John Mcain in a environmental speech this week said he had been around the world and has personally seen the (negative) changes it has brought. That is presumably why he is such a believer. Can someone tell me the observable changes that come about by global warming and not natural variations due to things like the NAO?

We constantly talk about greenhouse gases and their influence on the world's climate.

Sorry Brett, this forum only talks about the supposed influence of CO2 and CH4 on the world's climate. I do not recall ever seeing once here or anywhere else any actual studies, tests, or experiments showing a qualification and a quantification of CO2 or CH4's role in climate, specifically Global Warming. It is the effects of GW that we are constantly talking about and Water Vapor is ignored.

The strongest AGW Advocates visiting this site cannot produce any, nor can the supposed Climate "Experts" (Self Proclaimed) at RealClimate. A former President of the United States of America cannot get his hands on any of the supposed settled science and the IPCC's reports are full of language that shows definitively that they have no clue what the future holds and specifically state that there are
"Substantial Scientific Uncertainties" with regarding to CO2's role in GW.

There are also several large-scale global atmospheric circulation patterns which influence short-term climate across large regions on the planet, and one of those patterns in the North Atlantic Oscillation or NAO.

I take issue with you saying there are "also" when they are actually the only phenomena besides the Sun that we KNOW influence climate. CO2 does not cause GW or GC. I challenge you to find any information that shows otherwise. If you can, please provide the skeptics an opportunity to question them.

Have a great day,

Steve

Nice post Brett, Thanks

GW Steve,

Thanks. Well said.

Just wanted to say thank you Brett for an excellent, brief, and educational exposition of a weather phenomenon that is little understood; I came away from it better informed which is what I always hope for when visiting.

I probably won't be responding much to the spectacular bias of many of the participant bloggers here in the future, which prevents honest conversation in a hurtful and wasteful manner, but wanted to compliment Brett on continuing to provide informative items like this one. I found it telling that the topic of the blog was immediately abandoned in favor of an opinion which claims there are no facts since he or she doesn't agree with them, though they are abundantly available.

So what is the correlation between this, ENSO and the temp in say Denver or KC? I woke to snow in the foothills south of Boulder, CO yesterday.

This warm weather from global warming this year is really cutting into my bike riding. I had to abandon a 250 mile bike Sunday Morning at 1:00 due to 45 degree (F) temps and winds out the NW at 30 w/ gust to 60.

Hi Doug,

I think John McCain has recognized the value of talking "global warming" to Arnie's success in a Democratic state. Even Bush is pretending to play along.
http://blogs.abcnews.com/politicalradar/2008/05/obama-gaffes-on.html

Check out all the SUV's in the Accuweather parking lot
http://www.accuweather.com/promotion.asp?traveler=0&dir=aw&page=cam

Reply: Not mine, I own a civic. By the way, I had help posting the comments earlier today since I was out of town with my daughter's 5th grade class on a field trip to Gettysburg. A ton of history there.

Thanks Brett for explaining NAO. I knew it occurred but didn't understand its effects. I thought it stayed in one state (negative or positive) longer, but may have been thinking of the PDO or other longer term events.

I notice you said its mainly effects wintertime weather. I would think, according to your graphs, that it would also effect the path of Atlantic hurricanes. During a negative NAO, storms would tend to move north as they approach the US and than back out to sea. In a positive, they would move farther west since the sub tropic high is stronger.

John Mcain in a environmental speech this week said he had been around the world and has personally seen the (negative) changes it has brought. That is presumably why he is such a believer. Can someone tell me the observable changes that come about by global warming and not natural variations due to things like the NAO?

Like many politicians, John McCain believes that government must solve all our problems. And like many ill-informed people, John McCain mistakenly believes that climate change must be primarily man-made and primarily bad.

There is little doubt in my mind that humanity has some influence on the climate, but the primary factors in climate change are entirely natural. The climate system is also self-regulating and robust. The planet is not in peril.

The best response government can have to climate change is to do nothing. The climate will do what it will and we can't do much to stop it. If government must do something, then it can seriously study the likely effects of climate change and help us adapt.

Certainly, one of the worst responses to climate change is the cap-and-trade system McCain advocates. I don't know how anybody can use "cap-and-trade" and "free market" in the same sentence, but to his credit, McCain said it and kept a straight face will doing it. Cap-and-trade will do little but add new regulations, new bureaucracy and hidden costs to everything we do.

Can you say "Enron"? Cap-and-trade was a favorite scheme of Ken Lay. Profiteers are lobbying Congress right now so they can benefit from this scheme.

Thanks Brett. :)

The UK Met Office will be monitoring the Atlantic SST closely during this month to try and decipher where the NAO will be heading through winter 08/09.

Do you have an opinion to which way they might go?

With the apparent negative PDO, and possible about to be / or already negative NAO, we are moving into territory the likes of which have not been experienced for at least 50 years. In fact, there has been zero experience with this combination during the "modern" (e.g. satellite, supercomputer, etc) era. Into the great unknown ...

On that note, anyone notice the polar jet, over in the 40 - 60 E longitude range? It is actually reaching the Persian Gulf today. Pretty bizarre for mid May.

