Something that fascinates me about the science of global warming is that some climate ‘experts’ do not have any better understanding of the basic physical processes involved than the lay person does.

For instance, in a recent paper of mine that was rejected for publication in Geophysical Research Letters, the editor assigned only a single peer reviewer, who did not even understand what causes temperature to change. And yet, the reviewer was casting judgment on my analysis that showed that the cloud-altering behavior of the Pacific Decadal Oscillation over the last 100 years might explain most of what we now call climate change and global warming.

So, let’s review the basics of why the temperature of an object changes. In a few minutes, you will have a better understanding than even that (presumed) climate expert has. It doesn’t matter whether it is the Earth, or a pot of water on the stove, the fundamental concepts are the same. And if you think you already understand why a pot of water on the stove warms up, you might be in for a surprise.

Question: TRUE or FALSE? A pot of water on the stove warms because the stove is transmitting heat into the pot.

Answer: FALSE.

Well…it’s only half true. Let’s examine what happens when we place a pot of room temperature water on a hot stove. In the following figure I’ve illustrated the flows of heat with arrows.

Let’s say it is a gas stove, so that we can produce a small, constant flame under a pot of room temperature water, with no lid. Heat flows from the stove into the pot, and the water gradually warms.

After about 10 minutes, though, the water reaches a certain temperature and just stays there. But how can this be? How can the stove still be pumping heat into the pot, and yet the water has stopped warming? Obviously, what controls the temperature of the water is more than just the rate of heat input from the stove.

What we are missing is that the pot was losing heat to its surroundings at the same time it was gaining heat from the stove. As illustrated in the above figure, the temperature of the pot will only change if there is an imbalance between the rate of heat flow into the pot and the rate of heat flow out of the pot.

As the water started to warm on the stove, the pot became warmer than its surroundings, and so it also started to lose heat to its surroundings. This happens through three processes: (1) faster evaporation of the water, (2) air currents flowing past the pot and picking up heat and carrying it away, and (3) loss of infrared (heat) radiation of the warmer pot to its cooler surroundings.

As the water got warmer and warmer, those three heat loss processes accelerated. Finally, a temperature was reached where the rate of heat loss by the pot equaled the rate of heat gain from the stove. It is only at this point of energy balance that the temperature stops changing.

And, as I have illustrated in the following figure, it doesn’t matter whether it is a pot of water or the Earth, the basic concept is the same. An imbalance in the rate of energy flows in and out of the Earth, or the pot, will lead to a temperature change.

The main difference is the length of time involved for the temperature to respond to an imbalance: It takes only minutes for a few inches of water in a pot to come to a new equilibrium temperature. But it can take years for an energy imbalance of the Earth to cause hundreds or thousands of meters of ocean depth to fully respond with a temperature change.

Also note that warming can be caused either by (1) increasing the rate of energy gained, OR (2) decreasing the rate of energy lost. It is the second process that is involved in the theory of manmade global warming: Increasing atmospheric CO2 concentrations slightly reduce the rate at which infrared heat is lost by the Earth to outer space, leading to an energy imbalance. Warming then results, which stops after energy balance is once again restored as a warmer Earth radiates infrared energy at a greater rate to outer space.

In fact, the mechanism of heat loss by the Earth is simpler than that of a pot of water on the stove. Because there is no air in outer space to carry heat away from the Earth, there is only one heat loss mechanism, not three: Infrared radiation.

Of course, anything that can change the rate of energy input or output can cause climate change. For instance, natural fluctuations in atmospheric circulation patterns can alter global cloud cover by a small amount, thereby changing how much sunlight is allowed to reach the Earth’s surface. Or, circulation changes might result in small wind shear-induced changes in precipitation efficiency, thereby altering how much water vapor – our main greenhouse gas – is allowed to remain in the atmosphere. These natural fluctuations can cause warming or cooling.

And these are only two examples of the many potential kinds of natural climate change that the Intergovernmental Panel on Climate Change (IPCC) simply assumes do not exist.

The issue of global warming has so many facets that it has always been difficult to concisely state the objections we skeptics have to the theory (yes, ‘theory’) that our present warmth is caused by all of you consumers out there driving your SUVs and eating Big Macs. What follows is a demonstration of my main objection.

