Donald Rapp has posted on the two papers that appeared at Climate Etc in the post by the authors titled Two new papers vs. BEST. [note: he prepared this post before Richard Tol’s post appeared late yesterday at Climate Etc in the post Tol’s critique of the Ludecke et al. papers].
where it is written that
“Dr. Donald Rapp is author of two new books, “Human Missions To Mars” plus “Assessing Climate Change: Temperatures, Solar Radiation, and Heat Balance.” Dr. Donald Rapp has 48 years of post-doctoral experience. He is a true generalist. I am 50% scientist and 50% engineer. He has worked on an extremely wide variety of technical problems over the years and has wide knowledge of things technical. Dr. Rapp has a solid grounding in chemistry and physics and did fundamental work in these sciences for many years. In the second half of his career he worked on more applied problems, particularly in space technology and space mission design. He is an expert in requirements, architectures and transportation systems for space missions, with particular emphasis on impact of in situ resource utilization, and water resources. He has surveyed the wide field of global climate change and is familiar with the entire literature of climatology. Dr. Rapp is known far and wide in the NASA community as for my abilities to plan, organize and lead studies of broad technical systems. My services have been often sought in writing and reviewing major proposals for space ventures. His education includes B.S. Chemical Engineering, Cooper Union, 1955, M.S. Chemical Engineering, Princeton, 1956, Graduate study, California Institute of Technology, 1957, Ph.D. Chemical Physics, University of California (Berkeley) – January, 1960. From 2005-2008, Dr. Rapp has been at JPL as a Consultant through Skillstorm, Inc.”
Brief Commentary on Two Recent Papers by Donald Rapp
(L) Lüdecke, H.-J. (2011) “Long-Term Instrumental and Reconstructed Temperature Records Contradict Anthropogenic Global Warming”, Energy and Environment 22, 723-745.
(LLE) Lüdecke, H.-J., R. Link, and F.-K. Ewert (2011) “ How Natural is the Recent Centennial Warming? An Analysis of 2249 Surface Temperature Records”, International Journal of Modern Physics C 22, xxx.
Lüdecke (2011) and Lüdecke et al. (2011) were primarily concerned with the question of how to determine how much of warming in the 20th century was due to anthropogenic influence, and how much was due to natural fluctuations in the climate. They “analyzed 2249 worldwide monthly temperature records from GISS (NASA) with a 100-year period covering 1906-2005 and the two 50-year periods from 1906 to 1955 and 1956 to 2005”. All of their sites were on land, although they noted which ones were within 30 km from an ocean. They divided the data into groups based on the estimated population near the measurement site. Most of their sites were located in a rather narrow range of northern latitudes (30-50°N) as shown in the left side Figure 1. The distribution of measured temperature anomalies is shown in the right side of Figure 1.
Figure 1. Left figure: Distribution of latitudes of measurement sites. Right figure: Distribution of temperature anomalies over these sites for the 100-year interval 1906-2005. One vertical line is drawn at zero. The other is drawn at +0.58°C (Lüdecke, 2011).
Figure 2. The number of stations vs. the population of the location (Lüdecke, 2011).
Lüdecke (2011) showed that the distribution of measurement stations vs. population was as shown in Figure 2. About 25% of the sites were located in areas where the population was > 100,000. He found that the mean of all stations indicated a temperature rise of 0.58°C from 1906 to 2005. But 85% of the stations were concentrated in the latitude range 30-50°N. Since climate models indicate that temperature changes are amplified at these latitudes by roughly 25% compared to the global average (e.g. Holland and Bitz, 2003), we might guess that their data suggest that the global average rose by perhaps 0.48°C. Restricting consideration to stations with a population of under 1,000 (and below 800 m in elevation) the 0.58°C figure drops to 0.41°C. However the scatter in the data vs. population and elevation was very large. They concluded from this that a strong UHI warming could be identified from this. About a quarter of all records indicated falling temperatures from 1906 to 2005. According to Lüdecke (2011) this would be “an indication that the observed temperature series are predominantly natural fluctuations”.
These papers did not provide much detail on the temperature station data used by Lüdecke (2011) or the proxies that were used by Lüdecke et al. (2011). In fact, the treatment of the data acquisition was very cursory. They provide references to the sources of their data but they don’t really introduce any new discussion of the credibility, uncertainty or completeness of the data. In fact, in both papers, the data are presented rather late in the papers.
These papers were mainly concerned with the question of whether one can discern a human influence in the station temperature data, as opposed to natural variability. There is quite an extensive literature attempting to deal with this question. From the start, both papers plunge into mathematics aimed at determining to what extent there is long-term correlation in the data. In other words, is there a detectable long-term trend? However they are not very clear on the philosophy of their approach. Perhaps the closest they come is in the passage:
“Temperature series are persistent – other notations are ‘long-term correlated’ or ‘long-term memory’ -, which is a well-known phenomenon. A warm day is more likely to be followed by another warm day than by a cold day, and vice versa. Short-term persistence of weather states on a time scale of about one week is caused by general weather situations. Longer-term persistence over several weeks is generally caused by blocking situations that arise when a high pressure system remains in place for many weeks. Persistence over many months, seasons, years, decades, and even longer periods is usually associated with anomaly patterns in sea surface temperatures, and even with the influence of long-term variations in the activity of the sun, but there is no universal explanation that can be used in all causes.”