As I wrote, into the great unknown ...

So Brett, Would you say , as a meteorologist that this effect falls in the catagory of Internal Radiant Forcing? Or ,because these are atmospheric pressure phenomonon [instead of oceanic currents] ,they would be catagorized as something else. Dave.

Goes to show there are so many factors in weather/climate that jumping to the conclusion of man made global warming is ridiculous. The problem is nobody questions anything, and if more reports of the "other side' {a.k.a the truth} were on t.v public opinion would change, but my we don't want that to happen because children would not have heroes like Al Gore to look up to.

PH, your link to the accuweather parking lot was wicked funny!

GW Steve,

Keep up the good fight. Hopefully you can go the distance. This AGW fad/hysteria has yet to peak. The next 4-8 years should be interesting.

BrooklineTom,

Why are you avoiding me? How much warmth has 100 ppm of CO2 created? One sentence will do just fine. No links or longwinded explanations are needed. Just one sentence please! Here let me help you get started. Simply fill in the blank.

"I, BT, feel that 100 ppm of CO2 has created approximately (blank) degrees of warmth."

Please fill in the blank. I look forward to your response.

As for RICH, I will continue to do my part in emitting GREENhouse gases. And by doing so, I can proudly tell all of the enviro-wackos that I "AM" being GREEN.

Please don't cite politicians for anything other than the political gain they hope to get from their stance.

Another brilliant phonyclimate prediction from three years ago

Scenarios for future global warming show tropical SST rising by a few degrees
http://www.realclimate.org/index.php/archives/2005/09/hurricanes-and-global-warming/

The tropics just had their coldest month on record.

Brett - Gettysburg sounds great My son's fifth grade class considers history to be anything prior to the invention of the PSP.

Interesting history is difficult to come by in this part of Colorado.

Reply: I always enjoy that trip, but the class trips barely touch the surface. You really need 2-3 days there.

The ice went out of Lake Vermilion in northern Minnesota on May 13 of this year. They have been keeping this statistic since 1906. In that time of 100 years plus, there have been only 3 times the ice stayed longer - 1950, 1966 and 1996. I am afraid that if this global warming continues that the opening of fishing season is going to have to be moved to June instead of May 10.

Reply: Blame a lot of that on solid snow season and a persistent block in the northern latitudes this spring which has forced cold air from the far north consistently south into that region, grewatly slowing the melting process.

Interesting post. Did we discover this oscillation lately like the PDO (1996) or has it been known for some time?
Reply: No, it has been known for quite a while.

My first reaction to the NAO oscillation graph is that the 1990s had a lot more in the red (positive) showing. This seemed to change to about equal or a little negative. Is this a cause or an effect of general warming. (Reply: I don't think that answer is truly known.) In other words is it climate change or is it mistaken for climate change like solar activity?

Before I start, I'd like to state that this information is available to anyone doing research on global warming. You can google it or research it at the library. I was surprised at the amount of info available by Googling �Arrhenius studies CO2�.

As I�ve said before, I believe in the scientific method. That method is at work today. What appears to be scientists changing data or back pedaling, is simply the scientific method at work. Take the following paragraph as an example:

The scientific method is the best way yet discovered for winnowing the truth from lies and delusion. The simple version looks something like this:

1. Observe some aspect of the universe.
2. Invent a tentative description,called a hypothesis, that is consistent with what you have observed.
3. Use the hypothesis to make predictions.
4. Test those predictions by experiments or further observations and modify the hypothesis in the light of your results.
5. Repeat steps 3 and 4 until there are no discrepancies between theory and experiment and/or observation.

When consistency is obtained the hypothesis becomes a theory and provides a coherent set of propositions which explain a class of phenomena. A theory is then a framework within which observations are explained and predictions are made.

GW Steve � If you truly are interested in the �science� then you must understand this methodology.

Arvid H�gbom, Thomas C. Chamberlin, James Croll, Svante Arrhenius, Joseph Fourier, John Tyndall, Knut �ngstr�m, E.O. Hulburt, Guy Stewart Callendar all studied climate change dating back to the early 1800�s. Some of these men also studied CO2 and how it affects the temperature of the atmosphere. Below is an excerpt from an article about CO2. The link to the article is below the text.