The claim that global warming is due to people is indeed a valid hypothesis. Human activity produces carbon dioxide, carbon dioxide in the atmosphere is increasing, and CO2 is indeed a greenhouse gas. Ergo….

But how often in science is it decided that the first hypothesis to come along will forever be the only one allowed? That is effectively what the United Nations Intergovernmental Panel on Climate Change (IPCC) has done.

Ever since the IPCC was formed twenty years ago, their intent has been to tie global warming to human greenhouse gas emissions. They have never seriously investigated potential natural sources of global warming…except to say they can’t think of any that are large enough to cause the warming.

They then run their climate models with tiny forcings, such as a tiny change in solar output, and then say, “See? Natural forcings can not explain warming…only increasing CO2 can!” This conclusion is then advertised with words like “this demonstrates that natural forcings can not explain global warming”.

As I keep emphasizing, though, this only shows how little we know about natural climate variability. The assumption that the climate system has always been in balance, with a constant temperature, until humans came along is just that: an assumption. There is no way to prove it because we do not have the global measurements needed to prove it.

AN EXAMPLE OF NATURAL GLOBAL WARMING

To demonstrate how easy it is for nature to cause global warming, I’ve run an enhanced version of the simple climate model described by Spencer & Braswell (2008), and assumed daily random changes in cloud cover, smoothed them with a 10-year averaging filter, and run the model over a 50 year period of time. I have also included the increasing global energy imbalance due to increasing carbon dioxide at the rate of 0.2 Watts per sq. meter per decade. A 30 meter deep ocean mixed layer absorbs or loses energy in response to the imbalances, and the resulting heating and cooling slowly diffuse to a second layer 300 meters deep. I’ve assumed zero net feedback, as suggested by some observational studies.

The following plot (Fig. 1) shows how much of a global radiative energy imbalance would be observed by satellites…if we had satellites that far back in time. The fluctuations seen here average about 1.4 Watts per sq. meter, which is similar to the 1.5 Watts per sq. meter that a recent reanalysis of Earth Radiation Budget Satellite data has shown (Wong. et al., 2006).

Fig. 1. Global average top-of-atmosphere radiative imbalance from increasing carbon dioxide and random cloud variations, the forcings from which drive the simple model’s temperature variations seen in Fig. 2.

By way of comparison, these variations are only 0.6% of the average amount of energy the Earth is continuously absorbing from the sun. So we are talking about small changes in global average cloud cover.

The temperature response of the global oceans to the CO2- and cloud-induced energy imbalances is shown in Fig. 2.

Fig. 2. Temperature response of the simple model to the random cloud and increasing CO2 forcing shown in Fig. 1.

As can be seen, realistic temperature variability is produced, and there are substantial warming and cooling trends that occur on time scales of 10 to 30 years or more. I picked this particular simulation (each one is different as the random numbers change) because it looks similar to the global-observed temperature variations since the 1940s…cooling for a couple of decades, then strong warming for 30 years, which then levels off.

In this particular simulation, 50% of the fifty year warming trend is due to the natural cloud variations, the other 50% is due to increasing CO2. If I remove the cloud variations, the temperature curve follows a trend line that looks like the one in Fig. 2, but with only half the slope.

The assumed (neutral) feedback corresponds to a net surface warming of about 1 deg. C for a doubling of carbon dioxide. Since we’ve already experienced that amount of warming in the last 100 years, this would mean that global warming would now be ended for about the next 50 years….which is about how long it will take to reach CO2 doubling in the atmosphere.

If feedbacks end up being negative, though, then extra CO2 will have caused even less warming, which means that there is even more room for natural cloud variability to explain the warming experienced in the last 50 to 100 years. More about that possibility later.

The first objection to what I have just presented would probably be, “How do we know that natural cloud changes like that even exist?” Well, previous satellite studies (e.g. Wong et al.) have shown that similar fluctuations in the Earth’s radiative energy balance exist. All I’m claiming is that they existed in nature before we had satellites to measure them, which seems like an entirely reasonable assumption.

