Anna, I'm happy to see you reading through the comments! As you may have guessed, it was I who posted said comment regarding weather forecasting. And yes, you are correct...forecasting weather is, one would think, far simpler than predicting climate...correct?

Now...here's the common sense part I'd like to dwell on. HOW do meteorologists forecast weather? Well...they use mathematical models based on historical behavior. Numerical models use millions of data points related to temperature, pressure, wind, humidity, landscape...it's mind-boggling, right? All for a small region of the planet.

Now...imagine the complexity involved in a climate model. Land temperatures, ocean temperatures at depths of 2000 feet, atmospheric composition, solar irradience, planetary orbit...holy cow!

So...as you can imagine...I agree with your original statement....it just makes sense.

Jeff,

Predicting climate is MUCH EASIER than predicting weather. Weather is fairly random whereas climate refers to long-term averages which are far easier to forecast. For example, I can tell you with much greater certainty that July will average a warmer T than December than I can tell you the high or low T on any given day in the next few days.

Interesting you mentioned Lobby groups & Self-Serving Interests. Kind of explains some of the mainstream science in the first place, doesn't it?

Anna-Maria, I apologize...I have done a poor job of communicating my point. Let's agree on some basic points:

Weather forecasting is based on a numerical model, focused on a region, narrow spatial parameters, and small temporal range. True?
Climate forecasting is based on a numerical model, focused on the globe, course spatial parameters, and large temporal range. True?

From my understanding...and based on information at climateprediction.net, both forecast models use General Circulation Models (GCM). In fact, the EXACT same model used by climateprediction.net at Oxford Univ is used for every regional forecast in England (according to their website). BUT..

The volume of horizontal (spatial regions on the map) AND vertical (various height and pressures) data points are exponentially more. Plus, the GCM model is "tweaked" during climate prediction to include clouds, surface, aerosols, ocean, and long-term model stability (making it SIGNIFICANTLY more complex than regional modeling).

As for "hindcasting"...please find a source on how that is conducted. Climate modelers use known, historical data to tweak parameters within the model to fit the data to the past. That is the scientific method used to provide assurance the model is correct. The models were not created and magically fit the past...they were massaged UNTIL they fit. Only...as with any numerical model...that does NOT imply successful prediction unless 100% correct.

I would add that climate models have been effective in predicting responses to major events like the Pinatubo volcano eruption. The SkepticalScience website (http://www.skepticalscience.com/climate-models.htm) says...

"Where models have been running for sufficient time, they have also been proved to make accurate predictions. For example, the eruption of Mt. Pinatubo allowed modellers to test the accuracy of models by feeding in the data about the eruption. The models successfully predicted the climatic response after the eruption. Models also correctly predicted other effects subsequently confirmed by observation, including greater warming in the Arctic and over land, greater warming at night, and stratospheric cooling."

My view is that even Hansen's very early climate model from the 1980s has been broadly validated. His temperature predictions were in the right direction (upward) and reasonably accurate in terms of magnitude. Time has shown that he was not wrong.

Gillian, from my research, and understanding of mathematical modelling used in climate research, scientists used data from the eruptions to CREATE the model. Variables and parameters are tweaked until the model closely resembles reality. Unfortunately, significant contributing factors are absent from the models due to enormous complexity.

For instance, precipitation, cloud modeling, and atmospheric aerosols are significant factors that not modeled, but their impact estimated. So...these estimates are some of the factors tweaked until previous data works.

Hence the reason skepticalscience.com (by the way, that is a non-peer reviewed, biased site...) discusses the need for more simulations. Each model run takes significant computational power, and time (months). Each tweak, estimate, inclusion...

The truth is (and those sites print it clearly), that the Earth's climate is SO complex, we have little hope of accurately modeling. Models will improve. Our understanding will improve. Science MUST be pursued. Rash actions must not.

Jeff,
Here are my 2 cents:
The fact that one model that tries to predict phenomenon A uses more parameters than some other model that tries to predict phenomenon B does not tell me anything about their relative chances of success (i.e. which one is more likely to make accurate predictions). Even if they tried to predict the same phenomenon it wouldn’t tell me anything. The point is, what they are trying to predict (climate) is inherently more predictable than what you are comparing it to (weather).
Re. the “massaged” models, I am not a climate modeler myself, but my general understanding of models is this: When you first develop a model you of course use real data and tweak the parameters until the model fits. That’s called learning. Then you go and run it with data that were NOT used in the development and see how well the model describes what really happened. That’s called testing.

Tamino has a great post on mathematical modeling: http://tinyurl.com/7t8rs8b This is a VERY stripped down version of computer modeling, but the point is that even something this "simple" can yield accurate information.

