Spencer

Measuring Global Temperature

This post is an essay by Dr. Roy Spencer, Principal Research Scientist at the University of Alabama in Huntsville and U.S. Team Leader for the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) flying on NASA’s Terra satellite.  You can read the essay in its original here at CFACT.

The official global temperature numbers are in, and NOAA and NASA have decided that 2015 was the warmest year on record. Based mostly upon surface Dr_-Roy-Spencerthermometers, the official pronouncement ignores the other two primary ways of measuring global air temperatures, satellites and radiosondes (weather balloons).

The fact that those ignored temperature datasets suggest little or no warming for about 18 years now, it is worth outlining the primary differences between these three measurement systems.

Three Ways to Measure Global Temperatures

The primary ways to monitor global average air temperatures are surface based thermometers (since the late 1800s), radiosondes (weather balloons, since about the 1950s), and satellites measuring microwave emissions (since 1979). Other technologies, such as GPS satellite based methods have limited record length and have not yet gained wide acceptance for accuracy.

While the thermometers measure near-surface temperature, the satellites and radiosondes measure the average temperature of a deep layer of the lower atmosphere. Based upon our understanding of how the atmosphere works, the deep layer temperatures are supposed to warm (and cool) somewhat more strongly than the surface temperatures. In other words, variations in global average temperature are expected to be magnified with height, say through the lowest 10 km of atmosphere. We indeed see this during warm El Nino years (like 2015) and cool La Nina years.

The satellite record is the shortest, and since most warming has occurred since the 1970s anyway we often talk about temperature trends since 1979 so that we can compare all three datasets over a common period.

Temperatures of the deep ocean, which I will not address in detail, have warmed by amounts so small — hundredths of a degree — that it is debatable whether they are accurate enough to be of much use. Sea surface temperatures, also indicating modest warming in recent decades, involve an entirely new set of problems, with rather sparse sampling by a mixture of bucket temperatures from many years ago, to newer ship engine intake temperatures, buoys, and since the early 1980s infrared satellite measurements.

How Much Warming?

Since 1979, it is generally accepted that the satellites and radiosondes measure 50% less of a warming trend than the surface thermometer data do, rather than 30-50% greater warming trend that theory predicts for warming aloft versus at the surface.

This is a substantial disagreement.

Why the Disagreement?

There are different possibilities for the disagreement:

1) Surface thermometer analyses are spuriously overestimating the true temperature trend
2) Satellites and radiosondes are spuriously underestimating the true temperature trend
3) All data are largely correct, and are telling us something new about how the climate system operates under long-term warming.

First let’s look at the fundamental basis for each measurement.

All Temperature Measurements are “Indirect”

Roughly speaking, “temperature” is a measure of the kinetic energy of motion of molecules in air.

Unfortunately, we do not have an easy way to directly measure that kinetic energy of motion.

Instead, many years ago, mercury-in-glass or alcohol-in-glass thermometers were commonly used, where the thermal expansion of a column of liquid in response to temperature was estimated by eye. These measurements have now largely been replaced with thermistors, which measure the resistance to the flow of electricity, which is also temperature-dependent.

Such measurements are just for the air immediately surrounding the thermometer, and as we all know, local sources of heat (a wall, pavement, air conditioning or heating equipment, etc.) can and do affect the measurements made by the thermometer. It has been demonstrated many times that urban locations have higher temperatures than rural locations, and such spurious heat influences are difficult to eliminate entirely, since we tend to place thermometers where people live.

Radiosondes also use a thermistor, which is usually checked against a separate thermometer just before weather balloon launch. As the weather balloon carries the thermistor up through the atmosphere, it is immune from ground-based sources of contamination, but it still has various errors due to sunlight heating and infrared cooling which are minimized through radiosonde enclosure design. Radiosondes are much fewer in number, generally making hundreds of point measurements around the world each day, rather than many thousands of measurements that thermometers make.

Satellite microwave radiometers are the fewest in number, only a dozen or so, but each one is transported by its own satellite to continuously measure virtually the entire earth each day. Each individual measurement represents the average temperature of a volume of the lower atmosphere about 50 km in diameter and about 10 km deep, which is about 25,000 cubic kilometers of air. About 20 of those measurements are made every second as the satellite travels and the instrument scans across the Earth.