It appears that a widely accepted underlying philosophy begins with the belief that natural variations are random and cannot generate long-term trends, whereas long-term trends are indicative of external impacts. Apparently, this belief was used by those of the alarmist persuasion (e.g. Barnett et al., 2005a) to infer that indeed, the effect of human influence is readily discernible in the data. I have the impression that just as Barnett et al. (2005) begin with the belief that human generation of greenhouse gases has impacted the climate significantly, Lüdecke (2011) began with just the opposite belief. To support this view, he showed (for example) in his Figures 1 and 2 that at least for some stations, there were down trends from 1800 to 1900 followed by up trends after 1900. If the up trends after 1900 were caused by an external influence (greenhouse gases), what caused the downtrends prior to 1900?
By some reasoning that I cannot follow, he concluded: “the impact of anthropogenic greenhouse gases is most probably a minor effect and – in view of the 19th century temperature fall of similar magnitude – not appropriate as an authoritative explanation for any temperature rise in the northern hemisphere during the 20th century”. But then by further reasoning that seems very far fetched to me, he suggested: “The hypothesis expressed here suggests that the Sun could be predominantly responsible for the 100-year-long rises and falls in temperature over the last 2000 years”.
There seems to be a fundamental unstated postulate underpinning the alarmist view of climate that is:
The climate of the earth is deterministic. Like Newton’s first law of motion, the earth’s climate will persist in its present state unless acted upon by external forces. Any significant change in climate must be attributable to external forces.
This is why it is so important for the alarmists to minimize the magnitude and extent of the Medieval Warm Period and the Little Ice Age (ala Mann, Jones, et al.). With a relatively constant climate persisting for thousands of years, a sudden change to a persistent warming would be a strong indicator of human influence, and what else could that be but rising greenhouse gases?
Spencer and Braswell (2007, 2010, 2011) pointed out that in addition to external forces “internal factors” operating near the Earth’s surface might affect global temperatures and heat flows. These might include random variations in cloud cover in the earth’s climate system, “brought about through circulation‐induced changes in tropospheric wind shear, frontal system behavior, precipitation efficiency, trade wind inversion strength, or any other of the myriad processes that can potentially affect cloud formation other than feedback upon temperature” and non-radiative forcing of temperature change such as tropical intra-seasonal oscillations in the rate of heat transfer from the ocean to the atmosphere.
Spencer and Braswell (2011) put it very succinctly:
“The sensitivity of the climate system to an imposed radiative imbalance remains the largest source of uncertainty in projections of future anthropogenic climate change. Here we present further evidence that this uncertainty from an observational perspective is largely due to the masking of the radiative feedback signal by internal radiative forcing, probably due to natural cloud variations…. It is concluded that atmospheric feedback diagnosis of the climate system remains an unsolved problem, due primarily to the inability to distinguish between radiative forcing and radiative feedback in satellite radiative budget observations.”
What this means, is that there is too much scatter to determine whether changes in cloudiness are directly due to changes in surface temperature vs. innate changes in cloudiness in the internal climate system that produce changes in temperature.
In other words, as the Earth goes through it chaotic variability, it is possible that it can generate its own long-term trends due to feedback effects. For example, if there is a random change in cloudiness or wind pattern or whatever that persists for quite a few years, this could set into motion feedback effects that could move the climate persistently in one direction, and the whole thing got started internally. Hence, the detection of a long-term trend it not necessarily proof of an external influence as the driver.
All of this remains unproven.
Barnett, T., F. Zwiers, G. Hegerl, M. Allen, T. Crowley, N. Gillett, K. Hasselmann, P. Jones, B. Santer, R. Schnur, P. Stott, K. Taylor and S. Tett (2005) “Detecting and Attributing External Influences on the Climate System: A Review of Recent Advances” LLRL Report UCRL-JRNL-209353.
Spencer, Roy W. and William D. Braswell (2007) “Potential Biases in Feedback Diagnosis from Observational Data: A Simple Model Demonstration” Journal of Climate 21, 5624-5628.
Spencer, Roy W. and William D. Braswell (2010) “On the diagnosis of radiative feedback in the presence of unknown radiative forcing” Journal of Geophysical Research, 115, D16109.
Spencer, Roy W. and William D. Braswell (2011) “On the Misdiagnosis of Climate Feedbacks from Variations in Earth’s Radiant Energy Balance” Remote Sensing 3, 1603-1613.