Jeff said: "from my research, and understanding of mathematical modelling used in climate research, scientists used data from the [volcanic] eruptions to CREATE the model."
Are you sure about that? This is my understanding: The model exists as hundreds (thousands?) of equations which describe the earth and its climate system. It can be as simple as Tamino's linked to above which only deals with the known climate forcings effects on global avg temp. Or it can be as complex as the GCMs which try to mimic as much of the climate system as possible. Data about known parameters is feed into the equations like amount of CO2 in the atmosphere, amount of solar radiation, etc. The program runs and spits out data showing how the climate system is likely to respond. So when Mt. Pinatubo erupted they had estimates of how much aerosol and dust was injected into the atmosphere, and how long it would stay there. They put this new data into the climate model, ran it and it spit out the result. The result was for a drop in global avg temp for a year or two which closely matched the real-world.

At least that's my understanding.

Jeff.. "scientists used data from the eruptions to CREATE the model"

I can't see how they could have. The climate models existed before the Pinatuba eruption. When it erupted, climate models were used to estimate/forecast the impacts.

So climate models have been verified by forecasting as well as by hindcasting.

Larry, Agreed, though I do not believe this was in question. Only the complexity of the model.

Chuck, do you mean “how can we possibly have affected climate” or do you mean “how can we possibly do enough about it considering the amount of concerted effort it will require?” If the latter, I’d say you have a point. It does seem daunting. Although, when you think of the kind of concerted effort that was made for e.g. World War II, why exactly is it that we cannot do a similar thing for the sake of saving our children’s future? In principle the technology is there to really stop the use of fossil fuels, although I happen to believe that nuclear energy is a significant part of the solution, -- something that gets the hackles up of many who otherwise agree with me.
Regardless, what we’ll need first and most of all is a better informed public. A public that trusts the world’s top climate scientists more than talk show hosts and backyard know-it-alls. A public that has enough education to be able to tell the difference between the two. If they did we could at least stop wasting our time rehashing old questions ad nauseam and instead focus on what to do about it.

Maybe we should ask, "What would it take for us to mobilise the necessary resources to be effective?"

Would it take another Pearl Harbour, another Twin Towers, for the US to mobilise forces to cut emissions quickly?

I think so. It seems to me that all our actions so far have just been warm-up exercises for what is to come. The more warm-ups we do, the better we will be prepared.

Gillian,
Yes, the tragedy of human psychology. Here we are as a species, where the best and brightest among us have figured out what’s going on (in enough detail to see the writing on the wall) and have told the rest of us all about it. And yet, brains and intellect alone will not be enough. There has to be enough adrenalin and heart ache to make us all move together in the right direction. Let’s hope it won’t be too late when there is finally enough momentum.
I don’t feel very relaxed about either.

Yes, I wonder what could have made the oceans more acidic now than they have been in 300 million years? (http://www.sciencedaily.com/releases/2012/03/120301143735.htm)

Seems to me that CO2 is the culprit.

And it seems to me that humans have been putting a lot of CO2 into the atmosphere in the past 150 years.

Humans burn fossil fuels --> CO2 in atmosphere --> oceans absorb more CO2 --> ocean acidification --> marine life crashes.

I accept the mainstream scientific view that human activity is disrupting climate and other earth systems.

I don't feel very relaxed about this.

Larry, you continue to mislead readers by restating this point. I understand you have the pulpit...but that does not change reality. If simply restating a point over and over would make it more true, then we're lucky Columbus didn't fall off the edge of the Earth. :)

It is a settled fact that increases in heat-trapping gases, especially CO2, are causing the climate to warm. The physics has been known for over a century and the PATTERN of warming matches what we expect from CO2-caused warming. The only question now is how much warmer it is going to get as humanity continues recklessly down the CO2 highway.

Jeff, the burden is now on you to prove otherwise just as it would be if you were claiming that gravity makes apples fall upward.

Prof. Mandia,

You are correct that greenhouse gases warm the Earth. In fact, I have stated as such earlier in this thread. You are correct that CO2 is a greenhouse gas. You are correct that human created numerical models have been created using parameterization and ensemble methods that closely resembled a limited number of known values (i.e. historical temperature for 160 years, estimated historical temperature for 750,000 years, historical atmospheric CO2 for 20+ years, estimated historical atmospheric CO2 for millions(?) of years)...

With that much, we completely agree. I'm convinced.

But...Larry Lazar is proposing that it is fact man caused the elevated levels of CO2, and that singular condition increased global temperatures. As you just stated...we have a pattern that matches. Yes. How many other patterns would match, Prof. Mandia? How many models have been created, or could be created, that would provide the same outcome? Aren't numerical models, by definition, biased to the model designers predefined notion of outcome?

For instance, no numerical model I am aware of can successfully model atmospheric aerosols or water vapor. To my knowledge, current GCM's simulate the effect through simplified algorithms. A we have no current model for chaos...only probability density functions.