The second objection to what I have presented would probably be, “But you have not assumed positive feedback, and climate models show that the climate system has positive feedback!”

This issue is, of course, what I spend most of my time working on. And, as I have been harping on ad nauseum, the illusion of a sensitive climate system has arisen also because previous investigations have ignored natural, internally-generated cloud fluctuations, which cause a bias in their estimates of feedback toward positive feedback (Spencer & Braswell, 2008).

Our new mega-paper, almost ready for submission to JGR, introduces a new method to separate the effects of cloud forcing from cloud feedback. It leads to a diagnosis of strongly negative feedback in our most recent 7.5 year record of satellite data. (BTW, the negative feedback is only in the reflected solar part – probably due to low clouds. The infrared feedback was positive, probably due to positive water vapor feedback). The method also works pretty well at diagnosing the feedbacks in the IPCC climate models.

Oh, and guess what happens if we use the old traditional method of estimating feedback from the model data shown in Figs. 1 and 2 by plotting yearly averages of each against each other? You get a ‘false positive’…stronger positive feedback than even any of the IPCC climate models exhibit…even though neutral feedback was assumed in the model simulation.

Natural climate variability is the 800 pound gorilla in the room that the IPCC has been ignoring.

I get an amazing number of e-mails from engineers who point out that the climate system can not be dominated by positive feedback, because that would mean the climate is unstable, in which case it would have careened out of control long ago.

So, I have to keep explaining to them that climate researchers have ‘redefined’ positive feedback. We borrowed the concept from electric circuit theory, which was elucidated back in the 1940s. And, yes, all of you engineers are right…in your terms, the climate system IS dominated by negative feedback. The Earth DOES lose extra energy to outer space when it warms, which then stabilizes the climate system against perturbations.

But in the climate research world, the dividing line between ‘positive’ and ‘negative’ feedback is not whether extra energy is gained or lost with warming, but whether the increase is greater (or not) than the ‘temperature-only’ increase in infrared energy loss with warming.

That temperature-only response is what you feel when you turn up the stove, or make a fire bigger — hotter objects give off more radiant energy. Positive feedback in the climate system is defined as any indirect change in response to the warming (for instance, fewer low clouds) which then reduces the energy loss below the temperature-only response. This causes more warming to occur before energy equilibrium is once more restored.

In the absence of feedbacks, this temperature-only response is estimated to be about 3.3 Watts per sq. meter per degree C at the effective radiating temperature of the Earth, which is about 255 Kelvin (-18 deg. C).

Of course, what this also means is that if positive feedbacks exceeded that 3.3 Watts, then we really DO have an unstable climate system. So, in some sense, the climate system is always 3.3 Watts in positive feedback away from oblivion.

If positive feedbacks decrease the response from 3.3 to 1 Watt, then warming from a doubling of atmospheric CO2 would be almost 4 deg. C. That’s a lot of warming.

But if negative feedbacks dominate, and they increase that 3.3 Watts to, say, 3.7 Watts then there would only be 1 deg. C of warming with doubling of CO2.

Or, if (like our latest research suggests), the loss of radiant energy is as large as 6 Watts per degree of warming, then manmade global warming becomes only 0.6 deg. C.

Obviously, the feedbacks operating in the real climate system is the most important question in global warming research. But, unfortunately, there is relatively little research going on in this area. Everyone is too busy playing with computerized climate models.

But you engineers are indeed correct: When we climate researchers talk about positive feedback, what we are really talking about (in electrical engineering terms) is weak negative feedback.

…my April Fools Day post was NOT real, folks. Please stop sending me e-mails.

As regular readers here are already aware, I am increasingly convinced that the greatest mistake that the IPCC and mainstream climate researchers have made is their assumption that cloud cover on the Earth remains the same on climate time scales, say over 30 years or longer. The issue is critical because clouds determine how much solar energy is absorbed by the Earth, which then largely determines average global temperatures.

Assuming that cloud cover remains the same is part of the climate modelers’ worldview in which nature was in balance before humans came along and upset that balance.