The satellite measurement itself is “radiative”: the level of microwave emission by oxygen in the atmosphere is measured and compared to that from a warm calibration target on the satellite (whose temperature is monitored with several highly accurate platinum resistance thermometers), and a cold calibration view of the cosmic background radiation from space, assumed to be about 3 Kelvin (close to absolute zero temperature). A less sophisticated (infrared) radiation temperature measurement is made with the medical thermometer you place in your ear.

So, Which System is Better?

The satellites have the advantage of measuring virtually the whole Earth every day with the same instruments, which are then checked against each other. But since there are very small differences between the instruments, which can change slightly over time, adjustments must be made.

Thermometers have the advantage of being much greater in number, but with potentially large long-term spurious warming effects depending on how each thermometer’s local environment has changed with the addition of manmade objects and structures.

Virtually all thermometer measurements require adjustments of some sort, simply because with the exception of a few thermometer sites, there has not been a single, unaltered instrument measuring the same place for 30+ years without a change in its environment. When such rare thermometers were identified in a recent study of the U.S., it was found that by comparison the official U.S. warming trends were exaggerated by close to 60%. Thus, the current official NOAA adjustment procedures appear to force the good data to match the bad data, rather than the other way around. Whether such problem exist with other countries data remains to be seen.

Changes in radiosonde design and software have occurred over the years, making some adjustments necessary to the raw data.

For the satellites, orbital decay of the satellites requires an adjustment of the “lower tropospheric” (LT) temperatures, which is well understood and quite accurate, depending only upon geometry and the average rate of temperature decrease with altitude. But the orbital decay also causes the satellites to slowly drift in the time of day they observe. This “diurnal drift” adjustment is less certain. Significantly, very different procedures for this adjustment have led to almost identical results between the satellite datasets produced by UAH (The University of Alabama in Huntsville) and RSS (Remote Sensing Systems, Santa Rosa, California).

The fact that the satellites and radiosondes – two very different types of measurement system — tend to agree with each other gives us somewhat more confidence in their result that warming has been much less than predicted by climate models. But even the thermometers indicate less warming than the models, just with less of a discrepancy.

And this is probably the most important issue…that no matter which temperature monitoring method we use, the climate models that global warming policies are based upon have been, on average, warming faster than all of our temperature observation systems.

I do believe “global warming” has occurred, but (1) it is weaker than expected, based upon independent satellite and weather balloon measurements; (2) it has been overestimated with poorly adjusted surface-based thermometers; (3) it has a substantial natural component; and (4) it is likely to be more beneficial to life on Earth than harmful.

More evidence that climate models are wrong

“It doesn’t matter how beautiful your theory is; it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong.” – Richard Feynmann

“No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”– Albert Einstein

Dr. Roy Spencer and Dr. John Christy have published a graph comparing the predictions of 73 climate models versus the observations of radiosondes and satellites for tropical mid-troposphere global temperatures.  On the graph, the “spaghetti” are the model predictions and the heavy black line is the average of the models.  Actual observed temperature measurements (boxes and circles) from four balloon-borne radiosonde data sets and two satellite data sets are show to be lower than even the lowest model prediction since 1998 and lower than the average model prediction since 1979.

CMIP5-73-models-vs-obs-20N-20S-MT-5-yr-means1

It is obvious from the graph that model predictions diverge markedly from reality.  Why?  The models are programed with a false assumption, namely, that carbon dioxide is a major driver of global temperature.  That hypothesis further assumes that as carbon dioxide warms the atmosphere, more water will evaporate (water vapor is a much stronger greenhouse gas), thereby producing “an enhanced greenhouse effect” i.e., a strong positive feedback.

It appears however, that the feedback is very small and perhaps negative. The models are wrong, probably because water vapor has a net negative feedback: clouds reflect sunlight and water vapor removes heat by convection. NASA says that even carbon dioxide can act as a coolant at the top of the atmosphere, see here.

