in the lower atmosphere to have been reduced. One reason for this is that carbon dioxide concentrations have increased, such that the effect of well-mixed greenhouse gas concentrations on near-surface temperature measurements has also increased. This increase is also expected to be higher for growing urban and industrial locations where carbon dioxide can locally accumulate when the large-scale wind flow is weak. An increase of water vapor over time would have the same effect. Also, an increase of cloudiness has been reported which has the effect of reducing nighttime cooling [Karl et al., 1997].
The term "greenhouse" makes 10 appearances in the Klotzbach paper: "land use" a mere 3. For the much shorter Pielke and Matsui paper, the score is 2:0 in favour of "greenhouse". That's right, the main "issue" of land use is never once mentioned in that paper, which provides the entire theoretical underpinning for Klotzbach et al. (I'll note in passing that the arguments I have made in relation to CO2 and other GHGs also applies equally to cloudiness: clouds do not impose a forcing of the type applied by PM05, so those results are equally inapplicable in that case.)

RPJr adds some emphasis, with It is important to underscore that our hypothesis depends upon (a) the presence of a real warming trend, and (b) (to some extent) an increase in greenhouse gases. So if you accept our arguments, then you necessarily are accepting the presence of a warming trend and corresponding increases in greenhouse gases.

I wonder if anyone is fooled by Pielke Sr's lame attempt to distract from the fatal error of PM05 (and therefore Klotzbach et al 2009 which rests on it)? I'd love to hear from anyone who can argue with a straight face that the real "issue" of Klotzbach et al 2009 (and Pielke and Matsui 2005 on which it rests) was impacts of land use cover change on climate.

For the record, I agree that land use cover change may impact on the climate. But unless Roger Pielke can find some way of arguing that this has changed the net average surface flux by the order of 1Wm-2 at night, his whole theory is still a bust. And even if he did, it would not rescue his erroneous claims that the trends in temperature due to GHG or the other most significant forcings induce a significant change in the lapse rate in the boundary layer.

17 comments:

SteveF said...

This is clearly yet another example of "pathologies in climate science".

EliRabett said...

Jr. is setting the old switcheroo up, but slipping on the banana peel. He has the order wrong, the increase in greenhouse gases is what is causing the warming trend. Correctly put he should say if you accept the increases in greenhouse gases and the corresponding warming trend.

The second step in the process is to claim this means you accept the entire Pielke klotz

Hank Roberts said...

Ding. I was going to point out the same waffle Eli notes:

> the presence of a warming trend
> and corresponding increases in
> greenhouse gases.

Dirk said...

Roger:

James has already touched on the flaws of Klotzbach et al and PM05 with respect to LULC (land-use land cover) change. This is your research question for Lin et al. (2007) (para 3):

This study is a first investigation on a regional scale of near-surface, two-height temperature observations to evaluate the lapse rate variation and trends. Our analysis includes the near-surface wind effect to test the hypotheses on whether lapse trends are different during light wind versus strong wind nights [Pielke and Matsui, 2005]. We do not attempt to attribute any trends to particular climate forcings [Pielke et al.,2007], because the length of time series is limited and the knowledge of anthropogenic and natural external forcing in Oklahoma is not adequate.

Yet, you somehow have the chutzpah to conclude in your Mahmood (and ANTHONY WATTS!) et al essay that:

Using the Lin et al. (2007) observational results, a conservative estimate of the warm bias resulting from measuring the temperature from a single level near the ground is around 0.21°C per decade (with the nighttime minimum temperature contributing a large part of this bias). Since land covers about 29% of the Earth.s(sic) surface, extrapolating this warm bias could explain about 30% of the IPCC estimate of global warming. In other words, consideration of the bias in temperature could reduce the IPCC trend to about 0.14°C per decade; still a warming, but not as large as indicated by the IPCC.”

Logic fail, no?

And I'm not even going to comment on the dubious suitability of the dataset from the OKC Mesonet for examining LULC change or the warm bias. I'll save that for something else.

Dirk said...

Also, Roger -

My current weblog is an invitation to them to comment on the above paragraph (either as guest weblogs or on their sites). If they ignore this request, it would further demonstrate that they are commenting outside of their expertise on the subject of our papers, and that their real goal is simply to malign papers they disagree with.

If they ignore your request, it could also mean that folks do not wish to talk to someone who:

(a) simply does not get it;
(b) uses illogical arguments and distraction when the logical lapses are pointed out;
(c) has the hypocrisy of shutting down comments on his "weblog"(sic) despite appealing to open discussion and;
(d) questions the scientific competence of others when one's own nascent knowledge in the subject is overstated.