Basic Physics (19th century)
"As a dam built across a river causes a local deepening of the stream, so our atmosphere, thrown as a barrier across the terrestrial rays, produces a local heightening of the temperature at the Earth's surface." Thus in 1862 John Tyndall described the key to climate change. He had discovered in his laboratory that certain gases, including water vapor and carbon dioxide ( CO2), are opaque to heat rays. He understood that such gases high in the air help keep our planet warm by interfering with escaping radiation.
This kind of intuitive physical reasoning had already appeared in the earliest speculations on how atmospheric composition could affect climate. It was in the 1820s that Joseph Fourier first explained that the Earth's atmosphere retains heat radiation. He had asked himself a deceptively simple question, of a sort that physics theory was just then beginning to learn how to attack: what determines the average temperature of a planet like the Earth? When light from the Sun strikes the Earth's surface and warms it up, why doesn't the planet keep heating up until it is as hot as the Sun itself? Fourier's answer was that the heated surface emits invisible infrared radiation, which carries the heat energy away into space. But when he calculated the effect with his new theoretical tools, he got a temperature well below freezing, much colder than the actual Earth.
The difference, Fourier recognized, was due to the Earth's atmosphere. Somehow it kept part of the heat radiation in. He tried to explain this by comparing the Earth with its covering of air to a box with a glass cover. That was a well-known experiment � the box's interior warms up when sunlight enters while the heat cannot escape. This was an over simple explanation, for it is quite different physics that keeps heat inside an actual glass box, or similarly in a greenhouse. (The main effect of the glass is to keep the air, heated by contact with sun-warmed surfaces, from wafting away, although the glass does also keep heat radiation from escaping.) Nevertheless, trapping of heat by the atmosphere eventually came to be called "the greenhouse effect."
Not until the mid-20th century would scientists fully grasp, and calculate with some precision, just how the effect works. A rough explanation goes like this. Visible sunlight penetrates easily through the air and warms the Earth�s surface. When the surface emits invisible infrared heat radiation, this radiation too easily penetrates the main gases of the air. But as Tyndall found, even a trace of CO2, no more than it took to fill a bottle in his laboratory, is almost opaque to heat radiation. Thus a good part of the radiation that rises from the surface is absorbed by CO2 in the middle levels of the atmosphere. Its energy transfers into the air itself rather than escaping directly into space. Not only is the air thus warmed, but also some of the energy trapped there is radiated back to the surface, warming it further.
That�s a shorthand way of explaining the greenhouse effect � seeing it from below, from "inside" the atmosphere. Unfortunately, shorthand arguments can be misleading if you push them too far. Fourier, Tyndall and most other scientists for nearly a century used this approach, looking at warming from ground level, so to speak, asking about the radiation that reaches and leaves the surface of the Earth. So they tended to think of the atmosphere overhead as a unit, as if it were a single sheet of glass. (Thus the "greenhouse" analogy.) But this is not how global warming actually works, if you look at the process in detail.
What happens to infrared radiation emitted by the Earth's surface? As it moves up layer by layer through the atmosphere, some is stopped in each layer. (To be specific: a molecule of carbon dioxide, water vapor or some other greenhouse gas absorbs a bit of energy from the radiation. The molecule may radiate the energy back out again in a random direction. Or it may transfer the energy into velocity in collisions with other air molecules, so that the layer of air where it sits gets warmer.) The layer of air radiates some of the energy it has absorbed back toward the ground, and some upwards to higher layers. As you go higher, the atmosphere gets thinner and colder. Eventually the energy reaches a layer so thin that radiation can escape into space.
What happens if we add more carbon dioxide? In the layers so high and thin that much of the heat radiation from lower down slips through, adding more greenhouse gas means the layer will absorb more of the rays. So the place from which most of the heat energy finally leaves the Earth will shift to higher layers. Those are colder layers, so they do not radiate heat as well. The planet as a whole is now taking in more energy than it radiates (which is in fact our current situation). As the higher levels radiate some of the excess downwards, all the lower levels down to the surface warm up. The imbalance must continue until the high levels get warmer and radiate out more energy. As in Tyndall's analogy of a dam on a river, the barrier thrown across the outgoing radiation forces the level of temperature everywhere beneath it to rise until there is enough radiation pushing out to balance what the Sun sends in.
While that may sound fairly simple once it is explained, the process is not obvious if you have started by thinking of the atmosphere from below as a single slab. The correct way of thinking eluded neary all scientists for more than a century after Fourier. Physicists learned only gradually how to describe the greenhouse effect. To do so, they had to make detailed calculations of a variety of processes in each layer of the atmosphere. (For more on absorption of infrared by gas molecules, see this discussion in the essay on Basic Radiation Calculations.)

A link to the full article here:

http://www.aip.org/history/climate/simple.htm#L_0141

Simply put, the atmosphere is in equilibrium, based on the laws of thermodynamics, correct? This process implies that a system of objects tends to move to a state where all of the objects are at the same temperature. When this occurs, heat ceases to flow. Such a state is called "thermodynamic equilibrium", and all systems tend to evolve toward this equilibrium naturally. To reach equilibrium between different particles and different degrees of freedom in a system, the different parts of the system must be able to exchange energy. The rate of energy exchange determines how long it takes to establish equilibrium. So, CO2, CH4 are interacting with water vapor and other �greenhouse gases� in the atmosphere exchanging heat to reach equilibrium. Adding more CO2 to the atmosphere, theoretically (my term), adds more heat to the atmosphere. Correct? As Brookline Tom has said many times, it is �basic physics� and it has been studied and verified since the early 1800�s.

Hope this answers some questions.
Sorry Brett for the long post. Reply: No doubt about that.

Why are you avoiding me?

I am attempting to practice the widely-embraced internet policy called "Do Not Feed The Troll" ("DNFTT"). Feel free to check out any of the hits returned when you Google "do not feed the trolls".

When