I'm not a CO2 salesman. I have no benefit from its continued use. I only want unbiased truth.

Jeff,

Models? The pattern of observed climate change matches increased CO2 and we know for a fact that the net increase in CO2 is from human activities. If we never had climate models the planetary system would still be warming and that warming has been caused by increasing CO2 and other heat-trapping gases.

As I stated before, it is up to you to prove otherwise. What HAS caused the warming pattern that precisly matches increased CO2 while at the same time completely masking the known physical effects of a massive increase in CO2?

A dead body with a .45 cal bullet hole in the head is found in the room. There are human fingerprints on the gun and the gun is a .45. I say the murder was human-caused and that was the gun. You wish to keep telling me it might be a ghost?

Larry, I give you credit for sticking to your talking points. You've used the "man's impact on climate is accepted by everybody" statement in a half dozen responses.

Fortunately for us...science is not based on consensus. Science is about gathering data, making a hypothesis, and testing. Consensus is irrelevant.

Jeff, scientific evidence RESULTED in the overwhelming consensus. Just as plate tectonics and evolution eventually became the consensus. At first scientists were mostly doubtful but as the evidence kept pouring in more and more scientists accepted the theory. If you understood how scientists think you would realize that we are very skeptical and it takes quite a bit of proof to make us change our minds.

Historian of science, Naomi Oreskes of UC San Diego, states: "Scientific knowledge is the intellectual and social consensus of affiliated experts based on the weight of available empirical evidence, and evaluated according to accepted methodologies. If we feel that a policy question deserves to be informed by scientific knowledge, then we have no choice but to ask, what is the consensus of experts on this matter."

Jeff,
I’ll let Larry respond to the numbers and the background of e.g. the Petition Project scientists and how these numbers compare to the number of scientists, who actually do have a background in climate science and do subscribe to what we would refer to as the mainstream scientific consensus.
But there is one other thing I just can’t let you get away with: “No one talks about the consensus that the planets orbit the sun, that the hydrogen molecule is lighter than the oxygen molecule, that salt is sodium chloride, that light travels about 186,000 miles per second in a vacuum ….” That’s another classic example of an argument that superficially sounds so clever but if you took just one moment to really think about it, it ought to be obvious: Any chance this may have something to do with the fact that none of these insights threatens the status quo of how people conduct their lives (at least nowadays) or asks us to get off our lazy asses and actually do something, such as get informed and change things that we are so pleasantly used to? Never mind the first item (the thing with the planets and the sun), which at one time did threaten a lot of people’s worldview, and for exactly that reason delayed the scientific consensus much beyond what would have been a truly scientific debate. Or may I mention the word evolution? Any chance there may be some parallels here?

P.S.
I got a little bit too carried away with “scientific”….. haha… there was one “scientific” too many. The sentence should of course have read …”…. and for exactly that reason delayed the consensus much beyond what would have been a truly scientific debate.”

Anna-Maria, you do have zest!

Sadly, I cannot claim credit for the above paragraph, as indicated by the byline (it originated from "The American").

However, you seem to have missed the point of my statement. Science is based on facts...ultimately determining TRUTH. Those arguments relying heavily on convincing others of "consensus" do so because they lack the evidence otherwise.

As for your comments regarding the plants and sun...Yes...Copernicus did propose something that was quite different. Heliocentrism. But...the CONSENSUS was Geocentrism...and people didn't like hearing Nick's ideas. But...facts were on his side. It was a tough ride against consensus...When Galileo took up the cause, it was VERY unpopular. You see, geocentrism was the consensus. And the head of the church, the Pope argued that Heliocentrism was heresy. Galileo spent the end of his life under house arrest...because he went against the consensus.

Ironic, since many believe environmentalism akin to a religion. The religion of green. Something to think about...

Jeff, so let me get this straight: The current mainstream scientific consensus on climate change is like the old consensus on geocentrism. Along comes the maverick idea of “nothing much is happening with our climate, it doesn’t matter how much heat trapping CO2 we put into the atmosphere”, which is just like Copernicus and Galileo’s realization that what they observed is a whole lot more consistent with the idea that the planets revolve around the sun, rather than the other way around. I get it. Well, to be totally honest, I don’t. I guess I don’t have enough zest to follow that argument.

Jeff, since you like words (I do too …haha) how about we have another go at it? Let’s meditate on the concept of “rash decisions” for a little bit, shall we? Decisions made without fully considering the consequences.

There is some amount of uncertainty in the current scientific consensus. I happen to believe there is little, you think there is a lot. Ok, either way, - some degree of uncertainty.

The decision we are faced with is: Should we or should we not drastically reduce CO2 emissions? So let’s weigh the potential consequences, lest we make a rash decision! To do that we multiply the likelihood of something being true with the severity of what happens if it is true:

What are the potential consequences of:
1) We drastically reduce carbon emissions and
1-a) the scientific consensus is true
1-b) the scientific consensus is not true
2) We do not drastically reduce carbon emissions and
2-a) the scientific consensus is true
2-b) the scientific consensus is not true

You do the math.

