Guest essay by Leland Park
Global warming theories propose positive feedbacks to explain magnified greenhouse effects that might trigger catastrophic warming. Naturally, any clues in temperature observations that might indicate feedback would be of great interest to climate science.
It turns out that climate feedback is very real, large and negative.
Climate Cause and Effect.
The concept of feedbacks presupposes a dynamic system in which cause and effect are linked through a consistent timing relationship. Thus, evidence of climate operating as a system, if it exists, should be found in comparing a cause of climate behavior with its effects. It is well known that solar energy is a dominant factor in the climate. Thus, the timing relationship between solar levels and temperatures might provide insight into climate cause and effect timing.
Figure 1 is a seasonal timeline of US average daily highs (Tmax) for US HCN stations at 36 degrees North Latitude. On that graph is an overlay of the daylight hours for same latitude, where the amount of daylight serves as a rough proxy for the pattern of solar level changes. (The two vertical scales are not adjusted for proportionality.)
Figure 1 Patterns of Daylight and Tmax for US HCN Stations at 36 No Latitude.
Several interesting observations can be made from this figure;
o the patterns of daylight hours and temperatures are both sinusoidal,
o Temperatures lag solar levels by about a month throughout the year,
o winter to summer temperature changes in excess of 40 deg F are entirely normal,
o this seasonal pattern is a consistent, recurring feature of climate behavior,
Though climate is often thought of as chaotic, it is readily apparent that the historical, repetitive pattern of cause (solar level) and effect (temperature change) means this pattern is not accidental. In fact, the cause and effect nature linking the two functions is a systematic behavior known as stimulus-response in control systems. Since this seasonal pattern actually repeats every year, the huge lag is actually a characteristic of climate behavior. In systems terms, this lag, from cause to effect, constitutes negative feedback.
As a systematic behavior we are interested in the consistency of the stimulus-response behavior. Most aspects of climate behavior exhibit variation over time, it is of interest to examine the statistical behavior associated with the seasonal patterns. Unfortunately, the ideal solar function used in Figure 1 cannot be used to match up with short term temperature variations. However, the statistical pattern of temperatures through the seasonal changes may provide insight into climate operation under change.
Figure 2 is a composite of the histograms for four selected months representing the solstice and equinox periods. Because of the climate lag, the solstice and equinox periods fall in the months of January, April, June and October. Variations in Tmax were calculated for individual stations by reference to station historical averages before inclusion into the histogram counts.
The statistical patterns for each month are nominally symmetrical about those historical averages so they correlate with the Tmax function in Figure 1. The results of these calculations is presented in Figure 2 where the mean of the distributions (and the monthly Tmax average) is represented by the 0 axis. While we do not have measured solar levels for comparison, it is clear that the climate is following the solar pattern with remarkable precision.
Figure 2 Tmax Variation Statistics for Selected Months
There are many factors that can produce variations in the seasonal Tmax. Among these are variations (by time and location) in the albedo, cloud cover, water vapor and ocean and atmospheric circulations. Despite the many reasons for variation, the climate follows the seasonal pattern closely even though the solar level is undergoing continuous change. In fact there is at least a 90 deg F round trip from winter to summer that is entirely normal at this latitude.
Figure 2 is, thus, an excellent illustration of the dynamic stability in the climate system. A passive system could not deliver the demonstrated seasonal tracking precision in following the solar stimulus. In short, the climate is behaving as if it is an active control system. More precisely, Figures 1 and 2 illustrate behavior that is consistent with that of a linear control system subjected to a sinusoidal stimulus.
Naturally, the temperature data alone is inadequate for explaining all of the effects. It should be sufficient, however, to establish that the dynamics are not “out of control”..
The Lag is Produced by Retarding Heat Changes.
During the January to July phase, the effect of the negative feedback is to retard temperature increases despite the increasing solar levels (Figure 1). Conversely, from July on, the negative feedback retards the loss in temperatures despite the waning solar levels. So the effect of the negative feedback is to retard, or delay, the effects of the solar level changes, whether increasing or decreasing.
So the cause of the temperature lag is something in the climate that can retard both heat gains and losses across the entire continent. Although atmospheric lag contributes, the daily lag of about 4 hours is far too small to account for the seasonal lag.
It is possible to surmise major characteristics of the cause of the lag. These are; 1) high relative heat capacity, 2) very large total heat capacity and 3) global impact. Those characteristics can only be met by the water in the oceans. In effect, the ocean contains such enormous amounts of water (high relative heat capacity) that they represent a vast thermal reservoir for heat absorption and subsequent release as the seasonal solar changes require.
In addition to its high heat capacity, water has special thermal properties that provide a critical link between the oceans and global climate. For example, as the sun heats the ocean a portion of the surface is evaporated carrying a large amount of heat energy into the atmosphere to be globally circulated. The relationship between water and the climate is far too complex for elaboration here, but it is clearly critical to the global climate.
Implications for Climate When Feedback is Negative.
A system with a large negative feedback is inherently stable in its operation. In this case, climate behavior is operating as if it is a linear control system where the stimulus is sinusoidal. That is, the climate will dutifully follow the solar stimulus but with a persistent delay (lag). Not only is it responding to the solar stimulus, it is responding with great precision, despite the approximately 90 deg F seasonal round trip in ambient temperatures over the year.
In fact, a system with this much lag would be quite stable with respect to minor perturbations. Inducing such a system to a permanent change in equilibrium conditions would not cause catastrophic instability. Instead the system would slowly seek a new equilibrium operating condition. For a major change in equilibrium conditions, however, a correspondingly large change in the system fundamentals would be required as well as considerable time for the change to take effect. Suffice it to say that minor changes in atmospheric trace gases would not be likely to force an equilibrium change in the system.
Implications for Climate Science.
US HCN data was mined for the graphs used in this analysis and the illustrative graphs. However, awareness of the climate lag and its approximate size could have been gleaned from an ordinary calendar. The seasonal pattern of solar level changes is well known and the solstice and equinox points are often marked on the calendars. Furthermore, calendars and almanacs have long noted that the warmest and coldest temperatures lag the solstice points.
Climate science should have begun to understand that the climate is stable when they found it necessary to continuously adjust temperature measurements to maintain the fiction that the earth is warming. If ever there was an excuse for “adjusting” field measurements, making continuing adjustments demonstrates that climate science has knowingly perpetrated a fraud.
The negative feedback between solar levels and temperatures has always existed – but never noticed, officially. I, for one, will be interested to learn how quickly climate science can adapt CO2 theory to explain away its implications.