But there is no way to support this worldview with data…it is a matter of faith. It takes only a 1% change in global average cloud cover to cause substantial climate change, either warming or cooling. It has only been since 2000 that have we had sufficiently stable satellite data (from NASA’s Terra and Aqua satellites) to determine whether there are any long-term, natural changes in global cloudiness, and unfortunately eight years of data is not much in the context of climate change.

Even our latest, state-of-the-art radiation budget instruments on those same satellites are still not sufficient to measure whether an imbalance in the Earth’s radiative budget exists to better than about 1% (about 4 Watts per sq. meter). That’s five times the ‘manmade imbalance’ that has been theorized to exist today from anthropogenic greenhouse gas emissions.

But there’s an interesting consequence of this assumption that the climate system has always been in balance: The assumption ends up leading to a tautology – a process of circular reasoning – regarding the role of mankind in climate change. Let me explain.

As we demonstrated in our 2008 J. Climate paper, chaotic fluctuations in cloud cover can give the illusion of positive feedback – that is, of a sensitive climate system. Climate researchers who have previously tried to determine how sensitive the climate system is from satellite data have ignored the biasing effect that natural, chaotic cloud fluctuations have on their estimates of feedback. And as a result, they have overestimated climate sensitivity. (As I have mentioned before, this can also be explained as getting cause and effect mixed up when observing cloud and temperature variations.)

This, in turn, has influenced how the climate modelers build their climate models. All of the IPCC climate models now produce a sensitive climate system, which amplifies the small amount of warming from the extra carbon dioxide in the atmosphere by a sufficient amount to explain most, if not all, of the warming we have seen in the last 50 years.

So, if the climate system is sensitive, then there is no need for a natural explanation for global warming (such as clouds) because increasing CO2 concentrations are sufficient to explain the warming.

But do you see what has happened here? By ignoring natural, chaotic fluctuations in clouds, researchers have come to the (mistaken) conclusion that there is no need to look for clouds as a cause of climate change. They ended up concluding only what they had assumed to begin with!

But I will admit that circular reasoning has one advantage: It always results in a self-consistent explanation.

So, when you hear that climate researchers have determined that the only way they can explain warming in the last 50 years is with human influences, you need to be very wary. The reason they can explain the warming only when they include humanity’s greenhouse gas emissions is because we do not have sufficiently accurate global observations to say otherwise.

So, since they don’t have the data to determine whether there are natural sources of climate change, they simply ASSUME it does not happen. This makes the theory of manmade global warming to large extent a matter of faith. From talking to a few of them, I think that many of these researchers are not even aware they have made this implicit assumption.

And the truth is there is no unique human fingerprint of global warming to identify our present warmth as manmade, either. For instance, a slight natural decrease in cloud cover would let more sunlight in and cause the oceans to warm, thus causing an increase in water vapor (our main greenhouse gas), which would then look like manmade warming. Even the greater warming over land than the ocean we have experienced can be explained by warming oceans…because warmer oceans send more humid airmasses over land, which then causes a naturally-enhanced greenhouse effect over land. (This finding was published here.)

I find that meteorologists (by training) are perfectly comfortable with the idea of natural cloud fluctuations causing climate change. But climate modelers tend to look down on meteorologists, who as a group are generally distrustful of climate models.

I would argue that, until climate modelers begin to appreciate the complexities of weather – especially of clouds — as much as meteorologists do, then their efforts to predict climate change with computer programs will be as futile as tilting at windmills.

…hot off the press…N. Hemisphere & tropics really cooled off last month.

YR MON GLOBE   NH   SH   TROPICS
2009   1   0.304   0.443   0.165   -0.036
2009   2   0.347   0.678   0.016   0.051
2009   3   0.208   0.313   0.104   -0.150

1979-2009 Graph

(corrected 2 April 2 p.m. CDT for error in discussion of Kirchoffs Law…kudos to Ben Herman, U. Arizona)

One of the points that Dr. Richard Lindzen made during his keynote speech at the 2nd International Conference on Climate Change, held in New York City March 8-10 this year, is that we global warming skeptics need to be careful about what aspects of the theory of manmade global warming we dispute.

And I fully agree.

