North Carolina combined temperatures

The last post in this series, on South Carolina, brought up an unexpected temperature variation that, coincidentally, was being discussed both at Real Climate and at Climate Audit. The controversy at those two sites relates to the dip in sea surface temperatures (SST's) prior to 1970, and how accurately these were measured with the controversy relating to how many ships used a thermometer stuck into a bucket to measure the temperature, and how many used a measure of the temperature made at the inlet for the engine cooling water. Not wishing to step into that argument at the moment, what is interesting to me is that while the temperatures in Georgia and South Carolina showed a drop in temperatures over the same period and a quick check shows some drop in Maine, and Vermont, but looking at Massachusetts it seems more that the higher temperatures of around 1950 are the aberrant ones. But these are land-based and therefore not subject to the variations based on how the water was collected and held. So we will see how this pans out for North Carolina.

Location of the USHCN stations in North Carolina

North Carolina has the same number of USHCN stations as South Carolina (29) but it also has four GISS stations (whereas SC had none). The four stations are at Asheville (with data from 1903, a complete set from Charlotte, Greensboro has only data from 1948 on, and Raleigh. The average of the GISS stations shows the same drop that occurred in the states further South.

Average temperature in the state of North Carolina as a function of time, using the GISS station average.

Comparing this to the homogenized data from the stations in the USHCN, the drop is found, using the larger number of stations in that set of stations.

Average temperature in the state of North Carolina as a function of time, using the USHCN homogenized temperature average.

Average temperature in the state of North Carolina as a function of time, using the Time of Observation (TOBS) adjusted raw temperature average.

North Carolina is some 500 miles long and 130 miles wide. It runs from 75.5 deg W to 84.25 deg W, and from 34 deg N to 36.35 deg N. The central latitude is at 35.60 deg N. That of the GISS stations is at 35.65 deg N, while the USHCN is at 35.6 deg N. The state rises from sea level to 2,037 m, with a mean elevation of 213.4 m. The average GISS location is at 312.7 m, while that of the USHCN stations is at 260 m.

Looking to find the population around the different stations, Cape Hatteras is more the name of the barrier island than the community, so I checked with Google Earth:

Location of the USHCN station on Cape Hatteras near Frisco.

Frisco, checking with U.S. Beacon has a population of 401, though that was in 2000 and seems, from the photo, to be low.

And Transou does not appear in citi-data, so I also went to Google Earth for it. Looking around I decided it should have a population of about 50, although it turns out to be relatively close to Laurel Springs (population 1,400).

Location of Transou station in North Carolina – while there are lots of plots ready for housing development there are not a lot of houses yet.

The population around the GISS stations averages 361,732, while that of the USHCN stations is 61,431. That population difference might have caused a 0.47 deg difference making the GISS temperatures higher, while the difference is actually 0.22 degrees. That would be more than explained (about 0.5 deg) by the difference in elevation between the two averages.

Looking at the changes in temperature with location, North Carolina has the usual relationship with latitude:

Effect of latitude on average annual temperature in North Carolina

The state rises fairly significantly to the west:

Effect of longitude on average annual temperature in North Carolina

However the temperature fall is more likely correlated with elevation (since it goes down on the other side of the mountains).

Effect of elevation on average annual temperature in North Carolina

Looking at the population effect, and considering the average temperature over the past 5 years as the dependent variable:

Effect of local population on average temperature in North Carolina

Well it seems clear that the steep drop in temperatures around 1950 occurred in North Carolina also, so does it still hold true further north?

Oh, and that drop does not show up when one subtracts the TOBS data from the homogenized USHCN values, that adjustment is more linear.

Climate Hypotheses and the falsification thereof

There is much discussion in climate related circles about this topic being a scientifically based set of events, conclusions and predictions. In scientific circles when new ideas come along they are generally accorded the title of hypotheses and they are then subject to review, with the potential that they will ultimately be discarded because they have been shown to be wrong, or falsified as the technical term would describe it.

Essentially – to use the examples from Wikipedia, if I say that some men are immortal it is not possible to falsify the statement, since I just might not have met one of the immortals yet, but if I say all men are immortal, then production of the first dead body proves the hypothesis wrong.

The question then arises as to how much error a hypothesis is allowed, before it is considered wrong.

For instance I was looking at the Real Climate website, and noted their arguments about the data that they believe falsify Svensmark’s theories on the impact of Galactic Cosmic Rays on global climate. I find this a bit amusing really, since while they are quite happy to argue about falsification when it comes to theories that differ from theirs, they appear remarkably insensitive to seeing the shoe put on the other foot, when it comes to discussions of climate warming. (And incidentally there is some evidence that what Svensmark said is correct. (Which might be why folk, not generally considered to be idiots, are funding him).

RC's previous post, for example discusses the possibility of a pause in the steady progress of global warming that their theories have projected is still going on.

Trends in Global Temperature (from Real Climate – and previously from GISS)

Now the thing is that there is obviously some natural phenomenon going on that would (were greenhouse gases the villain they proclaim) negate the increasing effect of those gases over the past decade. And that has an impact on an earlier study.