Not everything you say is right, Roger. My old thesis advisor once said "a little humility when you have been shown to be in error goes a long way." How about admitting you are wrong on this?

Chuck said...

I'm not familiar with this particular dust-up, but anyone looking for regional land use effects on climate should have a look at John Magee's (no relation) Lake Eyre basin work. He basically shows a massive lake level decrease after human arrival around 45ka, dwarfing the climactic signals.

Has anyone actually suggested razing the Amazon to cool and dry the planet yet? It might gain you a tenth or two...

EliRabett said...

The Amazon is gone if present trends continue, it turns to dust. Peter Cox has been thinking about this for a while

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2373904

BTW, it does not have good consequences for the rest of the planet if that happens

James Annan said...

The Amazon may be gone in Hadley Centre future world, but it is hardly there in Hadley Centre present day world ;-)

Hank Roberts said...

James, you're being smarter than me again. You always do that. Not that I object, mind you. But ...

Does your comment refer to that paper at the link Eli posted? they aren't yet modeling the existing condition, or not getting consistent results modeling changes from present, or both?

"We conclude that several concurrent SST conditions are sufficient to reduce Amazon Basin NPP to a level at which rainforest is unsustainable. ... The establishment of these Atlantic and Pacific SSTAs under greenhouse warming is uncertain; current coupled atmosphere–ocean GCMs disagree ...."

Or are you thinking of something else?

James Annan said...

I'm talking generally (haven't read that particular paper). The Hadley Centre model has notoriously weak precip in the Amazon basin (roughly half the real value), so the trees are barely alive today and fall over at the slightest hint of warming.

Chuck said...

So how much do global temperatures drop if we turn it into a desert with cool, crisp nights?

If that works, my next trick will be to increase calc-silicate weathering by bulldozing all the central American, Phillipine, and PNG cloud forests...

Steve Bloom said...

I haven't seen a relevant paper yet, but Daniel Nepstad, someone not prone to alarmist statements, recently stated that much of the forest is very much in deep trouble:

'Southern states have suffered droughts in seven of the past 11 years and the first hurricane recorded in Brazil hit the southern coast in 2004. The Amazon area had its worst drought in decades in 2005.

'Warming also plays a key role in models of a so-called "tipping point" in which drier weather and deforestation combine to turn much of the Amazon forest into a savanna and possibly cut the flow of rain to southern farming states.

'Daniel Nepstad, a senior ecologist and Amazon specialist at the Gordon and Betty Moore Foundation in San Francisco, said about half of the forest was "teetering on the edge" of not having enough water to survive the more intense dry seasons.

'The drying process, which raises the amount of destruction by fires, was on course to release about 20 billion tons of carbon into the atmosphere over the next two decades, he said, about twice the current annual total of global emissions.

'"It's just really strange the weather we are seeing," he said. "If you talk to indigenous tribes ... they describe in detail how the rain has changed."'

Hank Roberts said...

Data:
http://mercury.ornl.gov/ornldaac/send/query?term2=amazon+precipitation&term2attribute=fullText&term6=ORNL+DAAC+Archived+Data&term6attribute=datasource

I wonder if anyone's built a tool to show model results alongside data sets graphically.

EliRabett said...

The Rabett sees all switcheroos

Dirk said...

OMG. Pielke, in an attempt to harrumph his way to oblivion, has walked straight into another logical wall.

Pielke says this is the crux:

"His challenge to document a change in the net surface flux by 1Wm-2 due to landscape change is a clear demonstration that he is poorly informed about boundary layer dynamics."

No Roger, it is not (good attempt to cherry-pick though). James' post is clear - the 1 Wm-2 forcing is with respect to the PM05 model which was the main focus of this post. Yup, the PM05 model which does not include any "urban" surface. Sorry Roger, you have failed basic reading comprehension.

And since we are talking about cherry picked references - how about looking at Fig 7 of Dandou et al 2005 ("Development and evaluation of an urban parameterization scheme in the MM5") in JGR (doi:10.1029/2004JD005192)? Take a look at those urban nocturnal near surface (<50 m) lapse rates and tell me that it is stable for both (sub)urban sites.

Try reading more urban climate stuff, Roger.

Den siste mohikanen said...

James,

can you show that the diffusion layer has not changed and is not cause for a bias in min temp measurements? Cause thats really where the argument is, isn't it?

James Annan said...

I don't know what detailed measurements there may be to document changes in lapse rate. I would expect there to be some, and that a near-surface warming of 1.5C on calm nights (that PM05 claims should have happened) would stand out in the observational record.