In an e-mail I just responded to this evening, I once again found myself defending the existence of the Earth’s “greenhouse effect”. I’m talking about the Earth’s natural greenhouse effect, not mankind’s small enhancement of it. And it’s amazing how many scientists, let alone lay people, dispute its existence.

I’ll admit I used to question it, too. So, many years ago Danny Braswell and I built our own radiative transfer model to demonstrate for ourselves that the underlying physics were sound.

To briefly review: because water vapor, clouds, carbon dioxide, and methane in the atmosphere absorb and emit infrared radiation, the atmosphere stays warmer in the lower atmosphere and cooler in the upper atmosphere than it would otherwise be without the greenhouse effect.

Even though the physical process involved in this is radiative, the greenhouse blanket around the Earth is somewhat analogous to a real blanket, which we all know tends to hold heat in where it is being generated, and reduce its flow toward the colder surroundings. A blanket – real or greenhouse — doesn’t actually create the separation between hot and cold…it just reduces the rate at which energy is lost by the hot, and gained by the cold.

In the case of the Earth, most sunlight is absorbed at the surface, which then heats and moistens the air above it. This solar heating causes the lower atmosphere to warm, and the greenhouse effect of the water vapor thus generated helps keep the lower atmosphere warm by reducing its rate of cooling. (Long before radiation can make the surface too warm, though, convective air currents kick in…e.g. thunderstorms…and transport much of the excess heat from the lower to the upper atmosphere. As a result, the lower atmosphere never gets as warm as the greenhouse effect ‘wants’ to make it.)

So where do the objections to the “greenhouse effect” come in?

IT’S NOT A REAL GREENHOUSE
The processes involved in the atmospheric greenhouse effect are not the same as what happens in a real greenhouse. Yes, we all know that, but the misnomer has stuck, and it is not going away anytime soon. A real greenhouse physically traps warm air, preventing convective air currents from carrying warm air out of the greenhouse, which would then be replaced by cooler air coming into the greenhouse. In contrast, the infrared atmospheric greenhouse effect instead slows the rate at which the atmosphere cools radiatively, not convectively.

IT VIOLATES THE SECOND LAW OF THERMODYNAMICS
A second objection has to do with the Second Law of Thermodynamics. It is claimed that since the greenhouse effect depends partly upon cooler upper layers of the atmosphere emitting infrared radiation toward the warmer, lower layers of the atmosphere, that this violates the 2nd Law, which (roughly speaking) says that energy must flow from warmer objects to cooler objects, not the other way around.

There are different ways to illustrate why this is not a valid objection. First of all, the 2nd Law applies to the behavior of whole systems, not to every part within a system, and to all forms of energy involved in the system…not just its temperature. And in the atmosphere, temperature is only one component to the energy content of an air parcel.

Secondly, the idea that a cooler atmospheric layer can emit infrared energy toward a warmer atmospheric layer below it seems unphysical to many people. I suppose this is because we would not expect a cold piece of metal to transfer heat into a warm piece of metal. But the processes involved in conductive heat transfer are not the same as in radiative heat transfer. A hot star out in space will still receive, and absorb, radiant energy from a cooler nearby star…even though the NET flow of energy will be in the opposite direction.

In other words, a photon being emitted by the cooler star doesn’t stick its finger out to see how warm the surroundings are before it decides to leave.

Furthermore, we should not confuse a reduced rate of cooling with heating. Imagine you have a jar of boiling hot water right next to a jar of warm water sitting on the counter. The boiling hot jar will cool rapidly, while the warm jar will cool more slowly. Eventually, both jars will achieve the same temperature, just as the 2nd Law predicts.

But what if the boiling hot jar was by all by itself? Then, it would have cooled even faster. Does that mean that the presence of the warm jar was sending energy into the hot jar? No, it was just reducing the rate of cooling of the hot jar. The climate system is like the hot jar having an internal heating mechanism (the sun warming the surface), but its ability to cool is reduced by its surroundings (the atmosphere), which tends to insulate it.