We see also that although atmospheric carbon dioxide has been rising, global relative humidity and specific humidity have been decreasing according to data from the NOAA Earth System Research Laboratory(see graphs below).  That, too, contradicts the modeling assumption. Relative humidity is the percentage of water vapor in the air relative to the maximum possible water content at a specific temperature.  Specific humidity is the ratio of water vapor to dry air in a particular mass. See here for a more detailed explanation.

Global-humidity

 

Specific-humidity

The models are wrong because of wrong assumptions.  Unfortunately, much government policy and spending billions of dollars are based on these faulty assumptions.

Temperature and humidity are not the only failures of climate models.  See: As Floods Hit Eastern Germany, Recent Potsdam Climate Institute Model Warned Of Summertime “Water Shortages”!

A new paper in Science, the journal of the American Association for the Advancement of Science says that models fail because they do not provide “an adequate description of basic processes like cloud formation, moist convection, and [air] mixing.”

See also:

A Basic Error in Climate Models

Failure of the Anthropogenic Global Warming Hypothesis

The Case Against the IPCC and Proponents of Dangerous Anthropological Global Warming

Carbon Dioxide and the Greenhouse Effect

The “greenhouse effect,” very simplified, is this: solar radiation penetrates the atmosphere and warms the surface of the earth. The earth’s surface radiates thermal energy (infrared radiation) back into space. Some of this radiation is absorbed and re-radiated back to the surface and into space by clouds, water vapor, methane, carbon dioxide, and other gases. Water vapor is the principle greenhouse gas; the others are minor players. Without the greenhouse effect the planet would be an iceball, about 34 C colder than it is. The term “greenhouse effect” with respect to the atmosphere is an unfortunate usage because it is misleading. The interior of a real greenhouse (or your automobile parked with windows closed and left in the sun) heats up because there is a physical barrier to convective heat loss. There is no such physical barrier in the atmosphere.

Carbon dioxide is a “greenhouse” gas, so let’s examine its theoretical and actual effect on temperature.

co2greenhouse3Even the IPCC agrees that the hypothetical capacity of carbon dioxide to change temperature is given by the formula: Tc = áln(C2/C1), where Tc is the change in temperature in degrees Centigrade and the term ln(C2/C1) is the natural logarithm of the CO2 concentration at time two divided by the concentration at time one. The constant á (alpha) is sometimes called the sensitivity and its value is subject to debate. This relationship was proposed by Svante August Arrhenius, a physicist and chemist, around 1896. This logarithmic formula produces a graph in the form shown at the left. This shows that as the concentration of carbon dioxide increases, its effects have less and less influence. This graph is the pure theoretical capacity of carbon dioxide to warm the atmosphere in absence of any confounding feedbacks. The different curves represent different values of alpha.

 Radiation transmitted by atmosphereThe reason it works this way is because carbon dioxide can absorb only a few specific wavelengths of thermal radiation. The current concentration of carbon dioxide has absorbed almost all available radiation in those wavelengths so there is little left for additional carbon dioxide to absorb. Notice too, that water vapor absorbs many of the same wavelengths of thermal radiation. Also notice that in a certain part of the spectrum there is an open window of no absorption.

We see, therefore, that increasing levels of carbon dioxide in the atmosphere will have a decreasing hypothetical effect on temperature. That is also why our proposed attempts to decrease atmospheric carbon dioxide will have almost no effect on temperature.

The IPCC says that warming will produce more water vapor which will enhance greenhouse warming, a positive feedback. All their climate models are based on this assumption. Sounds reasonable except in the real world, it doesn’t happen. Increased water vapor produces more clouds which block the sun thereby inducing cooling, a negative feedback.

Dr. Roy Spencer explains here why doubling the carbon dioxide concentration in the atmosphere will add only 3% to Earth’s greenhouse effect. Spencer has further discussion here in which he says, “that about 50% of the surface warming influence of greenhouse gases has been short-circuited by the cooling effects of weather.”

The atmosphere is not static; we have weather which tends to dissipate heat into space. According to real world measurements, the negative feedbacks overwhelm the theoretical positive feedback posed by the IPCC.