It should be remembered that when the whole issue of global warming was first brought to large-scale public attention, one of the arguments made for the influence of greenhouse gases on the climate was that the models of climate behavior without consideration of the influence of greenhouse gases, showed relatively little change over time.

Predicted global temperatures from 13 models run by James Hansen (from Dire Predictions)

You can see that from 1965 the graph set is pretty flat, with all models showing no significant change over the period. Thus, if one accepts that there is something natural that is precluding the global temperature following the theoretical prediction, then one must go back to one of the underlying hypotheses that Dr Hansen proposed - namely that there are no natural phenomena that will likely have any significant effect on global temperatures over the period of time that we are all concerned about. Given that RC is now saying that there are natural causes that are transiently diminishing the effects of carbon dioxide on global temperatures, it would seem that they are concurrently arguing that the initial premise upon which Dr Hansen built his case has now been falsified.

Now when we look at the predictions with greenhouse gas in them then the graphs show that temperatures match those predicted when greenhouse gases are included.

Predicted global temperatures from Hansen’s models (blue), against actual temperatures (red) (from Dire Predictions).

However if one then looks at what Dr Hansen projects from 2000 to 2010 and beyond, one gets a very distinctive upturn in the predicted temperatures:

Dr Hansen’s predicted global temperatures under 3 scenarios (A business as usual; B moderate gas emissions and a volcanic event of significant magnitude; C a volcanic event and reductions in the emission of carbon dioxide by 2000). (Again from Dire Predictions).

Looking at where we are actually at relative to those three scenarios – which have temperature anomalies of A – 1.1 degrees; B – about 1 degree; and C about 0.65 degrees, one can see that the actual temperatures from the top graph are actually closest to following line C at the moment with an increase of somewhere around 0.55 degrees, which is below even the increase that that model predicts, although it does predict a lowering value, suggesting that we have already reached the target for 2012. . However this result, given that carbon dioxide levels have not fallen as predicted, suggests that the model predictions, once outside the range of conditions that prevailed at the time they were written, are not correct. In fact one could conclude that if Dr Hansen’s predictions are summarized into the hypothesis that, without the control of greenhouse gases exemplified by those measures he calls for in scenario C, that global temperatures will increase unacceptably, then this hypothesis has been falsified.

Now Real Climate argues that global temperatures should actually be considered higher, since there is insufficient data from the Arctic, which is considered to be warming much faster than the rest of the globe, and were that considered, then the models and readings would be much closer. . (Interestingly, however, when the ocean temperatures from the North Atlantic are looked at, they now appear to be declining, perhaps falsifying that argument before long).

North Atlantic Heat content (after Tisdale )

The problem with the RC argument is that is that it was the available temperature readings, relative to the model predictions that were touted as being so close in performance (graph 2) during the global warming period of the last part of the last century. Changing the data base as one moves along a line of predictions is generally frowned upon.

There is some growing body of opinion that projects that – just as with curve C above – the global temperature may stabilize around current temperatures for a total of as much as 30-years, before beginning to rise again. That is inconsistent with the predictions of the models used in the above work. Thus it seems only rational to conclude that if there is no discernable increase in temperature, on a consistent basis, in the near future, that the climate change arguments that hang on these graphs for justification must themselves be considered to be falsified.

That would be the scientific conclusion, and were this really a scientific debate then this would be a subject of discussion. Since, however, this has long passed beyond the point where it has become an article of faith with many folk, and the weakness of the foundations on which the Climate Change debate is really built is not to be considered, then one is left wondering how many years of obfustication we must tolerate before the recognition that it is worthy of considerable debate actually occurs.

A Tale of three trees

When we bought our house, there were three trees at the end of the driveway, planted when the house was built. Over the years the central tree died, and I planted a vegetable garden behind the trees. As a result of the reduced competition the tree on the right of the trio grew dramatically relative to the other.

Two trees in our drive, planted at the same time. (Note the difference in size of trunk)

I mention this series of events since it helps illustrate a very significant problem that appears to have arisen over the credibility of the data used to generate many of the curves predicting serious global warming over the next century. In order to determine temperature over the past thousand years climate scientists have relied on the quality of the rings laid down within the tree structure each year, with the assumption that, among other things, the local temperature controls the quality of the tree ring for that year. However, if the tree on the right in my driveway had been cored to look at its rings, then it would have shown a significant uptick in growth when the competing tree beside it died. It would now get more light and nutrition, and as a result may very well exhibit a growth rate that produced successive ring widths that went like this (units are 0.01 mm):

200; 350; 240; 210; 280; 350; 280; 390; 610; 740; 970

This would be in marked contrast to the poor tree sitting in its shadow, which remains shaded and does not increase the tree ring widths at all. Then consider that the first tree, because of all the extra sunlight and nutrition grows increasingly faster than the other tree, so that it now protrudes considerably above it and the surrounding canopy of trees (as you can see in the photo which I took in the last hour). It therefore in the more recent stages of its life (it is now around 40 years old) gets sunlight over a longer time period each day, and so its ring widths may go up even more markedly perhaps to:

710: 840; 900; 1090; 1220; 1600; 2020; 1150; 1020; 1920; 2120; 2500

These patterns of differential growth are, according to those who know forestry ( here and here) to be expected for individual trees in the forest, when local neighbors die, allowing both additional exposure to sunlight from the survivor, and also some additional nutrient from the corpse of the victim.