Another way the objection is voiced is that a layer of the atmosphere that absorbs infrared energy at a certain rate must then also emit it at the same rate, so how can that layer “trap” any energy to warm? This misconception comes from a misunderstanding of Kirchoffs Law, which only says that the infrared opacity of a layer makes that layer’s ability to absorb and emit IR the same. The actual rate of infrared absorption by a layer depends upon that opacity AND the temperatures of the emitting layers above and below, but the rate of emission depends upon the the same opacity and the temperature of the layer itself. Therefore, the rate of infrared flows in and out of the layer do not have to be equal, and if they are not equal, the layer will either warm or cool radiatively.

THE ATMOSPHERE IS ALREADY OPAQUE TO THE TRANSFER OF INFRARED ENERGY

Some claim that since the atmosphere is already quite opaque to the transfer of infrared energy, adding a little more CO2 won’t do anything to warm the lower atmosphere and surface. While there is a grain of truth to this, it must be remembered that the Earth’s surface does not radiatively cool directly to outer space, but to the layer of air above it, which in turn cools to the next layer of air above it, etc.

Think of it like several blankets covering your body on a cold night. Your body does not lose energy directly to the cold air outside of the blankets, but to the first blanket, which then transfers heat to the second blanket, etc.

Finally, the most vivid evidence that infrared radiation can cool something below the temperature of its surroundings – in seeming contradiction to the 2nd Law — is what happens on a clear calm night. The Earth’s surface cools by losing infrared radiation, which then chills the air in contact with it. This nighttime cooling causes a thin layer of cold air to build up near the surface…even though it is colder than the ground below the surface, or the air immediately above it.

There is no way for cooler air aloft coming down to the surface to be causing this effect because when air descends from any altitude, it will always be warmer (not colder) than its surroundings, due to adiabatic compression.

Therefore, we have a cold air layer sandwiched in between two warmer layers, becoming colder still as night progresses. Is this a violation of the Second Law of Thermodynamics? No, because the entire depth of the atmosphere – as a system — is indeed losing infrared energy as a whole to the cold depths of outer space.

The same thing happens to the top of your car when the sun sets…it cools by infrared radiation to a temperature cooler than the air, and as a result is often the first place you will see dew form.

THE GREENHOUSE EFFECT WORKS…FOR NOW
The greenhouse effect is supported by laboratory measurements of the radiative absorption properties of different gases, which when put into a radiative transfer model that conserves energy, and combined with convective overturning of the atmosphere in response to solar heating, results in a vertical temperature profile that looks very much like the one we observe in nature.

So, until someone comes along with another quantitative model that uses different physics to get as good a simulation of the vertical temperature profile of the atmosphere, I consider objections to the existence of the ‘greenhouse effect’ to be little more than hand waving.

(OK, folks, this has gotten out of hand. I’m still getting e-mails asking what my source was for the information below. Note…I posted this on April Fools Day, and I dropped a pretty obvious hint in the last line, but some of you still think this was real. It’s not.)

In an unprecedented about-face, Al Gore last night recanted his claim that mankind is causing global warming. The announcement was made late Tuesday night from his Nashville home through his press secretary. Mr. Gore has remained unavailable for comment. In part, the announcement reads:

“While I will continue to support the development and rapid deployment of alternative energy technologies, I believe that the science can no longer support the view that catastrophic global warming is probable. This decision has required considerable soul searching on my part. But this is the nature of science, and scientific progress. I have no regrets over the path I have chosen.”

The announcement says that Mr. Gore will be publicly renouncing his portion of the Nobel Peace Prize, which was awarded to him in 2007 for his tireless efforts to raise global awareness of the climate crisis. In fact, he will no longer be referring to the fight against a ‘climate crisis’, but instead the fight will continue against a “global energy crisis”.

“The need for inexpensive and readily available energy is the most important issue facing the world’s poor”, the statement reads, “and I will be advocating free market approaches to the leaders of Third World countries in order to allow their citizens to enter and contribute to the 21st Century global economy.”

There is also the hint that he is considering returning his Academy Award for best documentary, although he hopes that a new movie category (best movie, science fiction) will be created to accommodate his highly acclaimed motion picture on global warming, An Inconvenient Truth.

Yesterday I received a request from a reader in Wisconsin for me to address a question I hear pretty frequently from the public: If weather can’t be predicted beyond 7 to 10 days, what then makes climate modelers think they can predict climate 50 years in advance?