An example of negative feedbacks:

In 2001, a paper by M.I.T. researchers proposed that warming dissipated high-altitude cirrus clouds which had the effect of dumping heat into space, thereby helping to regulate earth’s temperature. This paper was controversial because it went against the orthodoxy of global warming and there were many detractors. However, in 2007 researchers from the University of Alabama, using NASA satellite data found evidence to support the theory. In 2009, the original M.I.T. researchers, using National Centers for Environmental Prediction’s 16-year (1985-1999) monthly record of sea surface temperature, together with corresponding radiation data from the Earth Radiation Budget Experiment, found more real world evidence in support of the theory (see PDF). It might be noted that 11 major climate models used by the IPCC assume positive feedback, but real world data shows a temperature-moderating negative feedback. However, the role of clouds is still poorly-understood and more real-world data is needed.

What happens on other planets:

Venus:

Venus has a surface temperature of about 900 F and an atmosphere composed of 96% carbon dioxide. The temperature is the same from equator to poles, from day to night (Venus rotates on its axis in 2,802 hours rather than 24 hours). Venus is often touted as the extreme example of run-away greenhouse warming. But, there is almost no greenhouse warming on Venus because little, if any, direct sunlight gets to the surface. The atmosphere is too thick. In 1975, the Russian Venus lander Venera 9 measured clouds that were 30–40 km thick with bases at 30–35 km altitude. The surface air pressure on Venus is about 92 times greater than that on Earth. The high pressure alone can explain most of the high surface temperature. Although Venus gets almost twice the solar irradiation of Earth, Venus’ high albedo reflects back 65% of the sunlight.

 Venus has almost no water vapor in the atmosphere (about 0.002%), and therefore lacks the major greenhouse gas that Earth has.

Mars:

Mars has an atmosphere composed of 95% carbon dioxide and only a trace of water. Its atmosphere is very thin. Its surface pressure is about 2% that of Earth. The temperatures on the two Viking landers, measured at 1.5 meters above the surface, range from + 1° F, ( -17.2° C) to -178° F (-107° C). However, the temperature of the surface at the winter polar caps drop to -225° F, (-143° C) while the warmest soil occasionally reaches +81° F (27° C) as estimated from Viking Orbiter Infrared Thermal Mapper (NASA data). Again, no water vapor, no greenhouse effect.

***

The greenhouse model is a simplified story that helps explain how our atmosphere works. However, the real world is very complicated and still not fully understood. Even global warming alarmist James Hansen of NASA’s Goddard Institute for Space Studies, had this to say: “The forcings that drive long-term climate change are not known with an accuracy sufficient to define future climate change.” — James Hansen, “Climate forcings in the Industrial era”, PNAS, Vol. 95, Issue 22, 12753-12758, October 27, 1998.

And even the IPCC once admitted, “In climate research and modeling, we should recognize that we are dealing with a coupled non-linear chaotic system, and therefore that the prediction of a specific future climate state is not possible.” — Final chapter, Draft TAR 2000 (Third Assessment Report), IPCC.

Human carbon dioxide emissions are 3% to 5% of total carbon dioxide emissions into the atmosphere, and about 98% of all carbon dioxide emissions are reabsorbed through the carbon cycle. (Source )

Although Earth’s atmosphere does have a “greenhouse effect” and carbon dioxide does have a limited hypothetical capacity to warm the atmosphere, there is no physical evidence showing that human carbon dioxide emissions actually produce any significant warming. If you disagree with that statement, then produce some physical evidence to refute it.

UPDATE March 3, 2011: A new paper in Geophysical Research Abstracts (Vol. 13, EGU2011-4505-1, 2011) reports that detailed spectrographic analysis found that because of the overlap absorbance of the much more abundant water vapor for long wave radiation, the effective sensitivity of carbon dioxide and methane as greenhouse gases is only one-seventh that claimed by the IPCC and used in climate models.

How Mother Nature Fools Climate Scientists

This post is a review of the book: The Great Global Warming Blunder, How Mother Nature Fooled the World’s Top Climate Scientists, by Dr. Roy Spencer.