I would say the consequences of scenario 1-b) is benign (arguably, in the long run even positive for other reasons) compared to the consequences of 2-a). Therefore, even if I had reason to doubt the scientific consensus, even if I thought there was only a 50:50 chance they are right, I would still consider it wise to reduce carbon emissions.

Upshot is: don’t confuse “not doing anything” with “not making a rash decision”. They are not always the same thing.

Anna-Maria,

First, I hope I didn't offend you with the "zest" comment. If so, I apologize.

Second, this is not the first time I have seen Pascal's Wager applied to Global Warming. BusinessWeek ran a podcast on the subject in 2007, Others postulate the same argument first applied by Blaise Pascal to the existence of God.

I guess you and I see things just slightly (ever so...) differently. You see, I believe the rash decisions will be enacted by politicians because climate alarmists have incorrectly diagnosed reality.

I 100% support efforts to reduce pollution. I 100% support efforts to use less energy...if the INDIVIDUAL CHOOSES TO.

In fact...my whole reason for arguing this thread, and consuming incredible amounts of time, is to be the voice of reason. The science is NOT settled. The data is NOT conclusive as to the cause. Yes, the globe does appear to be increasing in temperature. But maybe it is the Earth returning to it's norm. Maybe we are 12,000 years into an interglacial period that lasts 50,000 years.

Maybe we should continue to research the subject, and drop the political agenda. Truth will win.

Jeff, I don't think you understand consensus. You seem to think that the consensus, the general agreement, that the vast majority of scientists/scientific bodies holds is totally separate from the data, facts, and evidence which science gathers. You seem to be saying that the evidence is lacking so the only thing the poor scientists can do is form a faulty consensus. This is the exact opposite of how a consensus works.

You might have gotten a clue about this from something you posted and linked to the other day from NASA: http://tinyurl.com/5wkx9sm "Most scientists agree that no single piece of data will likely resolve the global warming debate. In the end, the best we can expect is a scientific consensus based on a preponderance of evidence." First and foremost are the data, facts, and evidence. The preponderance of that evidence (a consensus of evidence, if you will) leads to the consensus among scientists. They are intrinsically linked. You don't get a consensus without the preponderance of evidence leading you there. A consensus is not something that scientists just vote on willy-nilly (like American presidential elections ;) ).

Continued...

Jeff, your remarks: "The science is NOT settled. The data is NOT conclusive as to the cause" may be enough for you. But for the vast majority of climatologists, who actually are expert in gathering and understanding the data, the preponderance of evidence points to human emissions of CO2 as the primary forcing in the global warming/climate change we are seeing today. You hold out hope that the warming is just part of some natural cycle: "Yes, the globe does appear to be increasing in temperature. But maybe it is the Earth returning to it's norm. Maybe we are 12,000 years into an interglacial period that lasts 50,000 years." But, see, the climatologists have looked into these natural forcings, and they don't add up to the current warming. The best explanation for the evidence at hand is AGW.

I repeat a question put to you by Scott Mandia in an earlier post: "Jeff, show us how record values of CO2 are not causing the warming that perfectly matches GHG heat trapping: nights, winters, and poles warming faster than days, summers, and tropics." If you don't think there is enough evidence for AGW, can you provide any evidence to support your theory that it is just due to natural causes and that the human-emitted CO2 is having no effect?

Yes, from where I stand (in the Southern Hemisphere), it looks like the US has lost the lead on this.

Countries are no longer looking to the US for leadership, but as the second biggest polluter on the planet, countries are insisting that the US pull its head out of the sand and catch up.

Because greenhouse gas emissions affect the whole planet, countries that have begun to reduce their own emissions will start putting penalties on the laggards, just as the EU is doing re emissions from aircraft that fly there.

Americans are not used to being followers. I wonder how they will cope?

Larry,

Please explain the difference in my statement above, and this statement from the second article:

From me...."Are we to assume that means we have conclusive evidence that CO2 is the cause of climate change?"

From Larry Lazar...according to NOAA, NASA, NCAR, UCAR and every other scientific orgazation that conducts research on atmospheric conditions, Yes.

So, I asked if conclusive evidence exists that elevated levels of CO2 are THE CAUSE of global warming. You responded, "Yes".

And in the first post, you wrote this:

"there are no scientific organizations in the world that dissent with the basic claim that the earth is warming, it's primarily caused by man".

Please explain how that differs from my statement.

And I did not quote you. I summarized your position based on previous posts. This is the second time you have responded with an aggressive posture.

As I have stated, this is your pulpit. If you believe I have misquoted anyone, on any of the 3 threads to this point, take the appropriate actions.