For many years I gave the ‘IPCC-approved’ reason…but now I’m not so sure anymore.

First let’s review the ‘scientific consensus’ explanation of the difference. In weather forecasting, you take a snapshot of global weather patterns with weather balloon, satellite, surface, and aircraft-based measurements, and then extrapolate them out in time using a set of equations. And as Ed Lorenz demonstrated in 1963, any unmeasured weather on very small space scales can cause huge differences in the forecast the farther out in time one projects the weather. This is the classic example of the chaotic, nonlinear variability inherent to atmospheric circulation systems. Even the flap of a butterfly’s wing will eventually change global weather patterns. Mathematically speaking, this is referred to as sensitive dependence on initial conditions.

Global warming forecasting, in contrast, has been claimed to be possible because we are instead dealing with a small change in the rules by which the atmosphere operates. The extra carbon dioxide we are putting into the atmosphere, it is argued, changes the Earth’s greenhouse effect slightly, which is then expected to change average weather (climate) to a lesser or greater extent. Mathematically speaking, this is referred to as a change in boundary conditions.

But upon closer examination, I have come to realize that the two kinds of variability – weather and climate – maybe are not so different after all. The only major difference between the two is just one of time scale.

The weather today is impacted by what has happened on the Earth, in the atmosphere and on the surface, every day previous to today. In a very real sense, today’s weather retains a memory of all weather which has occurred in the past.

But climate variability is really no different. This year’s climate is a natural result of average weather and climate in previous years. For instance, the slow overturning of the ocean can bring water to the surface which hasn’t been in contact with the atmosphere for maybe hundreds of years. Therefore, the climate we are experiencing today can be related to average weather conditions which occurred hundreds of years ago.

So, one might argue that climate variability is just as good an example of chaos as weather variability. Mathematically speaking, the ‘sensitive dependence on initial conditions’ we associate with chaos might also be called ‘sensitive dependence on continuously changing boundary conditions’.

In fact, nature does not distinguish between changing initial conditions and changing boundary conditions…it is all just change. The real question is how a human source of change (e.g. carbon dioxide emissions) stacks up against all of the natural sources of change.

“But”, one might object, “Nature has been the same until humans came along and changed it!” Well, is it really valid to think of nature as unchanging? I don’t think so. Nature causes its own changes, all the time. And each of those changes forever alters the future direction of both weather and climate.

But we aren’t aware of these continuous subtle changes — only the spectacular ones. For instance, a major volcanic eruption can inject millions of tons of sulfur into the stratosphere, leading to a couple of years of global cooling. But what isn’t mentioned is that such an event will also forever change the future course of weather and climate on the Earth simply because future weather and climate retain a memory of that event.

Similarly, a chaotic change in precipitation patterns in the Pacific Ocean will change ocean salinity, which will then change the circulation of that water into the deep ocean over time, which maybe a hundred years hence will then reemerge as a change in surface waters which will, in turn, affect weather patterns once again.

So, are these changes in initial conditions, or boundary conditions? I think the question is only one of semantics…it is all just change. And change in nature is ubiquitous.

The possibility that mankind can change climate, even for hundreds of years down the road, does not impress Mother Nature. She has been changing climate all by herself since time immemorial. Millions of tons of sulfur spewed into the stratosphere by a volcano illustrates the power of nature, and the spectacular sunrises and sunsets that result vividly display nature’s beauty.

Of course, if humans did the same thing as a volcano does, it would be called the greatest pollution disaster in history. But I digress….

The climate modelers assume there is no such thing as natural climate variability…at least not on time scales beyond maybe ten years. In effect, they believe that chaos only exists in weather, not in climate. But this view is entirely arbitrary, and there is an abundance of evidence that it is just plain wrong. Chaos occurs on all time scales. Climate change happens, with or without our help.

And maybe there is one more difference between weather forecasting and climate forecasting…a difference which has allowed climate alarmism today to flourish. When the TV meteorologist blows his forecast for tomorrow’s weather, people will remember his error, and hold him responsible. But climate modelers get to forecast any kind of climate change they want, knowing full well that no one 50 or 100 years down the road is ever going to remember how good – or how bad — their forecast was.