Meteorologist Dr. Roy Spencer is a principal research scientist at the University of Alabama in Huntsville, formerly a senior scientist for climate studies at NASA, and now leads the U.S. science team for the Advanced Microwave Scanning Radiometer for EOS on NASA’s Aqua satellite. Dr. Spencer is the co-developer of the original satellite method for precise monitoring of global temperature from Earth orbiting satellites.

Dr. Spencer makes two main contentions in his book. First, the climate is much less sensitive to carbon dioxide than the Intergovernmental Panel on Climate Change (IPCC) says it is. This means that carbon dioxide is not a significant driver of temperature. Second, the Pacific Decadal Oscillation (PDO) alone can account for most of the temperature variation in the 20th Century and can account for 75% of the global warming. He supports these contentions with both observational and experimental evidence in the book. Spencer published this evidence in the peer-reviewed, Journal of Climate in 2008, but it was ignored by the IPCC and by the mainstream press – hence the book. He is taking his case to the public. The book is written in layman’s terms with easy-to-understand examples of how the climate works. He also takes on the establishment and shows how there is a vested interest in maintaining the fiction that there is a climate change problem.

Some excerpts:

“Conceptually, there are two main processes that govern any kind of climate change: forcing and feedback.” This is cause and effect, which Spencer says the IPCC has gotten mixed up.

“Worries over catastrophic global warming rest entirely on the belief that our climate system is very sensitive, that is, dominated by positive feedbacks, which amplify any warming or cooling influence. A few scientists are predicting planetary doom as a result of our burning of fossil fuels, and politicians are now using standard propaganda techniques to convince you that we must act quickly to save the Earth.”

“Whether it is the Earth’s climate, or a pot of water on the stove, a temperature change is always caused by an imbalance between energy gained and energy lost.”

“While forcing (an energy imbalance) determines whether a temperature change will occur, feedback determines how big that temperature change will be. It is feedback that ultimately determines whether man-made global warming is catastrophic, or merely lost in the noise of natural climate change.”

“A mix-up between cause and effect in observations of cloud behavior from satellites has led to the false illusion that our climate system is dominated by positive feedback. This, in turn, has led to the development of highly sensitive climate models that predict large amounts of global warming. But when the separate influences of forcing and feedback (cause and effect) are isolated, recent satellite data reveal the climate system to be dominated by negative, not positive, feedback.”

“In order to convince Congress to fund research into a problem, you must first convince them that a problem exists. This automatically makes man-made global warming a particularly lucrative field for funding – as long as the threat of man-made global warming continues. There are managers at NASA, the National Oceanic and Atmospheric Administration, the National Science Foundation, and the Department of Energy whose careers now depend on a continuous flow of research dollars through them to the science community.” Spencer notes that his own research funding comes from NASA.

“…natural cloud fluctuations in the climate system will cause a bias in the diagnosed feedback in the direction of positive feedback, thus giving the illusion of an overly sensitive climate system.”

(This statement follows a discussion of radiative and non-radiative forcings; read the book to find out what these are.)

” … the IPCC has ignored… radiative forcing generated internal to the climate system as a potential source of climate change.” What that means is “that the climate models are too sensitive, which is why they predict so much global warming for the future. In contrast, the satellite evidence indicates that the climate system is quite insensitive, which means that it doesn’t really care how big your carbon footprint is. Rather than 1.5 to 6 deg. C (or more) of warming as predicted by the IPCC, a careful examination of the satellite data suggests that man-made warming due to a doubling of atmospheric carbon dioxide could be less than 1 deg. C (1.8 deg. F) – possibly much less.”

“It would take natural variations of little more than 1 percent in global average cloud cover to explain most of the climate change seen in the last 2,000 years, yet our ability to measure such small changes has existed for only the last ten years.”

“The idea that nature was in delicate balance before mankind came along is religious, not scientific. Given the necessity of carbon dioxide for life on earth, we need to consider the possibility that more CO2 in the atmosphere will be better for life on earth, not worse.”

I recommend this book. It is a good read. It gives an easily understandable explanation of how the climate works. The book is available from Amazon.com.