What makes this particularly germane at the moment is that such a tree record turns out to have played a very significant part in the development of the “hockey stick” curve that was made so much of in the 2004 IPCC report, and in subsequent reconstructions of temperatures over the past miilennium.

The numbers that I quoted above actually came from a tree that was found in the Yamal Peninsula (yes the home of much of Russia's future production of oil and gas) is known as YAD06 and its record was used by Keith Briffa in determining the rise in temperatures over the past century. If you look at the data for that tree, you can see (with the vertical scale normalized) that it shows a very strong increase in ring sizes since 1900.

Yamal tree ring growth (after Steve McIntyre)

Now one tree, obviously doesn’t create a viable record on its own, and in the original work Briffa and co-authors had used a dozen trees to generate the trend. And, when the data from them is examined, it does appear (although our tree is much more sensitive than the others) that there is some form of trend in the data.

Tree ring (and hence temperature) data for the 12 trees used by Briffa as a foundation to Mann’s hockey stick curve. (Source after Steve McIntyre)

However, what has not been clear until this week (there is a long story of efforts to block publication of the information which has been described by Bishop Hill and Ross McKitrick) is that there was a significantly larger body of data from which the above 12 tree chronologies were selected. When that larger body of data is examined it turns out that the trees that were not selected (of which there were a greater number) did not show this upward trend.

Tree ring (and hence temperature) measurements after being normalized, that were not included in the Briffa choice for his paper. (after Steve McIntyre)

It might be surmised after looking at this comparison that it would be more appropriate to use a more average value for the data from the region, rather than the smaller data set with the peculiarity of including our friendly example tree. But when one does that then hockey stick disappears. Briffa’s data was used extensively by other climate scientists in the past decade, and one might have thought that there would be some concern now that there is question on the validity of the underlying information used by the community.

Unfortunately the response to date at Real Climate seems to indicate, as has become increasingly obvious, that this is not about a search for truth, but rather part of the propaganda play in a political struggle. It is a curious statement that spends its time excoriating those that note the differences between the data selected and that admitted, rather than the meaning of the wider data set to the interpretation of how climate is changing. (I am however amused to see that we do see some evidence of a Medieval Warming Period now beginning to creep back into their posts).

Sadly I don't think that this is going to change the climate debate at all. Papers such as the Guardian are apparently blocking all attempts to blog about the topic on their Website (and a Google search of their site showed no hits) . and I imagine that the hope of the alarmists is that it will just go away. And in about a year they will come back with a "oh, yes we addressed that issue at the time" - citing their current post - and refuse to debate it further. It has worked for them before.

Real Climate vs Climate Science

There is a form of ongoing debate ocurring between Real Climate and Roger Pielke Sr about recent predictions in regard to what is going on with the current climate.

Basically the debate resolves around the comment

Some aspects of climate change are progressing faster than was expected a few years ago - such as rising sea levels, the increase of heat stored in the ocean and the shrinking Arctic sea ice. “The updated estimates of the future global mean sea level rise are about double the IPCC projections from 2007″, says the new report. And it points out that any warming caused will be virtually irreversible for at least a thousand years - because of the long residence time of CO2 in the atmosphere.”

Now it is an illustration of the way in which the debate is twisted that Roger Pielke begins the debate by pointing out that the conclusions drawn in that paragraph are not tenable, and provides graphic evidence to the point. (As an illustration if you look at the gradient of sea level records the most recent measurements (from the Jason satellite) have, over the time period from 2002, a shallower gradient than those from the TOPEX satellite that preceded it. (Note this is a corrected paragraph - I had written temperature instead of level, my apologies).

However, Gavin, over at Real Climate, changes the focus of the argument, from the error in the original conclusion, to interpreting the change in only the last couple of years as being a positive conclusion by Roger, and claiming that it is inaccurate because it is made over too short a period.

But the original conclusion, derived over this short time interval, is one made by the alarmists, so that, in reality the criticisms that Gavin is advancing argue against the conclusions that he is touting, rather than the criticisms of them. (Although it must be noted that the criticism that the report distorts data in its interpretation also holds true if one looks at the longer picture). It cannot be acceptable to sieze on short term changes - such as the transient drop in ice area - and accept the two-year interval over which this occured - but then deny the evidence, over the longer period, that this is purely transitory, on the criticism that the longer period is too short to allow a realistic conclusion (after drawing one from the shorter interval).

The criticism made of the conclusion that the climate changes are accelerating is not born out by the evidence, and such evidence as there is argues against the conclusions. It is a pity, therefore, that the conclusions are getting the scale of publicity and acceptance that they are.