I’ve been receiving a steady stream of e-mails asking when our latest work on feedbacks in the climate system will be published. Since I’ve been trying to fit the material from three (previously rejected) papers into one unified paper, it has taken a bit longer than expected…but we are now very close to submission.

We’ve tentatively decided to submit to Journal of Geophysical Research (JGR) rather than any of the American Meteorological Society (AMS) journals. This is because it appears that JGR editors are somewhat less concerned about a paper’s scientific conclusions supporting the policy goals of the IPCC — regulating greenhouse gas emissions. Indeed, JGR’s instructions to reviewers is to not reject a paper simply because the reviewer does not agree with the paper’s scientific conclusions. More on that later.

As those who have been following our work already know, our main conclusion is that climate sensitivity has been grossly overestimated due to a mix up between cause and effect when researchers have observed how global cloud cover varies with temperature.

To use my favorite example, when researchers have observed that global cloud cover decreases with warming, they have assumed that the warming caused the cloud cover to dissipate. This would be a positive feedback since such a response by clouds would let more sunlight in and enhance the warming.

But what they have ignored is the possibility that causation is actually working in the opposite direction: That the decrease in cloud cover caused the warming…not the other way around. And as shown by Spencer and Braswell (2008 J. Climate), this can mask the true existence of negative feedback.

All 20 of the IPCC climate models now have positive cloud feedbacks, which amplify the small amount of warming from extra carbon dioxide in the atmosphere. But if cloud feedbacks in the climate system are negative, then the climate system does not particularly care how much you drive your SUV. This is an issue of obvious importance to global warming research. Even the IPCC has admitted that cloud feedbacks remain the largest source of uncertainty in predicting global warming.

Significantly, our new work provides a method for identifying which direction of causation is occurring (forcing or feedback), and for obtaining a more accurate estimate of feedback in the presence of clouds forcing a temperature change. The method involves a new way of analyzing graphs of time filtered satellite observations of the Earth (or even of climate model output).

Well…at least I thought it was new way of analyzing graphs. It turns out that we have simply rediscovered a method used in other physical sciences: phase space analysis. This methodology was first introduced by Willard Gibbs in 1901.

We found that by connecting successively plotted points in graphs of how the global average temperature varies over time, versus how global average radiative balance varies over time, one sees two different structures emerge: linear striations, which are the result of feedback, and spirals which are the result of internal radiative forcing by clouds.

But such a methodology is not new. To quote from Wikipedia on the subject of ‘phase space’:

“Often this succession of plotted points is analogous to the system’s state evolving over time. In the end, the phase diagram…can easily elucidate qualities of the system that might not be obvious otherwise.”

Using a simple climate model we show that these two features that show up in the graphs are a direct result of the two directions of causation: temperature causing clouds to change (revealed by ‘feedback stripes’), and clouds causing temperature to change (revealed by ‘radiative forcing spirals’).

The fact that others have found phase space analysis to be a useful methodology is a good thing. It should lend some credibility to our interpretation. Phase space analysis is what has helped others better understand chaos, along with its Lorenz attractor, strange attractors, etc.

And the fact that we find the exact same structures in the output of the IPCC climate models as we do in the satellite observations of the Earth means that the modelers can not claim our interpretation has no physical basis.

And we can also use some additional buzzwords in the new article…which seems to help from the standpoint of reviewers thinking you know what you are talking about. The new paper title is, “Phase Space Analysis of Forcing and Feedback in Models and Satellite Observations of Climate Variability”.

It just rolls of the tongue, doesn’t it?

I am confident the work will get published…eventually. But even if it didn’t, our original published paper on the issue has laid the groundwork…it would just take awhile before the research community fully understands the implications of that work.

What amazes me is the resistance there has been to ‘thinking out of the box’ when trying to estimate the sensitivity of the climate system. Especially since the ‘new’ manner in which we analyze the data has been considered to be thinking in the box by other sciences for over a century now.

And it is truly unfortunate that the AMS, home of Lorenz’s first published work on chaos in 1963, has decided that political correctness is more important than the advancement of science.